Single Nucleotide Polymorphisms in Orexin-1 and BDNF Receptor Genes are Associated with Increased Risk of Developing Postpartum Depression among Women with Gestational Diabetes Mellitus.

INTRODUCTION

Global studies have shown a bidirectional association of gestational diabetes mellitus (GDM) with postpartum depression (PPD). Despite high GDM prevalence in Pakistan (3.3%-17.8%), no prior studies have explored its link with PPD. In this study, association between GDM and risk of developing PPD was investigated and risk factors for PPD were identified using the gold-standard Edinburgh Postnatal Depression Scale (EPDS). Evidence suggests that PPD has strong genetic basis. The BDNF gene is a known candidate for PPD pathogenesis, while the orexin system is linked to arousal, energy metabolism, with emerging role in neuropsychiatric disorders. This study is the first study to explore association of orexin SNP ORX1 10914456 with PPD together with the BDNF SNP rs6265 (Val/Met66), among participants with and without GDM diagnosis.

METHODS

Among 1,000 women approached in hospitals of Islamabad, Rawalpindi, 800 met inclusion criteria (400 GDM, 400 non-GDM controls) and were genotyped for BDNF and orexin SNPs. Participants completed the EPDS 1 week postpartum.

RESULTS

Using a cutoff of ≥13, 84.9% of GDM patients and 18% of non-GDM controls scored ≥13 on EPDS (χ2 = 78.337, p < 0.00001). Multivariate logistic regression revealed GDM diagnosis, BMI >25, fasting plasma glucose >126 mg/dL, 31-39-week gestation, <12 years of education, and urban locality as significant risk factors for PPD. GDM diagnosis increased odds of PPD by 2.5-fold (OR = 2.5, 95% CI: 21.48-4.31, p < 0.0001). The orexin SNP Orx1 10914456, CC genotype and BDNF SNP rs6265, AA genotype increased the odds of having higher EPDS scores in GDM patients by 3.11 (OR = 3.11, 95% CI: 1.29-7.47, p < 0.001) and 3.3 (OR = 3.3, 95% CI: 1.31-8.13, p = 0.04, p < 0.05), respectively, in comparison to other genotypic variants.

CONCLUSION

Our study supports orexin and BDNF system-targeted therapies for PPD.