Endocrine Abstracts

Background and Objectives: Polycystic ovary syndrome (PCOS) is a common female reproductive endocrine disorder with a prevalence of 15-20%. Although a majority of patients diagnosed with PCOS are overweight/obese, minority can present with normal body mass index of ≤25 kg/M² which complicate the effective diagnosis and management. We have studied the socio-demographic and clinical characteristics of lean PCOS patients in comparison to obese PCOS patients attending the Endocrinology clinic in a tertiary care institute in Sri Lanka.

Methods: A descriptive cross sectional study was conducted from September 2019 to September 2020 at the Endocrinology Unit of the National Hospital of Sri Lanka. Systematic sampling was done recruiting PCOS patients diagnosed with Rotterdam criteria. After obtaining informed written consent, the data was collected using an interviewer administered questionnaire. HOMA-IR was calculated using the fasting insulin and blood glucose level.

Results: The study enrolled sixty females. Out of that 23 (38.3%) patients were diagnosed to have lean PCOS while the rest (37, 61.6%) had overweight/obesity. The mean age was 25.1 years (range 18-37). The mean weight was 55.0 (SD=6.7) kg and BMI was 22.2 (SD=1.8) kg/m^-2. Twenty (83.0%) had irregular menstrual cycles while 11 (47.8%) patients had clinical or biochemical evidence of hyperandrogenism. Only 9 (39.1%) patients had polycystic ovaries on trans-abdominal ultrasound scan. According to the body fat percentage assessed by the whole body DEXA scan 90.9% patents had their body fat in the overweight and obese category in contrast to the BMI category. HOMA-IR detected 37.5% to have high insulin resistance. There was significant difference in the presence of acanthosis nigricans, hirsutism, polycystic ovaries on USS and non-alcoholic fatty liver disease (NAFLD) in the obese PCOS patients while acne was more prevalent in the lean PCOS females (P<0.05).

Conclusions: The minority of patents affected with PCOS are falling under the category of lean PCOS. The diagnosis and the therapeutic approach poses a significant clinical challenge due to the absence of typical clinical features such as acanthosis nigricans, hirsutism, and polycystic ovaries on USS in this group of patients. Use of body fat estimation is more sensitive in detecting overweight/obesity in this group rather than using conventional BMI measurement. Nevertheless, the suspicion and awareness among clinicians of the possibility of lean PCOS in this group of females can improve the diagnosis and patient outcomes.