Browsing by Subject "BOYS"

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  • Schiavone, Nella; Virta, Maarit; Leppämäki, Sami; Launes, Jyrki; Vanninen, Ritva; Tuulio-Henriksson, Annamari; Immonen, Satu; Järvinen, Ilkka; Lehto, Eliisa; Michelsson, Katarina; Hokkanen, Laura (2019)
    We investigated ADHD symptoms and life outcomes in adulthood and their association with childhood ADHD and subthreshold symptoms in a prospectively followed cohort with perinatal risks. We identified participants with childhood ADHD (cADHD, n = 37), subthreshold symptoms defined as attention problems (cAP, n = 64), and no ADHD or cAP (Non-cAP, n = 217). We compared the groups and a control group with no perinatal risks (n = 64) on self-reported ADHD symptoms, executive dysfunction, and life outcomes in adulthood. At age 40, 21.6% of the cADHD, 6.3% of the cAP, 6.0% of the Non-cAP group, and 1.6% of the controls reached a screener cutoff for possible ADHD. The cADHD group had lower educational level, more ADHD symptoms and executive dysfunction, and higher rates of drug use than the other groups. Childhood ADHD associated with perinatal risks persists into midlife whereas childhood subthreshold ADHD symptoms in this cohort were not associated with negative outcomes in adulthood.
  • Gatej, Alexandra-Raluca; Lamers, Audri; van Domburgh, Lieke; Crone, Matty; Ogden, Terje; Rijo, Daniel; Aronen, Eeva; Barroso, Ricardo; Boomsma, Dorret I.; Vermeiren, Robert (2019)
    Background: Severe behavioural problems (SBPs(1)) in childhood are highly prevalent, impair functioning, and predict negative outcomes later in life. Over the last decade, clinical practice guidelines for SBPs have been developed across Europe to facilitate the translation of scientific evidence into clinical practice. This study outlines the results of an investigation into academic experts' perspectives on the current prevalence, implementation, and utility of clinical guidelines for SBPs in children aged 6-12 across Europe. Methods: An online semi-structured questionnaire was completed by 28 psychiatry and psychology experts from 23 countries. Results: Experts indicated that approximately two thirds of the included European countries use at least an unofficial clinical document such as textbooks, while nearly half possess official guidelines for SBPs. Experts believed that, although useful for practice, guidelines' benefits would be maximised if they included more specific recommendations and were implemented more conscientiously. Similarly, experts suggested that unofficial clinical documents offer a wide range of treatment options to individualise treatment from. However, they stressed the need for more consistent, evidence-based clinical practices, by means of developing national and European clinical guidelines for SBPs. Conclusions: This study offers a preliminary insight into the current successes and challenges perceived by experts around Europe associated with guidelines and documents for SBPs, acting as a stepping stone for future systematic, in-depth investigations of guidelines. Additionally, it establishes experts' consensus for the need to develop official guidelines better tailored to clinical practice, creating a momentum for a transition towards European clinical guidelines for this population. (c) 2019 The Authors. Published by Elsevier Masson SAS. This is an open access article under the CC BY-NC-ND license (
  • Utriainen, Pauliina; Jääskeläinen, Jarmo; Saarinen, Anne-Riitta; Vanninen, Esko; Mäkitie, Outi; Voutilainen, Raimo (2009)
  • Leppänen, Marja H.; Lehtimäki, Aku-Ville; Roos, Eva; Viljakainen, Heli (2022)
    Body image dissatisfaction is a concern for adolescents' mental and physical well-being, and the role of body mass index (BMI) and physical activity (PA) in it is still unclear. This study investigates the associations of BMI and PA with body image, separately for boys and girls, in a large sample of Finnish adolescents. We also examine the associations of BMI with body image in varying PA levels. A total of 10,496 adolescents (girls 52.6%) were included in the analyses. Body image was assessed using a pictorial tool, and categorized as wishing for a smaller body, being satisfied, and wishing for a bigger body. BMI (kg/m(2)) was categorized as thin, normal weight, and overweight/obese. Self-reported PA was divided into three similar-sized categories as low, moderate, and high PA levels. Adjusted ordinal regression analyses were conducted. Our results show that adolescents with thinness had higher odds of wishing for a bigger body compared to their normal-weight peers, while adolescents with overweight/obesity had smaller odds of wishing for a bigger body. Adolescents in low and middle PA levels had lower odds of wishing for a bigger body compared to adolescents in the high PA level. Yet, the PA level modified the associations between BMI and body image, especially in adolescents with thinness and more so in girls than in boys. These findings highlight the need to pay attention to healthy weight gain and PA in adolescents to support their body image satisfaction.
