Endocrine Abstracts

Introduction

Centenarians are subjects living 100 years or older. They represent a model of successful aging. In 2020, the number of centenarians in the world was approximately 573.000. Multiple endocrine changes occur with normal aging. Most centenarians have managed to avoid, postpone, or overcome the important age-related and life-threatening diseases. The purpose of this review is to present the endocrine function in centenarians with special emphasis on two relevant endocrine glands in this population, the thyroid and the adipose tissue.

Methods

A systematic search of literature was conducted using the search terms centenarians, endocrine function, thyroid, thyroid hormones, thyroid-stimulating hormone (TSH), adipose tissue, and adipokines.

Results

According to most studies, free triiodothyronine (T3) levels decrease while reverse T3 and TSH levels increase with aging. There is also an increase in the levels of most adipokines produced by the adipose tissue (e.g., leptin, resistin, interleukin 6, tumor necrosis factor alpha, and adiponectin). Thyroid hormones play an important role in aging and lifespan. Lower thyroid hormone levels and higher TSH levels have been reported to be associated with increased longevity. Centenarians have higher TSH levels compared to controls, partly due to a genetic background. The elevated levels of pro-inflammatory adipokines (e.g., interleukin 6 and tumor necrosis factor alpha) can negatively impact aging and lifespan by promoting chronic diseases (e.g., obesity, type 2 diabetes, and ischemic heart disease). In contrast, elevated levels of adiponectin (anti-inflammatory adipokine) can be beneficial for lifespan. High adiponectin levels may represent a compensatory response to limit oxidative stress and inflammation. Adiponectin levels are elevated in centenarians and may explain the favorable metabolic phenotype of these individuals.

Conclusion

Hormones influence the aging process and longevity. Centenarians have higher TSH and adiponectin levels compared to controls. High TSH is likely related to a favorable outcome in centenarians regardless of its underlying mechanism. High adiponectin may contribute to extended longevity of centenarians.