Impaired nocturnal blood pressure dipping in patients with type 2 diabetes mellitus with microvascular complications

Abstract

Hypertension is a common comorbidity of type 2 diabetes mellitus (T2DM). Both conditions are associated with an increased cardiovascular risk, which is reduced by tight blood pressure (BP) and glycemic control. However, non-dipping BP status continues to be an enduring cardiovascular risk factor in T2DM. This study aimed to investigate the association between microvascular complications of diabetes and nocturnal dipping of BP. We compared 13 type 2 diabetic patients with (DM+) and 67 diabetic patients without (DM−) manifest microvascular disease. BP dipping status was assessed from 24-hour ambulatory BP measurements. DM+ patients were older 60.3 ± 8.7 years vs. 58.3 ± 10.4 years ( P = 0.47). There was no significant difference between the two groups in diabetes control, clinical systolic BP and clinical diastolic BP. Dyslipidemia was significantly more present in DM+, 84.7% vs. 47.8% ( P = 0.015). DM+ patients had significantly higher daytime and 24-hour mean SBP than DM− patients with P = 0.02 and 0.023 respectively. Pulse pressure was significantly ( P = 0.03) higher in DM+. The nocturnal blood pressure profile in DM+ was “non-dipper” and “reverse dipper” respectively in 69% and 15% of patients versus 27% and 11% in DM− ( P = 0.003; P = 0.026). Our findings once again highlighted the importance of ambulatory BP monitoring and targeted antihypertensive therapy directed toward to restore normal circadian BP in patients with T2DM.