  • Timonen-Soivio, Laura; Vanhala, Raija; Malm, Heli; Hinkka-Yli-Salomaki, Susanna; Gissler, Mika; Brown, Alan; Sourander, Andre (2016)
    We studied the association between specific congenital syndromes and autism spectrum disorders (ASD) in the large Finnish Register material. Our data include all children diagnosed with ASD (n = 4441) according to Finnish Hospital Discharge Register in 1987-2000. Four controls per each case were matched to sex, birthplace, date of birth (+/- 30 days) and residence in Finland (n = 17,695). The prevalence of specific congenital syndromes in the Finnish Register of Congenital Malformations was evaluated among the ASD group and the controls by sex. The results of this study suggest that there is an association between several etiologically different syndromes and ASD when compared to controls without ASD. Statistically significant associations were observed with 47,XYY, Sotos syndrome, neurofibromatosis I, and syndrome not otherwise specified. Syndromes were more common among males with ASD compared to controls. These results support the previous studies of etiological heterogeneity of ASD and have importance in clinical examination, management and rehabilitation.
  • Varimo, Tero; Miettinen, Paivi J.; Vaaralahti, Kirsi; Toppari, Jorma; Huopio, Hanna; Voutilainen, Raimo; Tenhola, Sirpa; Hero, Matti; Raivio, Taneli (2022)
    Context: Circulating levels of liver-enriched antimicrobial peptide 2 (LEAP2), a ghrelin receptor antagonist, decrease under caloric restriction and increase in obesity. The role of LEAP2 in male puberty, a phase with accelerated energy demand, is unclear. Objective: This work aimed to investigate whether circulating LEAP2 levels are downregulated in boys following the onset of puberty to respond to the energy need required for growth. Methods: We determined circulating LEAP2 levels in 28 boys with constitutional delay of growth and puberty (CDGP) who participated in a randomized controlled trial (NCT017977181, and were treated with letrozole (n = 15) or intramuscular low-dose testosterone (T) (n = 13) for 6 months. Blood sampling and dual-energy x-ray absorptiometry-measured body composition were performed at 0-, 6-, and 12-month visits. Results: Serum LEAP2 levels decreased statistically significantly during pubertal progression (0-6 months: mean decrease -4.3 (10.3) ng/mL, P = .036 and 0-12 months: -3.9 19.31 ng/mL, P = .033). Between 0 and 6 months, the changes in serum LEAP2 levels correlated positively with changes in percentage of body fat (r(s) = 0.48, P = .011), and negatively with growth velocity and estradiol levels (r(s) = -0.43, P = .022, r(s) = -0.55, P = .003, respectively). In the T group only, the changes in serum LEAP2 correlated negatively with changes in T and estradiol levels. Between 0 and 12 months, the change in LEAP2 levels correlated negatively with the change in high-density lipoprotein levels (r(s) = -0.44, P = .022) and positively with the change in insulin (r(s) = 0.50, P = .009) and HOMA-IR (r(s )= 0.51, P = .007) levels. Conclusion: Circulating LEAP2 levels decreased after induction of puberty reciprocally with increased growth rate and energy demand, reflecting the metabolic state of the adolescent. Further, the results suggest that estradiol levels may have a permissive role in downregulating circulating LEAP2 levels.
