Brain-derived neurotrophic factor gene variants and obesity in former smokers

Shan-Shan Yang; Yao He; Lin Xu; Yali Jin; Wei-Sen Zhang; Chao-Qiang Jiang; Kar Keung Cheng; Tai Hing Lam

doi:10.1186/s12864-021-07928-0

Brain-derived neurotrophic factor gene variants and obesity in former smokers

BMC Genomics. 2021 Sep 15;22(1):668. doi: 10.1186/s12864-021-07928-0.

Authors

Shan-Shan Yang^{1

2}, Yao He³, Lin Xu^{4

5}, Yali Jin⁶, Wei-Sen Zhang⁶, Chao-Qiang Jiang⁷, Kar Keung Cheng⁸, Tai Hing Lam^{1

5

6}

Affiliations

¹ Institute of geriatrics, the 2nd Medical Center,Beijing Key Laboratory of Aging and Geriatrics, National Clinical Research Center for Geriatrics Diseases, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China.
² Department of Disease Prevention and Control, the 1st Medical Center, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China.
³ Institute of geriatrics, the 2nd Medical Center,Beijing Key Laboratory of Aging and Geriatrics, National Clinical Research Center for Geriatrics Diseases, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China. yhe301@x263.net.
⁴ School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong, China.
⁵ School of Public Health, The University of Hong Kong, Hongkong, China.
⁶ Guangzhou Number 12 People's Hospital, Guangzhou, China.
⁷ Guangzhou Number 12 People's Hospital, Guangzhou, China. cqjiang@hkucc.hku.hk.
⁸ Institute of Applied Health Research, University of Birmingham, Edgbaston, Birmingham, UK.

Abstract

Objective: From genome-wide association studies, brain-derived neurotrophic factor (BDNF) locus on chromosome 11 was the only SNP associated with both smoking and body mass index (BMI) in European, African and Asian population. This study aims to explore the unique genetic predisposition to obesity in former smokers by examining the effects of BDNF on BMI and waist circumference (WC).

Methods: The study design is case-control study with a cohort validation in supplementary. We included 15,072 ethnic Chinese participants in the Guangzhou Biobank Cohort Study (GBCS) with data of four BDNF SNPs related to both BMI and smoking behavior. We used baseline smoke exposure data in 2003-2007 and follow-up outcomes of general obesity (by BMI) and central obesity (WC) in 2008-2012. Odds ratios (ORs) and 95% confidence intervals (CIs) for general obesity and central obesity associated with these SNPs were derived from logistic regression.

Results: Of 15,072 participants (3169 men and 11,903 women), 1664 (11.0%) had general and 7868 (52.2%) had central obesity. In 1233 former smokers, the rs6265 GG, versus AA, genotype was associated with higher risks of general obesity (OR = 1.79, 95% CI = 1.06-3.01) and central obesity (OR = 2.08, 95% CI = 1.47-2.92) after adjustment. These associations were not significant in never or current smokers. In former heavy (≥20 cigarettes/day) smokers, the rs6265 GG genotype showed a higher odds for general obesity (OR = 2.15, 95% CI = 1.05-4.40), while no association was found in former light (1-9 cigarettes/day) smokers. Similar results were found for the association of rs6265 with central obesity and for the associations of other two BDNF SNPs (rs4923457 and rs11030104) with both general and central obesity.

Conclusions: We firstly identified the genetic predisposition (BDNF SNPs) to general and central obesity in former smokers, particularly in former heavy smokers. The different associations of the SNPs for general/central obesity in different smoke exposure groups may be related to the competitive performance of the sites and epigenetic modification, which needs further study.

Keywords: BDNF; Central obesity; Obesity; Smoking cessation.

MeSH terms

Body Mass Index
Brain-Derived Neurotrophic Factor* / genetics
Case-Control Studies
Cohort Studies
Female
Genome-Wide Association Study*
Humans
Male
Obesity / genetics
Smokers

Substances

Brain-Derived Neurotrophic Factor
BDNF protein, human