FEATURES OF SYNDROME-X IN FIRST-DEGREE RELATIVES OF NIDDM PATIENTS

OBJECTIVE-To determine whether the features of syndrome X are more com mon in first-degree relatives of non-insulin-dependent diabetes mellit us (NIDDM) patients than in control subjects with no family history of diabetes. RESEARCH DESIGN AND METHODS-A total of 154 first-degree rel atives from 60 families with two or more NIDDM patients and 154 age- a nd sex-matched control subjects were studied. All subjects underwent a 75-g oral glucose tolerance test and baseline lipid blood and anthrop ometric measures. The features of syndrome X that were studied were ob esity, hypertension, dyslipidemia (high triglyceride levels and low hi gh-density lipoprotein [HDL] cholesterol concentrations), impaired glu cose tolerance (World Health Organization criteria), and insulin resis tance (as assessed by the homeostasis model assessment). RESULTS-Relat ives were heavier than control subjects (body mass index 27.5 +/- 5.2 vs. 25.2 +/- 4.6 kg/m(2), respectively [mean +/- SD], P < 0.0002), had lower HDL cholesterol concentrations (1.2 +/- 0.3 vs. 1.4 +/- 0.4 mmo l/l, P < 0.001), were more insulin-resistant (2.3 [0.7-7.6] vs. 1.6 [0 .5-5.1], geometric mean [95% confidence intervals], P < 0.0001), and h ad more individuals classified as having impaired glucose tolerance (2 8 of 154 [18%] vs. 7 of 154 [7%], chi(2), P < 0.001). The differences in insulin resistance and HDL cholesterol concentrations between the g roups were independent of obesity. CONCLUSIONS-Features of syndrome X occur more frequently in relatives of NIDDM patients than in control s ubjects with no family history of diabetes.