Association between serum LDL‐C concentrations and risk of diabetes: A prospective cohort study

BACKGROUND: Low‐density lipoprotein cholesterol (LDL‐C) and diabetes mellitus are both modifiable risk factors for cardiovascular disease; however, whether elevated LDL‐C levels confer a risk for diabetes remains unclear. OBJECTIVE: We aimed to examine the association between serum LDL‐C concentrations at baseline and the risk of developing diabetes at follow‐up in the general population of Chinese adults. METHODS: This study included 5274 adults aged ≥ 40 years from a community cohort who were without diabetes and followed for a median of 4.4 years. A standard 75‐g oral glucose tolerance test was conducted at baseline and follow‐up visits to diagnose diabetes. Logistic regression models and a restricted cubic spline were used to examine the association between baseline serum LDL‐C levels and the risk of diabetes development. Subgroup analyses were conducted stratifying on age, sex, body mass index, hypertension, family history of diabetes, and LDL‐C levels. RESULTS: A total of 652 participants (12%) developed diabetes during the follow‐up period. Compared to quartile 1 of serum LDL‐C, quartiles 2, 3, and 4 were associated with a 30%, 33%, and 30% significantly higher risk of diabetes, respectively after adjustment for confounders including homeostatic model assessment for insulin resistance. The linear relationship between baseline LDL‐C down to 30.1 mg/dL and incident diabetes was demonstrated by restricted cubic spline analysis, and each 1‐SD increase in LDL‐C concentration (28.5 mg/dL) was associated with a 12% increase in the risk of diabetes (odds ratio 1.12, 95% confidence interval 1.03–1.22). CONCLUSION: In this community‐based general population, higher serum LDL‐C levels were linearly associated with an elevated risk of incident diabetes.