  • Taskinen, Seppo; Mäkelä, Eija; Raivio, Taneli (2020)
    Purpose: To evaluate short-term testicular outcome after torsion in children. Methods: Fifty-four children and adolescents were evaluated after 6 months of the operation for testicular torsion. Testicular volume was measured and circulating Inhibin B, FSH, LH and testosterone levels were checked. Results: Delay from the onset of symptoms to surgery was shorter in the orchidopexy group (n = 47), than in the orchiectomy group (n = 7, p = 0.001). In the orchidopexy group, the median volume of the affected testis was 83% (IQR 43-104) of the contralateral testis (p = 0.002). The plasma hormone levels in orchidopexy and orchiectomy groups were: 148 ng/l (IQR 108-208) vs. 129 ng/l (IQR, 123-138, p = 0.269) for Inhibin B; 4.5 IU/L (IQR2.6-6.9) vs. 11.7 IU/L (IQR 4.3-12.8, p = 0.037) for FSH; 2.9 IU/L (IQR 1.3-3.7) vs. 4.8 (IQR 3.0-5.6, p = 0.066) for LH; and 13.6 nM(IQR 6.5-18.0) vs. 14.5 nM(IQR 6.7-15.9, p = 0.834) for testosterone. The association between FSH, LH as well as testosterone levels was most clear with the volume of the contralateral testis (Rho = 0.574, p <0.001, Rho = 0.621, p = 0.001 and Rho 0.718, p <0.001 respectively). Conclusions: Testicular function is mainly dependent on the volume of contralateral testicle after testicular torsion. However, testis preserving surgery tends to maintain better function than orchiectomy. Type of study: Retrospective review. (c) 2019 Elsevier Inc. All rights reserved.
  • Raitio, Arimatias; Kalliokoski, Nelly; Syvänen, Johanna; Harju, Samuli; Tauriainen, Asta; Hyvärinen, Anna; Gissler, Mika; Helenius, Ilkka; Sankilampi, Ulla (2021)
    The aim of this nationwide population-based case-control study was to assess the incidence of inguinal hernia (IH) among patients with congenital abdominal wall defects. All infants born with congenital abdominal wall defects between Jan 1, 1998, and Dec 31, 2014, were identified in the Finnish Register of Congenital Malformations. Six controls matched for gestational age, sex, and year of birth were selected for each case in the Medical Birth Register. The Finnish Hospital Discharge Register was searched for relevant diagnosis codes for IH, and hernia incidence was compared between cases and controls. We identified 178 infants with gastroschisis and 150 with omphalocele and selected randomly 1968 matched, healthy controls for comparison. Incidence of IH was significantly higher in gastroschisis girls than in matched controls, relative risk (RR) 7.20 (95% confidence interval [CI] 2.25-23.07). In boys with gastroschisis, no statistically significant difference was observed, RR 1.60 (95% CI 0.75-3.38). Omphalocele was associated with higher risk of IH compared to matched controls, RR 6.46 (95% CI 3.90-10.71), and the risk was equally elevated in male and female patients. Conclusion: Risk of IH is significantly higher among patients with congenital abdominal wall defects than in healthy controls supporting hypothesis that elevated intra-abdominal pressure could prevent natural closure of processus vaginalis. Parents should be informed of this elevated hernia risk to avoid delays in seeking care. We also recommend careful follow-up during the first months of life as most of these hernias are diagnosed early in life.
  • Tolonen, Tarja (2019)
    This article draws on ethnographic fieldwork and interviews to explore young minority men's relation to school and city space in Helsinki from the perspective of their everyday experiences of racialisation in public spaces. The article uses the concept of 'power geometrical' relations of space by drawing on several research traditions, including youth and masculinity studies, studies on social space, racialisation and ethnicity, and human geography. The evidence shows the school to be an important site of local and national power geometry (Massey, D. [1994]. Space, Place and Gender. Cambridge: Polity Press), in which 'informal' and 'physical' spheres are dominated by peers and connect to streets and public spheres (Gordon, T., J. Holland, and E. Lahelma. [2000]. Making Spaces: Citizenship and Difference in Schools. Houndsmills et al. London: MacMillan Press Ltd). The article shows how young minority men knew their place both in narrow local power geometries, and within the wider city and school spaces, exploring how they formed their own lived spaces (Lefebvre, H. [1991]. The Production of Space. Oxford: Blackwell), claimed their spaces and marked their spaces with diverse tactics. Some tactics were socially open, such as making friends; some were very mobile, such as claiming their own urban spaces by mobility, or marking and 'hanging around'; and some involved big groups of friends, crowds, defence and embodied accounts.
