Socioeconomic status and type 2 diabetes complications among young adult patients in Japan

Objective To assess the relationship between socioeconomic status (SES) and complications of type 2 diabetes among young adults in Japan. Design A cross-sectional study. Setting Outpatient wards of 96 member hospitals and clinics of the Japan Federation of Democratic Medical Institutions. Participants A total of 782 outpatients with type 2 diabetes (525 males, 257 females), aged 20-40 years as of March 31, 2012. After excluding 110 participants whose retinopathy diagnosis was in question, 672 participants were analyzed. Measurements We examined the relations between SES (educational level, income, type of public health-care insurance, and employment status) and diabetes complications (retinopathy and nephropathy) using a multivariate logistic regression analysis. Results The prevalence of type 2 diabetic retinopathy was 23.2%, while that of nephropathy was 8.9%. The odds of having retinopathy were higher among junior high school graduates (OR 1.91, 95% CI 1.09-3.34), patients receiving public assistance (OR 2.19, 95% CI 1.20-3.95), and patients with irregular (OR 1.72, 95% CI 1.03-2.86) or no employment (OR 2.23, 95% CI 1.36-3.68), compared to those with a higher SES, even after covariate adjustment (e.g., age, gender, body mass index). Similarly, the odds of having nephropathy were higher among patients with middle (OR 3.61, 95% CI 1.69-8.27) or low income levels (OR 2.53, 95% CI 1.11-6.07), even after covariate adjustment. Conclusions Low SES was associated with a greater likelihood of type 2 diabetes complications in young adults. These findings suggest the necessity of health policies that mitigate socioeconomic disparity and thereby reduce the prevalence of diabetic complications.