Effects of Metformin Treatment on Soluble Leptin Receptor Levels in Women with Polycystic Ovary Syndrome

The effects of metformin treatment on soluble leptin receptor (sOB-R) levels in women with polycystic ovary syndrome (PCOS) were investigated.This prospective and open-label study was conducted by the Department of Obstetrics & Gynecology at Union Hospital,Tongji Medical College of Huazhong University of Science and Technology,China.Fifty-five women with PCOS and insulin resistance (IR) were treated with metformin for 6 months.According to body mass index (BMI),the patients were divided into two groups:lean PCOS group (BMI <23 kg/m^2,n=34) and overweight or obese PCOS group (BMI >23 kg/m^2,n=21).Before and after treatment,serum luteinizing hormone (LH),follicle stimulating hormone (FSH),testosterone (T),androstenedione (A),dehydroepiandrosterone sulfate (DHEAS),insulin and sOB-R levels were determined.Thirty-one BMI-matched ovulatory women served as controls.The results showed:(1) The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR),androgen levels and hirsutism scores were higher,and sOB-R levels were lower in PCOS groups than in control group.A subgroup analysis of lean and overweight or obese PCOS patients revealed there was significant difference in sOB-R level between lean PCOS group and overweight or obese PCOS group.There were no significant differences in anthropometric parameters between lean PCOS patients and BMI-matched controls.However,sOB-R level was significantly lower in lean PCOS women than in controls.(2) There was no correlation between sOB-R level and BMI,waist and hip circumference,total testosterone,androstendione,DHEAS,LH or hirsutism scores in PCOS patients,but there was a significant negative correlation between sOB-R and HOMA-IR.(3) After treatment with metformin for 6 months,serum insulin levels decreased,and sOB-R levels increased significantly (P<0.01).It was suggested that considering low sOB-R levels supposedly compensate diminished leptin action,PCOS per se might cause leptin resistance.It is likely that reduction of hyperinsulinemia produced by metformin effectively improves the sOB-R levels in PCOS.

Effect of N-acetyl-cysteine treatment on sensorineural hearing loss: a meta-analysis

N-acetyl-cysteine (NAC) is an efficacious treatment for sensorineural hearing loss in animal models, such as noise-induced hearing loss (NIHL), however previous research into the effect of NAC on patients with hearing loss produced contradictory results. In this study, we investigated the effect of NAC treatment on sensorineural hearing loss. PubMed, Web of Science and Embase databases were searched in their entirety using the key words: hearing loss, NAC, N-acetylcysteine, and sensorineural hearing loss. Studies which included assessment of hearing loss with pure-tone threshold (PTA) data were selected. Eligible studies regarding the effects of NAC treatment on patients with hearing loss were collected by two independent reviewers. A total of 1197 individuals were included from seven published studies. Two studies reported data for a sudden idiopathic sensorineural hearing loss (SISNHL) group. Three studies reported data for a NIHL group. Other studies reported data for drug-induced hearing loss. The meta-analysis demonstrated that the overall effect of NAC treatment on sensorineural hearing loss was invalid. However, NAC treatment was linked with improved patient outcomes of hearing tests in cases of sudden hearing loss, but did not prevent hearing loss induced by noise or ototoxicity. However, there is a need for better-designed studies with larger samples to further prove the correlation between the effect of NAC and hearing loss.