  • Klemetti, R.; Perry, B.; Henningsen, A. K. Aaris; Spangmose, A. Laerke; Pinborg, A.; Opdahl, S.; Romundstad, L. Bente; Bergh, C.; Wennerholm, U. B.; Tiitinen, A.; Gissler, M. (2022)
    STUDY QUESTION Do ART-conceived children have an increased risk for puberty disorders? SUMMARY ANSWER Both ART-conceived boys and girls had a higher risk of puberty disorders; early puberty was more common among girls and late puberty among boys. WHAT IS KNOWN ALREADY Some physiological differences in growth and metabolism have been reported for ART-conceived children compared to non-ART-conceived children. Knowledge on pubertal development and disorders in ART-conceived children is limited. STUDY DESIGN, SIZE, DURATION A register-based cohort study was carried out including data from 1985 to 2015. The Committee of Nordic Assisted Reproductive Technology and Safety (CoNARTaS) study population consists of all live and stillborn children, as well as their mothers, registered in the Medical Birth Registers during the study period in Denmark, Sweden, Finland and Norway. PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 122 321 ART-conceived singletons and 6 576 410 non-ART singletons born in Denmark (1994-2014), Finland (1990-2014), Norway (2002-2015) and Sweden (1985-2015) were included. Puberty disorders were defined using International Classification of Diseases and Related Health Problems (ICD)-9/ICD-10 codes and classified in the following groups: late puberty (6268/E30.0), early puberty (2591 and 2958/E30.1 and E30.8) and unspecified disorders (V212 and V579/E30.9 and Z00.3 as well as Z51.80 for Finland). The results in Cox regression were adjusted for maternal age, parity, smoking, gestational diabetes, chronic hypertension, hypertensive disorders during pregnancy and country, and further for either gestational age, birthweight, small for gestational age or large for gestational age. MAIN RESULTS AND THE ROLE OF CHANCE There were 37 869 children with diagnoses related to puberty disorders, and 603 of them were born after ART. ART-conceived children had higher risks for early (adjusted hazard ratio (aHR) 1.45, 95% CI: 1.29-1.64) and late puberty (aHR 1.47, 95% CI: 1.21-1.77). Girls had more diagnoses related to early puberty (aHR 1.46, 95% CI: 1.29-1.66) and boys with late puberty (aHR 1.55, 95% CI: 1.24-1.95). LIMITATIONS, REASONS FOR CAUTION Using reported puberty disorders with ICD codes in health care registers might vary, which may affect the numbers of cases found in the registers. Register data may give an underestimation both among ART and non-ART-conceived children, especially among non-ART children, who may not be as carefully followed as ART-conceived children. Adjustment for causes and duration of infertility, mothers' own puberty characteristics and BMI, as well as children's BMI, was not possible because data were not available or data were missing for the early years. It was also not possible to compare ART to non-ART siblings or to study the pubertal disorders by cause of subfertility owing to a small number of discordant sibling pairs and a large proportion of missing data on cause of subfertility. WIDER IMPLICATIONS OF THE FINDINGS This large, register-based study suggests that ART-conceived children have a higher risk for puberty disorders. However, the mechanisms of infertility and pubertal onset are complex, and ART is a rapidly advancing field with various treatment options. Studying the pubertal disorders of ART-conceived offspring is a continuing challenge. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk (71450), the Central Norway Regional Health Authorities (46045000), the Nordic Federation of Obstetrics and Gynaecology (NF13041, NF15058, NF16026 and NF17043), the Interreg oresund-Kattegat-Skagerrak European Regional Development Fund (ReproUnion project), the Research Council of Norway's Centre of Excellence funding scheme (262700), the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (ALFGBG-70940) and FLUX Consortium 'Family Formation in Flux-Causes, Consequences and Possible Futures', funded by the Strategic Research Council, Academy of Finland (DEMOGRAPHY 345130). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. The authors have no conflicts of interest to disclose.
