Masked nocturnal hypertension as a result of high prevalence of non-dippers among apparently well-controlled hypertensive patients with type 2 diabetes mellitus: data from a prospective study.

BACKGROUND: Ambulatory blood pressure monitoring (ABPM) in patients with diabetes mellitus (DM) and hypertension (HTN) show the dipping patterns, identify masked uncontrolled hypertension (MUCH), and demonstrate the effectiveness of the blood pressure (BP) treatment. MUCH is associated with a two-fold higher risk of adverse events. Prevalence in patients with DM is between 13.3 and 66.4%. Our study aims to investigate the prevalence of MUCH and the BP patterns in a population of apparently well-controlled hypertensive patients with type 2 DM (T2DM). A second aspect was the assessment of the effectiveness of antihypertensive treatment.

METHODS: One hundred and sixty-three consecutively treated hypertensive patients with T2DM and an office BP between 130-139 and 80-89 mmHg performed a 24 h ABPM. The circadian BP variation, the presence of MUCH, and the correlations with the treatment were assessed.

RESULTS: There were 75 dippers (46.02%), 77 non-dippers (47.23%), 4 reverse dippers (2.45%), and 7 extreme dippers (4.30%). Eighty-one patients (77 non-dippers + 4 reverse dippers; 49.7%) had isolated nocturnal MUCH according to the mean night ABPM criteria. Dippers and extreme dippers (75 dippers + 7 extreme dippers; 51.3%) did not have any MUCH criteria. The patients took, on an average, 3 antihypertensive drugs with no difference between those with controlled HTN and the isolated nocturnal MUCH group. Significant factors associated with isolated nocturnal MUCH and a non-dipping BP pattern included age > 65 years (OR = 1.9), DM duration > 10 years (OR = 1.4), HTN duration > 6.5 years (OR = 1.2), obesity (OR = 1.6), and cardiovascular comorbidities (OR = 1.4).

CONCLUSIONS: The current study shows that half of the treated hypertensive patients with T2DM and office clinical normotension are non-dippers or reverse dippers. They experience isolated nocturnal MUCH due to their elevated nocturnal BP values, which comply with the actual definition of masked nocturnal hypertension. Bedtime chronotherapy in those patients could be linked to better effectiveness of antihypertensive treatment during the night with the important goal of reducing cardiovascular and cerebrovascular adverse events. ABPM should be performed in hypertensive patients with DM for better risk stratification and more effective control of HTN.