Association between Sleep Duration, Serum Trace Minerals, Electrolytes and Academic Performance in Medical Students in Nigeria: A Cross-sectional Study

Abstract

Background: Medical students are at high risk of chronic sleep restriction due to demanding academic schedules, clinical duties, and examination pressure. Although the psychological and academic consequences of poor sleep in this group are well documented, comparatively little is known about how sleep duration relates to serum electrolyte and nutritional biomarker profiles. Objective: This study assessed the relationship between self-reported sleep duration and serum bicarbonate, chloride, sodium, potassium, total protein, albumin, zinc, and iron levels among medical students, and whether sleep duration was associated with academic performance. Place and Duration of Study: This study was conducted at a private tertiary institution in Ibadan between December 2025 and February 2026. Study Design: This was an analytical cross-sectional study involving 80 undergraduate medical students at a private tertiary institution in Ibadan, Nigeria. Methodology: In this cross-sectional study, participants were categorised into four sleep-duration groups (<4 hours, 4–5 hours, 5–6 hours, and >7 hours per night). Serum HCO3⁻, Cl⁻, Na⁺, K⁺, total protein, albumin, zinc, and iron were measured and compared across groups using one-way ANOVA with post hoc testing. Academic performance was categorised as poor, average, or excellent, and its association with sleep duration was assessed using the chi-square test. Results: Serum bicarbonate, chloride, potassium, albumin, and zinc all showed statistically significant, graded increases with longer sleep duration (p < 0.05), with zinc showing a distinct three-tier stepwise pattern across sleep categories. Sodium, total protein, and iron did not differ significantly across sleep-duration groups. Sleep duration category was not significantly associated with academic performance. Conclusion: Longer sleep duration was associated with more favourable serum electrolyte and nutritional biomarker profiles among medical students, independent of any measurable association with academic performance. These findings suggest that inadequate sleep may have physiological consequences for electrolyte and micronutrient status in this population, warranting further longitudinal studies with larger sample sizes.