METABOLIC AND ADIPOSE RISK-FACTORS FOR NIDDM AND CORONARY-DISEASE IN 3RD-GENERATION JAPANESE-AMERICAN MEN AND WOMEN WITH IMPAIRED GLUCOSE-TOLERANCE

Since second-generation (Nisei) Japanese Americans are prone to develo p the insulin resistance syndrome, younger third-generation (Sansei) J apanese Americans from a cross-sectional 10 % volunteer sample of Sans ei men (n = 115) and women (n = 115) 34 years or older in King County, Washington with normal glucose tolerance or IGT were examined for met abolic and adipose risk factors associated with this syndrome. After a n overnight 10-h fast, blood samples were taken for measurement of glu cose, insulin, C-peptide, lipids, and lipoproteins, followed by a 3-h 75-g oral glucose tolerance test with blood samples taken for glucose, insulin, and C-peptide measurement. BMI (kg/m(2)), skinfolds, and bod y fat areas (by computed tomography) were measured. IGT was diagnosed in 19 % of the men and 31 % of the women. Men with IGT had more adipos ity, both overall and in thoracic and visceral sites, had higher fasti ng plasma insulin and C-peptide, and tended to have higher fasting tri glyceride and lower HDL cholesterol than men with normal glucose toler ance. Women with IGT had more thoracic subcutaneous fat and intra-abdo minal fat and lower fasting HDL cholesterol than women with normal glu cose tolerance, and tended to have higher fasting triglyceride and LDL cholesterol. Women with IGT also had higher fasting plasma insulin th an women with normal glucose tolerance but tended to be less hyperinsu linaemic than men. Differences in fasting insulin, C-peptide, and lipi ds were best predicted by intra-abdominal fat. Thus metabolic (higher fasting insulin and a tendency to higher triglyceride and lower HDL ch olesterol) and adipose (visceral adiposity) risk factors associated wi th the insulin resistance syndrome are identifiable among Sansei men a nd women with IGT, who may therefore be at increased risk of future de velopment of NIDDM and CHD.