Background/aims: To compare the cardiovascular disease (CVD) risk factors between subjects with impaired fasting glucose (IFG) and those with impaired glucose tolerance (IGT) in the first-degree relatives (FDR) of type 2 diabetic patients.

Methods: A cross-sectional study, conducted between 2004 and 2006 in 1,893 (1,412 females and 481 males) FDR of type 2 diabetic outpatients of the Isfahan Endocrine and Metabolism Research Center. In all participants, blood pressure, weight, height, waist circumference, serum lipids and HbA1c were measured and a standard 75-g 2-hour oral glucose tolerance test was performed. The diagnosis of IGT, IFG and diabetes was made according to American Diabetes Association criteria.

Results: Isolated IGT and isolated IFG, and both IFG and IGT were observed in 8.8%, 17.4% and 11.2% of subjects, respectively. In comparison to subjects with normal glucose levels and tolerance (control group): the mean waist circumference was significantly higher in both IFG and IGT groups; BMI, HDL-c and LDL-c in the IFG group; and triglycerides in the IGT group. The means of all studied CVD risk factors were significantly higher in the IGT+IFG group than the control group, except for blood pressure, HDL-c and HbA1c. No significant differences were found regarding CVD risk factors between IFG and IGT groups.

Conclusions: The prevalence of IFG and IGT is high in FDR of type 2 diabetic patients. CVD risk factors are similar in these 2 groups and higher than in the control group. More attention should be paid to screening and treatment of this high-risk population.