PMID- 18593278
OWN - NLM
STAT- MEDLINE
DCOM- 20080821
LR  - 20211020
IS  - 1549-1684 (Print)
IS  - 1557-8577 (Electronic)
IS  - 1549-1684 (Linking)
VI  - 11
IP  - 3
DP  - 2008 Jun
TI  - Caloric restriction but not exercise-induced reductions in fat mass decrease 
      plasma triiodothyronine concentrations: a randomized controlled trial.
PG  - 605-9
LID - 10.1089/rej.2007.0622 [doi]
AB  - Caloric restriction (CR) decreases circulating triiodothyronine (T(3)) 
      concentration. However, it is not known if this effect is due to body fat mass 
      reductions or due to CR, per se. The purpose of this study was to test the 
      hypothesis that plasma T(3) concentration decreases with CR-induced reductions in 
      fat mass but not in response to similar decreases in fat mass that are induced by 
      exercise. Sedentary, nonobese 50- to 60-year-old men and women with no clinical 
      evidence of cardiovascular or metabolic disease and not taking thyroid 
      medications were randomly assigned to 12 months of caloric restriction (n = 18) 
      or exercise-induced weight loss (n = 17) or to a control group (n = 9). Body 
      weight and composition and plasma concentrations of the thyroid hormones T(3), 
      thyrotropin (TSH), thyroxine (T(4)), and free thyroxine (FT(4)) were measured at 
      baseline and 12 months. Fat mass changed significantly in the CR (-6.3 +/- 1.0 
      kg) and exercise (-5.5 +/- 1.0 kg) groups but not in the control group (-0.6 +/- 
      1.4 kg). The changes were not significantly different between the CR and exercise 
      groups. Plasma T(3) concentration decreased in the CR group (-9.8 +/- 2.0 ng/dL, 
      p < 0.0001) but not in the exercise (-3.8 +/- 2.1 ng/dL, p = 0.07) or control 
      (-1.3 +/- 2.8 ng/dL, p = 0.65) groups. TSH, T(4), and FT(4) did not change in any 
      of the study groups. Twelve months of CR decreased circulating T(3) 
      concentrations in middle-aged adults. This effect does not appear to be 
      attributable to changes in body fat mass because a comparable decrease in T(3) 
      concentration was not observed in response to an exercise-induced fat mass 
      reduction.
FAU - Weiss, Edward P
AU  - Weiss EP
AD  - Division of Geriatrics and Nutritional Sciences, Department of Internal Medicine, 
      Washington University School of Medicine, St Louis, MO, USA. eweiss4@slu.edu
FAU - Villareal, Dennis T
AU  - Villareal DT
FAU - Racette, Susan B
AU  - Racette SB
FAU - Steger-May, Karen
AU  - Steger-May K
FAU - Premachandra, Bhartur N
AU  - Premachandra BN
FAU - Klein, Samuel
AU  - Klein S
FAU - Fontana, Luigi
AU  - Fontana L
LA  - eng
GR  - P30 DK056341-08/DK/NIDDK NIH HHS/United States
GR  - M01 RR000036/RR/NCRR NIH HHS/United States
GR  - P30 DK056341/DK/NIDDK NIH HHS/United States
GR  - AG 00078/AG/NIA NIH HHS/United States
GR  - RR 00036/RR/NCRR NIH HHS/United States
GR  - T32 AG000078-24/AG/NIA NIH HHS/United States
GR  - AG 20487/AG/NIA NIH HHS/United States
GR  - DK 56341/DK/NIDDK NIH HHS/United States
GR  - T32 AG000078/AG/NIA NIH HHS/United States
GR  - U01 AG020487-07/AG/NIA NIH HHS/United States
GR  - U01 AG020487/AG/NIA NIH HHS/United States
GR  - M01 RR000036-47/RR/NCRR NIH HHS/United States
PT  - Journal Article
PT  - Randomized Controlled Trial
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Rejuvenation Res
JT  - Rejuvenation research
JID - 101213381
RN  - 0 (Dietary Carbohydrates)
RN  - 06LU7C9H1V (Triiodothyronine)
RN  - 9010-34-8 (Thyroglobulin)
SB  - IM
MH  - Adipose Tissue/*metabolism
MH  - Body Weight
MH  - *Caloric Restriction
MH  - Dietary Carbohydrates/administration & dosage
MH  - *Exercise
MH  - Female
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Thyroglobulin/blood
MH  - Triiodothyronine/*blood
PMC - PMC2649744
MID - NIHMS95541
EDAT- 2008/07/03 09:00
MHDA- 2008/08/22 09:00
PMCR- 2009/06/01
CRDT- 2008/07/03 09:00
PHST- 2008/07/03 09:00 [pubmed]
PHST- 2008/08/22 09:00 [medline]
PHST- 2008/07/03 09:00 [entrez]
PHST- 2009/06/01 00:00 [pmc-release]
AID - 10.1089/rej.2007.0622 [pii]
AID - 10.1089/rej.2007.0622 [doi]
PST - ppublish
SO  - Rejuvenation Res. 2008 Jun;11(3):605-9. doi: 10.1089/rej.2007.0622.