Leptin resistance may be responsible for elevated leptin levels in obese women with polycystic ovary syndrome, according to authors of this study.
Reference: Hahn S, Haselhorst U, Quadbeck B, et al. Decreased soluble leptin receptor levels in women with polycystic ovary syndrome. Eur J Endocrinol. 2006;154:287-294.Â
Susanne Hahn and colleagues in Germany discovered a link between soluble leptin receptors (sOB-R), leptin resistance, and obesity in polycystic ovary syndrome (PCOS). Click through the slides above for details on their study and take home points for clinical practice.
PCOS, Insulin Resistance, and Obesity. PCOS is a common endocrine disorder that is associated with peripheral insulin resistance that impacts reproductive-age women. PCOS increases risk factors for cardiovascular disease and most women with PCOS are insulin resistant and overweight or obese. Studies have shown that sOB-R correlates inversely with total serum leptin levels and BMI in reproductive-age women. Authors of the study sought to analyze the correlation between sOB-R, obesity, leptin and insulin resistance, and other endocrine parameters in women with PCOS.
The Study. This study recruited 122 women with PCOS, but that were otherwise healthy, from outpatient clinics at the University of Duisburg-Essen in Germany. Experimental groups were compared to matched control subjects with PCOS. The clinical and laboratory parameters assessed were: Presence of hirsutism, body weight and BMI, insulin resistance and β-cell function, testosterone level, serum leptin, sex hormone-binding globulin, luteinizing hormone, estradiol, cortisol, TSH, cholesterol, triglycerides, blood glucose, and leptin-to-sOB-R ratio.
The Results. The authors found that leptin levels correlated significantly with BMI and metabolic parameters in PCOS women, but negatively correlated with sOB-R levels in PCOS patients and controls. BMI, sOB-R, body fat, waist circumference, and insulin resistance were all significantly related. sOB-R levels were significantly lower in lean PCOS women vs controls and TSH correlated with sOB-R in entire PCOS cohort. There was no consistent relationship found between androgens, estrogens, and elevated leptin.
Take Home Points:
Leptin levels directly proportional to BMI, likely have a role in insulin resistance
Lean PCOS women didn't have elevated leptin levels underscoring the benefit of maintaining a healthy weight
Leptin resistance may be responsible for elevated leptin levels in obese PCOS women
Low sOB-R levels increased free leptin ratio
Neither leptin or sOB-R levels influenced by hyperandrogenism or severity of menstrual disturbances
Unclear how relationship between sOB-R, obesity, and leptin effects reproductive health of PCOS women
Consider environmental factors, diet, body composition, and genetic differences as part of comprehensive treatment strategy
