Lääketieteellinen tiedekunta


Recent Submissions

  • Kaartinen, Niina (Helsingin yliopisto, 2018)
    In the modern abundant food environment, the relationship between dietary carbohydrates and health outcomes is complex. The main aims of this thesis were to investigate the role of added sugar intake in the diet, and the relationship between dietary carbohydrates, the dietary glycaemic index (GI) and load (GL) and obesity. Another aim was to examine the dietary assessment methodology from the dietary carbohydrates perspective. This study was based on health examination surveys in the Finnish adult population conducted in 2000-2007: the DILGOM Study, the National FINRISK/FINDIET 2007 Study, the Health 2000 Survey and the Helsinki Birth Cohort Study (overall n=13 800, age 25+). The examinations included measured anthropometrics and questionnaires. The habitual diet was assessed with a food frequency questionnaire (FFQ). Food records served as a reference method in FFQ validation. Food GI values were based on a previous Finnish epidemiological GI database and were documented using international controlled vocabularies used in the Finnish national food composition database (Fineli). Intake of added sugars was estimated based on sucrose and fructose derived from foods other than fruits, berries, vegetables, and 100% fruit juices. On average, 40% of sucrose and fructose were from natural sources and the remaining 60% were added sugars. Subjects in the highest added sugar intake quartile were younger and had lower fibre, fruit, vegetable, rye, and fish intakes than subjects in the lowest added sugar intake quartile. Added sugar intake was associated positively with the intake of butter and butter mixtures. These results support the recommendation for the restriction of added sugars in the diet. In the meta-analysis of three cross-sectional studies (n=12 342), 23% of the subjects were classified as obese (body mass index, BMI ≥ 30 kg/m2). The likelihood of being obese was 35% lower in the highest quartile of total carbohydrate intake than in the lowest quartile. Total sucrose intake and dietary GL were also inversely associated with obesity. Dietary GI and fibre intake were not associated with obesity. Prospective cohort studies are needed to assess possible temporal relations. Instead of sucrose only, added sugars should be investigated. Between-method Spearman rank-correlation coefficients ranged from 0.27 (total sugars, men) to 0.70 (lactose, men). Based on the two methods, 73% of the subjects were correctly classified into the same or adjacent carbohydrate intake distribution quintile. Between-method agreement improved with decreasing age and with higher education, especially in women. The ability of the FFQ in ranking subjects according to most carbohydrate-related exposures is on the same level as in the international literature. However, sex, age and education represent important confounding factors. The origin and derivation methods of the GI values were successfully documented with the controlled vocabularies generally used in Fineli. This provides a foundation for the comparison of GI databases in international contexts.
  • Wikström, Katja (Helsingin yliopisto, 2018)
    During recent decades, changes in society and environment have led to changes in lifestyle. As a result, risk factors for type 2 diabetes, such as obesity and physical inactivity, have increased in the population. Further, socioeconomic factors play a role in the development of type 2 diabetes. The aim of the present study was to examine the role of socioeconomic status in determining the risk factors, occurrence, comorbidities, and prevention of type 2 diabetes. The present study is based on three population-based, cross-sectional surveys (FIN-D2D, FINRISK and AVTK), and one clinical, longitudinal, randomized intervention study (DPS). When appropriate, the incident diagnoses of type 2 diabetes and other chronic diseases were identified through linkage with the national registers on reimbursement rights, hospitalizations, and mortality. Hyperglycaemia was more common among those with low education compared with those with medium and high education. The incidence of type 2 diabetes has increased among Finnish men, but not among women, and has occurred predominantly among men with low and middle educational attainment. Obesity explained some but not all of this variation between socioeconomic classes. On the other hand, no evidence was found to suggest that low socioeconomic status increases the development of comorbidities among people with diabetes or decreases the effectiveness of lifestyle intervention aiming to prevent type 2 diabetes among people at risk. Furthermore, the national diabetes prevention programme succeeded in increasing awareness of type 2 diabetes among the population, regardless of socioeconomic status. This study provides knowledge to support future activities to prevent type 2 diabetes and other chronic diseases and suggests that interventions can diminish health disparities.
