Aims/hypothesis: Non-HDL cholesterol (the sum of LDL, VLDL and IDL cholesterol) is considered to be particularly valuable in the management of dyslipidaemia in type 2 diabetes. However, it remains uncertain whether the association between non-HDL cholesterol and cardiovascular risk in type 2 diabetes depends on the status of hyperglycaemia. We aimed to determine whether non-HDL cholesterol predicts CHD events among diabetic women independently of currently established risk factors and the status of glycaemic control.
Methods: We prospectively followed 921 diabetic women in the Nurses' Health Study, who were free of cardiovascular disease at the time that blood was drawn in 1989/90. During 10 years of follow-up, we identified 122 incident CHD cases.
Results: After adjustment for age, BMI, smoking, alcohol consumption, and other lifestyle risk factors, the multivariate relative risks (RRs) of CHD for extreme quartiles were 1.97 (95% CI: 1.14-3.43) for non-HDL cholesterol, 1.78 (1.02-3.11) for apolipoprotein B-100, and 1.93 (1.15-3.22) for LDL cholesterol. However, the association between non-HDL cholesterol and CHD risk was only apparent among women with elevated fasting triglycerides (RR for extreme quartiles: 3.80; p=0.045). HbA(1)c was strongly associated with increased CHD risk (RR for increase by 1 unit: 1.24; 95% CI: 1.13-1.35), and both non-HDL cholesterol and HbA(1)c additively predicted CHD risk (RR for the combination of high non-HDL cholesterol and high HbA(1)c [tertiles]: 4.59).
Conclusions/interpretation: Our study suggests that non-HDL cholesterol and HbA(1)c are potent predictors of CHD risk in diabetic women. Therapies to lower CHD risk in diabetic patients should emphasise both glycaemic control and lipid lowering.