Decrease in low-density lipoprotein cholesterol is associated with an increased risk of mortality in patients with diabetes mellitus

TL;DR

A drop in LDL cholesterol is linked to higher mortality risk in diabetic patients not on statins.

Contribution

Identifies decreased LDL cholesterol as a potential mortality marker in non-statin-treated diabetes patients.

Findings

Non-statin users had higher mortality and sudden cardiac arrest rates than statin users.

Decreased LDL cholesterol in non-statin users was associated with increased mortality and sudden cardiac arrest risk.

Findings suggest LDL cholesterol decrease may indicate higher mortality risk in untreated diabetes patients.

Abstract

Research on the effect of low-density lipoprotein (LDL)-cholesterol levels and its serial change on all-cause mortality is limited. This study investigated serial change in LDL-cholesterol and its association with all-cause mortality or sudden cardiac arrest (SCA) in patients with diabetes mellitus.

Data was obtained from the nationwide health insurance database of South Korea. Patients with diabetes mellitus who underwent health screening between 2009 and 2012 and those with 4-year follow-up health screening data were included. Patients were further stratified by statin use and change in LDL-cholesterol levels during this 4-year interval. The primary and secondary outcomes were all-cause mortality and SCA, respectively. Outcomes were followed up from the day of health screening till December 2018. Kaplan–Meier analysis and the Cox-proportional hazards model were used to evaluate associations between LDL-cholesterol changes, all-cause mortality, and SCA.

A total of 1,329,982 patients were included, including 532,260 patients who did not receive statin therapy (non-statin users). Compared to statin users, non-statin users had a higher incidence of all-cause mortality (incidence rate 13.9–16.4 per 1,000 person-years) and SCA (1.6–1.9). Among non-statin users, patients with decreased LDL-cholesterol had the highest risk of all-cause mortality (adjusted hazard ratio 1.26, 95% confidence interval 1.21–1.31, P < 0.001) and SCA (1.21, 1.10–1.34, P < 0.001). Thus, in patients with diabetes mellitus not receiving statin therapy, a decrease in LDL-cholesterol may be a surrogate marker for all-cause mortality and SCA.

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