Sociodemographic and clinical determinants of health-related quality of life among patients with type 2 diabetes mellitus: a cross-sectional analysis using the WHOQOL-BREF in a South Indian tertiary care setting

Abstract Background Type 2 diabetes mellitus (T2DM) diminishes health-related quality of life (QOL), but the sociodemographic and clinical factors that shape QOL are incompletely characterised in South Indian tertiary care populations. We examined the determinants of QOL across the four WHOQOL-BREF domains among adults with T2DM in Mysuru, India. Methods This cross-sectional analysis used baseline data from 360 adults with T2DM attending the diabetic clinic of a tertiary care teaching hospital. QOL was assessed with the validated WHOQOL-BREF instrument (physical, psychological, social relationships, and environmental domains, each transformed to a 0–100 scale). Associations with sociodemographic and clinical characteristics were examined using the Kruskal–Wallis and Mann–Whitney U tests and Spearman correlation, followed by multivariable linear regression for each domain (predictors: age, sex, residence, education, socioeconomic status, and duration of diabetes). A p value < 0.05 was considered significant, and all analyses were independently verified against the raw dataset. Results Median (IQR) domain scores were 56 (44–63) for physical, 56 (44–63) for psychological, 50 (44–56) for social, and 50 (44–63) for environmental. Longer duration of diabetes was independently associated with lower QOL across all four domains (β per year: physical − 0.70, psychological − 0.73, social − 1.15, environmental − 0.62; all p < 0.01). Higher educational attainment was independently associated with higher QOL in the physical (β = 1.68, p < 0.001), social (β = 1.89, p = 0.003), and environmental (β = 1.70, p = 0.006) domains. Older age and rural residence were associated with lower QOL in univariate analysis. Sex, body mass index, and glycaemic-monitoring frequency were not significantly associated with QOL. Conclusions Among South Indian adults with T2DM, longer disease duration and lower educational attainment were the most consistent determinants of poorer quality of life. These groups should be prioritised for targeted psychosocial and self-management support within diabetes care.