  • Quarto, Tiziana (Helsingin yliopisto, 2018)
    During the last decades neuroscientists have put significant efforts towards a definition of a unique and comprehensive emotion brain circuit. However, internal and external variables influencing emotion behavior are much more prominent than expected. The present doctoral thesis aims to add some crucial knowledge on individual differences of emotions, as well as their biological underpinnings, by merging evidence obtained with psychological, genetic and brain imaging assessments. In particular, I adopted a protocol of affective state induction, by which I investigated the effect of temporary variations of mood on the emotion processing in healthy subjects at both the behavioral and neuronal level. Then, I have also investigated the interaction between affective states and affective traits on the emotional behavior as well as the interaction between affective states and genetic traits. Moreover, this thesis has characterized in healthy subjects the neural correlates of the emotion intelligence ability, an additional important aspect in the emotional panorama. Finally, I studied emotion brain connectivity in a schizophrenia population and in a population of healthy subjects at familial or genetic risk for schizophrenia. Findings of the thesis demonstrated that temporary affective states are capable of modulating emotions even at an early, automatic stage of processing, at both behavioral and neuronal level. Moreover, this modulation is affected by personality and genetic traits of the individual. Furthermore, this thesis revealed that social and emotional abilities also represent a source of variability in the way brain processes the emotional information, positing the neural basis of conceivable interventions in this direction. Finally, the present work discovered that emotional anomalies in schizophrenia subtend a specific breakdown of the brain connectivity. Particularly, this breakdown is also found in healthy individuals at familial risk for schizophrenia or simply carrying a dopamine variant conferring risk for the disorder.
  • Tuovinen, Eeva-Liisa (Helsingin yliopisto, 2018)
    Smoking-specific weight concerns are one factor involved in smoking and the smoking cessation process. Previous literature has reported inconsistent findings regarding the association of weight concerns with self-efficacy and motivation to quit. In addition, inconsistent findings about smoking-specific weight concerns as an obstacle for quitting have been reported. Even though daily smokers tend to weigh less, they tend to have more abdominal obesity than never smokers. This thesis aimed to assess the level of smoking-specific weight concerns according to smoking status, the association of weight concerns with self-efficacy and motivation to quit, and weight concerns as a predictor of subsequent smoking status in the Finnish adult population. An additional aim was to assess the association of smoking with abdominal obesity. This thesis is based on national FINRISK/DILGOM studies conducted in 2007 and 2014. Four different datasets were used in this study. In 2007, a population-based sample of 10,000 Finnish people (67% participation rate) aged 25 to 74 years from six geographical regions was drawn from the Population Register to form FINRISK 2007. FINRISK 2007 data was used in Study IV. DILGOM 2007, a subsample of FINRISK 2007, was formed to study metabolic factors and obesity. Studies I and II utilised a special sub-sample of ever smokers identified within the DILGOM 2007 study. A sub-sample of ever smokers and follow-up DILGOM 2014 was used in Study III. Smoking status was mainly self-reported, with biochemically-verified data among sub-samples. Weight concerns were measured by a modified Weight Concern Scale administered in the 2007 questionnaire, and nicotine dependence by the Fagerström Test for Nicotine Dependence (FTND). Self-efficacy and motivation to quit, as well as the majority of confounders, were also self-reported measures. Weight, height, waist circumference, and expired air carbon monoxide were measured by study nurses. Cotinine, a metabolite of nicotine, was derived from blood samples. Daily smokers were found to have higher levels of weight concerns compared to occasional smokers, recent quitters, and former smokers. Among daily smokers, weight concerns were associated with lower self-efficacy to quit but not with lower motivation to quit. Nicotine dependence attenuated the association between weight concerns and self-efficacy to quit. Baseline weight concerns predicted smoking cessation and reduced tobacco usage by 2014 (from daily smoking to occasional use) among those daily smokers with low nicotine dependence (FTND 0–3), but not among those with high nicotine dependence (FTND ≥4). The association of smoking status with abdominal obesity was significant among women who were overweight/obese heavy daily (≥20 cigarettes per day) or ex-smokers. Daily smokers report more weight concerns compared to other ever smokers. Weight concerns are associated with a lower self-efficacy to quit among daily smokers. Weight concerns predict subsequent smoking status only among smokers who are not highly dependent on nicotine. Hence, in the Finnish population, weight concerns seem to have a role in some factors involved in the smoking cessation process. However, considering successful cessation as the outcome, those concerns seem to interplay with nicotine dependence. Among overweight/obese women, daily heavy smokers and ex-smokers have more abdominal obesity compared to never smokers. Further investigations in clinical settings, including longitudinal designs and repeated measurements during the smoking cessation process, may be useful to provide a deeper understanding of the complex interplay between weight concerns and other determinants of smoking cessation.
