Diabetes mellitus type two in Stockholm County, Sweden : examining ethnicity as an independent risk factor—a cross-sectional study

Abstract

Background: Diabetes mellitus type two (T2DM) is a major global health issue. It is caused by an interaction between genetic and environmental factors. It is a metabolic disorder characterised by elevated blood glucose which can lead to serious health complications. Global prevalence is expected to increase, reaching nearly 600 million cases by 2033. It carries massive disease and economic burden, especially in low to middle income countries. Global studies on different ethnic groups have revealed that ethnicity can increase or decrease the risk of developing T2DM. Aim: Our aim is to shed light on ethnicity as an independent risk factor for T2DM by analysing population data from Stockholm County, Sweden where 20 per cent of individuals are foreign born and T2DM is a growing public health concern. Methods: We used cross-sectional data from the Stockholm Public Health Survey 2010 (n=71,972) combined with information from national registries. We approximated ethnicity by country of birth (COB) which was then grouped into nine geographical categories. Established risk factors include age, gender, body mass index (BMI), education level, diet, tobacco, alcohol, physical activity and sedentary behaviour, which were adjusted for. First, we explored the prevalence of T2DM by COB group. Second, we conducted a univariate analysis to determine the significance of the selected risk factors and T2DM. Third, by logistic regression, we analysed the risk for T2DM by COB group compared to Swedish-born individuals adjusting for all significant risk factors from the univariate analysis. Then, we stratified our data set by COB group, and introduced all significant risk factors to explore differences in magnitude. Results: Prevalence of T2DM was highest in the North Africa and the Middle East group (8.4 per cent). Relative to Swedish-born individuals, COB was a risk factor for T2DM in the Sub-Saharan Africa (OR 2.34), North Africa and the Middle East (OR 2.32) and Asia (OR 3.14) groups when all other risk factors were adjusted for. All studied risk factors were statistically significant for T2DM except fish consumption and snus use. Age, BMI and gender were the most consistent risk factors across groups in the stratified models. We found that moderate to high alcohol consumption appeared to reduce risk for T2DM considerably. Conclusion: Ethnicity is an independent risk factor for T2DM. Prevalence differs across ethnic groups. Not all established risk factors affect ethnic groups in the same way. The results can inform future prevention and management programmes.