The Intricate Relationship between Insulin Resistance and Adipokines in Non-obese Patients with Polycystic Ovarian Syndrome

Background: Dyslipidemia and metabolic complications related to Insulin resistance are closely linked to patients suffering from polycystic ovarian syndrome (PCOS).

Aims: To find out the changes in serum testosterone, leptin and adiponectin levels and explore their relative importance in alterations of insulin resistance (IR) in non obese PCOS patients.

Study Design: Hospital based, case control, non interventional study. Both cases and control subjects were selected following the method of convenience according to prefixed inclusion and exclusion criteria.

Methodology: In 33 non obese PCOS patients and 35 controls Leptin, insulin, testosterone, leutinizing hormone (LH), follicular stimulating hormone (FSH) and adiponectin were measured by enzyme linked immunoassay (ELISA). Fasting plasma glucose (FPG) was measured by spectrophotometric method. Insulin resistance (IR) was calculated through homeostatic model for assessment of insulin resistance (HOMA-IR) technique. Waist hip ratio (WHR) and body mass index (BMI) were calculated as anthropometric parameters to assess distribution of body fat.

Results: Mean +/- Standard error of mean values for the HOMA-IR (1.98 +/- 0.19 vs 1.04 +/ - 0.04), FBG (4.98 +/- 0.27 vs 4.52 +/- 0.07) serum leptin (12.55 +/- 1.00 vs 8.23 +/- 1.03), serum testosterone (1.19 +/- 0.07 vs 0.41 +/- 0.04), serum LH (30.74 +/- 1.73 vs 5.69 +/- 0.44), serum FSH (10.93 +/- 0.38 vs 6.29 +/- 0.46) and WHR (0.82 +/- 0.01 vs 0.74 +/- 0.01) were significantly elevated in the PCOS patients compared to the control group. On the other hand, serum adiponectin was significantly decreased in PCOS group (11.41 +/- 1.21 vs 23.55 +/- 2.94) while BMI showed no significant difference. Although, individual bivariate correlation analysis suggested IR to be significantly associated with serum leptin, adiponectin, testosterone and WHR, but multivariate linear regression analysis revealed significant predictive values for serum leptin (β = .467,), adiponectin (β = -.324,) and testosterone (β = .266,) only on the HOMA-IR.

Conclusion: Increased androgen and leptin along with decreased adiponectin levels have crucial determining effects on increased IR that might play a major role in mediating the pathogenesis and metabolic abnormalities in non obese PCOS.