Background

Obstructive sleep apnea (OSA) is a widespread sleep-related disease with rising prevalence associated with increased risk of cardiovascular complications. OSA seems to overlap in clinical and biochemical features with catecholamine-secreting tumors. This study aimed to measure the level of plasma metanephrine in patients diagnosed with OSA to determine whether biochemical markers of sympathetic activity are consistently elevated in this group.

Methods

An observational cross-sectional study conducted in Jordan University Hospital, between Augest 2023  to March 2024. Medical history, physical examination, and blood samples for plasma metanephrine were obtained from patients who were undergoing sleep study.  Fasting Plasm metanephrins levels in a supine rested individuals  were measures using  a validated commercial ELIZA kit and samples were obtained under standardized conditions .

Results

A total of 83 participants were included in the study, including 54 (65.1%) with severe obstructive sleep apnea (OSA) and 29 (34.9%) with moderate OSA. The average plasma metanephrine concentration was normal ( 15.3 ± 6.81 pg/m). The mean plasma metanephrines level was slightly higher in participants with severe osa but  no statistically significant correlation between plasma metanephrine levels and the apnea-hypopnea index (AHI) (p = 0.456)or other clinical parameters .

Conclusion

This study demonstrated that in obese middle- aged patients with moderate to severe OSA patients , plasma metanephrines levels remain normal and do not correlate with OSA severity in contrast to prior studies based on urinary catecholamine metabolites which may suggest that plasma metanephrines can be used to distinguish between the episodic and transient SNS overactivity in OSA compared to the more constant behavior in catecholamine-secreting tumors.