Effects of Altering Levothyroxine Dose on Energy Expenditure and Body Composition in Subjects Treated With LT4.

ABSTRACT:

Background

It is unclear whether variations in thyroid status within or near the reference range affect energy expenditure, body mass, or body composition.

Methods

138 subjects treated with levothyroxine (LT4) for hypothyroidism with normal TSH levels underwent measurement of total, resting, and physical activity energy expenditure; thermic effect of food; substrate oxidation; dietary intake; and body composition. They were assigned to receive an unchanged, higher, or lower LT4 dose in randomized, double-blind fashion, targeting one of three TSH ranges (0.34 to 2.50, 2.51 to 5.60, or 5.61 to 12.0 mU/L). The doses were adjusted every 6 weeks to achieve target TSH levels. Baseline measures were reassessed at 6 months.

Results

At study end, the mean LT4 doses and TSH lev

SUBMITTER: Samuels MH 

PROVIDER: S-EPMC6194808 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature