The Causal Associations between Adipokines and Alzheimer's Disease: A Two-Sample Mendelian Randomization Study

Observational studies have indicated the association of alteration of adipokines with Alzheimer's disease (AD). However, it remains unclear whether the associations are causal.

To determine the causal associations between adipokines and AD.

A Mendelian randomization (MR) method was applied to investigate the causal relationships of adipokines, including adiponectin and resistin, with risk of AD. Genetic proxies from genome-wide association studies (GWAS) of adiponectin and resistin were selected as instrumental variables. GWAS summary statistics for AD were extracted as outcome.

In this study, we found evidence of the causal effects of adiponectin on AD (OR: 0.850, 95% CI: 0.731-0.990, p = 0.037). However, no relationship between resistin and AD (OR: 0.936, 95% CI: 0.851-1.029, p = 0.171) was detected. In the reverse causation analysis, null associations of AD were found for adiponectin and resistin (all p > 0.05).

This study provides evidence of causality between adiponectin and risk of AD. However, no genetic susceptibility of resistin was discovered for AD.