Association between genetically predicted leukocyte telomere length and non-scarring alopecia: A two-sample Mendelian randomization study

Abstract

BackgroundThe most commonly acknowledged non-scarring alopecia are androgenetic alopecia (AGA) and alopecia areata (AA). Previous studies have revealed various risk factors associated with alopecia. However, the relationship between leukocyte telomere length (LTL) and non-scarring alopecia remains unclear.MethodsA two-sample Mendelian randomization (MR) analysis was performed to evaluate the causality between genetically predicted LTL and the risk of non-scarring alopecia. MR analyses were performed using the inverse variance-weighted (IVW) method and complemented with other MR methods.ResultsThe summary statistics of the genome-wide association studies (GWAS) for AGA and AA were obtained from the FinnGen biobank, which included 119,185 and 211,428 individuals, respectively. A total of 126 single nucleotide polymorphisms (SNPs) with genome-wide significance were selected as the instrumental variables for LTL. The MR analyses suggested a causal relationship between LTL and AGA, and the risk of AGA increased by 3.19 times as the genetically predicted LTL was shortened by one standard deviation in log transformed form under the IVW method (OR = 4.19, 95% CI = 1.20–14.61, p = 0.024). The other MR methods also demonstrated a similar trend of the effect of LTL on AGA. There was no causal relationship between LTL and AA (p > 0.05). Sensitivity analyses further demonstrated that the current results were less likely to be affected by confounders and bias.ConclusionOur results suggested a potential causal relationship between LTL and AGA, and shortened LTL was associated with an increased risk of AGA.

The association between testosterone, estradiol, estrogen sulfotransferase and idiopathic pulmonary fibrosis: a bidirectional Mendelian randomization study

“…Previous studies have reported signi cantly reduced testosterone levels in IPF patients, with a positive correlation between testosterone levels and telomere length, a common susceptibility factor in sporadic and familial IPF [17,29]. Telomere length has been inversely associated with IPF development in previous Mendelian randomization studies [30], suggesting that modulation of telomere length could be one of the mechanisms through which testosterone in uences IPF. IPF predominantly affects elderly males, and the decline in testosterone levels with aging may be associated with this trend.…”

Elucidating causal relationships of diet-derived circulating antioxidants and the risk of non-scarring alopecia: A Mendelian randomization study

“…[7][8][9] Previous Mendelian randomization (MR) analysis found that shortened leukocyte telomere length was associated with the risk of non-scarring alopecia. [10] Importantly, oxidative stress accelerates telomere attrition, leading to telomere shortening. [11][12][13] Hence, new insights into the treatment of nonscarring alopecia may be gained by elucidating the causal role of antioxidants in the disease.…”