  • Nikolakaros, Georgios; Vahlberg, Tero; Sillanmäki, Lauri; Sourander, Andre (2020)
    Background: Cardiorespiratory fitness (CRF) strongly influences health, but very little is known about the childhood determinants of adult CRF. Our longitudinal study investigated whether childhood psychopathology and socioeconomic status (SES) were related to adult CRF in 1647 Finnish male military conscripts. Methods: Childhood psychopathology was assessed at the age of eight using the Rutter and Children's Depression Inventory questionnaires. Parental education and family structure were used to assess childhood SES. In late adolescence, depressive symptoms were assessed with the Beck Depression Inventory and smoking with a questionnaire. CRF in early adulthood was examined with the Cooper's 12-minute run test. Results: General linear models showed that low parental education (p = 0.001), depressive symptoms in childhood (p = 0.035) and late adolescence, smoking, underweight, and overweight/obesity (all p <0.001) independently predicted lower CRF. The interaction between depressive symptoms in childhood and adolescence was significant (p = 0.003). In adolescents with depressive symptoms, childhood depressive symptoms (p =0.001) and overweight/obesity (p <0.001) predicted lower CRF. In adolescents without depressive symptoms, conduct problems in childhood predicted lower CRF in the initial models, but the effect disappeared after taking into account smoking and body mass index. Mediational analysis confirmed these results. Limitations: We lacked data on physical activity and only studied males at three time-points. Conclusions: Recurrent depression in childhood and adolescence and low SES in childhood predict lower adult CRF. Conduct problems in childhood predict lower CRF, but the effect is mediated by overweight/obesity and smoking. Psychiatric treatment for children and adolescents should promote physical activity, particularly for children with low SES.
  • Oshukova, Svetlana; Kaltiala-Heino, Riittakerttu; Hillege, Sanne; de Ruiter, Corine; Joffe, Grigori; Miettunen, Jouko; Marttila, Riikka; Marttunen, Mauri; Kaivosoja, Matti; Lindberg, Nina (2016)
    Background: Culture-related differences in psychopathic traits have been reported for adults, but for adolescents such knowledge is lacking. The aim of this cross-national study was to compare self-reported psychopathic traits between Finnish and Dutch samples of mid-adolescent community youth. Methods: The Youth Psychopathic traits Inventory (YPI) was filled in by 372 Finnish and 474 Dutch 15- to 16-year-old pupils. As gender-specific differences exist in psychopathic traits, we analyzed the data separately for boys and girls. Results: Dutch boys scored significantly higher than Finnish boys on total and all dimensional scores of the YPI as well as on most sub-dimensional scores. Dutch girls scored significantly higher than Finnish girls on the Affective dimension and on the two corresponding sub-dimensions: remorselessness and callousness. Finnish girls scored significantly higher on grandiosity, which loads to the Interpersonal dimension of the YPI. Conclusions: Our findings suggest that culture influences the manifestation of psychopathic traits already in adolescence and that this relation is more prominent in boys.
