Background: Regulator of calcineurin 2 (RCAN2) has been documented to cause weight gain and related pathology and metabolism abnormalities in animal researches. The aim of the study was to compare serum RCAN2 concentrations in metabolically healthy (MH) and metabolically unhealthy (MUH) individuals.Methods: 872 subjects (581 MH and 291 MUH) were recruited to the study. Basic anthropometric, metabolic parameters and concentration of RCAN2 were measured. Results: Serum RCAN2 levels differ between MH and MUH subjects (9.22 ± 3.21 vs. 11.09 ± 5.01 ng/mL, p < 0.001). Circulating RCAN2 level was an independent predictor of MUH compared with MH group (9.3% higher rate of MUH incidence per 1 ng/mL increment of RCAN2) after adjust other potentially confounding variables. Higher serum RCAN2 levels were significantly correlated with SBP, FBG, WHR. Receiver-operating characteristic (ROC) curve analysis suggested that serum RCAN2 [area under the curve (AUC) = 0.615, 95% CI 0.575-0.655, p < 0.001] might be used as a candidate biomarker for MUH. Men had considerably greater RCAN2 levels than female in the MH group, but this difference was not significant in the MUH group.Conclusion: Higher circulating RCAN2 levels are associated with MUH individuals regardless of the BMI status.

Background Maresin-1 is one of anti-inflammatory pro-resolving mediators, which is considered as a potential regulator of metabolic diseases. However, little information is available on the relationship between Maresin-1 and non-alcoholic fatty liver disease (NAFLD) in humans. Therefore, this study explored the associations between serum Maresin-1 levels and NAFLD. Methods A cross-sectional study was conducted in 240 Chinese people, including 116 non-NAFLD subjects and 124 NAFLD patients. NAFLD was diagnosed by abdominal ultrasonography. Serum Maresin-1 levels were determined by ELISA. The association between Maresin-1 and NAFLD was assessed. Results Serum Maresin-1 levels in NAFLD patients were markedly lower than those in non-NAFLD subjects (63.63 [59.87–73.93] vs 73.11 [65.12–84.50] pg/mL, P = 0.000). The percentages of patients with NAFLD gradually decreased in tandem with increasing quartiles of Maresin-1 (P < 0.001). Furthermore, serum Maresin-1 levels were positively associated with AST/ALT, albumin, Albumin-globulin-ratio, and HDL-C (all P < 0.05) and negatively associated with BMI, waist circumference, hip circumference, waist-to-hip ratio, ALT, GGT, uric acid, TG, and FBG (all P < 0.05) after adjusting for sex and age. We found that serum Maresin-1 levels were significantly associated with NAFLD by binary logistic regression analysis. Conclusions Circulating Maresin-1 levels were decreased in patients with NAFLD, and there was a negative correlation between NAFLD and serum Maresin-1 concentrations. Decreased Maresin-1 might be involved in the development of NAFLD.