Association Between Thyroid Dysfunction and Lipid Profiles Differs According to Age and Sex: Results from the Korean National Health and Nutrition Examination Survey.

Background: Lipid profiles of men and women change differently during the aging process. Guidelines recommend that dyslipidemia patients should consider screening for hypothyroidism without consideration of age or sex.

Methods: Data from the sixth Korean National Health and Nutrition Examination Survey were used. A total of 4275 participants without thyroid disease and without a past history of dyslipidemia or dyslipidemia medication were evaluated. The association between thyroid dysfunction and lipid profiles (total cholesterol [TC], low-density lipoprotein cholesterol [LDLC], and triglycerides [TG]) was analyzed by age and sex.

Results: The prevalence of thyroid dysfunction was significantly different according to TC and LDLC levels (p = 0.003 and p = 0.021, respectively). In women, the weighted prevalence of thyroid dysfunction was significantly different according to levels of TC, LDLC, and TG (p = 0.007, p = 0.016, and p = 0.044, respectively). However, in men, no association was found in any of the lipid profiles. Female participants were divided into two groups using a cutoff age of 55 years. In younger women, the weighted prevalence of thyroid dysfunction was different according to the levels of TC, LDLC, and TG (p = 0.013, p = 0.007, and p = 0.007, respectively). However, in older women, no association was found for any of the lipid profiles.

Conclusions: The prevalence of thyroid dysfunction was significantly different according to lipid profiles, and this association differed by age and sex.