Habitual physical activity is associated with circulating irisin in healthy controls but not in subjects with diabetes mellitus type 2

Eur J Clin Invest. 2015 Aug;45(8):775-81. doi: 10.1111/eci.12468. Epub 2015 Jul 17.

Abstract

Background: Irisin, a novel myokine, has been shown to increase following vigorous exercise, with studies suggesting that it mediates some of the beneficial effects of exercise. Irisin might play a role in 'browning' of white adipocytes, thus increasing energy expenditure. The role of irisin in exercise and energy expenditure in subjects with diabetes mellitus type 2 (DMT2) remains largely unknown. We aimed to investigate the association between circulating irisin and habitual physical activity in subjects with and without DMT2.

Material and methods: In this cross-sectional study, 164 Saudi adults: 81 non-DMT2 controls [age: (mean ± SD) 51.6 ± 10.9; BMI: 29.6 ± 4.3 kg/m(2) ] and 83 DMT2 subjects [age: 54.3 ± 10.3 year; BMI: 29.4 ± 4.7 kg/m(2) ] were studied. Anthropometric and fasting serum biochemical data were collected. Circulating irisin was measured using an enzyme-linked immunosorbent assay (ELISA). Frequency intensity time (FIT) index was used to assess the level of habitual physical activity.

Results: We observed significantly higher levels of irisin in DMT2 subjects than in controls (P < 0.001). FIT index was positively associated (r = 0.20, P = 0.03) with circulating irisin in controls only. Additionally, irisin levels were significantly higher in tertile 3 (0.75 ± 0.07 μg/mL) than tertile 1 (0.49 ± 0.06 μg/mL) of the FIT index in healthy controls, whilst no such relation with physical activity was observed in DMT2 subjects.

Conclusion: This cross-sectional study has shown a weak association of irisin with physical activity levels in healthy controls but not in DMT2 subjects, suggesting the possibility of discordant regulation in the condition of DMT2.

Keywords: Diabetes; frequency intensity time index; irisin; physical activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Case-Control Studies
  • Cross-Sectional Studies
  • Diabetes Mellitus, Type 2 / blood*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Fibronectins / blood*
  • Humans
  • Male
  • Middle Aged
  • Motor Activity*
  • Saudi Arabia

Substances

  • FNDC5 protein, human
  • Fibronectins