0277 Sleep-disordered Breathing Is Associated With Vascular Aging In Older Men

Abstract

Introduction: Sleep-disordered breathing (SDB) is highly prevalent in older men and is associated with biomarkers of vascular aging that are linked to greater cardiovascular risk, including arterial stiffening and endothelial dysfunction. Serum testosterone (T) declines with age in men and may play a role in driving both SDB and vascular aging. The extent to which low T is associated with objective measures of SDB and biomarkers of vascular aging in older men remains unknown and was investigated in this analysis. Method(s): This cross sectional analysis included older men with normal T (n=9, age=62 +/- 7, T=507 +/- 69 ng/dl) and low T (n=7, age=62 +/- 7, T=263 +/- 24 ng/dl) enrolled in an ongoing parent study investigating the role of T on vascular aging. Sleep was assessed at-home on one occasion using the WatchPAT device (Itamar Medical, Caesarea, Israel). The WatchPAT uses a combination of peripheral arterial tone, pulse oximetry, heart rate, and actigraphy to calculate indices of SDB; apnea-hypopnea index (AHI) respiratory disturbance index (RDI), and oxygen desaturation index (ODI). Within a week of the at-home sleep study, conduit and microvascular endothelial function were measured by brachial artery flow-mediated dilation (FMD) and peripheral arterial tonometry (reactive hyperemia index [RHI], pulse wave velocity [PWV], augmentation index [AIx], and aortic blood pressure [BP]). Result(s): WatchPAT derived indices of SDB were similar between normal and low T groups (P>;0.49 for all comparisons). Augmentation index was higher in the normal T group compared to the low T group (P=0.02). In the pooled population, T levels were not related to sleep measures, but were correlated with AIx (R=0.63, P=0.008). RHI was inversely related to RDI (RDI range=6.7 - 57.6 events/hour, R=-0.51, P=0.04). Elevated aortic systolic BP tended to correlate with a higher RDI (R=0.42, P=0.10) and AHI (AHI range=3.0 - 53.4 events/hour, R=0.46, P=0.07). Conclusion(s): RDI and AHI as measured by the WatchPAT were related to biomarkers of vascular aging in older men. Sleep and vascular outcomes were largely not different between men with normal and low T, but further research is warranted.