Gene Variants Relate To Morning DHEA Concentrations In Military Personnel

Dehydroepiandrosterone (DHEA), a steroid hormone involved in stress management, plays a potentially antagonistic role to cortisol. Understanding why DHEA levels differ among individuals under variable stress conditions (e.g., military settings) would be especially informative for maintaining optimal readiness. To this end, the current study examined the relationship between gene variants and salivary DHEA. PURPOSE: Our preliminary findings have demonstrated that specific gene variants of the mineralocorticoid receptor (MR −2C/G) and serotonin transporter (5HTTLPR, triallelic version) are linked to salivary DHEA levels across the day. The current study replicates and extends these findings in a larger cohort while specifically focusing on morning DHEA concentrations. METHODS: In a cohort of male, U.S. Navy Explosive Ordnance Disposal Technicians (N = 91), saliva samples were collected to determine single nucleotide polymorphism genotypes and measure DHEA levels. TaqMan genotyping assays were performed for MR −2C/G. Variable number tandem repeat analyses were conducted for 5HTTLPR. One-way analysis of variance and general linear models were conducted to assess main effect of variant and interaction with time. RESULTS: Higher salivary DHEA levels were observed in homozygous G-carriers of MR −2C/G, F(1, 91) = 5.99, p = .016, and homozygous S-carriers of 5HTTLPR, F(1, 90) = 4.79, p = .031. Further, 5HTTLPR showed a significant interaction between genotype and time of day, F(1.6, 88) = 4.93, p = .013, with homozygous S-carriers showing higher DHEA levels than L-carriers at 30 and 60 minutes after waking, respectively. CONCLUSION: Taken together, these results confirm the stability of our preliminary findings and suggest that gene variants of MR −2C/G and 5HTTLPR modulate DHEA levels, thereby impacting hypothalamic-pituitary-adrenal function in military members. Such information has the potential to optimize readiness at the individual level, ensuring resilience even in highly variable stress environments. NIWC Pacific NISE FY24