Background: Obesity is a common feature of women with PCOS in different ethnic cohorts. It is suggested that retinol binding protein 4 (RBP4) is a central mediator of obesity-induced insulin resistance in mice and humans. In addition, elevated serum RBP4 levels have been associated with cardiovascular risk factors and metabolic syndromes.
Aim: To investigate whether serum RBP4 level is correlated with metabolic parameters, indices of insulin resistance, and endocrine variables in PCOS women.
Subjects and methods: Our study was conducted on 90 women their age ranged from 20 to 39 years. They were divided into:Group I: 30 lean patients with PCOS, Group II: 30 obese patients with PCOS, Group III: 15 lean control women and Group IV: 15 obese control women excluding those receiving oral contraceptives, glucocorticoids, oral hypoglycemic, anti-obesity or anti-androgenic drugs. Fasting and 2 h postprandial plasma glucose (2 h PPPG), HbA1c, fasting insulin level, HOMA IR, lipid profile, LH, free testosterone, serum RBP4, serum uric acid, pelvic ultrasonography were done for all subjects.
Results: We found that serum RBP4, fasting insulin level and HOMA IR were higher in PCOS group than control group. Furthermore, there was a high significant positive correlation between RBP4 and weight, BMI, waist circumference, W/H ratio, fasting insulin, HOMA-IR, triglyceride and LDL-c with P value <0.01, and a positive significant correlation between RBP4 and 2 h PPPG and HbA1c with P value <0.05 but there was a high significant negative correlation between RBP4 and HDL-c with P value <0.01.
Conclusion: Serum RBP4 is higher in the PCOS group than non-PCOS group, so RBP4 may play a role in the pathophysiology of PCOS. Further studies are needed to clarify the role of RBP4 in these women.