Thyroid functions and serum lipids in older women: a population-based study.
OBJECTIVE
To determine if thyroid hormone deficiency, manifested by elevated serum thyrotropin (TSH), is associated with alterations in serum lipids in an unselected population of older women.


METHODS
Population-based sampling of 279 ambulatory white women over age 65 studied at four US clinical centers, randomly selected from a cohort of 9,704 participants enrolled in the Study of Osteoporotic Fractures. A third-generation chemiluminescent TSH assay and serum lipid levels--total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides--were measured on fasting sera collected at the baseline visit. The cross-sectional relationships between TSH and lipid levels were analyzed.


RESULTS
TSH was high (>5.5 mU/L) in 19 women (6.8%), and was low (< or =0.1 mU/L) in 10 (3.6%). After multiple adjustment, LDL-C was 17 mg/dL or 13% higher (95% confidence interval [CI] 1%, 25%), and HDL-C was 6.5 mg/dL or 12% lower (CI -0.2%, -25%) in women with high TSH compared with those with normal TSH. The ratio of LDL-C to HDL-C was 29% greater (CI 4%, 53%) among women with elevated TSH. Although total cholesterol was 8% higher among women with high TSH, this difference was not statistically significant (CI -1%, 15%). High TSH was found in 12% of the women with the combination of high cholesterol (>240 mg/dL), high LDL-C (>160 mg/dL), and low HDL-C (<45 mg/dL); likelihood ratio = 1.8) whereas high TSH was found in only 2.2% of women with normal lipids (likelihood ratio = 0.3).


CONCLUSIONS
Among older white women, high TSH is associated with deleterious changes in serum lipids, particularly HDL-C, LDL-C, and the ratio of LDL-C to HDL-C cholesterol. Women with multiple lipid abnormalities are twice as likely to have an increased TSH.
Bauer
D C
DC
Department of Medicine, University of California, San Francisco, USA.
Ettinger
B
B
Browner
W S
WS
D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood*; D011237:Predictive Value of Tests; D013963:Thyroid Hormones / Q000172:deficiency*; D013972:Thyrotropin / Q000097:blood*
D008055:Lipids; D013963:Thyroid Hormones; D013972:Thyrotropin