Abstract P548: Poorer Objective Sleep is Associated With Greater Arterial Stiffness and Worsening Cardiac Diastolic Function

Aim: Few studies have examined the association between objective sleep metrics and arterial and echocardiographic (left ventricular systolic/diastolic function) markers of sub-clinical cardiovascular disease (CVD). The present study examined the association of wrist actigraphy-assessed sleep metrics with arterial stiffness, endothelial dysfunction, and left ventricular systolic/diastolic function. Methods: Fifteen young, healthy adults (21-39y; 60% women) with no history of CVD, and no current sleep-disordered breathing (WatchPat200, Itamar Medical) or sleep complaints wore Actiwatch Spectrum Plus actigraphs for eight nights (Philips Respironics, Bend OR) with accompanying sleep logs. Participants underwent fasting vascular testing including central augmented aortic pressure (AP), carotid-femoral pulse wave velocity (cfPWV) to assess arterial stiffness (SphymocorXCEL TM ), brachial artery flow mediated dilation (FMD) to assess endothelial function, and 2D echocardiography to assess left ventricular function (Terason uSmart 3300 TM ). Left ventricular function was assessed by ejection fraction (EF%), left atrial volume index (LAVI), deceleration time (DT), and mitral valve E/e’ ratio (MVE/e’) using standardized methods. Bivariate correlations investigating the association between mean total sleep time (TST), sleep efficiency % (SE), sleep-onset latency (SOL), and wake after sleep time (WASO) with cardiovascular indices were conducted. Curvilinear regression models examining quadratic relationships between TST and the cardiovascular indices were conducted. Results: On average, participants obtained 6 hrs 44 min of TST (SD=29.1), with 86.0% SE (SD=3.1), 10.6 min SOL (SD=8.5), and 37.0 min WASO (SD=11.6). cfPWV (range: 4.8-7.5), EF% (range: 60.0-72.0), LAVI (range: 15.0-26.7 mL/m 2 ), and MVE/e’ (range: 3.2-7.8) were all within normal ranges according to age and sex normative standards. Mean FMD was 9.2% (SD=4.62, range: 4.3-19.8). Correlations indicated that greater SOL was associated with greater cfPWV (r=.63, p=0.01), and AP (r=.57, p=0.03). Lower SE (r= -.70, p=0.003) and higher WASO (r=.71, p=0.003) were associated with higher MVE/e’. WASO was associated with higher DT (r=.57, p=0.04). Curvilinear regression models revealed a quadratic relationship between TST and cfPWV (F[2,11]=9.78, p=0.004) such that shorter and longer TST were associated with greater cfPWV. No sleep metrics were associated with FMD, EF%, or LAVI. Conclusions: Among normal sleeping, apparently healthy young adults, with no history of CVD, lower levels of objective sleep quality and both shorter and longer sleep duration were associated with greater arterial stiffness, whereas only lower levels of objective sleep quality were related to worsening left ventricular diastolic dysfunction. These data may have implications for CVD risk reduction in young, healthy adults.