Mild thyroid hormone excess is associated with a decreased physical function in elderly men

Abstract

Introduction In the adult, subclinical hyperthyroidism (Shyper) may alter skeletal muscle mass and strength. However, whether these effects are present in elderly subjects is not known. We explored the relationship between mild hyperthyroidism and physical function in a population-based sample of older persons. Methods In a cross-sectional analysis, calf muscle cross-sectional area (CMA), handgrip strength, nerve conduction velocity (NCV), and Short Physical Performance Battery (SPPB) scores were compared between 364 euthyroid (Eut) and 28 Shyper men as well as between 502 Eut and 39 Shyper women. In a longitudinal analysis, we evaluated the relationship between baseline plasma TSH, FT3 and FT4 and the 3-year change in SPPB score in 304 men and 409 women who were euthyroid at enrolment. Results At the cross-sectional analysis, Shyper men, but not women, had a significantly (p = 0.02) lower SPPB score than Eut controls, although with comparable CMA, grip strength and NCV, and were more likely to have poor physical performance (odds ratio = 2.97, p< 0.05). Longitudinal analysis showed that in Eut men higher baseline FT4 was significantly (p=0.02) predictive of a lower SPPB score at the 3-year follow-up. Conclusion Even a modest thyroid hormone excess is associated with a reduced physical function in elderly men.

MANAGEMENT OF ENDOCRINE DISEASE: l-Thyroxine replacement therapy in the frail elderly: a challenge in clinical practice

“…Similar findings had been reported by van den Beld et al who noted that in euthyroid men aged 73-94 years, higher serum FT4 concentrations were associated with reduced physical function, while low serum FT4 was associated with better 4-year survival (77). Interesting data came from a study by Ceresini and coworkers who evaluated the relationship between physical function and thyroid hormones in a large cohort of independently living ≥65 years subjects (78). In the study population, the authors measured muscle strength and mass and physical performance, all parameters that are closely related to frailty.…”

“…On this evidence, frail individuals who suffer from weight loss and reduced lean mass, appear to be particularly at risk of overtreatment among older people, and thyroid hormone excess may have negative consequences beyond the well-known adverse effects, contributing to the pathogenesis of frailty itself. Indeed, besides lowering TSH, thyroid replacement therapy excess affects serum FT4 levels, which are independent predictors of frailty (68,70,77,78). Several studies have demonstrated that patients under l-T4 therapy have higher levels of FT4 than controls, even if within normal values, and serum FT4 concentrations are often at the upper limits of normal range (27,45).…”

Multiple Hormonal Dysregulation as Determinant of Low Physical Performance and Mobility in Older Persons

“…[146] explored the relationship between mild hyperthyroidism and physical function in the elderly. The first part of the study was a cross-sectional analysis in the InCHIANTI Study, in which several parameters of physical function were compared between 364 Eut men and 28 Shypert men and between 502 Eut and 39 Shypert women.…”

“…The second part of the study was a longitudinal analysis, in which the authors evaluated the relationship between TSH, FT3 and FT4 and 3-year change in SPPB score in 304 men and 409 women who were Eut at enrolment. The analysis showed that in Eut men higher baseline FT4 was a significant independent predictor of steeper decline in SPPB score during 3-year follow-up period (P=0.02) [146]. …”

“…The findings of this study suggest that Shypert may negatively affect physical function through its detrimental effects on muscle mass and/or muscle strength, especially in older men who already have reduced LBM and mobility [146]. Simonsick et al .…”