The effect of thyroid hormone therapy on muscle function, strength and mass in older adults with subclinical hypothyroidism—an ancillary study within two randomized placebo controlled trials

Abstract

Background loss of skeletal muscle function, strength and mass is common in older adults, with important socioeconomic impacts. Subclinical hypothyroidism is common with increasing age and has been associated with reduced muscle strength. Yet, no randomized placebo-controlled trial (RCT) has investigated whether treatment of subclinical hypothyroidism affects muscle function and mass. Methods this is an ancillary study within two RCTs conducted among adults aged ≥65 years with persistent subclinical hypothyroidism (thyrotropin (TSH) 4.60–19.99 mIU/l, normal free thyroxine). Participants received daily levothyroxine with TSH-guided dose adjustment or placebo and mock titration. Primary outcome was gait speed at final visit (median 18 months). Secondary outcomes were handgrip strength at 1-year follow-up and yearly change in muscle mass. Results we included 267 participants from Switzerland and the Netherlands. Mean age was 77.5 years (range 65.1–97.1), 129 (48.3%) were women, and their mean baseline TSH was 6.36 mIU/l (standard deviation [SD] 1.9). At final visit, mean TSH was 3.8 mIU/l (SD 2.3) in the levothyroxine group and 5.1 mIU/l (SD 1.8, P < 0.05) in the placebo group. Compared to placebo, participants in the levothyroxine group had similar gait speed at final visit (adjusted between-group mean difference [MD] 0.01 m/s, 95% confidence interval [CI] −0.06 to 0.09), similar handgrip strength at one year (MD −1.22 kg, 95% CI −2.60 to 0.15) and similar yearly change in muscle mass (MD −0.15 m2, 95% CI −0.49 to 0.18). Conclusions in this ancillary analysis of two RCTs, treatment of subclinical hypothyroidism did not affect muscle function, strength and mass in individuals 65 years and older.

Thr92Ala-DIO2 heterozygosity is associated with skeletal muscle mass and myosteatosis in patients with COVID-19

“…Skeletal muscle is a primary target of TH signaling, influencing structural and metabolic properties, thus several studies have addressed the role of TH in muscle health (33) There (2022) on 267 older adults with persistent subclinical hypothyroidism revealed that LT4 treatment did not significantly affect gait speed, handgrip strength, or annual muscle mass change when compared to a placebo (35).…”

Hypothyroidism in Older Adults: A Concise Review of the Recent Literature

“…The mean age was 77.5 years, and 48.3% were women. 30 Compared to the placebo, participants in the L-T4 group had similar gait speed at the final visit (adjusted between-group mean difference, similar handgrip strength at 1 year, and similar yearly change in muscle mass). These findings suggest that the ancillary analysis of two RCTs and treatment of SCH did not affect muscle function, strength, and mass in individuals 65 years and older.…”

“…Three studies on the subject were published recently. [28][29][30] The impact of L-T4 therapy for SCH on appendicular bone geometry and volumetric density was studied in a nested study within the TRUST trial by Büchi et al 28 assessing the effect of L-T4 therapy on bone geometry as measured by peripheral quantitative computed tomography. In the TRUST trial, community-dwelling adults aged 65 years with SCH were randomized to L-T4 with dose titration versus placebo with mock titration.…”

“…In conclusion, over 1 year levothyroxine did not affect bone health in older adults with SCH. 29 Netzer et al 30 reported an ancillary study within two RCTs conducted among adults aged 65 years with persistent SCH. Participants received daily levothyroxine with TSH-guided dose adjustment or placebo and mock titration.…”

Sarcopenia, a condition shared by various diseases: can we alleviate or delay the progression?

“…Restoration of normal albumin concentrations, associated with dietary supplementation of BCAA, is correlated with a reduction of fat accumulation in skeletal muscle, preservation of muscle mass and improved glucose sensitivity in patients with liver cirrhosis [ 72 ]. Interestingly, an ancillary analysis of two RCTs, treatment of subclinical hypothyroidism had no significant effect on function, strength and muscle mass in subjects aged 65 years and older [ 73 ]. Compared to placebo, testosterone replacement (7.5 g testosterone gel at 1% per day) in elder men with low to moderate–normal testosterone levels for 3 years was associated with modest but significantly greater improvements in muscle mass [ 74 ].…”