Association between circulating fatty acid metabolites and asthma risk: a two-sample bidirectional Mendelian randomization study

Abstract Background Fatty acids are involved in a wide range of immunological responses in humans. Supplementation of polyunsaturated fatty acids has been reported to help alleviate symptoms and airway inflammation in asthma patients, whereas the effects of fatty acids on the actual risk of asthma r...

Full description

Bibliographic Details
Main Authors: Tingting Huang, Yichen Long, Yang Ou, Jia Li, Yilin Huang, Jinming Gao
Format: Article
Language:English
Published: BMC 2023-05-01
Series:BMC Medical Genomics
Subjects:
Online Access:https://doi.org/10.1186/s12920-023-01545-4
_version_ 1797817727058968576
author Tingting Huang
Yichen Long
Yang Ou
Jia Li
Yilin Huang
Jinming Gao
author_facet Tingting Huang
Yichen Long
Yang Ou
Jia Li
Yilin Huang
Jinming Gao
author_sort Tingting Huang
collection DOAJ
description Abstract Background Fatty acids are involved in a wide range of immunological responses in humans. Supplementation of polyunsaturated fatty acids has been reported to help alleviate symptoms and airway inflammation in asthma patients, whereas the effects of fatty acids on the actual risk of asthma remain controversial. This study comprehensively investigated the causal effects of serum fatty acids on asthma risk using two-sample bidirectional Mendelian Randomization (MR) analysis. Methods Genetic variants strongly associated with 123 circulating fatty acid metabolites were extracted as instrumental variables, and a large GWAS data of asthma was used to test effects of the metabolites on this outcome. The inverse-variance weighted method was used for primary MR analysis. The weighted median, MR-Egger regression, MR-PRESSO, and leave-one-out analyses were utilized to evaluate heterogeneity and pleiotropy. Potential confounders were adjusted by performing multivariable MR analyses. Reverse MR analysis was also conducted to estimate the causal effect of asthma on candidate fatty acid metabolites. Further, we performed colocalization analysis to examine the pleiotropy of variants within the fatty acid desaturase 1 (FADS1) locus between the significant metabolite traits and the risk of asthma. Cis-eQTL-MR and colocalization analysis were also performed to determine the association between RNA expression of FADS1 and asthma. Results Genetically instrumented higher average number of methylene groups was causally associated with a lower risk of asthma in primary MR analysis, while inversely, the higher ratio of bis-allylic groups to double bonds and the higher ratio of bis-allylic groups to total fatty acids, were associated with higher probabilities of asthma. Consistent results were obtained in multivariable MR when adjusted for potential confounders. However, these effects were completely eliminated after SNPs correlated with the FADS1 gene were excluded. The reverse MR also found no causal association. The colocalization analysis suggested that the three candidate metabolite traits and asthma likely share causal variants within the FADS1 locus. In addition, the cis-eQTL-MR and colocalization analyses demonstrated a causal association and shared causal variants between FADS1 expression and asthma. Conclusions Our study supports a negative association between several PUFA traits and the risk of asthma. However, this association is largely attributed to the influence of FADS1 polymorphisms. The results of this MR study should be carefully interpreted given the pleiotropy of SNPs associated with FADS1.
first_indexed 2024-03-13T08:58:45Z
format Article
id doaj.art-b7e901fa87d343809d0497e366d4d1da
institution Directory Open Access Journal
issn 1755-8794
language English
last_indexed 2024-03-13T08:58:45Z
publishDate 2023-05-01
publisher BMC
record_format Article
series BMC Medical Genomics
spelling doaj.art-b7e901fa87d343809d0497e366d4d1da2023-05-28T11:30:17ZengBMCBMC Medical Genomics1755-87942023-05-0116111310.1186/s12920-023-01545-4Association between circulating fatty acid metabolites and asthma risk: a two-sample bidirectional Mendelian randomization studyTingting Huang0Yichen Long1Yang Ou2Jia Li3Yilin Huang4Jinming Gao5Department of Respiratory and Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeDepartment of Epidemiology, School of Public Health, Southeast UniversityCenter for Tumor Diagnosis and Therapy, Jinshan Hospital, Fudan UniversityDepartment of Respiratory and Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeDepartment of Respiratory and Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeDepartment of Respiratory and Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeAbstract Background Fatty acids are involved in a wide range of immunological responses in