We aimed to investigate whether subjective sleep disturbance during overnight blood pressure (BP) monitoring results in higher night-time BP levels, and whether this affects the correlation between nocturnal BP and hypertensive target-organ damage.
In 203 untreated hypertensive patients (104 men) without a history of cardiovascular disease, with a mean age of 52.1 ± 12.5 years, and with office BP levels of 170 ± 23/104 ± 12 mmHg, we performed duplicate ambulatory BP monitoring (ABPM), assessed subjective sleep quality using the Groningen Sleep Quality Scale, and obtained information on hypertension-related cardiac damage by echocardiography.
Overnight BP monitoring disturbed sleep significantly, but habituation to nocturnal measurements occurred on the second ABPM. Participants whose subjective sleep quality was less than usual on either ABPM did not have higher nocturnal BP levels than those who slept similar to usual (P > 0.05). When comparing the nocturnal BP levels between the first and second ABPM, we found that participants whose subjective sleep quality was less on the second ABPM had significantly higher pressure levels and a smaller BP dip than participants with a similar sleep quality for both ABPMs (P < 0.05). Accordingly, the correlations between the nocturnal BP and cardiac damage tended to be weaker based on the ABPM with the lowest sleep quality.
Subjectively assessed sleep disturbance during overnight BP monitoring increases the nocturnal BP level and potentially attenuates the correlation with hypertension-related cardiac damage, even though habituation to overnight BP monitoring occurs.