Clinical significance of HbA1c as a marker of circulating lipids in male and female type 2 diabetic patients.

Diabetic patients with accompanied (but often unnoticed) dyslipidemia are soft targets of cardiovascular deaths. An early intervention to normalize circulating lipids has been shown to reduce cardiovascular complications and mortality. Glycated hemoglobin (HbA(1c)) is a routinely used marker for long-term glycemic control. This investigation is an attempt to evaluate the diagnostic value of HbA(1c) in predicting diabetic dyslipidemia. Venous blood samples were collected from 2,220 type 2 diabetic patients (ages, 35-91 years; male/female ratio, 1.07). The sera were analyzed for HbA(1c), fasting blood glucose (FBG), total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL) and low-density lipoprotein cholesterol (LDL). The levels of HbA(1c) did not differ significantly between males (8.33 +/- 0.06%) and females (8.47 +/- 0.07%), whereas female patients had significantly higher FBG (10.01 +/- 0.13 mmol/l) than males (9.31 +/- 0.11 mmol/l). HbA(1c) showed direct and significant correlations with cholesterol, triglycerides and LDL and inverse correlation with HDL. Female diabetic patients had significantly higher levels of serum cholesterol (5.42 +/- 0.03 vs. 5.18 +/- 0.03 mmol/l) and HDL (1.32 +/- 0.01 vs. 1.12 +/- 0.01 mmol/l) as compared to males. There was no significant difference in triglycerides and LDL between the two genders. Older patients (>70 years) had significantly lower FBG, cholesterol, triglycerides and LDL. There was a linear and significant increase in triglycerides in the patients of both genders with impaired glycemic control. Both male and female patients with worse glycemic control (HbA(1c) > 9%) had significantly high cholesterol and LDL levels. Serum HDL showed a significant and inverse relationship with uncontrolled hyperglycemia in females but not in males. These findings clearly suggest that HbA(1c) can provide valuable supplementary information about the extent of circulating lipids besides its primary role in monitoring long-term glycemic control. Further studies are warranted to reinforce the potential of HbA(1c) as a biomarker for screening of high-risk diabetic patients.