Corrélation entre les dosages des dérivés methoxylés urinaires et l’index d’apnée-hypopnée dans une population d’hypertendus : étude pilote

Aims

Sleep disorders like obstructive sleep apnea in adults are associated with increased sympathetic activity, which induced high blood pressure and could be associated with resistant hypertension. Some studies have demonstrated that high urinary catecholamine levels in obstructive sleep apnea patients may be decreased with continuous positive airway pressure therapy. However, very few studies have demonstrated a correlation between apnea-hypopnea index and urinary catecholamine levels in hypertension patients.

Methods

In this pilot study, 20 hypertensive patients referred for hypertension work-up including night-time polygraphy and 24 h urinary catecholamine dosage were included.

Results

Mean age was 51 ± 11 years (30–76), 68% were males. Diagnosis of obstructive sleep apnea was confirmed in 13 patients at the end of the work-up. Mean apnea-hypopnea index was 14 ± 9 (2–32). The only urinary catecholamine parameter significantly increased in patients with obstructive sleep apnea was 24 h urinary normetanephrine (1931 ± 1285 vs 869 ± 293 nmol/24 h; P < 0.05). However, this difference was not significant when this parameter was adjusted to 24 h urinary creatinine. We observed a significant positive correlation between AHI and 24 h urinary normetanephine (r = 0.486; P = 0.035).

Conclusion

This pilot study confirms an isolated elevation of 24 h urinary normetanephrine in hypertensive patients with obstructive sleep apnea and shows a significant correlation between sleep disorders expressed by apnea-hypopnea index and urinary catecholamines excretion.