Supplementary Material for: Single Nucleotide Polymorphisms in Orexin-1 and BDNF Receptor Genes are Associated with Increased Risk of Developing Post-Partum Depression among Women with Gestational Diabetes Mellitus

Objectives: 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 Post natal 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. Methodology: Among 1000 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 one 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, p25, FPG>126 mg/dl, 31–39-week gestation, middle age (33–46 years), <12 years of education, and urban locality as significant risk factors for PPD. GDM diagnosis increased PPD odds by 3.2-fold (OR=3.2, 95% CI 2.392–3.991, 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, CI 95% (1.29-7.47) p<0.001) and 3.8-fold (OR=3.8, CI 95% (3.9-37), p<0.05) respectively in comparison to other genotypic variants. Conclusions: Our study supports Orexin and BDNF system-targeted therapies for PPD.