Short Sleep Duration, Late Sleep Timing, And Late Eating Timing: A Trilogy Of Behavioral Risk Factors For High Blood Pressure?

Introduction: Short sleep duration (<7 h/night) is a risk factor for hypertension and other cardiovascular diseases (CVD). Not clear is if delayed timing of sleep or eating behaviors adds to this risk. We tested the hypothesis that later sleep and eating timing would be associated with higher blood pressure (BP), and that adults with short sleep + late behavior timing would have the highest BP vs those with one (short sleep OR late timing) or no risk behaviors (adequate sleep + early timing). Methods: Over a 14-day period, 30 healthy, non-shift working adults wore wrist actigraphs to evaluate sleep duration and onset timing, and completed image-assisted diet records to estimate eating onset (time of first caloric intake after awakening) and offset (time of last caloric intake before sleep). Fasted morning systolic (SBP) and diastolic BP (DBP) were obtained. Regression models of SBP and DBP tested associations with sleep onset, eating onset, and eating offset. Sleep duration (<7 vs ≥7h) and behavior timing metrics (median split) were dichotomized, and ANOVAs compared BP between sleep duration + behavior timing groups. Results: Participants were 28±7y, 43% male, BMI 23.9±2.6 kg/m 2 , and BP 114±10/70±7 mmHg. Sleep duration was 6.8±0.8 h, sleep onset 23:45±1.3 h, eating onset 08:49±1.5 h, and eating offset 20:40±1.2 h. Independent of age and sex, later sleep onset was associated with higher SBP (B= 3.0±1.3 mmHg/h, p =0.03) and DBP (B= 2.5±0.9 mmHg/h, p =0.01). Later eating onset was associated with higher DBP (B= 2.1±0.9 mmHg/h, p =0.03), and later offset with higher SBP (B= 4.1±1.4 mmHg/h, p <0.01) and DBP (B= 3.3±1.0 mmHg/h, p <0.01). When grouped according to sleep duration and eating offset, short sleep + late timing participants exhibited higher DBP vs adequate sleep + early timing (75±7 vs 67±7, p =0.03) and tended to exhibit higher SBP and DBP vs short sleep OR late timing (both p =0.07). Conclusion: These data indicate later sleep and eating timing, especially in the setting of short sleep, exemplifies a chrono-behavioral phenotype of CVD risk.