Genome-wide study links cardiometabolic factors to cognition via APOA4-APOA5-ZPR1-BUD13 and other loci in rural Indians.

INTRODUCTION

Cardiometabolic risks affect cognition during aging, yet genetic basis for both remain understudied in Indians.

METHODS

This study constructs an ancestry-matched Indian haplotype reference panel for genotype imputation of 5111 rural Indians. Single-locus, gene-based, conditional genome-wide association analyses are performed on 20 cognitive and 10 cardiometabolic traits, with subsequent follow-up of identified associations through multimodal functional annotation. Furthermore, causal interrelationships between cardiometabolic and cognitive phenotypes by Mendelian randomization are investigated.

RESULTS

One novel memory-associated and 17 novel cardiometabolic phenotypes-associated (high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], triglycerides [TG], total cholesterol [TC], TG:HDL, and visceral adiposity index [VAI]) genome-wide significant loci, and multiple genes are identified. AMIGO1 (delayed-recall) and ZPR1-APOA5 (metabolic syndrome) exhibit distinct haplotype structure compared to other populations. Causal roles of cardiometabolic traits on various cognitive domains are identified via genetic instruments in APOC3-APOA4-APOA5-ZPR1-BUD13 among others.

DISCUSSION

These findings illustrate the impact of cardiometabolic factors on cognition in a rural socioeconomically disadvantaged population, advancing efforts to address health disparities.

HIGHLIGHTS

Our newly constructed ancestry-matched haplotype reference panel gives better genotype imputation accuracy for the Indian population. One and 17 novel genome-wide significant single-loci were identified to be associated with cognitive and cardiometabolic traits, respectively. Several subgenome-wide hits for all phenotypes were identified. Collapsing protein truncating variants (PTVs), there were two genes identified to be associated with cardiometabolic traits at a genome-wide level of significance, correcting for multiple phenotypes tested. Haplotypic differences were identified compared to 1000 Genomes superpopulations for genes influencing delayed recall and metabolic syndrome. Adverse causal roles of cardiometabolic traits on cognition were uncovered via genetic instruments in APOC3-APOA4-APOA5-ZPR1-BUD13, among others, through Mendelian randomization.