Isolated nocturnal hypertension and its association with sleep duration and quality

Nocturnal blood pressure (BP) is associated with cardiovascular events independently of daytime BP. Isolated nocturnal hypertension (INH), defined by elevated nocturnal BP with normal daytime BP, increases cardiovascular risk. However, its underlying; mechanisms remain unclear. This study aims to assess the association between nocturnal BP and INH with sleep quality and duration. This cross-sectional study analyzed 2297 individuals (57% women, 49.5 ± 15 years) using ambulatory blood pressure monitoring (ABPM) to evaluate the relationship between INH and sleep quality. Individuals with secondary hypertension and sleep disorders were excluded. Sleep quality and duration were primarily assessed using the Pittsburgh Sleep Quality Index (PSQI) and the STOP-BANG score. Results showed that 64% had poor sleep quality (PSQI > 5), and 18.7% slept less than 6 h. No significant differences in sleep quality were found among hypertensive phenotypes. INH was associated with older age, diabetes, and waist circumference; however, sleep quality and duration were not independent factors in its development. Nonetheless, nocturnal BP exhibited a slight association with sleep quality and disturbances of mild clinical significance.