Verho, Anastasiya
(Helsingin yliopisto, 2020)
Non-communicable diseases, especially cardiovascular disease (CVD), account for the majority of deaths worldwide. It is well known that population health is vulnerable to political and economic influences. Russia has faced significant political and economic changes over the past few decades. The country became world-famous for its high CVD morbidity and mortality rates after the collapse of the USSR and the shift towards a market economy (transitional period). While CVD risk factors in adults have been widely investigated by international scholars, scientific evidence regarding changes in CVD risk factors among Russian youth in recent decades appears to be rather scarce. Long ago it was established that CVD risk factors, both biological and behavioural, develop early in life and are shaped by environmental influences. Once formed, CVD risk factors – especially health behaviours – are difficult to change. Epidemiological studies have shown that the development of CVD risk factors among children and adolescents follows the same trends as among adults.
This thesis investigates changes in cardiovascular risk factors among Russian youth during the transition in the country between 1995 and 2013. No previous study has investigated changes in CVD risk factors in relation to adolescents’ social environment in Russia. The study period coincides with the highest CVD mortality rates in the country and significant economic changes.
Biological and behavioural CVD risk factors were studied using an internationally comparable methodology among all 15-year-old students, from all schools in the Pitkäranta district in the Republic of Karelia in Russia, between 1995 and 2013. Cross-sectional surveys were conducted in 1995, 2004 and 2013. The total sample consisted of 1072 students: 368 in 1995 (response rate of 95%), 340 in 2004 (response rate of 85%) and 364 students in 2013 (response rate of 98%). In 1995 and 2004, to study changes in biological risk factors for CVD, the blood pressure, height and weight of subjects were obtained for calculation of body mass index, together with venous blood samples for the determination of lipid levels. Participants filled in a questionnaire with pre-coded answers to study smoking, drinking of alcohol and nutrition behaviour, together with nutrition literacy in all years of the survey. In 2013, data was collected using only the questionnaire.
Biological risk factors (blood pressure, total cholesterol, high-density lipoprotein cholesterol, weight, height, BMI) were within a normal range initially and did not show negative changes until 2004 for both genders.
Significant changes were observed in behavioural risk factors. They mostly worsened during the study period, especially among girls. Thus, the prevalence of daily smoking among boys was high and did not change during the study period. Among girls, daily smoking had more than doubled by 2004 from 7% to 15%. The proportion of non-smoking girls, believing that quitting smoking is easy for young people, increased by 2004. Also, the proportion of girls smoking at home with parents being aware of it increased compared with 1995. Both genders reported smoking at school during breaks. Especially among boys the prevalence was high but did not change between the survey years. Among girls, smoking at school during breaks increased by 2004. Even though the prevalence of smoking remained high among boys and increased among girls during the study period, the prestige of smoking, as a means of improving image, decreased among participants of both genders, except for smoking boys. Among both genders, the odds of smoking were higher among participants if the best friend smoked compared with the presence of smokers among family members. In both survey years, adolescents reported that it was possible to purchase tobacco and alcohol themselves. The self- purchasing of alcohol increased among both genders by 2004. The proportion of youth that had never tried alcohol decreased among both genders. Early initiation of alcohol-drinking increased among boys and in 2004 they consumed alcohol more frequently compared with 1995. Weekly alcohol consumption increased among both genders by 2004. Gender differences in alcohol-drinking behaviour have mostly diminished. Beer consumption among girls almost tripled and the prevalence of drunken behaviour increased among girls by 2004.
The consumption of vegetables increased by 2013 but was still insufficient among both genders. Fruit and berry consumption among girls increased by 2004, with a consequent decrease almost to previous levels by 2013. The purchasing of food high in saturated fat during breaks at school and after school increased among both genders by 2004 and decreased again by 2013. The consumption of sugary drinks and snacks among boys increased from 2004. Among girls it increased steadily from 1995. Milk-drinking decreased among both genders. Nutritional literacy was rather low and further deteriorated among both genders.
The country’s transition had an effect on behavioural CVD risk factors among Russian adolescents. With regard to some positive changes, negative changes in smoking, alcohol use and some dietary aspects prevailed. It is important to be aware of potential environmental influences on youth CVD risk factors, especially in countries with fluctuating economic situations. A regular country-wide surveillance system should be established to monitor changes in CVD risk factors with regard to environmental influences. Public health interventions and control over the implementation of health policies are needed to improve the CVD risk factor profile of Russian adolescents.