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

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.

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.

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.

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).

In this community-based general population, higher serum LDL-C levels were linearly associated with an elevated risk of incident diabetes.