LAUSR

Objectives: Sleep affects nocturnal blood pressure (NBP) stability with unknown mechanism in hypertension. Connections between gut microbes and hypertension have been established. Lipopolysaccharide binding protein (LBP), a marker for gut permeability, disrupts sleep architecture and parasympathetic and sympathetic balance. We hypothesized alteration in serum LBP may influence NBP variability (NBPV). Methods: This is a cross-sectional study. Hypertensive men without sleep apnea confirmed by polysomnography were recruited. 24 h ambulatory BP monitoring data was applied for BPV evaluation by BP standard deviation (SD) and coefficient of variability (CV). Serum LBP was measured using ELISA method. Subjects were divided into two groups via sleep stage 1 percentage (N1%) and LBP median. Results: 39 hypertensive men were recruited, with mean age 42.46 years. Subjects with higher LBP showed significantly prolonged N1% than did those with lower LBP. Compared to shorter N1% group, nocturnal diastolic BPSD and CV, nocturnal systolic BPCV, and nocturnal mean arterial pressure SD and CV showed significant increase in prolonged N1% group (P < 0.05 for all). Also, nocturnal systolic and diastolic BPSD and CV, mean arterial pressure SD and CV significantly increased in higher LBP group than did lower LBP group (P < 0.05 for all). Significant positive correlations were observed between serum LBP and nocturnal SBPSD (r = 0.464, p = 0.004), DBPSD (r = 0.394, p = 0.0130), mean arterial pressure SD (r = 0.466, p = 0.003), SBPCV (r = 0.406, p = 0.013), DBPCV (r = 0.401, p = 0.013) and mean arterial pressure CV (r = 0.426, p = 0.008) and remained significant after adjusting confounding factors. Conclusion: prolonged N1% might aggravate NBPV. Serum LBP might predict NBPV in middle-aged hypertensive men.