Causal linkage of Graves’ disease with aging: Mendelian randomization analysis of telomere length and age-related phenotypes

Abstract

Abstract Background Aging is an irreversible progressive decline in physical function. Graves' disease (GD) is a common cause of hyperthyroidism and is characterized by elevated levels of the thyroid hormone (TH). High TH levels are associated with aging and a shortened lifespan. The causal relationship between GD and aging is yet to be investigated. Methods We used genome-wide association study (GWAS) datasets and Mendelian randomization (MR) analysis to explore the causal link between GD and aging. To assess the statistical power of instrumental variables (IVs), F-statistics and R2 were used. MR analysis was conducted using inverse-variance weighting (IVW), MR-Egger, weighted median, and weighted modes. The odds ratio (OR) and 95% CI were calculated to estimate the relative risk of GD to the outcomes. The Cochran Q test, I2, MR-PRESSO test, and MR-Egger regression intercept were calculated using statistical and leave-one-out analyses to test the heterogeneity, horizontal pleiotropy, and stability of the IVs on the outcomes. Results The F-statistic of the five IVs were greater than 10, and the R2 values ranged from 0.033 to 0.156 (R2 > 0.01). According to the results of the IVW analysis, outcomes with no statistical differences were facial aging (p = 0.189), age-related macular degeneration (p = 0.346), and Alzheimer's disease (p = 0.479). There were significant statistical differences in the remaining outcomes: telomere length (TL) (OR = 0.982; 95%CI:0.969–0.994; p = 0.004), senile cataract (OR = 1.031; 95%CI:1.002–1.060; p = 0.033), age-related hearing impairment (OR = 1.009; 95%CI:1.004–1.014; p = 0.001), chronic obstructive pulmonary disease (COPD) (OR = 1.055; 95%CI:1.008–1.103; p = 0.020), and sarcopenia (OR = 1.027; 95%CI:1.009–1.046; p = 0.004). Conclusions GD accelerates the occurrence of age-related phenotypes including TL, senile cataracts, age-related hearing impairment, COPD, and sarcopenia. In contrast, there are no causal linkages between GD and facial aging, age-related macular degeneration, or Alzheimer's disease. Further experimental studies could be conducted to elucidate the mechanisms by which GD facilitates aging, which could help slow down the progress of aging.