Subclinical hypothyroidism, weight change, and body composition in the elderly: The cardiovascular health study

Abstract

Background: Subclinical hypothyroidism is common in the elderly, yet its relationship with weight and body composition is unclear. Objective: We examined the relationship between subclinical hypothyroidism and weight change and body composition in older adults. Methods:Atotal of 427 subclinically hypothyroid and 2864 euthyroid U.S. individuals-65 years old enrolled in the Cardiovascular Health Study and not taking thyroid preparations were included. Analyses of 6-year weight change were performed, compared by thyroid status. A cross-sectional analysis of thyroid statusandbody compositionwasperformed in a subset of 1276 participantswho had dual-energy x-ray absorptiometry scans. Models were risk factor-adjusted and stratified by sex. Results: Overall, participants lost weight during follow-up (-0.38 kg/y in men, -0.37 kg/y in women).Subclinical hypothyroidism,whenassessed at a single time point or persisting over 2 years, was not associated with a difference in weight change compared with euthyroidism. Subclinical hypothyroidism was also not associated with differences in lean mass, fat mass, or percent fat compared with euthyroidism. A TSH level 1 mU/L higher within the euthyroid or subclinical hypothyroid range was associated with a 0.51-kg higher baseline weight in women only (P - .001) but not with weight change in either sex. A 1 ng/dL higher free T4 level was associated with lower baseline weight and 0.32 kg/y greater weight loss in women only (P - .003). Baseline weight and weight change did not differ by T3 levels. Conclusions: Our data do not support a clinically significant impact of subclinical hypothyroidism on weight status in the elderly. Copyright © 2014 by the Endocrine Society.