Relationship of serum irisin levels, physical activity, and metabolic syndrome biomarkers in obese individuals with low-calorie intake and non-obese individuals with high-calorie intake.

Background: Despite all the advances in our knowledge regarding obesity, our understanding of its etiology is still far from complete. This study aimed to evaluate the association of serum irisin levels with physical activity and some of the metabolic syndrome-related biomarkers among obese people with low-calorie intake and non-obese people with high-calorie intake.

Methods: Obese and non-obese healthy individuals with respectively low and high-calorie intakes were recruited. Irisin and other biomarkers were measured using standard biochemical methods. Participants' physical activity was evaluated by administering the International Physical Activity Questionnaire (IPAQ). To analyze the body composition of the participants, a standard body composition device (ioi 353) was applied. Logistic regression was used to calculate the odds ratio (OR) and to examine the effect of confounders such as age, sex, genetics, and activity.

Results: Data from the seventy-seven participants were included in the final analysis. The mean age of the participants in the obese and non-obese groups was 38.33 ± 14.88 and 30.24 ± 13.37 years, respectively. Participants in the obese group had lower physical activity compared to the non-obese group (3395.38 ± 2801 MET-min/week vs. 6015.18 ± 3178 MET-min/week; p < 0.001). The Irisin concentration in the obese and non-obese groups was 7.84 ± 2.49 ng/ml and 8.06 ± 1.89 ng/ml, respectively, which wasn't significantly different (p = 0.66). We observed a noteworthy and favorable association between irisin concentration and total body water (TBW), lean body mass (LBM), and soft lean mass (SLM) in the non-obese group.

Conclusions: These data indicated that although obese participants were relatively inactive compared to non-obese individuals, circulating irisin level wasn't significantly different between the two groups.