Thyroid dysfunction and serum lipids: A community-based study

Authors

John P. Walsh
Alexandra P. BremnerFollow
Max K. Bulsara, University of Notre Dame AustraliaFollow
Peter O'Leary
Peter J. Leedman
Peter Feddema
Valdo Michelangeli

Publication Details

Walsh, J. P., Bremner, A. P., Bulsara, M. K., O’Leary, P., Leedman, P. J., Feddema, P., et al. (2005). Thyroid dysfunction and serum lipids: A community-based study. Clinical Endocrinology, 63(6), 670–675. doi: 10.1111/j.1365-2265.2005.02399.x

Abstract

Objective: It is uncertain whether subclinical hypothyroidism (SCH) is associated with hypercholesterolaemia, particularly in subjects with SCH and serum TSH ≤ 10 mU/l.

Design, patients and measurements: Cross-sectional study of 2108 participants in a 1981 community health survey in Busselton, Western Australia. Serum total cholesterol and triglycerides were measured in all subjects and high density lipoprotein cholesterol (HDL-C) measured (and low density lipoprotein cholesterol (LDL-C) calculated) in a subgroup of 631 subjects at the time of the survey. In 2001, TSH and free T4 concentrations were measured on archived sera stored at −70 °C. Serum lipid concentrations in subjects with thyroid dysfunction and euthyroid subjects were compared using linear regression models.

Results: In the group as a whole, serum total cholesterol was higher in subjects with SCH (N = 119) than in euthyroid subjects (N = 1906) (mean ± SD 6·3 ± 1·3 mmol/l vs. 5·8 ± 1·2 mmol/l, P < 0·001 unadjusted, P = 0·061 adjusted for age, age² and sex). Serum total cholesterol was similarly elevated in subjects with SCH and TSH ≤ 10 mU/l (N = 89) (6·3 ± 1·3 mmol/l, P < 0·001 unadjusted, P = 0·055 adjusted for age, age² and sex). In the subgroup analysis, LDL-C was higher in subjects with SCH (N = 30) than in euthyroid subjects (N = 580) (4·1 ± 1·2 mmol/l vs. 3·5 ± 1·0 mmol/l, P < 0·01 unadjusted, P = 0·024 adjusted for age, age² and sex). LDL-C was significantly increased in subjects with SCH and TSH ≤ 10 mU/l (N = 23) (4·3 ± 1·3 mmol/l, P < 0·001 unadjusted, P = 0·002 adjusted for age, age² and sex).

Conclusion: SCH is associated with increased serum LDL-C concentrations, which is significant after adjustment for age, age² and sex.

Keywords

peer-reviewed