  • Cousminer, Diana L.; Leinonen, Jaakko T.; Sarin, Antti-Pekka; Chheda, Himanshu; Surakka, Ida; Wehkalampi, Karoliina; Ellonen, Pekka; Ripatti, Samuli; Dunkel, Leo; Palotie, Aarno; Widen, Elisabeth (2015)
    Constitutional delay of growth and puberty (CDGP) is the most common cause of pubertal delay. CDGP is defined as the proportion of the normal population who experience pubertal onset at least 2 SD later than the population mean, representing 2.3% of all adolescents. While adolescents with CDGP spontaneously enter puberty, they are at risk for short stature, decreased bone mineral density, and psychosocial problems. Genetic factors contribute heavily to the timing of puberty, but the vast majority of CDGP cases remain biologically unexplained, and there is no definitive test to distinguish CDGP from pathological absence of puberty during adolescence. Recently, we published a study identifying significant linkage between a locus at the pericentromeric region of chromosome 2 (chr 2) and CDGP in Finnish families. To investigate this region for causal variation, we sequenced chr 2 between the genomic coordinates of 79-124 Mb (genome build GRCh37) in the proband and affected parent of the 13 families contributing most to this linkage signal. One gene, DNAH6, harbored 6 protein-altering low-frequency variants (<6% in the Finnish population) in 10 of the CDGP probands. We sequenced an additional 135 unrelated Finnish CDGP subjects and utilized the unique Sequencing Initiative Suomi (SISu) population reference exome set to show that while 5 of these variants were present in the CDGP set, they were also present in the Finnish population at similar frequencies. Additional variants in the targeted region could not be prioritized for follow-up, possibly due to gaps in sequencing coverage or lack of functional knowledge of non-genic genomic regions. Thus, despite having a well-characterized sample collection from a genetically homogeneous population with a large population-based reference sequence dataset, we were unable to pinpoint variation in the linked region predisposing delayed puberty. This study highlights the difficulties of detecting genetic variants under linkage regions for complex traits and suggests that advancements in annotation of gene function and regulatory regions of the genome will be critical for solving the genetic background of complex phenotypes like CDGP.
  • Whipp, Alyce M.; Vuoksimaa, Eero; Bolhuis, Koen; de Zeeuw, Eveline L.; Korhonen, Tellervo; Mauri, Matteo; Pulkkinen, Lea; Rimfeld, Kaili; Rose, Richard J.; van Beijsterveldt, Catharina (Toos) E. M.; Bartels, Meike; Plomin, Robert; Tiemeier, Henning; Kaprio, Jaakko; Boomsma, Dorret I. (2021)
    Aggressive behavior in school is an ongoing concern. The current focus is on specific manifestations such as bullying, but the behavior is broad and heterogenous. Children spend a substantial amount of time in school, but their behaviors in the school setting tend to be less well characterized than at home. Because aggression may index multiple behavioral problems, we used three validated instruments to assess means, correlations and gender differences of teacher-rated aggressive behavior with co-occurring externalizing/internalizing problems and social behavior in 39,936 schoolchildren aged 7-14 from 4 population-based cohorts from Finland, the Netherlands, and the UK. Correlations of aggressive behavior were high with all other externalizing problems (r: 0.47-0.80) and lower with internalizing problems (r: 0.02-0.39). A negative association was observed with prosocial behavior (r: -0.33 to -0.54). Mean levels of aggressive behavior differed significantly by gender. Despite the higher mean levels of aggressive behavior in boys, the correlations were notably similar for boys and girls (e.g., aggressive-hyperactivity correlations: 0.51-0.75 boys, 0.47-0.70 girls) and did not vary greatly with respect to age, instrument or cohort. Thus, teacher-rated aggressive behavior rarely occurs in isolation; boys and girls with problems of aggressive behavior likely require help with other behavioral and emotional problems. Important to note, higher aggressive behavior is not only associated with higher amounts of other externalizing and internalizing problems but also with lower levels of prosocial behavior.
