Familial partial lipodystrophy, Dunnigan type (FPLD; Mendelian Inheritance in Man #151660), is an autosomal dominant disorder characterized by loss of sc fat from the extremities and trunk since puberty and predisposition to insulin resistance and its complications. However, for lack of recognition of affected men, previous studies could not ascertain any gender differences in phenotypic expression. Therefore, anthropometric variables and prevalence of diabetes mellitus, dyslipidemia, hypertension, and atherosclerotic vascular disease were compared among 17 postpubertal men and 22 women with FPLD from eight pedigrees. All individuals completed a questionnaire, and fasting blood was analyzed for glucose, insulin, and lipoprotein concentrations. Both affected men and women had similar patterns of fat loss. Compared with the affected men, women had higher prevalence of diabetes (18% and 50%, respectively; P = 0.05) and atherosclerotic vascular disease (12% and 45%, respectively; P = 0.04) and had higher serum triglycerides (median values, 2.27 and 4.25 mmol/L, respectively; P = 0.02) and lower high-density lipoprotein cholesterol concentrations (age-adjusted means, 0.94 and 0.70 mmol/L, respectively; P = 0.04). The prevalence of hypertension and fasting serum insulin concentrations were similar. In conclusion, women with FPLD are more severely affected with metabolic complications of insulin resistance than men. These observations raise the possibility that women with generalized and regional obesity may also have more severe metabolic sequelae of insulin resistance.