  • Kiiski, Ville (Helsingin yliopisto, 2018)
    Atopic dermatitis (AD) is a common inflammatory skin disease characterized by impaired epidermal skin barrier and a mainly Th2 deviated immune profile. Filaggrin is an important protein of the skin barrier, and loss-of-function (null) mutations in the filaggrin gene (FLG) are the most significant genetic risk factor of AD. Genetic factors cannot explain the rapid increase of AD, and gene–environment interactions seem important. Outcome-predicting biomarkers could help in identifying the patients in need of closer follow-up. FLG null mutations and serum total immunoglobulin E (IgE), a general marker of Th2 immune deviation, are proposed biomarkers. Adulthood AD is often accompanied by atopic blepharoconjunctivitis that can at worst lead to vision-threatening complications. Topical calcineurin inhibitors (TCIs) pimecrolimus and tacrolimus are commonly used for this indication, but the long-term ocular safety data are scarce. There is a paucity of epidemiological research on adulthood AD and little is known about the effect of acquired factors. We investigated associations of FLG mutations with AD in the Finnish population and tested the usefulness of these mutations and total IgE as outcome-predicting biomarkers. Addi¬tionally, we explored the effect of other patient-related deter¬minants on the long-term outcome and gained novel ocular safety data of TCIs. We determined the prevalence of adulthood AD in Finland and explored the effect of acquired risk factors. We utilized university clinic cohorts of 501 patients with AD and 338 ophthalmologist-followed patients with atopic blepharoconjunctivitis, and a nationally representative cohort of 8,026 Finns ≥ 30 years of age. FLG mutations were associated with AD, asthma, early onset, palmar hyperlinearity, and keratosis pilaris but they did now show associations with long-term outcome. Only a fraction of patients carried the common European FLG mutations—a possibility of an unrecognized Finnish-specific mutation remains. Their value as a predictive biomarker in adulthood AD seems low. Conversely, total IgE seems an inexpensive outcome-predicting biomarker in adulthood AD with values ≥ 10,000 IU/ml being the most significant factor predicting poor outcome. Both TCIs demonstrated good safety in the treatment of atopic blepharoconjunctivitis with no long-term safety concerns. Tacrolimus seemed better tolerated and more effective than pimecrolimus. Female sex and current smoking were associated with AD in adult subjects of 30–50 years of age. Ex-smokers and subjects with highly educated parents had more AD. The prevalence of adulthood AD in Finland is among the highest in the world with a lifetime prevalence of 21.8% and a 12-month prevalence of 10% making it an important public health issue.
  • Jääskeläinen, Tuija (Helsingin yliopisto, 2018)
    Vitamin D is essential for skeletal health. In recent decades, vitamin D deficiency has also been suggested to be an independent risk factor for other harmful health outcomes. In the early 2000s, vitamin D status of the Finnish population was insufficient. Thus, during 2000s nutritional policy acts, including voluntary, systematic fortification of fluid milk products and fat spreads, were executed to improve the vitamin D status of the Finnish population. The aims of the present study were to examine the vitamin D status of Finnish adults, its sociodemographic, lifestyle and metabolic health related determinants and the temporal change between the years 2000-2011. The study also aimed to examine whether low vitamin D status is associated with depression prevalence or predicts weight gain or an increase in waist circumference during the 11-year follow-up. The study population consisted of participants aged 30 years and over from the nationally representative Health 2000 Survey (n=8028) and its follow-up, the Health 2011 Survey (n=7964).The Health 2000/2011 Survey included questionnaires, interviews and a comprehensive health examination including laboratory measurements. Serum 25-hydroxyvitamin D concentration, a measure of vitamin D status, was analysed by radioimmunoassay in 2000 for 6134 (76%) participants and in 2011 by chemiluminescent immunoassay for 4051 (51%) participants. To improve the comparability of the methods, measurements were standardized according to the Vitamin D Standardization Program (VDSP). Information on diet was assessed by a validated food frequency questionnaire (FFQ). Diagnosis of depression was based on a Composite International Diagnostic Interview (CIDI) and current depressive symptoms on the Beck Depression Inventory (BDI). Statistical analyses were based on linear and logistic regression models adjusted for potential confounding factors. In 2000, more than half of the Finnish adult population had a vitamin D status under 50 nmol/L, which is generally considered to be insufficient. Remarkable improvement was seen during the 2000s leading to over 90% of adults having sufficient vitamin D status in 2011. The increase was mainly explained by the systematic vitamin D fortification policy and increased use of vitamin D supplements, but also other factors may have contributed to improvement. In 2011, a sufficient vitamin D status was possible to reach without the use of supplements if vitamin D fortified milk products and fat spreads were consumed daily and fish at least twice a week. Further, the results showed that vitamin D status was positively associated with a healthy lifestyle measured with 5-item lifestyle index. In men, low vitamin D status was cross-sectionally associated with a higher prevalence of depressive disorder and predicted an increase in waist circumference during the 11-year follow-up but not weight gain. In women, vitamin D status was not associated with either depressive disorder and symptoms or increase in waist circumference and weight gain. In conclusion, low vitamin D status as a potential public health concern in Finland has improved during the 2000s, indicating the success of nutritional policy acts. The results of the present study do not overall consistently support the hypothesis that low vitamin D status is an independent risk factor for depression or obesity. However, it is possible that low vitamin D status may be associated with a higher risk of abdominal obesity especially in men, but the association may also be due to residual confounding.
