Irisin Serum Levels in Metabolic Syndrome Patients Treated with Three Different Diets: A Post-Hoc Analysis from a Randomized Controlled Clinical Trial

Abstract

Background: Irisin, a hormone-like myokine, regulates energy homeostasis and mediates the benefits of physical activity on health. Methods: To estimate the effect of different diets on irisin concentrations in subjects with the Metabolic Syndrome (MetS). Methods: Subjects with MetS were derived from a population survey; 163 subjects were enrolled and randomized to a: Low Glycaemic Index (LGID), Mediterranean (MD) or Low Glycaemic Index Mediterranean (LGIMD) Diet, and the groups were compared, also with 80 controls without MetS. Sociodemographic, medical and nutritional data were collected and fasting blood samples drawn. Subjects underwent LUS and bioimpedentiometry. Generalized Estimating Equations were performed. Results: At baseline, lower irisin concentrations were observed in MetS subjects. Mean irisin levels increased in all diet groups but only the LGID group reached statistical significance, as well as showing an interaction between LGID and time at the sixth month examination (4.57, 95% CI −1.27, 7.87). There was a positive effect of Vegetable Proteins (0.03, 95% CI −0.01,0.06) and Saturated Fatty Acids (0.04, 95% CI 0.01, 0.07) on irisin concentrations. In the LGIMD, a positive effect on Fat-Free Mass (0.38, 95% CI 0.19, 0.57) and a negative effect on the Body Mass Index (−0.75, 95% CI −1.30, −0.19) were observed. Conclusions: There seems to be a link between diet and muscle physiology. We showed that patients following a LGID had higher levels of irisin, a promising biomarker of muscle activity.

A Randomized Controlled Trial on the Effects of 12 Weeks of Aerobic, Resistance, and Combined Exercises Training on the Serum Levels of Nesfatin-1, Irisin-1 and HOMA-IR

“…The results showed greater expression of FNDC5 in the intervention group compared with that of the control group (Timmons et al, 2012 ). Although Osella et al ( 2018 ) examined the effects of different diets on the serum irisin-1 concentration and found that vegetable proteins and saturated fatty acids were positively associated with serum irisin-1. The authors did not examine the effects of exercise on serum irisin-1 concentration.…”

Whole-Body Cryotherapy Is an Effective Method of Reducing Abdominal Obesity in Menopausal Women with Metabolic Syndrome

“…Since the change in caloric content and composition of the diet can significantly affect the change in body composition [ 47 ] and in the level of irisin [ 48 , 49 ], the volunteers were asked not to change their diet and to record the composition of the meals consumed on a daily basis. The portion size was determined based on a photo album of products and dishes [ 50 ].…”

The Interplay Between Bone and Glucose Metabolism

“…In experimental and human studies, adiponectin, visfatin, and omentin-1 had negative effects on bone, while leptin exerted positive actions (8)(9)(10). Additionally, the role of a specific adipo-myokine, irisin, has been recently described (11,12). It is thought that irisin plays a positive effect on hyperglycemia by stimulating glucose uptake in muscle cells (13).…”

“…As far as bone metabolism, irisin may promote osteogenic differentiation, increase in cortical bone mass and strength, and reduction in the number of osteoclasts (14). Irisin resistance has been postulated in diabetes, with a consequent theoretical loss of all these positive effects on bone mass and strength (12,15).…”