OBJECTIVE -Hyperandrogenemia, insulin resistance, and dyslipidemia demonstrate familial aggregation in the female first-degree relatives of women with polycystic ovary syndrome (PCOS), suggesting that these defects are heritable. Hyperandrogenemia also appears to be the male reproductive phenotype. We performed this study to test the hypothesis that brothers of women with PCOS have metabolic defects similar to those of their proband sisters.RESEARCH DESIGN AND METHODS -This was a prospective case-control study performed at four academic medical centers in the U.S. Fasting blood was obtained from 196 non-Hispanic white brothers of women with PCOS and 169 control men of age, BMI, and ethnicity comparable to those of brothers. A separate analysis was performed by study site to assess potential regional variations in metabolic parameters.RESULTS -Overall, brothers of women with PCOS had significantly higher total (P ϭ 0.001) and LDL cholesterol (P ϭ 0.01) as well as triglyceride levels (P ϭ 0.01) compared with control men, although there were regional variations in these differences. There were significant positive correlations between brothers and their sisters with PCOS for total ( ϭ 0.2, P ϭ 0.009) and LDL cholesterol ( ϭ 0.3, P ϭ 0.001) and triglyceride ( ϭ 0.2, P ϭ 0.05) levels. Brothers also had significantly higher fasting insulin levels and homeostatic index of insulin resistance (P ϭ 0.02 for both comparisons) compared with control men.CONCLUSIONS -Brothers of women with PCOS have dyslipidemia as well as evidence for insulin resistance similar to that of their proband sisters with PCOS. These findings are consistent with the hypothesis that some metabolic abnormalities in PCOS are heritable and are not sex specific.
Diabetes Care 31:1237-1241, 2008P olycystic ovary syndrome (PCOS) is a complex genetic disorder that affects ϳ7% of premenopausal women (1). It is the leading cause of anovulatory infertility and an important risk factor for type 2 diabetes and metabolic syndrome in young adult women as well as in adolescent girls (1). The major reproductive phenotype is hyperandrogenemia and up to 40% of premenopausal sisters are affected (2). Moreover, mothers (3) and brothers (4) also have elevated mean androgen levels compared with control subjects of comparable sex, age, weight, and ethnicity. We have identified one PCOS susceptibility allele within a dinucleotide repeat (D19S884) in intron 55 of the fibrillin-3 gene on chromosome 19p13.2 that is linked and associated with hyperandrogenemia (5).Abnormalities in insulin action and secretion, glucose tolerance, and lipid levels also demonstrate familial aggregation in first-degree female relatives of women with PCOS (3,6 -9). Elevated LDL cholesterol levels are the most consistent lipid abnormality in affected women as well as in their sisters and mothers (3,8 -10). In addition, the prevalence of metabolic syndrome is increased in these groups (3,9). Further, increased LDL levels and metabolic syndrome are significantly associated with hyperandrogenemia, sugg...