  • Ruohoalho, Johanna (Helsingin yliopisto, 2018)
    The incidence of complications is one of the most commonly used outcome measure in surgery. Systematic registration of complications creates possibilities to monitor and improve quality of care, allows comparison between the treating units and provides tools for treatment decisions and patient education. Complication prevalence of three common procedures in Otorhinolaryngology – Head and Neck Surgery (ORL-HNS) was evaluated to discover predisposing factors for complications, and to develop a feasible prospective registration system for surgical complications in ORL-HNS. Additionally, this pursuit of register development has resulted in Department of ORL-HNS, HUH, participation in the Nordic Tonsil Surgery Register Collaboration (NTSRC). Postoperative complications of tonsil surgery and comprehensiveness of prospective complication data recording was assessed in 573 patients. The overall complication rate was 13.8%, with secondary hemorrhage being the most common complication (9.6%). Altogether 69.6% of patients with a complication were identified in prospective data retrieval. The pitfalls of registration process were assessed. Procedure-specific incidences of complications after benign parotid surgery and predictive factors for the postoperative facial nerve dysfunction were evaluated in 132 patients. On the first postoperative day, 40.2% of patients had facial palsy. Palsy rates in the subgroups of extracapsular dissection, partial superficial parotidectomy, superficial parotidectomy, and extended parotidectomy were 6.3%, 41.5%, 43.8%, and 53.8%, respectively. Age, duration of surgery and use of ultrasound knife were identified as independent risk factors for transient facial palsy. Third study evaluated the outcome of percutaneous endoscopic gastrostomy (PEG) inserted by ORL-HN surgeons and assessed the delays in comparison with earlier practice of referring the patients needing PEG to gastrointestinal surgeons. Four patients (3.2%) had a major complication. Peristomal granulomatous tissue was the most common minor complication (18.5%). Independence from gastrointestinal surgeons’ services reduced the time-delay and enhanced the availability of urgent PEG placements. The fourth study was a systematic literature review of tonsil surgery quality registers, and an introduction of the NTSRC, which is the first reported international register collaboration project within the specialty of ORL-HNS. The systematic review revealed five registries, quality improvement programs, or comprehensive audit programs with an inclusion principle of tonsil surgery. Two of them had ongoing activity. The three prospective studies acted as pilot projects for surgical complication registration at Department of ORL-HNS, HUH, and a long-term objective is to develop a systematic surgical quality register to our unit. One part of it is the tonsil surgery register, which features are more specifically discussed.