humans. Supplementation of polyunsaturated fatty acids has been reported to help alleviate symptoms and airway inflammation in asthma patients, whereas the effects of fatty acids on the actual risk of asthma remain controversial. This study comprehensively investigated the causal effects of serum fatty acids on asthma risk using two-sample bidirectional Mendelian Randomization (MR) analysis. Methods Genetic variants strongly associated with 123 circulating fatty acid metabolites were extracted as instrumental variables, and a large GWAS data of asthma was used to test effects of the metabolites on this outcome. The inverse-variance weighted method was used for primary MR analysis. The weighted median, MR-Egger regression, MR-PRESSO, and leave-one-out analyses were utilized to evaluate heterogeneity and pleiotropy. Potential confounders were adjusted by performing multivariable MR analyses. Reverse MR analysis was also conducted to estimate the causal effect of asthma on candidate fatty acid metabolites. Further, we performed colocalization analysis to examine the pleiotropy of variants within the fatty acid desaturase 1 (FADS1) locus between the significant metabolite traits and the risk of asthma. Cis-eQTL-MR and colocalization analysis were also performed to determine the association between RNA expression of FADS1 and asthma. Results Genetically instrumented higher average number of methylene groups was causally associated with a lower risk of asthma in primary MR analysis, while inversely, the higher ratio of bis-allylic groups to double bonds and the higher ratio of bis-allylic groups to total fatty acids, were associated with higher probabilities of asthma. Consistent results were obtained in multivariable MR when adjusted for potential confounders. However, these effects were completely eliminated after SNPs correlated with the FADS1 gene were excluded. The reverse MR also found no causal association. The colocalization analysis suggested that the three candidate metabolite traits and asthma likely share causal variants within the FADS1 locus. In addition, the cis-eQTL-MR and colocalization analyses demonstrated a causal association and shared causal variants between FADS1 expression and asthma. Conclusions Our study supports a negative association between several PUFA traits and the risk of asthma. However, this association is largely attributed to the influence of FADS1 polymorphisms. The results of this MR study should be carefully interpreted given the pleiotropy of SNPs associated with FADS1.https://doi.org/10.1186/s12920-023-01545-4Genome-wide association studyMendelian randomizationAsthmaFatty acidsFatty acid desaturase gene
spellingShingle Tingting Huang
Yichen Long
Yang Ou
Jia Li
Yilin Huang
Jinming Gao
Association between circulating fatty acid metabolites and asthma risk: a two-sample bidirectional Mendelian randomization study
BMC Medical Genomics
Genome-wide association study
Mendelian randomization
Asthma
Fatty acids
Fatty acid desaturase gene
title Association between circulating fatty acid metabolites and asthma risk: a two-sample bidirectional Mendelian randomization study
title_full Association between circulating fatty acid metabolites and asthma risk: a two-sample bidirectional Mendelian randomization study
title_fullStr Association between circulating fatty acid metabolites and asthma risk: a two-sample bidirectional Mendelian randomization study
title_full_unstemmed Association between circulating fatty acid metabolites and asthma risk: a two-sample bidirectional Mendelian randomization study
title_short Association between circulating fatty acid metabolites and asthma risk: a two-sample bidirectional Mendelian randomization study
title_sort association between circulating fatty acid metabolites and asthma risk a two sample bidirectional mendelian randomization study
topic Genome-wide association study
Mendelian randomization
Asthma
Fatty acids
Fatty acid desaturase gene
url https://doi.org/10.1186/s12920-023-01545-4
work_keys_str_mv AT tingtinghuang associationbetweencirculatingfattyacidmetabolitesandasthmariskatwosamplebidirectionalmendelianrandomizationstudy
AT yichenlong associationbetweencirculatingfattyacidmetabolitesandasthmariskatwosamplebidirectionalmendelianrandomizationstudy
AT yangou associationbetweencirculatingfattyacidmetabolitesandasthmariskatwosamplebidirectionalmendelianrandomizationstudy
AT jiali associationbetweencirculatingfattyacidmetabolitesandasthmariskatwosamplebidirectionalmendelianrandomizationstudy
AT yilinhuang associationbetweencirculatingfattyacidmetabolitesandasthmariskatwosamplebidirectionalmendelianrandomizationstudy
AT jinminggao associationbetweencirculatingfattyacidmetabolitesandasthmariskatwosamplebidirectionalmendelianrandomizationstudy