Does vitamin D affect the association between FTO rs9939609 polymorphism and depression?

ABSTRACT

Background & objectives: Depression is a highly prevalent and multifactorial psychological disorder. Fat Mass and Obesity-Associated (FTO) gene and the serum vitamin D level are proposed to be involved in pathophysiology of depression. This study aimed to investigate the interactions between one FTO gene single nucleotide polymorphism, depression, and serum vitamin D level in overweight adults.

Methods: One hundred and ninety-seven overweight adults were recruited in this cross-sectional study. FTO genotyping was performed by amplification refractory mutation system polymerase chain reaction (ARMS-PCR). Depression severity was assessed using Beck’s depression inventory (BDI-II). Serum vitamin D levels were measured using a direct competitive enzyme-linked immunosorbent assay (ELISA) method.

Results: A-allele carriers had higher Beck’s depression score (P = 0.03). Multivariate regression models showed a positive association between the A-allele of FTO rs9939609 polymorphism and depression. Serum vitamin D level had no effect on the association between FTO genotype and depression.

Conclusion: A-allele of FTO rs9939609 polymorphism might be associated with depression independent of serum vitamin D level. Further longitudinal studies are needed to confirm these results.

KEYWORDS:

• Vitamin D
• depression
• FTO
• genetic loci
• psychological tests

Acknowledgments

We appreciate all the Health Center’s staffs for their excellent cooperation and also the participants who cooperate with the study protocol.

Author contribution

Conception and design: MM, MHE. Analysis and interpretation of the data: HAN, MM. Drafting of the paper or revising it critically for intellectual content: FJ, MM, MGH and MHE. Final approval of the version to be published: MHE, MM. All authors agree to be accountable for all aspects of the work.

Ethical approval

This study has been approved by Local ethics review boards at Shiraz University of medical sciences (ir.sums.rec.1395.100).

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers in this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This study was funded by Shiraz University of Medical Sciences, Shiraz, Iran [code 94-01-84-11190].