The phenotype and genotype of polycystic ovary syndrome (PCOS) in Sri Lankans: an update

Abstract

BACKGROUND: We reported previously a high insulin resistance among 80 Lankan women with PCOS, but a low prevalence of Insulin VNTR Class III allele. We update this information in double the number of affected subjects OBJECTIVE: To determine phenotype and genotype of PCOS in indigenous Sri Lankans (SL). METHOD: Cross sectional observational case control study of consecutive consenting Sri Lankans (173) and controls (95) in a specialist endocrine centre in Colombo. OUTCOME MEASURES: Age, BMI & waist: hip ratio (WHR), menstrual & skin manifestations, family history of diabetes; fasting blood sugar, fasting plasma insulin, insulin sensitivity (QUICKI), serum testosterone (T), sex hormone binding globulin (SHBG), and frequency of Insulin VNTR polymorphism. RESULTS: SL PCOS versus Controls; Mean age 26.23 ñ 6.16 vs. 30.8 ñ 6.0 (p=0.4), BMI 26.51 ñ 4.78 vs. 23.07 ñ 1.7 (p=0.001), WHR 0.95 ñ 0.12 vs. 0.75 ñ 0.05 (p=0.0001); age of onset of oligomenorrhoea 16.09 ñ 5.6; age of onset of hirsutism 17.18ñ 4.87; acne 46 (26.59 percent); acanthosis nigricans 122 (70.52 percent). Excluding diabetics FBS (mmol/l) 5.26 ñ 1.55 vs. 4.39 ñ 1.18 (p=0.33); plasma insulin (pmol/l) 213.77 ñ 330.31 vs. 93.1 ñ 9.3.6 (p=0.0001), QUICKI 0.3135 ñ 0.036 vs. 0.334 ñ 0.005 (p =0.0008), T (nmol/l) 2.61 ñ 1.763 vs. 1.55ñ 0.9 (p=0.0002), SHBG (nmol/l) 28.88 ñ16.91 vs. 54.29 ñ 16.91 (p=0.0001). Class III Insulin VNTR gene frequency is currently available in 131 PCOS. This was 0.25 vs 0.27 (p=0.747) with no correlation to QUICKI. CONCLUSIONS: Sri Lankans with PCOS have greater central adiposity for a given BMI, are more insulin resistant with abnormal lipids than unaffected Lankan women. Sri Lankans with PCOS demonstrate a lower frequency of Insulin VNTR Class III allele than that reported among affected Caucasians. FUNDING: Association of Physicians of Great Britain & Ireland & Special Trustees, General Infirmary at Leeds UK.