Association between prolactin and non-alcoholic fatty liver disease in overweight and obese patients

Abstract

Objective To investigate the association between serum prolactin (PRL) and non-alcoholic fatty liver disease (NAFLD) in overweight and obese (body mass index ≥ 24 kg/m2) patients. Methods A total of 494 patients from September 2015 to January 2017 in our hospital were retrospectively analyzed. Patients were classified to non NAFLD (n=353) and NAFLD group (n=141) according to abdominal ultrasound. Twenty female obese patients who received bariatric surgery were also underwent liver biopsy. All patients' fasting blood samples were collected for the PRL and other metabolic parameters measurements. Abdominal ultrasound was also performed. The Mann-whitney U or Kruskal-wallis H rank test were used to compare the data between two groups, and the relationship between serum PRL and NAFLD was analyzed by non-conditional Logistic regression. Results Serum PRL levels were significantly lower in patients with NAFLD in males (n=277) and females (n=217) [7.7 (5.9, 10.8) vs 8.7 (6.9, 11.8) μg/L, Z=-2.500, P=0.012 in men; 8.4 (6.2, 12.2) vs 10.7 (7.7, 13.4) μg/L, Z=-3.890, P<0.001 in women] than those without NAFLD. Moreover, there was a stepwise decrease in prevalence of NAFLD in both gender from the lowest to the highest PRL tertiles (both P<0.05). After normalized for confounding factors, PRL level became a protective factor against NAFLD (OR=0.923, P=0.008). In obese patients with pathology diagnosis, NAFLD patients (n=16) also exhibited lower PRL levels than those without NAFLD [n=4, 9.2 (5.0, 13.5) μg/L vs 16.8 (11.8, 20.9) μg/L]. Conclusion In overweight and obese patients, decreased PRL is a risk factor for NAFLD. Key words: Overweight; Obesity; Prolactin; Non-alcoholic fatty liver disease