Differential Associations of Social Determinants of Health with Diabetic Kidney Disease and Treatment Targets in Korean Adults with Diabetes.
Abstract
Background Social determinants of health (SDOH) are linked to adverse diabetes outcomes internationally, but it remains unclear whether these associations are uniform or concentrated across major treatment targets in Korea's universal-coverage setting. Methods We analyzed two Korea National Health and Nutrition Examination Survey cohorts (2021??024, n=3,129; 2011??014, n=2,602). A 4-item SDOH composite was derived from 14 candidate items; because the cohort×SDOH interaction was nonsignificant (P=0.36), the cohorts were pooled (n=5,731). Outcomes included diabetic kidney disease (DKD)-related laboratory abnormalities, defined using Kidney Disease: Improving Global Outcomes (KDIGO)-consistent single-measurement thresholds, severe hyperglycemia (glycosylated hemoglobin [HbA1c] ≥8%), uncontrolled blood pressure (≥140/85 mm Hg), and elevated low-density lipoprotein cholesterol (LDL-C; ≥100 mg/dL). Associations were analyzed using survey-weighted logistic regression adjusted for age, sex, body mass index, and cohort. Results The composite showed a dose-response association with DKD-related laboratory abnormalities (15.9% [score 0] to 34.2% [score ??]; odds ratio [OR] per +1 item, 1.23; 95% confidence interval [CI], 1.14 to 1.33; P<0.001). It was associated with severe hyperglycemia (OR, 1.13; 95% CI, 1.03 to 1.23), but not uncontrolled blood pressure (OR, 0.95; 95% CI, 0.88 to 1.02) or elevated LDL-C (OR, 1.00; 95% CI, 0.94 to 1.08). The HbA1c association was threshold-dependent, emerging only at severe-hyperglycemia levels. This pattern persisted among actively treated patients. Sequential adjustment for HbA1c ≥8% and blood pressure attenuated the SDOH-DKD association by less than 1%. Conclusion Cumulative social disadvantage was associated with DKD-related laboratory abnormalities and severe hyperglycemia, but not failure to meet blood pressure or lipid targets. These exploratory findings may inform future SDOH assessment in Korean diabetes care. Longitudinal registry-linked studies are needed to confirm chronicity and temporality.