  • Reinvall, Outi (Helsingin yliopisto, 2018)
    Abstract Autism spectrum disorders (ASD) are characterized by social interaction and communication difficulties, and by restrictive, repetitive and stereotyped patterns of behavior. In many ways, ASD is a highly heterogeneous disorder, and it is not known why some individuals with ASD end up having a poor outcome while others may cope well. Understanding of associated neurocognitive and psychiatric factors in ASD is crucial for enabling planning suitable follow-ups, as well as planning effective interventions. This thesis investigates neurocognitive functioning and psychiatric symptoms comprehensively in children and adolescents with higher functioning ASD (HF-ASD) in four studies. In Studies I and II, the neurocognitive functioning of children and adolescents with HF-ASD were compared with that of typically developing (TD) children and adolescents. In Study III, psychiatric symptoms of children and adolescents with HF-ASD were compared to that of TD children and adolescents, and to the reported prevalence rates of psychiatric symptoms by Ford, Goodman, and Melzer (2003). In Study IV, children and adolescents with HF-ASD were divided into three groups based on the level of symptoms of sluggish cognitive tempo (SCT): the ASD+High SCT group, the ASD+Medium SCT group, and the ASD+Low SCT group. The groups were compared on social skills and academic functioning, internalizing and externalizing psychiatric symptoms and processing speed. The present results showed that children and adolescents with HF-ASD had strengths in verbal reasoning skills and weaknesses in attention and executive functions (EF), facial recognition memory, and visuomotor functions. Overall, the neurocognitive deficits in children and adolescents with HF-ASD at the group-level were mild. In contrast, children and adolescents with HF-ASD had high rates of co-occurring psychiatric symptoms. Particularly anxiety and depression, attention deficit hyperactivity disorder and tic disorders were frequent in these individuals. Finally, the HF-ASD+High SCT group and the HF-ASD+Medium SCT group had more pronounced social difficulties than the HF-ASD+Low SCT group. Additionally, the HF-ASD+High SCT group had a higher rate of symptoms of anxiety and depression compared to the HF-ASD+Low SCT group. To conclude, these results suggest that children and adolescents with HF-ASD are characterized by mild neurocognitive deficits in single clinical neuropsychological subtests. High co-occurrence of psychiatric symptoms in children and adolescents with HF-ASD emphasize the importance of evaluating psychiatric symptoms systematically in HF-ASD. Results on SCT symptoms in HF-ASD indicate that individuals with HF-ASD and high levels of SCT symptoms may be at risk for pronounced social difficulties and internalizing psychiatric symptoms. Therefore, identifying individuals with HF-ASD and with symptoms of SCT would be important for planning systematical follow-ups and preventive support for these individuals.
  • Ilmarinen, Ville-Juhani (Helsingin yliopisto, 2018)
    Examinations of the relationship between individuals’ personal characteristics and the social positions that individuals receive in everyday peer networks have often found an association between extraversion and popularity. This thesis assesses the conditions (when) and mechanisms (why) of this association. Four research questions focus on when the link between extraversion and popularity is present. The study examines whether extraversion is already associated with popularity among seven- to eight-year-olds (Study I), if extraversion is associated with popularity in a less talkative and more stereotypically introverted culture as well (i.e. in Finland; Studies I and II), whether the association is more reflective of the popularity of extraverts or the unpopularity of introverts (Studies II and III), and if the size of the surrounding social ecology is an important precondition of this association (Study III). In addition, the study considers two why research questions. Studies II and III examine if dyadic combinations of extraversion could serve as popularity particles that would explain why extraverts are ultimately more popular in the group, whereas Study I evaluates the mediating role of oral fluency between extraversion and popularity among children. The association between extraversion and popularity is found to be highly generalizable, as it is present among young and adult Finns as well as in social networks of varying sizes. In addition, the association is linear and unilateral: introverts are unpopular as much as extraverts are popular, and dyadic combinations of extraversion are not significant in explaining this phenomenon. Finally, the higher oral fluency of extraverts partially explains their popularity in middle childhood. The discussion focuses on the causality of this association and engages with the ontological status of trait extraversion throughout the thesis. The research also highlights the role of popularity and social networks in accounting for the coalescence of extraversion.
  • Saukkonen, Kapo (Helsingin yliopisto, 2018)
    Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide. Radical surgical resection combined with chemotherapy, the only potentially curative treatment, is possible in only a small proportion of patients. Although overall survival is poor, marked variation exists between patients of the same tumor stage. New biomarkers could be helpful in predicting prognosis. Despite considerable research on potential biomarkers, since the discovery of CA19-9, none has gained a role in clinical practice. Identification of new biomarkers to predict PDAC patient outcome more accurately and to enhance our knowledge of the molecular mechanisms behind the disease is crucial. Differential diagnosis between PDAC and chronic pancreatitis (CP) can be challenging. A pancreatic mass can prove to be benign or malignant. A clear preoperative diagnosis would be valuable for patients to avoid unnecessary and extensive surgery. The standard serum- based marker for diagnosis of PDAC, CA19-9, has diagnostic limitations because it can be normal in patients with localized disease or high in patients with benign pancreatic disease, including CP. The aim of this thesis was to explore, tissue expression of tumor biomarkers in PDAC. The prognostic significance of these biomarkers in patient survival was evaluated. In each study, we used different biomarkers: podocalyxin (PODXL), PROX1, β-catenin, UCHL5, and REG4. In the last study, we also evaluated the diagnostic significance of serum REG4 levels in patients with PDAC and in those with CP. Immunohistochemical expression of tumor markers was evaluated in 154 surgical specimens and serum REG4 level in 130 samples from PDAC patients treated between 2000 and 2011. The CP control group comprised 34 patients who underwent resection because of suspicion of malignancy. PODXL, PROX1, β-catenin, and UCHL5 were independent prognostic markers. High tissue expression of PODXL prognosticated poor survival among PDAC patients compared with low tissue expression, whereas high tissue expression of both PROX1 and β-catenin was associated with increased survival. Positive nuclear UCHL5 expression was an independent factor for favorable prognosis. REG4 failed to be an independent marker of prognosis in PDAC, but serum REG4 levels were higher in PDAC than in CP suggesting its utility in differential diagnosis. These studies provide novel knowledge of potential prognostic tumor markers in PDAC. Moreover, we identified a serum biomarker, REG4, that may be useful in differential diagnosis between PDAC and CP.
