Impact of low-density lipoprotein cholesterol on cardiovascular outcomes in people with type 2 diabetes: A meta-analysis of prospective cohort studies

Aims: To estimate the prospective association of low-density lipoprotein (LDL) cholesterol on cardiovascular disease (CVD) risk among people with type 2 diabetes. Methods: We used extensive literature searching strategies to locate prospective cohort studies that reported LDL cholesterol levels as a risk factor for cardiovascular events. We conducted meta-analytic procedures for two outcomes: incident CVD and CVD mortality. Results: A total of 16 studies were included in this analysis with a mean follow-up range of 4.8-11 years. The pooled relative risk associated with a 1. mmol/L increase in LDL cholesterol in people with type 2 diabetes was 1.30 (95% confidence interval [CI], 1.19-1.43) for incident CVD, and 1.50 (95% CI, 1.25-1.80) for CVD mortality, respectively. Subgroup analyses showed that for incident CVD, the pooled relative risk was 1.28 (95% CI, 1.17-1.41) for 7 studies adjusted for blood pressure and/or glucose concentration (or insulin concentration, glycated hemoglobin) and 1.40 (95% CI, 1.05-1.86) for 3 studies that did not adjust for these variables. Conclusions: Our study demonstrates that LDL cholesterol was associated with an increased risk for cardiovascular outcomes in people with type 2 diabetes, independent of other conventional risk factor.