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Serum irisin level affects insulin resistance in adults with obesity
Japanese adults with obesity and higher levels of the myokine irisin are less likely to have insulin resistance, according to recent study findings.
“In this study of Japanese patients with obesity without diabetes, the serum irisin level was positively correlated with [homeostasis model assessment of insulin resistance] in males and females,” Yaeko Fukushima, of the department of health science, Graduate School of Medicine at Kansai Medical University in Osaka, Japan, and colleagues wrote. “Our results suggest that compensatory enhancement of irisin secretion may occur in response to insulin resistance in patients with obesity.”
In a cross-sectional study, researchers analyzed data from 66 adults without diabetes and a BMI of at least 30 kg/m² who visited an obesity clinic in Japan between 2013 and 2014 (47 women; mean age, 46 years; mean body weight, 93.8 kg; mean BMI, 36.5 kg/m²). Participants provided blood samples and underwent DXA scanning and an exercise test; researchers measured homeostasis model assessment of insulin resistance (HOMA-IR), HbA1c and serum irisin.
In men, serum irisin was positively associated with immunoreactive insulin (P < .05), HOMA-IR (P < .01), body weight (P < .05), lean trunk body mass (P < .05), whole lean body mass (P < .05) and fasting blood glucose (P < .05). However, in women, serum insulin was positively correlated only with HOMA-IR (P < .01) and immunoreactive insulin (P < .01).
Using stepwise multiple linear regression analysis, researchers found that HOMA-IR was independently associated with irisin level in men and women (P < .01 for both).
“In this study, serum irisin in females with obesity was significantly higher than that in males with obesity, and there were also sex differences in body weight, [percentage of] lean body mass, [skeletal mass index], peak VO, and [visceral fat area] (all higher in males), and in [percentage of] body fat (higher in females),” the researchers wrote. “Increases in [percentage of] lean body mass and exercise tolerance promote irisin secretion, but females had a higher level of irisin, suggesting the presence of a mechanism for irisin secretion control to compensate for an excess level of fat. ... Closer investigation of these effects is required in further studies.” – by Regina Schaffer
Disclosure: The researchers report no relevant financial disclosures.