Social Inequalities in Child Health: Type 1 Diabetes, Obesity, Cardiovascular Risk Factors and the Role of Self-control

The Swedish Commission on Health Inequality defined health inequality as systematic differences in health between groups in society with different social positions. All avoidable socioeconomic health inequalities are unfair, and as stated by WHO's Commission on the Social Determinants of Health, we have a moral obligation to try to reduce them. "Putting these inequities right is a matter of social justice. Reducing health inequities is, for the Commission on Social Determinants of Health, an ethical imperative." This ethical imperative is especially apparent regarding the health of children and adolescents. Children’s right to the highest attainable standard of health is also enshrined in Article 24 of the Convention on the Rights of the Child. To reach the goal of a reduction of health inequalities, research is necessary to describe the social gradients of health. Research is also needed to better understand why these gradients occur. A better understanding and knowledge about health inequalities can lead to policies that reduce these inequalities and ensure children’s right to health. This thesis investigates social inequality in child health using data from a Swedish population-based prospective birth cohort, the All Babies in Southeast Sweden (ABIS) cohort. Social inequality in obesity in the ABIS cohort is also compared with other birth cohorts participating in the Elucidating Pathways to Child Health Inequality (EPOCH) collaboration which includes cohorts from six high-income countries; Sweden, the Netherlands, Canada (one national and one cohort from Quebec), UK, Australia, and USA. In Paper 1 we show that health inequalities in overweight and obesity are detectable already at two years of age and that these inequalities increase during childhood. In adolescents, low socioeconomic status increases the risk of becoming overweight and the risk of components of the metabolic syndrome, including high blood pressure and dyslipidemia (low high-density cholesterol). The level of inequality in obesity in the Swedish ABIS cohort was lower than in the other participating countries in the EPOCH collaboration (Paper 2). Inequality was lower in absolute and relative terms when SES was measured by household income. Inequality was also lower in absolute, but not relative, terms when SES was measured by maternal education. This finding indicates that some of the policies implemented in Sweden may attenuate social inequalities in obesity in children. Examples of suc