Type 2 Diabetes Risk in Turkey: A Multilevel Analysis of Individual Versus Regional Determinants

Abstract Background and Aim Type 2 diabetes mellitus (T2DM) is a global health concern shaped by individual and social factors. Although regional-level socioeconomic conditions may influence disease risk, their impact compared to individual-level factors is unclear. This study aimed to explore the relative impact of individual versus regional factors in the development of T2DM in Turkey, using a multilevel modeling approach. Methods We used data from the 2011 Turkiye Chronic Disease Risk Factors Survey (TKHRF).Incidence of T2DM over the six-year period was assessed using a two-level generalized linear mixed model, with individuals nested within the 12 NUTS-1 regions. Individual-level variables included age, sex, education, smoking, obesity, insurance status, and systolic blood pressure. Regional-level variables were income inequality (Gini coefficient), unemployment, number of hospitals, number of beds per hospital, and population per family physician. Data were anonymized and approved by ethics. Missing data were handled via multiple imputation. Analyses used R (v4.3.2). Results Out of 13,479 individuals, 4.1% developed T2DM during the study period. In the final model, older age (OR 1.60, 95% CI 1.43-1.79), female (OR 1.51, 95% CI 1.22-1.86), higher education (OR 1.50, 95% CI 1.19-1.87), former smoking (OR 1.42, 95% CI 1.06-1.91), current smoking (OR 1.32, 95% CI 1.05-1.65), elevated systolic blood pressure (OR 1.17, 95% CI 1.08-1.28), and obesity (OR 2.84, 95% CI 1.30-6.18) were all significantly associated with an increased risk of T2DM. In contrast, regional-level variables such as income inequality (Gini coefficient), number of hospitals, hospital beds, and population per family physician showed no significant association with T2DM incidence. Conclusions Among Turkish adults, individual-level sociodemographic and behavioral factors better predict T2DM risk than regional conditions. Public health efforts targeting individual risk factors may be more effective for prevention. Key messages • Individual-level factors like age, education, smoking, and obesity play a more substantial role in type 2 diabetes risk in Turkey than regional socioeconomic conditions. • Targeting individual risk profiles may be more effective in preventing diabetes than interventions focused on regional health disparities.