Higher TSH associated with human longevity

SAN DIEGO — High total thyroid-stimulating hormone and decreased bone turnover, without changes in energy metabolism or circulating thyroid hormone levels are typical characteristics of offspring of families who live to old age, according to study findings presented here.

“Only few studies have included subjects with a propensity to reach old age in good health, aiming to disentangle mechanisms contributing to staying healthier for longer,” the researchers wrote. “Greater longevity has been associated with higher TSH levels in humans and lower thyroid hormone levels in animals, but the mechanisms underlying TSH/[thyroid hormone] differences and longevity are unknown.”

Diana van Heemst, PhD, of Leiden University Medical Center in the Netherlands, and colleagues evaluated 61 middle-aged offspring (offspring) of siblings who lived into their 90s and 51 of their partners (controls) not from parents who lived into their 90s from the Leiden Longevity study to determine TSH and thyroid hormone regulation in relation to familial longevity. Energy metabolism measures were taken from all participants, and bone resorption and bone formation markers were measures as indicators of bone turnover.

Blood was frequently sampled over 24 hours where circulating TSH levels were measured every 10 minutes and thyroid hormone levels were measured every hour in a subset of 20 offspring and 18 controls.

Compared with controls, offspring had significantly higher total geometric mean TSH secretion (P < .007). Serum levels of TSH were on average 0.8 µ/L higher in offspring at all time points whereas circulating thyroid hormone levels were similar between the groups.

Resting metabolic rate and core body temperature were also similar between the groups whereas bone resorption marker beta-crosslap levels were significantly lower in offspring compared with controls (P = .02).

“We propose that pleiotropic effects of differences in thyroid status favor longevity by slowing rates of tissue turnover, without altering whole body metabolism,” the researchers wrote. “Our findings provide new targets for studying mechanisms to improve healthy life expectancy, including experimental studies to determine the effects of TSH on tissue regeneration and repair.”

Reference:

Wilhelmina Hansen S, et al. OR11-6. Presented at: The Endocrine Society Annual Meeting; March 5-8, 2015; San Diego.

Disclosure: The researchers report no relevant financial disclosures.