title: Thyroid status, insulin sensitivity and glucose tolerance in overweight and obese adults before and after 36 weeks of whey protein supplementation and exercise training.
abstract: Research suggests that subclinical hypothyroidism (SHT) influences insulin sensitivity and glucose tolerance. Reductions in thyroid stimulating hormone (TSH) concentrations are associated with exercise training (ExTr), which improves insulin sensitivity and glucose uptake.
  
  
  OBJECTIVE
  A secondary analysis of previously published data was conducted to examine the relationship between SHT, TSH and glucose homeostatic control at baseline and to assess the impact of ExTr on thyroid status and how SHT affects changes in insulin sensitivity after ExTr.
  
  
  METHODS
  Data were obtained from a 36-week ExTr and whey protein supplementation intervention trial. Subjects (n = 304, 48 ± 7 years, females = 186) were randomized to a specific whey protein group (0, 20, 40, or 60 g per day) and all subjects participated in a resistance (2 d/wk) and aerobic (1 d/wk) training program. Testing was conducted at baseline and post-intervention.
  
  
  RESULTS
  At baseline, 36% (n = 110) and 12% (n = 35) of subjects were classified with SHT based on the TSH ≥ 3 µIU/L or TSH ≥ 4.5 µIU/L cut-offs, respectively. No association was found between baseline TSH and baseline measures of glucose homeostatic control. Whey protein supplementation did not influence intervention outcomes. Post-intervention (n = 164), no change was observed in TSH. SHT did not affect changes in insulin sensitivity following ExTr.
  
  
  CONCLUSIONS
  These results support that the health benefits of ExTr for the management of insulin resistance (IR) are not blunted by SHT.
authors.affiliation: a Department of Nutrition Science , Purdue University , West Lafayette , IN , USA.
authors.forename: Christian S
authors.initials: CS
authors.lastname: Wright
authors.affiliation: b Department of Clinical Medicine , Trinity College Dublin, College Green, University of Dublin , Dublin , Ireland.
authors.forename: Amy
authors.initials: A
authors.lastname: Craddock
authors.affiliation: a Department of Nutrition Science , Purdue University , West Lafayette , IN , USA.
authors.forename: Eileen M
authors.initials: EM
authors.lastname: Weinheimer-Haus
authors.affiliation: c Johns A. Burns School of Medicine, Biostatistics & Data Management Core , University of Hawaii , Honolulu , HI , USA.
authors.forename: Eunjung
authors.initials: E
authors.lastname: Lim
authors.affiliation: a Department of Nutrition Science , Purdue University , West Lafayette , IN , USA.
authors.forename: Travis B
authors.initials: TB
authors.lastname: Conley
authors.affiliation: a Department of Nutrition Science , Purdue University , West Lafayette , IN , USA.
authors.forename: Elsa M
authors.initials: EM
authors.lastname: Janle
authors.affiliation: a Department of Nutrition Science , Purdue University , West Lafayette , IN , USA.
authors.forename: Wayne W
authors.initials: WW
authors.lastname: Campbell
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D003131:Combined Modality Therapy; D019587:Dietary Supplements; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000178:diet therapy / Q000628:therapy*; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000178:diet therapy / Q000628:therapy; D017063:Outcome Assessment, Health Care; D050177:Overweight / Q000097:blood* / Q000178:diet therapy / Q000628:therapy*; D013972:Thyrotropin / Q000097:blood; D000067816:Whey Proteins / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D001786:Blood Glucose; D000067816:Whey Proteins; D013972:Thyrotropin
keywords: Subclinical hypothyroidism; glucose tolerance; insulin resistance; insulin sensitivity; thyroid stimulating hormone