Prevalence and Risk Factors of Thyroid Dysfunction in Older Adults in the Community

Nermin Diab,Elizabeth Selvin,Anna Köttgen,Stephen P Juraschek,Seth S Martin,Natalie R Daya,John W Mcevoy,Ulla T Schultheiß

doi:10.1038/s41598-019-49540-z

Abstract

Prevalence estimates and evidence informing treatment targets for thyroid dysfunction largely come from studies of middle-aged adults. We conducted a cross-sectional analysis to determine the prevalence of thyroid dysfunction and risk factors for abnormal thyroid tests in participants aged ≥65 in the Atherosclerosis Risk in Communities (ARIC) study (N = 5,392). We measured serum concentrations of triiodothyronine (T3), free thyroxine (FT4), thyroid peroxidase antibody (Anti-TPO), and thyroid stimulating hormone (TSH). In this population (58% women, 22% black), 17% reported medication use for thyroid dysfunction. Among those not on treatment, the prevalence of overt and subclinical hypothyroidism was 0.82% and 6.06%, respectively. Overt and subclinical hyperthyroidism affected 0.26% and 0.78%, respectively. Multivariable adjusted TSH, FT4 and T3 levels were 25%, 1.3% and 3.9% lower in blacks compared to whites, respectively. Men were less likely to be anti-TPO positive compared to women (p < 0.001). Former and never smoking were associated with lower T3 and FT4 levels compared to current smoking. The prevalence of thyroid dysfunction in older adults is nearly 25%. Multiple illnesses can interact to contribute to declines in health. Additional attention to thyroid dysfunction and screening in this age group is recommended.

Highlights

Thyroid dysfunction is one of the most common endocrine disorders seen in clinical practice
Subclinical hypothyroidism and treated hypothyroidism were significantly greater in whites compared to blacks (P < 0.001), while prevalence of subclinical hyperthyroidism was greater in blacks compared to whites (P = 0.002)
We assessed the prevalence of thyroid dysfunction, and the associations of thyroid stimulating hormone (TSH), FT4, T3 levels and anti-TPO positivity with various demographic and clinical risk factors

Summary

Introduction

Thyroid dysfunction is one of the most common endocrine disorders seen in clinical practice. Current estimates of the prevalence of thyroid dysfunction are largely derived from data in predominantly white middle-aged populations[8,9,10]. There are limited available data on the prevalence of thyroid dysfunction in older adults. In clinical practice, guidelines recommend the same cut-points for thyroid hormones irrespective of age, race, or sex[13,14]. While multiple studies have examined associations of race, sex, BMI, dyslipidemia, heart rate, glycemic control, kidney function and smoking with thyroid hormone levels in middle-aged cohorts[6,9,10,12,15,16,17,18], few studies have addressed these associations exclusively in an older adult population[19,20]. In light of the above, the objectives of this study were to (1) investigate the prevalence of thyroid dysfunction in an older community-based U.S population, (2) better understand demographic and clinical risk factors for thyroid dysfunction in this older age group, and (3) examine the relationship between serum concentrations of triiodothyronine (T3), free thyroxine (FT4), thyroid peroxidase antibody (anti-TPO), and thyroid stimulating hormone (TSH) with demographic and clinical risk factors

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Conclusion