  • Stenroos, Antti (Helsingin yliopisto, 2018)
    The equipment and body mechanics in skiing and snowboarding are different, exposing participants to a distinctive array of risks and injuries. Recreational skiing and snowboarding have gone through major changes during the last decade due to rising popularity of terrain parks and evolution of equipment. The modern skis provide the opportunity to ski faster with less skill than with traditional skis. The aim of this thesis was to provide information on the incidences and the nature and mechanisms of injury, in both recreational and competitive alpine skiing and snowboarding in Finland. Study I covered six seasons (2006–2012), assessing injured recreational alpine ski¬ers and snowboarders at the Levi Ski Resort Ltd., Finland. The data was collected from the ski resort’s files which registers ski lift rides, injuries and conditions leading to injury on a standardized form of all injured persons. In study II, data of injuries in Finnish ski racers during the seasons of 2009 and 2010 were retrospectively studied. The data collection (patient characteristics, mechanism and type of injury, the length of recovery and a subjective outcome at six months post injury) was conducted with a standardized written questionnaire. For study III, all patients with tibial fracture in recreational skiing or snowboarding were reviewed in four hospitals between years 2006–2012. The fracture morphology and injury mechanism were analysed to compare fracture patterns between these two sports. Study IV focused on traumatic brain injuries. All patients referred to the Trauma Unit of Helsinki University Hospital with acute head injury due to skiing or snowboarding between years 2006 and 2015 were reviewed. The overall injury incidence in recreational skiing and snowboarding in study I was 0.98 injuries per 10 000 lift runs. Snowboarders were more likely to sustain upper extremity injuries when compared to skiers (59% vs. 34% p<0.05) whereas skiers were more likely to injure lower extremity (43% vs. 17%, p<0.05). Most of the accidents (n=2062, 72%) took place on slopes, but injuries in terrain parks were more likely to be more serious injuries (22%, vs. 9%, p< 0.05). In study II, the lower extremity was the most commonly injured body area (n=39, 64%) in ski racing. Knee injury was the most common injury (n=21, 34%), followed by tibial fracture (n=16, 26%). The most common tibia fracture type in recreational skiers (study III) was spiral shaft fracture (n=180, 53%), followed by tibial plateau fractures (n=62, 18%). Where as among snowboarders tibial plateau fractures were most common (n=7, 23%). In study IV, the majority (n=51, 70%) of head injuries were concussions without injury findings in computed tomography. Seventeen patients (24%) had serious to critical injuries graded by Abbreviated Injury Scale. Patients who fell while jumping or trying to balance on handrails in urban environment were more likely to be admitted to ICU than patients injured on skiing slopes (32% vs. 10%, p<0.05). In conclusion, the injury incidence in recreational skiing and snowboarding was lower than in previous studies conducted in the United States and continental Europe, but similar to studies from other Nordic countries. Among ski racers the high number of lower leg fractures is alarming when comparing to previous studies. Additionally, the number of recreational skiers’ tibia plateau fractures was higher than in earlier studies conducted before the era of modern skies. Head injuries occurring in small hills and in urban environments can be serious
  • Engberg, Elina (Helsingin yliopisto, 2018)
    Physical inactivity, mental health problems and obesity, whilst interrelated, each represent a major global health challenge. Furthermore, obesity substantially contributes to the increasing prevalence of gestational diabetes mellitus (GDM), an emerging worldwide epidemic amongst pregnant women. Life events such as pregnancy may affect physical activity as well as mental well-being. This doctoral thesis systemically reviews the literature concerning the effects of life events, especially pregnancy, on physical activity, and examines mental wellbeing and physical activity in women at risk for GDM. The thesis also evaluates the effects of a randomised lifestyle intervention aimed at preventing GDM on self-rated health from early pregnancy throughout the first year following birth. The systematic review consisted of studies amongst healthy adults. In addition, this doctoral thesis includes participants from two randomised controlled trials: the Finnish Gestational Diabetes Prevention Study (RADIEL) and the Finnish Gestational Diabetes Prevention Study Part II: Autonomic Nervous System and Exercise (ANS-EXE). The participants consisted of 482 pregnant women and 39 women planning a pregnancy at high risk for GDM (a history of GDM or a prepregnancy body mass index [BMI] ≥ 29 kg/m2 or both), and 358 pregnant