Ambulatory Blood Pressure Monitoring in Type 2 Diabetes Mellitus: A Cross-sectional Study

Background: Ambulatory blood pressure (ABP) monitoring in type 2 diabetes (T2DM) is not yet routine in clinical practice. Objectives: To quantify abnormal ABP patterns and their associations with diabetic complications, and to assess the reliability of office blood pressure (OBP) for assessing BP in T2DM. Methods: In a cross-sectional study, eligible patients with T2DM underwent OBP and 24- hour ABP measurements under standardized conditions and screening for diabetic complications. Results: 56 patients (mean age 67 +/- 10 years, males 50%) completed assessment. 43(73%) had a known history of hypertension. Non-dipping and nocturnal systolic hypertension (SHT) were prevalent in 31(55%) and 32(57%) patients, respectively. 16(29%) demonstrated masked phenomenon, but only three (7%) demonstrated white coat effect. Nocturnal SHT had a significant association with composite microvascular complications independent of daytime systolic BP control (adjusted odds ratio (OR) 1.72(CI 1.41-4.25). There was no association between other abnormal ABP patterns and diabetic complications. The sensitivity and specificity of OBP for diagnosing HT or assessing BP control was 59% and 68% respectively. The positive and negative predictive values were 74% and 52% respectively. Conclusion: Non-dipping, reverse dipping, nocturnal SHT and masked phenomenon are highly prevalent in patients with T2DM with or without a blown history of hypertension. Compared with non-dipping, nocturnal SHT may be a stronger predictor of end organ damage. The reliability of OBP for assessing BP in T2DM is only modest. Patients with T2DM are likely to benefit from routine ABP monitoring.