  • Laakso, Saila; Viljakainen, Heli; Lipsanen-Nyman, Marita; Turpeinen, Ursula; Ivaska, Kaisa K.; Anand-Ivell, Ravinder; Ivell, Richard; Mäkitie, Outi (2018)
    Background: Previous studies suggest increased risk for hypoandrogenism and fractures in men with obesity. We aimed to describe the effects of severe childhood-onset obesity on the cross talk between metabolic state, testes, and skeleton at late puberty. Methods: A cohort of adolescent and young adult males with severe childhood-onset obesity (n = 21, mean age 18.5 years) and an age-matched control group were assessed for testicular hormones and X-ray absorptiometry-derived bone mass. Results: Current median body mass indexes for the obese and control subjects were 37.4 and 22.9. Severe early-onset obesity manifested with lower free testosterone (median [interquartile range] 244 [194-332] vs. 403 [293-463] pmol/L, p = 0.002). Lower insulin-like 3 (1.02 [0.82-1.23] vs. 1.22 [1.01-1.46] ng/mL, p = 0.045) and lower ratio of testosterone to luteinizing hormone (2.81 [1.96-3.98] vs. 4.10 [3.03-5.83] nmol/IU, p = 0.008) suggested disrupted Leydig cell function. The degree of current obesity inversely correlated with free testosterone (t = -0.516, p = 0.003), which in turn correlated positively with bone area at all measurement sites in males with childhood-onset obesity. Conclusions: Severe childhood-onset obesity is associated with impaired Leydig cell function in young men and lower free testosterone may contribute to impaired skeletal characteristics. (C) 2018 S. Karger AG, Basel
  • Serra, Laura; Farrants, Kristin; Alexanderson, Kristina; Ubalde, Monica; Lallukka, Tea (2022)
    Background Trajectory analyses are being increasingly used in efforts to increase understanding about the heterogeneity in the development of different longitudinal outcomes such as sickness absence, use of medication, income, or other time varying outcomes. However, several methodological and interpretational challenges are related to using trajectory analyses. This methodological study aimed to compare results using two different types of software to identify trajectories and to discuss methodological aspects related to them and the interpretation of the results. Methods Group-based trajectory models (GBTM) and latent class growth models (LCGM) were fitted, using SAS and Mplus, respectively. The data for the examples were derived from a representative sample of Spanish workers in Catalonia, covered by the social security system (n = 166,192). Repeatedly measured sickness absence spells per trimester (n = 96,453) were from the Catalan Institute of Medical Evaluations. The analyses were stratified by sex and two birth cohorts (1949-1969 and 1970-1990). Results Neither of the software were superior to the other. Four groups were the optimal number of groups in both software, however, we detected differences in the starting values and shapes of the trajectories between the two software used, which allow for different conclusions when they are applied. We cover questions related to model fit, selecting the optimal number of trajectory groups, investigating covariates, how to interpret the results, and what are the key pitfalls and strengths of using these person-oriented methods. Conclusions Future studies could address further methodological aspects around these statistical techniques, to facilitate epidemiological and other research dealing with longitudinal study designs.
  • Funke, Miriam; Yang, Yifan; Lahtinen, Atte; Benninghoven-Frey, Klara; Kliesch, Sabine; Neuhaus, Nina; Stukenborg, Jan-Bernd; Jahnukainen, Kirsi (2021)
    Objective: To normalize age-dependent effects on standardized measures of spermatogonial quantity such as the number of spermatogonia per tubular cross-section (S/T) or fertility index. Design: Published quantitative histologic data on human spermatogonial numbers were used to create Z-scores for reference means and tested on archived testicular tissue samples. Setting: Retrospective cohort study. Patient(s): The sample cohort comprised testicular samples from 24 boys with cancer diagnosis and 10 with Klinefelter syndrome, as part of the fertility preservation programs NORDFERTIL and Androprotect, as well as archived histologic samples from 35 prepubertal boys with acute lymphoblastic leukemia and 20 testicular biobank samples. Intervention(s): None. Main Outcome Measure(s): Z-score values for S/T and fertility index on the basis of morphology and germ cell-specific markers (MAGEA4 and/or DDX4) were calculated, and the impact of cancer therapy exposure and genetic disorders on Z-score values was evaluated. Result(s): The Z-scores for S/T values in the nontreated samples (-2.08 +/- 2.20, n = 28) and samples treated with nonalkylating agents (-1.90 +/- 2.60, n = 25) were comparable within +/- 3 standard deviations of the reference mean value but differed significantly from samples exposed to alkylating agents (-12.14 +/- 9.20, n = 22) and from patients with Klinefelter syndrome (-11.56 +/- 4.89, n = 8). The Z-scores for S/T were correlated with increasing cumulative exposure to alkylating agents (r = -0.7020). Conclusion(s): The Z-score values for S/T allow for the quantification of genetic and cancer treatment-related effects on testicular tissue stored for fertility preservation, facilitating their use for patient counseling. (C) 2021 by American Society for Reproductive Medicine.