Impact of obstructive sleep apnea on hematocrit levels and erythrocytosis - a clinical study.

OBJECTIVE

Assess differences between hematocrit levels in a population with and without obstructive sleep apnea (OSA) and determine if these differences correlate with disease severity and/or with levels of hypoxemia.

MATERIAL AND METHODS

Data was collected from patients who underwent level I polysomnography (PSG) in the sleep laboratory at Hospital Rainha Santa Isabel, Torres Novas, Portugal, between January 2018 and December 2022. The patients' medical data was analyzed and sociodemographic (gender, body mass index (BMI) and age), polysomnographic (Apnea and Hypopnea Index (AHI), mean SpO2, minimum SpO2, Oxygen Desaturation Index (ODI), T90 and T85) and laboratory data (hematocrit (HCT), hemoglobin (HGB) and erythrocyte count) were collected. Statistical analysis included one-way ANOVA with Tukey's HSD for pairwise comparisons, Pearson's correlation for associations between polysomnographic and hematological parameters, and multivariate regression to identify independent factors.

RESULTS

HCT levels were found to be higher in the moderate OSA group, particularly compared to the no OSA group (42.34 ± 4.09% vs 40.28 ± 2.75%), with significant differences between groups (p = 0.032). Although HCT levels were shown to be higher in the OSA group, the mean values remained within normal range, so no patient manifested erythrocytosis.

CONCLUSION

Our results suggest that moderate OSA is associated with increased HCT levels but does not seem to cause secondary erythrocytosis. Future research should further evaluate the hypoxic burden of OSA, as increased HCT may raise the risk of cardiovascular complications.