A twin study of polycystic ovary syndrome and lipids

Abstract

Our objective was to assess the relative contribution of genetic and environmental factors (particularly androgens) on circulating levels of lipid fractions and to determine the effect, if any, of polycystic ovary syndrome (PCOS) on lipid fractions. The study was carried out in the outpatient clinic of the Royal Hospital for Women, Paddington, Sydney, Australia. A group of 19 monozygotic (MZ) and 15 dizygotic (DZ) twin pairs was identified from the National Twin Register. Ultrasound clinical and biochemical parameters were used to define polycystic ovaries. Serum androgen and lipid fractions were also measured. Eleven pairs of twins (five MZ, six DZ) were scan discordant (i.e. one twin had polycystic ovaries and the co-twin did not). Serum levels of the lipoprotein fractions in twins with polycystic ovaries were not significantly different from the levels found for their co-twins with normal ovaries. There were no significant correlations between androgen-related hormones and any of the lipid measurements. Body mass index (BMI) was positively correlated with triglycerides and lipoprotein (a), and negatively correlated with high-density lipoprotein cholesterol (HDL-C). Sex hormone-binding globulin (SHBG) levels were negatively correlated with triglycerides and lipoprotein (a) and positively associated with HDL-C. Fasting insulin levels were significantly correlated with triglycerides and negatively with HDL-C. The MZ intraclass correlation exceeded that of the DZ twin pairs for all the lipid variables measured. The heritability estimates for lipoprotein (a), apolipoprotein B, total cholesterol and HDL-C were 0.95, 0.56, 0.48 and 0.54, respectively. However, the intraclass correlation coefficient for triglycerides was not significantly different between MZ and DZ twins, but maximum likelihood analysis indicated that at least 10% of the variance of the circulating triglyceride concentration is determined by genetic factors. We conclude that twins discordant for the PCOS do not have significantly different lipid fractions.

RETRACTED: Comparison of finasteride versus flutamide in the treatment of hirsutism

“…5a-Reductase is therefore a key step in hirsutism. The activity of 5a-R and consequently the formation of dihydrotestosterone (DHT) and 5a-reductase metabolites such as 3a-androstanediol glucuronide (3a-diolG) (10), can be regulated by an increase in the circulating androgenic precursors, as well as genetic factors (11,12) and the insulin-insulin-like growth factor-I (IGF-I) system (13).…”

Prevalence of Type II diabetes mellitus and insulin resistance in parents of women with polycystic ovary syndrome

“…This has been investigated in several studies on PCOS phenotypes in different populations [17] and in family studies which indicated that a high number of female relatives are affected [18,19,20,21]. Most of these studies have used ovarian morphology [22,23] and endocrine abnormalities such as hyperandrogenaemia and anovulation to assign affected status [24]. However, the antecedents of metabolic disorders in family members of PCOS patients has not been widely studied.…”

Association of Genetic Polymorphism in cyp19a Gene in Patients with Polycystic Ovarian Syndrome (PCOS) and Its Correlation with Androgen Excess in South-Indian Population

“…This is based on the assumption that at least 50% of the siblings of the PCOS probands are affected with the disorder 15 . Twin studies on PCOS have revealed an incidence of 50% has suggested a complex pattern of polygenic inheritance 17 . Other studies have reported that 50% hirsutism cases among the affected sisters of PCOS 18 .…”