Cholesterol and Cardiovascular Risk in Type 2 Diabetes: The Role of Kidney Function

The association of lipid parameters with cardiovascular disease (CVD) and the impact of kidney function on this association have not been thoroughly evaluated in patients with type 2 diabetes mellitus (T2DM).

Using the Korean National Health Insurance Service Cohort database, we identified 2,343,882 subjects with T2DM in 2015-2016. Baseline lipid levels and kidney function were evaluated and followed up until December 2020. Subjects were classified into three groups according to their estimated glomerular filtration rate (eGFR): ≥60, 30-59, or <30 mL/min/1.73 m². We analyzed the diabetes group with eGFR ≥60 and low-density lipoprotein cholesterol (LDL-C) <70 mg/dL as a reference group.

The risk of CVD began to increase at LDL-C ≥100 mg/dL in the eGFR ≥60 mL/min/m² group. The risk of CVD in the eGFR 30-59 mL/min/m² group was increased by 43%, even in the LDL-C <70 mg/dL, and the risk increased progressively with LDL-C category. Among subjects with eGFR 30-59 mL/min/m², LDL-C 70-99, 100-129, 130-159, and ≥160 mg/dL were significantly associated with the risk of CVD, with hazard ratio (95% confidence interval) of 1.48 (1.43-1.53), 1.54 (1.49-1.60), 1.55 (1.48-1.63), and 1.88 (1.77-2.00), respectively. In the eGFR <30 mL/min/m² group, a 3.3-fold increased risk of CVD was seen, even at LDL-C <70 mg/dL.

The cutoff levels of LDL-C that increase CVD risk in patients with T2DM depend on kidney function, which influences the relationship between LDL-C and CVD risk in patients with T2DM.