Prolactin (PRL) exerts favorable actions on obesity, besides lactation and reproduction. To explore those actions we investigated the metabolism in obesity with increased PRL and the change in PRL levels after laparoscopic sleeve gastrectomy (LSG). Patients with obesity were divided into two groups: obesity with normal PRL (OB, n=123) and with mildly elevated PRL (OB+PRL↑, n=108). Markers of glucose-lipid metabolism and chronic low-grade inflammation were measured. 115 obese patients (OB, n=64; OB+PRL↑, n=51) underwent LSG. PRL and metabolic markers at 6 and 12 months after LSG were measured. Results showed that blood glucose (BG) at five points of oral glucose tolerance test, blood lipid (total cholesterol (TCH), low-density lipoprotein cholesterol (LDL-C), triglyceride) and tumor necrosis factor-α were lower in OB+PRL↑ than OB group (all P<0.05). PRL was negatively associated with neck circumference, waist-to-hip ratio, systolic pressure, heart rate, basal metabolic rate (BM), alkaline phosphatase (AKP), TCH and LDL in all obesity (all P<0.05). PRL levels were positively associated with weight, hip circumference and BM in males while negatively associated with alanine transaminase, glutamic oxaloacetic transaminase, AKP, BG30min, BG60min, free fatty acid and TCH in females (all P<0.05). PRL was descended in OB+PRL↑ (P=0.015) while increased in the OB group at 12 months after surgery(P=0.009). Increased PRL was associated with the change in TCH(P<0.05).
In conclusion, we found that the increased PRL levels in obesity results in better glucose-lipid metabolism and lower chronic low-grade inflammation. LSG led to increased PRL in obesity and decreased PRL in obesity with mildly elevated PRL. Improved lipid metabolism was associated with increased PRL after surgery.
S. Qu: None. X. Wang: None.
National Key Research and Development Program of China (2018YFC1314100); National Natural Science Foundation of China (81970677)