Abnormal Thyroid Function in the Elderly： an Epidemiological Study in Taipei City

• Main Authors: Mei-hsing Chuang, 莊美幸
• Other Authors: Pesus Chou
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/xq59q3

博士 === 國立陽明大學 === 公共衛生研究所 === 104 === Part I Prevalence of Abnormal TSH in the Elderly in Taipei City OBJECTIVES: To examine serum TSH in older people aged >=65 year, to determine the prevalence of abnormal TSH in the elderly persons in Taipei City. DESIGN: Descriptive analysis. SETTING: Taipei Databank for Public Health Analysis (DoPHA). PARTICIPANTS: Individuals aged 65 and older .(N= 41,564). MEASUREMENTS: We analyzed TSH, and TSH frequency distribution curves for different age groups. RESULTS: Hyperthyroidism was found in 3.7% , hypothyroidism was found in 5.9% of the elderly. Hyperthyroidism was found in 2.4% , hypothyroidism was found in 5.2% of the males. Hyperthyroidism was found in 5.2% , hypothyroidism was found in 6.8% of the females. The central 95 percentile interval of the serum TSH level was 0.29-6.52 mIU/liter for total participants. For the self-reported disease-free people, the central 95 percentile interval of the serum TSH level was 0.34-6.15 mIU/liter. The 97.5 centiles for the 65–74 year and 85+ groups were 6.17 and 7.39 mIU/liter, respectively, and was higher in females than males. CONCLUSION: In summary, TSH was greater in females, increased with age, and a large proportion of the Taipei elderly had laboratory evidence of abnormal thyrotropin, which supports the need of screening for early detection. Keywords: Thyrotropin, Hypothyroidism, Hyperthyroidism   Part II Abnormal Thyrotropin and Chronic Kidney Disease in the Elderly in Taipei City OBJECTIVES: To examine whether older people with abnormal thyroid function were more likely to develop chronic kidney disease (CKD) over a 5-year follow-up period. DESIGN: Retrospective cohort study. SETTING: Health check-up data from the Taipei Databank for Public Health Analysis (DoPHA). PARTICIPANTS: Individuals aged 65 and older (n=41,454). MEASUREMENTS: The thyrotropin levels were repeatedly measured. The subjects were categorized into four thyroid function groups (hyperthyroid, euthyroid, subclinical hypothyroid, and overt hypothyroid). The risk of incident CKD was evaluated using a stepwise Cox proportional hazard regression model that adjusted for sex, baseline age, hypertension, diabetes mellitus (DM), dyslipidemia, hyperuricemia, anemia, obesity, liver function, smoking, and alcohol drinking. RESULTS: Higher thyrotropin levels were associated with an increased risk of subsequent CKD. Compared to the euthyroid group, the multivariable-adjusted HRs of CKD were 1.15 (95% CI, 1.05-1.26) for individuals with subclinical hypothyroidism and 1.27 (95% CI, 1.04-1.55) for individuals with overt hypothyroidism. Women were more likely to suffer from 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 non-diabetics (HR, 1.19; 95% CI, 1.07-1.31; and HR, 1.34; 95% CI, 1.08-1.65, respectively). CONCLUSION: In this cohort study of elderly persons in Taipei City, we found a significant association between hypothyroidism and the development of CKD among females and non-diabetics. Keywords: thyrotropin, chronic kidney disease, glomerular filtration rate, hypothyroidism, proteinuria   Part III Abnormal Thyrotropin and All-Cause Mortality in Elderly Patients with Chronic Kidney Disease OBJECTIVES: To examine the associations of abnormal thyroid function with all-cause mortality in older CKD patients over a 5-year follow-up period. DESIGN: Retrospective cohort study. SETTING: Health check-up data from the Taipei Databank for Public Health Analysis (DoPHA). PARTICIPANTS: Individuals aged 65 and older with chronic kidney disease (n=24,453). MEASUREMENTS: The thyrotropin levels were repeatedly measured. The subjects were categorized into four thyroid function groups (hyperthyroid, euthyroid, subclinical hypothyroid, and overt hypothyroid). The risk of mortality was evaluated using a stepwise Cox proportional hazard regression model that adjusted for sex, baseline age, hypertension, diabetes mellitus (DM), CKD stages, hypoalbuminemia, history of cancers, history of COPD, dyslipidemia, hyperuricemia, anemia, BMI, liver function, smoking, and alcohol drinking. RESULTS: Compared to the euthyroid group, subclinical hypothyroid patients showed an increased risk of all-cause mortality with a hazard ratio (HR) of 1.18 and 95% confidence interval (95% CI) of 1.03-1.35. Overt hypothyroid individuals had an increased risk of all-cause mortality (HR, 1.70, 95% CI, 1.12-2.56). In analyses stratified by age group, subclinical hypothyroidism was associated with higher mortality risk in the 65-79 age group (HR, 1.27; 95% CI, 1.03-1.57). When stratified by DM, subclinical hypothyroidism and overt hypothyroidism were associated with an increased mortality risk in non-diabetics (HR, 1.30; 95% CI, 1.11-1.52; HR, 2.21; 95% CI, 1.44-3.40, respectively). CONCLUSION: In this cohort study of elderly persons in Taipei City, we found a significant association between hypothyroidism and all-cause mortality. An increased death risk in the non-diabetic group and in subjects <80 years old was observed. Keywords: thyrotropin, chronic kidney disease, all-cause mortality, glomerular filtration rate, hypothyroidism