The effects of taurine supplementation on serum levels of adiponectin, irisin, fibroblast growth factor-21, sirtuin-1, metabolic parameters, oxidative/ inflammatory indicators and nutritional status in patients with Type 2 Diabetes

Abstract

Background and aim: Type 2 diabetes mellitus (T2DM) is the most common endocrine disease, and its prevalence is increasing in all of the world, and it is one of the most important threats to human health in the health care system. In recent years, the use of complements with antioxidant and anti-inflammatory properties to prevent, reduce and treatment the complications of T2DM has been considered as one of the important and non-side effects in the management of this disorder. Taurine, as a functional nutrient with anti-diabetic, anti-obesity, anti-inflammatory and antioxidant properties, performs functions beyond an amino acid in the body. Studies show that serum taurine levels are lower in patients with T2DM than in healthy people. Animal and human studies reported that taurine supplementation lead to the improving the glycemic status, lipid profile, oxidative stress and inflammatory biomarkers. On the other hand, the effects of taurine on gene expression and serum levels of adiponectin, irisin, fibroblast growth factor 21 and sirtuin 1 that are factors involved in activating the AMPK pathway (known as a new therapeutic goal in improving T2DM) have been reported. however, human studies are limited. Accordingly, the aim of this study was to determine the effects of taurine supplementation on glycemic status, lipid profile, oxidative stress, inflammation, serum levels of adiponectin, irisin, fibroblast growth factor 21 and sirtuin 1 in patients with T2DM. Materials and methods: A randomized, double-blind, placebo-controlled trial was performed in 45 patients with T2DM of both sexes with an age range of 30-60 years and BMI (25-35) were randomly divided into two groups of taurine (containing 1000 mg taurine), or placebo (containing crystalline microcellulose) three times per day for 2 months. Measurements of anthropometric indices (height, weight, waist circumference, waist circumference and WHR), body composition and resting energy expenditure (REE), nutritional intake, biochemical analysis including glycemic status (fasting insulin, fasting blood sugar (FBS), glycosylated hemoglobin (HbA1c) and insulin resistance index (HOMA-IR), lipid profile (triglyceride (TG), total cholesterol (TC), low density cholesterol (LDL-c) and high density cholesterol (HDL-c)), oxidative stress status (serum levels of TAC and MDA, and SOD and CAT enzymes activity), serum levels of inflammatory biomarkers (hs-CRP, IL-6 and TNF-α) and adiponectin, irisin, fibroblast growth factor 21 and sirtuin 1 were assessed before and after intervention. The nutritional intakes of all participants were calculated using Nutritionist IV software. All data were analyzed using SPSS 23 software (IBM/SPSS Inc., Chicago, IL, USA). Independent t-test, paired t-test, Pearson’s correlation, and analysis of covariance were used for analysis. Results: Out of a total of 50 patients, 45 completed the trial (taurine group, n = 23; placebo group, n= 22). There were no statistically significant differences in food intake, anthropometric indices and biochemical parameters other than HDL between the 2 group (p>0.05). At the end of the study, there wasn't significant differences in anthropometric indices and dietary intakes between the two groups (P> 0.05). At the beginning of the study, there were no statistically significant differences in general characteristics, dietary intake, physical activity, measurement indicators and biochemical measurements between the two groups. As well, at the end of the study, there was no significant difference in the anthropometric or food intake indicators (P <0.05). Taurine supplementation leads to a significant increase in serum levels of adiponectin and sirtuin 1 in the taurine group compared with placebo. However, no significant changes in serum levels of fibroblast growth factor 21 and irisin are observed between the two groups. Also, taurine supplementation resulted in a significant reduction in FBS, insulin serum levels, and HOMA-IR and TC, LDL-c in the compared with placebo. However, changes for HbA1c, TG, HDL-c, systolic, and diastolic blood pressure between the two groups were not significant (P> 0.05). Although taurine supplementation improved some indicators of oxidative stress, including CAT, SOD, MDA, and serum levels hs-CRP and TNF-α, changes for other indicators between the two groups weren't significant (P> 0.05). Conclusion: According to the findings, taurine supplementation improved glycemic status, some lipid profile, oxidative and inflammatory stress indicators and increased serum levels of adiponectin and sirtuin 1 in patients with T2DM. However, further studies are recommended to exploring the long-term and dose-dependent effects of taurine supplementation in prevent of the complication of T2DM.