serval:BIB_6CBC385F2349
Improvements in insulin sensitivity are blunted by subclinical hypothyroidism.
10.1249/MSS.0b013e318187c010
19127201
000262601200002
Amati
F.
author
Dubé
J.J.
author
Stefanovic-Racic
M.
author
Toledo
F.G.
author
Goodpaster
B.H.
author
article
2009
Medicine and Science in Sports and Exercise
1530-0315
0195-9131
journal
41
2
265-269
PURPOSE: Exercise- and weight loss-induced improvements in insulin resistance (IR) are variable; some individuals experience robust enhancements in insulin sensitivity, whereas others do not. Thyroid hormone status is related to IR, but it is not clear whether subclinical hypothyroidism may help to explain the variability in improvements in IR with diet and exercise. The purpose of this study was to examine whether thyroid hormone status is related to the improvement in insulin sensitivity and physical fitness after weight loss and exercise training.
METHODS: By retrospective nested case-control analysis, eight subclinical hypothyroid (sHT) subjects and eight matched euthyroid controls underwent a euglycemic hyperinsulinemic clamp and peak oxygen uptake test, before and after a 16-wk program of moderate aerobic exercise combined with diet-induced weight loss. All subjects were middle-aged (57.3 +/- 3.3 yr), were overweight to obese (body mass index = 33.1 +/- 0.8 kg m(-2)), and had impaired glucose tolerance.
RESULTS: The improvement in insulin sensitivity was significantly lower (P < 0.05) in the sHT group than in the euthyroid group. Both groups performed similar amounts of regular exercise and lost a significant amount of body weight during the intervention. VO(2peak) tended to improve in the euthyroid group but not in the sHT group.
CONCLUSION: Subclinical hypothyroidism may interfere with beneficial adaptations on muscle metabolism and physical fitness that typically occur with weight loss and increased physical activity. These results may have significant clinical implications because of the high prevalence of both hypothyroidism and insulin resistance in the aging population.
Case-Control Studies
Exercise
Exercise Therapy
Female
Humans
Hypothyroidism/complications
Hypothyroidism/physiopathology
Insulin Resistance/physiology
Male
Middle Aged
Motor Activity
Obesity/complications
Obesity/physiopathology
Treatment Outcome
Weight Loss
eng
60_published
Publication types: Clinical Trial ; Journal Article
University of Lausanne
mailto:serval_help@unil.ch
http://www.unil.ch/serval
http://serval.unil.ch/disclaimer
https://serval.unil.ch/notice/serval:BIB_6CBC385F2349