Article

Subclinical Hypothyroidism and Functional Mobility in Older Adults

Clinical Research Branch, National Institute on Aging, Harbor Hospital, 3001 S Hanover St, Fifth Floor, Baltimore, MD 21225, USA.
Archives of internal medicine (Impact Factor: 17.33). 11/2009; 169(21):2011-7. DOI: 10.1001/archinternmed.2009.392
Source: PubMed

ABSTRACT

Health risks associated with subclinical hypothyroidism in older adults are unclear. Our objective was to compare the functional mobility of people aged 70 to 79 years by thyroid function categorized by thyrotropin (TSH) level as euthyroid (>or=0.4 to <4.5 mIU/L), mild subclinical hypothyroid (>or=4.5 to <7.0 mIU/L), or moderate subclinical hypothyroid (>or=7.0 to <or=20.0 mIU/L with a normal free thyroxine level) cross-sectionally and over 2 years.
A total of 2290 community-dwelling residents participating in the year 2 clinic visit (July 1998-June 1999) of the Health, Aging, and Body Composition (Health ABC) Study, who had measured TSH level, had the capacity to walk 20 m unaided, and were not taking thyroid medication or had TSH levels consistent with hyperthyroidism or hypothyroidism. Main outcome measures included self-reported and performance-based measures of mobility (usual and rapid gait speed and endurance walking ability) assessed at study baseline (year 2) and 2 years later.
In age- and sex-adjusted analyses, the mild subclinical hypothyroid group (vs the euthyroid group) demonstrated better mobility (faster mean usual and rapid gait speed [1.20 vs 1.15 m/s and 1.65 vs 1.56 m/s, respectively; P < .001] and had a higher percentage of those with good cardiorespiratory fitness and reported walking ease [39.2% vs 28.0% and 44.7% vs 36.5%, respectively; P < .001]). After 2 years, persons with mild subclinical hypothyroidism experienced a similar decline as the euthyroid group but maintained their mobility advantage. Persons with moderate subclinical hypothyroidism had similar mobility and mobility decline as the euthyroid group.
Generally, well-functioning 70- to 79-year-old individuals with subclinical hypothyroidism do not demonstrate increased risk of mobility problems, and those with mild elevations in TSH level show a slight functional advantage.

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Available from: Eleanor M Simonsick, Jan 07, 2014
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    • "While evaluating QOL in older people, functional capacity as assessed by ADL and IADL plays a fundamental role. The majority of the studies report no association between sHT and functional impairment [74] [89] [94] [132] [133]. Simonsick et al. documented that individuals aged between 70 and 79 years and with mild TSH elevation (4.5-7 mIU/L) had a faster usual and rapid gait speed and better cardiorespiratory fitness than euthyroid controls [134]. "
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    ABSTRACT: Subclinical hypothyroidism (sHT) is a common condition in the general population, the prevalence increases with age, especially in women. An association between sHT and increased coronary heart disease (CHD) and heart failure (HF) risk and mortality has been described. However, this association is far to be established in older people (>65 years), especially in the oldest old (>85 years). Individuals with sHT may experience symptoms that resemble those observed in the overt form of the disease, leading to an impaired quality of life (QoL). Although very old people are frequently frail and potentially more susceptible to the effects of a disease, few studies were designed to assess the effect of sHT on QoL in this subset of population. Interestingly, the serum TSH concentration curve of general population has a skewed distribution with a "tail" toward higher values, which is amplified with aging. Thus, the diagnosis of sHT and the interpretation of its potential effects on CV function and QoL in older people may be a challenge for the clinician. Giving these premises, we reviewed the English scientific literature available on National Library of Medicine (www.pubmed.com) since 1980 regarding hypothyroidism, sHT, elderly, cardiovascular risk, CHD or HF events and mortality, health-related QoL, and LT4 therapy. Consistent results among large prospective cohort studies suggest an age-independent relationship between sHT and HF progression, while an impact of sHT on CHD events and mortality is essentially reported in young adults (aged below 65-70 years) with long-lasting disease. Scanty data are available on QoL of older people with sHT (>65 years) and, generally, no significant alterations are described.
    Full-text · Article · Oct 2014 · Frontiers in Endocrinology
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    • "During exercise, no differences were found between maximal workload, maximal HR, VO 2 max, maximal SV, and anaerobic threshold. No ST-T wave changes were observed A2/2 Cardiopulmonary Simonsick et al., 2009 SCH 262 (134/128) 2028 (953/1075) "
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    • "While evaluating QOL in older people, functional capacity as assessed by ADL and IADL plays a fundamental role. The majority of the studies report no association between sHT and functional impairment [74] [89] [94] [132] [133]. Simonsick et al. documented that individuals aged between 70 and 79 years and with mild TSH elevation (4.5-7 mIU/L) had a faster usual and rapid gait speed and better cardiorespiratory fitness than euthyroid controls [134]. "
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