Longitudinal Changes in Thyroid Function in the Oldest Old and Survival: The Cardiovascular Health Study All-Stars Study

Abstract

TSH increased over time in these older individuals. This elevation was not associated with increased or decreased mortality, although higher FT4 levels were associated with death. These findings raise concern for treatment of mild elevations of TSH in advanced age. Further studies are needed to determine the potential benefit of treating age-related changes in thyroid function.

Higher free thyroxine levels are associated with all-cause mortality in euthyroid older men: the Health In Men Study

“…In that study, low TSH levels predicted an increased mortality risk and the lowest mortality risk was observed in adults with high TSH levels and low FT 4 levels. Waring et al (11) reported an analysis of 843 long-term survivors from the Cardiovascular Health Study (' All-Stars') aged a mean of 85.3 years in whom higher FT 4 levels, but not TSH levels, predicted mortality after adjustment for age, sex and race. However, it remained unclear whether a similar association was present in the more general population of older men rather than in the selected groups of the 'oldest old'.…”

“…It has been reported that an increase in TSH levels occurs during ageing, while free thyroxine (FT 4 ) levels remain relatively stable (9,10,11). This may reflect reduced sensitivity of the pituitary to T 4 -or liothyronine (T 3 )-mediated suppression of TSH levels, altered TSH bioactivity or reduced thyroid sensitivity to TSH, requiring compensatory elevation of levels to maintain thyroid homeostasis (10).…”

“…Small differences in thyroid function between euthyroid subjects have been reported to be associated with specific health-related outcomes including atrial fibrillation, reduced bone mineral density and incident dementia (12,13,14). However, the effect of differences in thyroid function in euthyroid older people on the key outcome of mortality remains unclear, with limited available data and inconsistent findings reported (11,15,16,17). In this study, we tested the hypothesis that thyroid hormone levels within the normal range are an independent predictor of mortality in a large cohort of community-dwelling older men.…”

The relationship between thyroid stimulating hormone within the reference range and coronary artery disease: impact of age

“…It has been reported that in elderly individuals (at least 65 year old or older) high levels of TSH were not associated with an increased risk of CAD and its mortality [19][20][21]. Furthermore, in the study by Gussekloo J et al [22], which included 599 subjects who were aged 85 years at enrollment and followed for a mean period of 3.7 years, individuals with higher TSH levels had a longer life span than controls, suggesting a protective effect of SCH in elderly individuals.…”

“…The underlying mechanisms remained unknown. Different Thyroid physiology in older and younger had been documented, with a decreased thyroid hormone metabolism [25] and increased TSH levels [20,26] in the elderly. This agerelated change of thyroid function may be one of the mechanisms explaining the effect of age on CAD risks.…”