New association of bone morphogenetic protein 4 concentrations with fat distribution in obesity and Exenatide intervention on it

Background: Bone morphogenetic protein 4 (BMP-4) has been proven to regulate white adipogensis. We aimed to demonstrate the correlation of BMP-4 with fat distribution and Exenatide treatment on it. Methods: We enrolled 69 obese patients. Anthropometric and metabolic indexes were collected. Fat distribution was measured by dual-energy X-ray absorptiometry. BPM-4 levels were assessed using enzyme-link immunosorbent assay kit. 30 obese patients were treated with Exenatide twice a day. Change in body weight, metabolic-related indices and BPM-4 levels were evaluated after 18 weeks. Results: 1) The mean(+/- SD) BMP-4 levels were 763.98 +/- 324.11 pg/ml in the obese. BPM-4 levels were significantly positively correlated with estimated visceral adipose tissue mass in all subjects and also in females (r = 0.377, r = 0.625, respectively, all P < 0.05). BPM-4 levels were also significantly positively correlated with body mass index, hip circumference and total fat% in females (r = 0.375, r = 0.429, r = 0.493, respectively, all P < 0.05). BPM-4 levels were negatively correlated with total cholesterol(TC) in all subjects and males also (r = -0.373, r = -0.332, respectively, all P < 0.05). BPM-4 levels were also significantly positively correlated with free triiodothyronine in males (r = 0.441, P < 0.05). 3) Multivariate analyses showed that TC was risk factor of BMP-4 concentration in males and Est. VAT Area was risk factor of BMP-4 levels in females. 4) BMP-4 levels were significantly higher in the obesity with slightly increased thyroid stimulating hormone(TSH) than the obesity without slightly increased TSH (902.08 +/- 354.74 pg/ml vs. 720.24 +/- 306.41 pg/ml, P < 0.05). 5) Exenatide treatment leads to a significant decreased in BMP-4 from 860.05 +/- 352.65 pg/ml to 649.44 + 277.49 pg/ml independent of weight loss(P < 0.05). Conclusion: BMP-4 levels were associated with the visceral adipose tissue and may play a certain role in fat distribution and subclinical hypothyroidism in obesity. Exenatide treatment reduced BMP-4 levels independent of weight loss.