Abstract | CONTEXT: Irisin is an exercise-induced novel myokine that drives brown-fat-like conversion of white adipose tissue and has been suggested to be a promising target for the treatment of obesity-related metabolic disorders. OBJECTIVE: To assess the association of circulating irisin concentrations with brown adipose tissue (BAT) and/or sarcopenia in humans. SETTING AND DESIGN: We examined irisin levels in 40 BAT-positive and 40 BAT-negative women detected by (18)F-fluorodeoxyglucose positron emission tomography ((18)FDG-PET). In a separate study, we also examined 401 subjects with or without sarcopenia defined by skeletal muscle mass index (SMMI) and appendicular skeletal muscle (ASM)/height(2) using dual-energy x-ray absorptiometry. RESULTS: Among 6877 consecutive (18)FDG-PET scans in 4736 subjects, 146 subjects (3.1%) had positive BAT scans. The BAT-detectable group and the matched BAT-undetectable group did not differ in circulating irisin levels measured using two different ELISA kits (P = .747 and P = .160, respectively). Serum irisin levels were not different between individuals with sarcopenia and those without sarcopenia using either kit (P = .305 and P = .569, respectively). Also, serum irisin levels were not different between groups defined by ASM/height(2) using either kit (P = .352 and P = .134, respectively). Although visceral fat area and skeletal muscle mass showed significant difference according to tertiles of SMMI levels, irisin concentrations did not differ. CONCLUSIONS: Circulating irisin levels were not different in individuals with detectable BAT or those with sarcopenia compared with control subjects and were not correlated with SMMI.
|
Authors | Hae Yoon Choi, Sungeun Kim, Ji Woo Park, Nam Seok Lee, Soon Young Hwang, Joo Young Huh, Ho Cheol Hong, Hye Jin Yoo, Sei Hyun Baik, Byung-Soo Youn, Christos S Mantzoros, Kyung Mook Choi |
Journal | The Journal of clinical endocrinology and metabolism
(J Clin Endocrinol Metab)
Vol. 99
Issue 8
Pg. 2778-85
(Aug 2014)
ISSN: 1945-7197 [Electronic] United States |
PMID | 24780049
(Publication Type: Clinical Trial, Journal Article, Observational Study, Research Support, Non-U.S. Gov't)
|
Chemical References |
- FNDC5 protein, human
- Fibronectins
- Fluorodeoxyglucose F18
|
Topics |
- Absorptiometry, Photon
- Adipose Tissue, Brown
(anatomy & histology, diagnostic imaging)
- Adipose Tissue, White
(anatomy & histology, diagnostic imaging)
- Adult
- Body Composition
- Body Mass Index
- Cohort Studies
- Female
- Fibronectins
(blood)
- Fluorodeoxyglucose F18
- Humans
- Male
- Muscle, Skeletal
(pathology)
- Obesity
(blood, diagnostic imaging, epidemiology)
- Positron-Emission Tomography
- Sarcopenia
(blood, diagnostic imaging, epidemiology, etiology)
|