Abnormal Thyroid-Stimulating Hormone and Chronic Kidney Disease in Elderly Adults in Taipei City

OBJECTIVES: To examine whether older people with abnormal thyroid function are more likely to develop chronic kidney disease (CKD) over a 5-year follow-up period. DESIGN: Retrospective cohort study. SETTING: Health examination data from the Taipei Databank for Public Health Analysis. PARTICIPANTS: Individuals aged 65 and older (N = 41,454). MEASUREMENTS: Thyroid-stimulating hormone (TSH) levels were repeatedly measured, and subjects were categorized into four thyroid function groups (hyperthyroid, euthyroid, subclinical hypothyroid, overt hypothyroid). The risk of incident CKD was evaluated using a stepwise Cox proportional hazards regression model adjusted for sex, baseline age, hypertension, diabetes mellitus (DM), dyslipidemia, hyperuricemia, anemia, obesity, liver function, smoking, and alcohol. RESULTS: Higher TSH levels were associated with greater risk of subsequent CKD. Individuals with subclinical hypothyroidism (hazard ratio (HR) = 1.15, 95% confidence interval (CI) = 1.05-1.26) and those with overt hypothyroidism (HR = 1.27, 95% CI = 1.04-1.55) were more likely than those who were euthyroid to have CKD. Women were more likely to have CKD than men (HR = 1.11, 95% CI = 1.06-1.16). When stratified by gender, subclinical hypothyroidism in women was associated with an increased risk of developing CKD (HR = 1.22; 95% CI = 1.08-1.39). When stratified by DM, subclinical hypothyroidism and overt hypothyroidism were associated with an increased risk of developing CKD in nondiabetics (HR = 1.19; 95% CI = 1.07-1.31; and HR = 1.34; 95% CI = 1.08-1.65, respectively). CONCLUSION: This cohort study of elderly persons in Taipei City found a significant association between hypothyroidism and development of CKD in women and individuals without DM.