Effects of insulin resistance and β-cell function on diabetic complications in Korean diabetic patients

Background Diabetes mellitus is characterized by insulin resistance (IR) and dysfunctional insulin secretion from pancreatic beta-cells. However, little research has been conducted on the relationship between IR and beta-cell function in relation to diabetic complications among Korean diabetic patients. This study aimed to examine the differential associations between IR and beta-cell function and various diabetic complications among Korean diabetic patients.Methods The analysis employed a common data model (CDM). IR and beta-cell function were quantified using the homeostasis model assessment for insulin resistance (HOMA-IR) and beta-cell function (HOMA-beta), respectively. Hazard ratios for diabetic nephropathy, diabetic retinopathy, and cardiovascular disease (CVD) events were calculated.Results The study cohort consisted of 2,034 diabetic patients aged over 20 years who visited EUMC between January 2001 and December 2019. Among diabetic patients in the highest quartile of HOMA-IR, the adjusted hazard ratio for total CVD events was 1.76 (95% confidence interval [CI], 1.20-2.57) compared with those in the lowest quartile of HOMA-IR (P = 0.004). In contrast, diabetic patients in the lowest quartile of HOMA-beta exhibited an adjusted hazard ratio of 3.91 (95% CI, 1.80-8.49) for diabetic retinopathy compared to those in the highest quartile of HOMA-beta (P = 0.001).Conclusion Insulin resistance and beta-cell function exhibited different associations with diabetic complications among Korean diabetic patients. Specifically, lower beta-cell function was associated with an increased risk of diabetic retinopathy, whereas higher IR was associated with an increased risk of CVD events. Individuals with pronounced IR should prioritize CVD prevention measures, and those with significant beta-cell dysfunction may benefit from early, intensive surveillance for diabetic retinopathy.