Socioeconomic consequences of obesity : Population-based longitudinal studies of Swedish men
The overall aim of the thesis was to study if Swedish obese male adolescents become socioeconomicly disadvantaged in later life. Among Swedish men born 1951-79, who went through military conscription examination at age 18-20 years, the associations between obesity and attained education, occupation, income, and disability pension have been studied. The target populations were identified in the Multi-Generation Register. A record linkage was made between this register and data from the following national registers: the Register of the Total Population, the Swedish Military Service Conscription Register, the Population and Housing Censuses, the Longitudinal Database of Education, Income and Occupation, Statistics Sweden s Register on School Marks, the Cause of Death Register, the Hospital Discharge Register, the Swedish Twin Register, and the Swedish Young Male Twin Study. The associations between body mass index in late adolescence and later socioeconomic outcomes were analyzed by logistic regression, polytomous logistic regression, and Cox regression among all study subjects and by linear regression estimated with generalized estimating equations and conditional logistic regression within brother pairs. The results showed that obese Swedish men are doing worse in the educational system than their normal weight counterparts even after adjustments for intelligence, parental education and parental socioeconomic position. Compared to normal weight counterparts, obese men were 40% less likely to start a university education (hazard ratio 0.63 95% confidence interval 0.60; 0.66) and 50% less likely to actually graduate (hazard ratio 0.48 95% confidence interval 0.44; 0.52). Second, obese Swedish men had an increased risk of approximately 35% of receiving disability pension (hazard ratio 1.35 95% confidence interval 1.19; 1.52) compared to their normal weight counterparts when own and parental socioeconomic factors were taken into account. Third, obese men were more likely to move downward and less likely to move upward in the social hierarchy compared to normal weight men. In addition, results showed that obesity was longitudinally associated to low educational level, low socioeconomic position and low income, irrespective of own intelligence, environmental and genetic factors shared by brothers, and parental socioeconomic position. In conclusion, the results show that obesity in late adolescence has socioeconomic consequences in later life. Explanations for these consequences may be sought in the non-shared environment and are speculated to be co-morbidities of obesity, personal characteristics of obese individuals such as aspirations and self-esteem, or factors on the societal level such as discrimination.