To investigate the effect of a family history of NIDDM on HbAlc and serum 1,5-anhydroglucitol (AG) in nondiabetic subjects.
A 75-g oral glucose tolerance test was performed; 258 subjects with normal glucose tolerance and 106 subjects with impaired glucose tolerance (IGT) were selected HbA1c and serum AG were compared between subjects with and without a family history of NIDDM. The relationships between age, BMI, HbA1c, serum AG, fasting and 2-h plasma glucose, and urinary glucose were also examined using principal component analysis with a varimax rotation.
In the normal group, only serum AG was lower in subjects with a positive family history than in those with no family history. On the other hand, in the IGT group, subjects with a positive family history were younger and had a higher 2-h plasma glucose, a higher urinary glucose, and a lower serum AG than those with no family history, whereas there was no difference in HbA1c. Principal component analysis identified three factors. The first factor, a linear combination of HbA1c and fasting plasma glucose, was labeled an average glycemic factor. The second factor, which included serum AG, 2-h plasma glucose, and urinary glucose, was labeled an oscillatory glycemic factor. The third factor, which contrasted age against BMI, was labeled an environmental factor.
Serum AG is related to glycosuria even among nondiabetic subjects, and its concentrations are decreased in those with a family history of NIDDM. Our results suggest that serum AG rather than HbA1c reflects early metabolic abnormalities in these subjects.
