Socio-economic status, obesity and prevalence of Type 1 and Type 2 diabetes mellitus

Aims The influence of socio-economic status on the prevalence of Type 1 and Type 2 diabetes mellitus, and on obesity, was explored using routinely collected healthcare data for the population of Tayside, Scotland. Methods Among 366 849 Tayside residents, 792 and 5474 patients with Type 1 and Type 2 diabetes, respectively, were identified from a diabetes register. The Carstairs Score was used as a proxy for socio-economic status. This is a material deprivation measure derived from the UK census, using postcode data for four key variables. Odds ratios for diabetes prevalence, adjusted for age, were determined for each of six deprivation categories (1 - least deprived, 6/7 - most deprived). The mean body mass index (BMI) in each group was also determined, and the effect of deprivation category explored by analysis of covariance, adjusting for age and sex. Results The prevalence of Type 2 diabetes, but not Type 1 diabetes, varied by deprivation. People in deprivation category 6 and 7 were 1.6-times (95% confidence interval 1.4-1.8) more likely to have Type 2 diabetes than those least deprived. There was no relationship between deprivation and BMI in Type 1 diabetes (P = 0.36), but there was an increase in BMI with increasing deprivation in Type 2 diabetes (P < 0.001; test of linearity P < 0.001). Conclusions The study confirms the relationship between deprivation and the prevalence of Type 2 diabetes. There are more obese, diabetic patients in deprived areas. They require more targeted resources and more primary prevention.