Irisin Levels are Not Affected by Physical Activity in Patients with Anorexia Nervosa - PubMed (original) (raw)

Irisin Levels are Not Affected by Physical Activity in Patients with Anorexia Nervosa

Tobias Hofmann et al. Front Endocrinol (Lausanne). 2014.

Abstract

Irisin was recently identified as muscle-derived hormone that increases energy expenditure. Studies in normal weight and obese subjects reported an increased irisin expression following physical activity, although inconsistent results were observed. Increased physical activity in a subgroup of patients with anorexia nervosa (AN) complicates the course of the disease. Since irisin could account for differences in clinical outcomes, we investigated irisin levels in anorexic patients with high and moderate physical activity to evaluate whether irisin differs with increasing physical activity. Hospitalized female anorexic patients (n = 39) were included. Plasma irisin measured by enzyme-linked immunosorbent assay and locomotor activity were assessed at the same time. Patients were separated into two groups (n = 19/group; median excluded): moderate and high activity (6331 ± 423 vs. 13743 ± 1047 steps/day, p < 0.001). The groups did not differ in body mass index (14.2 ± 0.4 vs. 15.0 ± 0.4 kg/m(2)), irisin levels (558.2 ± 26.1 vs. 524.9 ± 25.2 ng/ml), and body weight-adjusted resting energy expenditure (17.6 ± 0.3 vs. 18.0 ± 0.3 kcal/kg/day, p > 0.05), whereas body weight-adjusted total energy expenditure (46.0 ± 1.4 vs. 41.1 ± 1.1 kcal/kg/day), metabolic equivalents (METs, 1.9 ± 0.1 vs. 1.7 ± 0.1 METs/day), body weight-adjusted exercise activity thermogenesis (1.8 ± 0.5 vs. 0.6 ± 0.3 kcal/kg/day), duration of exercise (18.6 ± 4.7 vs. 6.2 ± 3.1 min/day), and body weight-adjusted non-exercise activity thermogenesis (21.6 ± 1.0 vs. 18.8 ± 0.8 kcal/kg/day) were higher in the high activity compared to the moderate activity group (p < 0.05). No correlations were observed between irisin and activity parameters in the whole sample (p > 0.05). In conclusion, the current data do not support the concept of irisin being induced by exercise, at least not under conditions of severely reduced body weight like AN.

Keywords: FNDC5; SenseWear™ armband; brown adipose tissue; energy expenditure; exercise; myokine.

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Figures

Figure 1

Figure 1

Parameters of energy expenditure in anorexic patients with moderate and high physical activity. Per definition, the high activity group showed a higher number of steps compared to the moderate activity group (A). Irisin levels did not differ between the two groups (B). The metabolic equivalents per day (C) as well as body weight-adjusted total energy expenditure (D) were higher in the high compared to the moderate activity group, while no differences were observed for body weight-adjusted resting energy expenditure (E). Duration of exercise (F), body weight-adjusted exercise activity thermogenesis (G), and body weight-adjusted non-exercise activity thermogenesis (H) were higher in the high compared to the moderate activity group. Data are expressed as mean ± SEM. *p < 0.05, **p < 0.01, and ***p < 0.001 in the high vs. moderate activity group (n = 19/group).

Figure 2

Figure 2

Correlations between circulating irisin concentrations and number of steps per day (A), metabolic equivalents per day (B), body weight-adjusted total energy expenditure (C), body weight-adjusted resting energy expenditure (D), body weight-adjusted exercise activity thermogenesis (E), and body weight-adjusted non-exercise activity thermogenesis (F). Values for r and p are indicated in each graph, n = 39 patients.

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References

    1. Boström P, Wu J, Jedrychowski MP, Korde A, Ye L, Lo JC, et al. A PGC1-alpha-dependent myokine that drives brown-fat-like development of white fat and thermogenesis. Nature (2012) 481(7382):463–810.1038/nature10777 - DOI - PMC - PubMed
    1. Puigserver P, Wu Z, Park CW, Graves R, Wright M, Spiegelman BM. A cold-inducible coactivator of nuclear receptors linked to adaptive thermogenesis. Cell (1998) 92(6):829–3910.1016/S0092-8674(00)81410-5 - DOI - PubMed
    1. Wu J, Boström P, Sparks LM, Ye L, Choi JH, Giang AH, et al. Beige adipocytes are a distinct type of thermogenic fat cell in mouse and human. Cell (2012) 150(2):366–7610.1016/j.cell.2012.05.016 - DOI - PMC - PubMed
    1. van Marken Lichtenbelt WD, Vanhommerig JW, Smulders NM, Drossaerts JM, Kemerink GJ, Bouvy ND, et al. Cold-activated brown adipose tissue in healthy men. N Engl J Med (2009) 360(15):1500–810.1056/NEJMoa0808718 - DOI - PubMed
    1. Yoneshiro T, Aita S, Matsushita M, Kameya T, Nakada K, Kawai Y, et al. Brown adipose tissue, whole-body energy expenditure, and thermogenesis in healthy adult men. Obesity (Silver Spring) (2011) 19(1):13–610.1038/oby.2010.105 - DOI - PubMed

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