0304 Caffeinated Beverage Intake Moderates the Relationship Between Sleep Quality and All-Cause Mortality in the Sleep Heart Health Study

Abstract Introduction Accumulating data indicates that poor sleep quality is associated with increased mortality. However, it is unclear whether caffeine moderates the effect of sleep-quality on longevity. This study determined whether caffeine intake moderates the association between sleep-quality parameters and all-cause mortality in the Sleep Heart Health Study (SHHS). Methods From an initial cohort of 6,641 participants, 5,628 patients (mean age: 62.25±10.86 years) remained after excluding 134 individuals who withdrew consent and 679 with prevalent major adverse cardiac events at baseline (revascularization [n=169], myocardial infarction [n= 88], stroke [n=156], and congestive heart failure [n=166]). The final analytic sample was predominantly White/Caucasian (84.1%), slightly more than half were female (54.2%), and approximately one-third were classified as obese. Sleep measures were obtained using in-home polysomnography (PSG). Average caffeine intake computed as the mean number of cups of tea/coffee and cans of soda consumed per regular day and the night preceding the PSG was 1.62 ± 1.73. All-cause mortality was identified through follow-up interviews, annual questionnaires, and linkage with the Social Security Administration Death Master File (mortality rate = 19.7%). Binary logistic regression models were run for each sleep measure, adjusted for age and sex. Results Wake After Sleep Onset (WASO) was significantly associated with mortality (β= 0.003, 95% CI: 0.000–0.006), indicating that longer nocturnal wakefulness was linked to elevated mortality risk. Sleep efficiency showed a protective effect (β= -0.015 [-0.028 to -0.001]), suggesting that more consolidated sleep was associated with lower mortality. Sleep latency, Epworth Sleepiness Scale, and total sleep time did not exhibit significant independent associations with mortality. A significant negative interaction was observed between WASO and the highest intake category (≥6 cups/day) (β= -0.011 [-0.022 to -0.001]), indicating that the WASO-mortality association differed across caffeine groups. In contrast, sleep latency exhibited a positive interaction with ≥6 cups/day (β= 0.018 [0.001, 0.035]), suggesting heightened mortality risk at longer sleep latencies within this high-intake group. Conclusion Elevated WASO and prolonged sleep latency showed differential mortality risk across high-intake caffeine groups. These findings highlight the strategic importance of considering caffeine exposure when evaluating sleep-related predictors of long-term mortality. Support (if any)