Aim: To determine whether systolic and diastolic blood pressure (BP) means, during ambulatory BP monitoring (ABPM), are more strongly correlated with microvascular complications and echocardiographic structural alterations than night-time/daytime (N/D) BP ratio.
Methods: A cross-sectional study was conducted in 270 Type 2 diabetes mellitus (DM) outpatients who underwent clinical and laboratory investigations, urinary albumin excretion rate (UAER) determination, echocardiography, office and 24-h ABPM (Spacelabs 90207).
Results: UAER, after multivariate adjustments, was associated with office BP (systolic: R(2)(a) 0.162, P < 0.001; diastolic: R(2)(a) 0.124, P < 0.001) and ABPM (24-h systolic: R(2)(a) 0.195, P < 0.001; 24-h diastolic: R(2)(a) 0.197, P < 0.001) but not with N/D BP ratios (systolic: R(2)(a) 0.062, P = 0.080; diastolic: R(2)(a) 0.063, P = 0.069). Similar results were observed for echocardiographic parameters. The presence of retinopathy was associated only with night-time BP values [systolic means: odds ratio (OR) 1.13, 95% confidence interval (CI) 1.03-1.24 and diastolic means: OR 1.21, CI 1.04-1.40 and N/D diastolic BP ratio > 0.90, OR 3.21, CI 1.65-6.25].
Conclusions: UAER and echocardiographic structural alterations had more consistent correlations of a greater magnitude with systolic BP means than with N/D BP ratios. The nocturnal BP values appear to be more relevant for diabetic retinopathy. BP measurement in patients with Type 2 DM should take into account the 24-h period rather than focusing on a specific time span of BP homeostasis.