Evidence of a role of ANGPTL6 in resting metabolic rate and its potential application in treatment of obesity
MINERVA ENDOCRINOLOGICA
Authors: Mirzaei, K.; Hossein-Nezhad, A.; Chamari, M.; Shahbazi, S.
Abstract
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.
Influence of thyroid dysfunction on serum levels of angiopoietin-like protein 6
METABOLISM-CLINICAL AND EXPERIMENTAL
Authors: Lim, Jung Ah.; Kim, Hyo Jeong; Ahn, Hwa Young; Park, Kyoung Un; Yi, Ka Hee; Park, Do Joon; Jang, Hak Chul; Park, Young Joo
Abstract
Angiopoietin-like protein 6 (ANGPTL6) is a novel metabolic regulator that modulates energy expenditure as well as glucose and lipid metabolism. Thyroid hormone can induce metabolic changes that are similar to those induced by ANGPTL6. Herein, we investigated whether circulating ANGPTL6 levels change according to thyroid hormone status in humans. We measured the serum levels of ANGPTL6 and metabolic parameters in 150 drug-naive subjects with overt hyperthyroid, subclinical hyperthyroid, euthyroid, subclinical hypothyroid, or overt hypothyroid status (n = 30 in each group). Serum ANGPTL6 levels were significantly higher in patients with overt hypothyroidism than in the other subjects. Women had significantly higher serum levels of ANGPTL6 than men. ANGPTL6 levels correlated positively with thyroid stimulating hormone (TSH), total cholesterol, aspartate aminotransferase, and alanine aminotransferase (ALT) and negatively with serum free thyroxine (T4) level. Multiple stepwise linear regression analysis revealed that sex, TSH, free T4, and ALT were independent predictors of serum ANGPTL6 levels. In summary, serum ANGPTL6 levels increased in patients with a hypothyroid status, and both TSH and free T4 levels are associated with ANGPLT6 levels, suggesting a possible association between thyroid function and ANGPTL6 levels. Whether the upregulated ANGPTL6 level in the hypothyroid status is primarily owing to a direct association or a compensatory mechanism remains to be determined (C) 2015 Elsevier Inc. All rights reserved.