women in the general Finnish population. A proportion of the pregnant women at risk for GDM received diet and physical activity counselling from early pregnancy to one-year postpartum. The studies included in the systematic review showed statistically significant changes in leisure-time physical activity after life events. Changes varied according to different life events and the age and gender of the study population. Physical activity decreased both from prepregnancy to pregnancy, and from prepregnancy to the postpartum period. Pregnant women at risk for GDM exhibited higher Edinburgh Postnatal Depression Scale scores compared to pregnant women in the general population during early pregnancy, but this difference disappeared after adjusting for age, BMI and income. In addition, cardiorespiratory fitness, as assessed by measuring the maximal oxygen consumption (VO2max) during a cycle ergometer test, and self-reported leisure-time physical activity were positively associated with the self-rated general health and physical well-being domains of the 36-Item Short-Form Health Survey in women planning a pregnancy and at risk for GDM, which held when controlling for BMI. Furthermore, self-rated general health and physical well-being differed between those women with very poor or poor cardiorespiratory fitness. The self-rated health of women at risk for GDM tended to improve amongst the lifestyle counselling group and to deteriorate in the control group from pregnancy to one-year postpartum, although the difference between groups was not statistically significant. Life events affect leisure-time physical activity; for example, pregnancy tends to decrease physical activity levels. The prevalence of depressive symptoms during early pregnancy is higher amongst women at risk for GDM compared to women in the general pregnant population. The higher prevalence seems to be explained by characteristics such as age, BMI and income. Moreover, even a slightly better cardiorespiratory fitness could be beneficial for the health-related quality of life amongst women at risk for GDM who are planning a pregnancy. The effectiveness of lifestyle counselling for high-risk pregnant women aimed at improving self-rated well-being requires further research.
  • Mattila, Tiina (Helsingin yliopisto, 2018)
    Background and aims: Subjects with chronic obstructive pulmonary disease (COPD) have comorbidities and increased mortality rate. However, a long-term follow-up data about COPD and mortality appear partly deficient. The aim of this study was to evaluate whether airway obstruction at baseline predicts acute myocardial infarction (MI) and coronary and all-cause mortality, and whether past pulmonary tuberculosis (TB) or low vitamin D status confound or modify the association between obstruction and mortality in 30 years´ follow-up. Methods: A national health examination survey, the Mini-Finland Health Survey performed in 1978–1980, collected data from 8000 subjects´ sample representing Finnish adult population. Studies I to IV included those 5576–6701 participants who had all necessary information, including spirometry, collected for each study. Obstruction was defined either with a fixed ratio of FEV1/FVC < 0.7 or with FEV1/FVC below the lower limit of normal (LLN) categorization, and staged for severity by the Global Initiative for Chronic Obstructive Lung Disease classification (GOLD stages 1–4). Results: In follow-up, decreasing lung function had a strong significant association with all-cause mortality. Respectively HRs with 95% CIs in GOLD stages 1 to 4 were 1.27 (1.06–1.51), 1.40 (1.21–1.63), 1.55 (1.22–1.97), and 2.85 (1.65–4.94) compared to those with FEV1/FVC ≥ 0.7. The risk for cardiovascular mortality was consistently increased in GOLD stages 1–4 but no association emerged after those with a cardiovascular disease at baseline were excluded. Obstruction predicted all-cause mortality strongest in subjects aged 30–49 at baseline (study I). Obstruction predicted coronary mortality but not MI in those without a cardiovascular disease at baseline, respectively, HRs with 95% CIs in subjects with obstruction were 1.40 (1.04–1.88) and 0.84 (0.54–1.31) when compared to those without (study II). Obstruction and past pulmonary tuberculosis (TB), determined either as a TB disease history or a scar indicating it on chest x-ray, predicted all-cause mortality with an additive pattern in follow-up (study III). The association between a low vitamin D status and mortality was pronounced among subjects with obstruction (study IV). Conclusions: Airway obstruction predicts all-cause mortality by decreasing lung function, and mortality risk appear increased especially in the younger population with obstruction. Additionally, obstruction strongly determines coronary mortality but not MI. Obstruction and past TB have an additive effect on all-cause mortality. A low vitamin D status may be particularly detrimental among subjects with obstruction.
