Abstract
Introduction: There is evidence that obstructive sleep apneas (OSA) are involved in the development of hypertension. However, the precise mechanism is still under discussion.
Methods: We anlysed 34 patients via polysomnography and simultaneous beat to beat measurement of systolic (Sys) and diastolic (Dia) blood pressure (BP) (NexfinHD). Group1: apnea/hypopnea index (AHI) 0-15/h, n=16; Group2: AHI >15/h n=18. All results during 10 min. stable N2 sleep were calculated after data export using the SPSS software. A p<0.05 was considered significant.
Results: In group1 BP decreased during N2 sleep (Sys -1,9±1.8 mmHg; Dia -1.3mmHg ±1.36 mmHg) while in group2 Sys showed no change (-0,05±1.6 mmHg) and Dia increased (+0.41 mmHg ±1.1 mmHg). However, these results did not reach significance. BP changes did not correlate with the AHI, desaturation-index, percent of oxygen<90%, cyclic alternating patterns or the Arousal-index but with the variation in Sys (Fig1) and Dia (R:0.50, P=0.002) BP.
Discussion: We could show, that in OSAS patients during a short period of sleep the changes of BP are not directly correlated with the expected sleep or respiratory parameters but with the variation of blood pressure values. The relevance of this result for the development of hypertension remains to be proven.
This work was supported by the Fundação para a Ciência e a Tecnologia PIC/IC/82991/2007
- © 2011 ERS