Evidence of a role of ANGPTL6 in resting metabolic rate and its potential application in treatment of obesity.

Aim: ANGPTL6 (Angiopoietin-related growth factor 6) is a circulating protein which is suggested to antagonize obesity. The purpose of this study was to evaluate a potential relationship between fasting serum ANGPTL6 and resting metabolic rate (RMR) as well as the body composition in obese and subjects with normal weight.

Methods: Participants were 62 obese and 41 non-obese subjects who were assessed following an overnight fasting for RMR by means of indirect calorimetry. Body composition was measured using Bodystat devise. Serum ANGPTL6 levels were quantified by ELISA method.

Results: Based on ROC analysis best RMR/kg cut-off value for predicting the risk of obesity was 20 kcal/24h /kg. The participants with RMR/kg≥20 kcal/24h/kg were considered as and subjects with RMR/kg<20 kcal/24h/kg were categorized as. In group I, 72.3% of subjects were obese, whereas, 47.4% subjects in group II were suffering from the disease. Participants in group II who showed significantly lower HDL and ANGPTL6 levels. Moreover, we found significantly higher triglyceride and hs-CRP levels in this group. There was significant difference in weight, body mass index, fat mass, visceral fat, RMR/kg, fasting serum glucose, insulin and hs-CRP among those with different levels of the serum ANGPTL6 concentration. We found higher values of RMR/kg in subjects with higher circulating ANGPTL6 concentration.

Conclusion: ANGPTL6 affects RMR and significantly improves lipid profile and slightly does so regarding insulin concentrations and sensitivity to it. Further study is warranted as it seems that the results of this study might potentially lead to advent of a pharmacological treatment for obesity.