  • Kuula-Paavola, Liisa (Helsingin yliopisto, 2018)
    Sleep has important functions for both health and cognitive performance. This thesis investigated typical, non-restricted sleep over a developmental span from middle childhood to early adulthood. Specifically, the focus was (1) identifying the cross-sectional associations between neurocognitive functioning and habitual sleep duration and sleep quality in early adolescence, and (2) studying the sleep behaviour associated with young adults’ executive functioning and self-control. Additionally, the goals included (3) studying the longitudinal associations between naturally occurring sleep and lipid profile in early adolescence, and, finally, (4) differentiating the developmental trajectories of sleep timing from middle childhood to adolescence from a circadian preference perspective. The participants came from two population-based cohorts, and all the studies in this thesis were done using actigraphs with piezoelectric accelerometers, which provide objective sleep measures based on movement. We found that during early adolescence, especially boys’ shorter sleep duration was associated with poorer performance in tests evaluating executive functioning. We found similar results in young adults, but also found that later sleep timing and regularity were associated with weaker trait-like executive functioning, such as self-control and behaviour regulation. Longitudinal analyses revealed that girls’ shorter sleep duration and irregular sleep in middle childhood were associated with a more detrimental lipid profile (higher levels of LDL cholesterol and triglycerides, lower levels of HDL cholesterol) in later life, during early adolescence. These associations survived controlling for body mass index and physical activity. We also analysed the sleep patterns of different circadian preference phenotypes longitudinally, and found that those adolescents with a preference for morningness differed from others in sleep timing already at age 8. This suggests long-term stability in sleep patterns. Based on these findings, objectively measured sleep and its timing have longitudinal pathways which connect to future health, and may act as risk factors or as protective features for various health related outcomes. It is also likely that sleep, self-control, and health behaviour are intertwined during development.
  • Hut, Suzanne (Helsingin yliopisto, 2018)
    The ability to speak more than one language is nowadays commonly the rule, rather than the exception. Many forms of bilingualism exist, varying from early bilingualism in which more than one language is acquired in early childhood, to late bilingualism, where another language is not learned until adulthood. Although a large amount of research has been devoted to the question of how these multiple languages are processed and controlled, conclusive answers have not yet been given. Especially regarding language perception, there have not been many studies to investigate whether active language control is needed in case one does not need to actively select and produce lexical items. The first aim of this thesis was thus to study language control during language perception in more detail, and secondly, to investigate to what extent lexical and semantic processing differs between early-acquired and later-learned languages. The first study examines the effects of language switching on semantic processing (Study I). The second study focuses on trilingual language switching, taking a closer look at the control mechanisms that play a role in this (Study II), while the third study investigates whether early bilingualism leads to possible disadvantages or qualitatively different lexical processing (Study III). This PhD work used various research methods, namely magneto- encephalography (MEG) and encephalography (EEG), as well as behavioural methods and extensive language background questionnaires. The findings of this thesis suggest that language control differs according to the strength of the language network. Even though language switching from L2 to L1 is costly at the neurocognitive level, evidenced by enhanced N400 effects, semantic processing remains unhindered (Study I). However, there is no apparent cost of switching between native languages (Study II) whereas an increase in N400(m) is seen after switches from a later-learned language to the native one (Study I and II). Furthermore, the acquisition of two languages at an early age does not notably affect the speed or accuracy with which lexical processing in either language occurs (Study III), as early bilinguals performed worse on only 1 out of 12 data sets, compared to monolingually raised native speakers. Taken together, the results of this thesis show that bilingual language processing and control is modulated by various language background factors, such as the experience and skills in each particular language, as well as the frequency of use. Provided that the language network is sufficiently strong, lexical and semantic processing of a second language will look similar to that of monolingual native speakers. This thesis proposes that bilinguals use their full linguistic knowledge to make sense of the linguistic input around them, while they are at the same time constantly aware of language membership.