Role of ambulatory blood pressure monitoring in hypertension and diabetes

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 clini-cal practice.

Objectives: To quantify abnormal ABP patterns and their associations with diabetic complications, and to assess the reliabil-ity 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 hyper-tension. Non-dipping and nocturnal systolic hypertension (SHT) were prevalent in 31(55%) and 32(57%) patients, respec-tively. 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 complica-tions. 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 known 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.

Comparisons of automated blood pressures in a primary health care setting with self-measurements at the office and at home using the Omron i-C10 device

Objective

We aimed to compare blood pressure (BP) levels recorded using the semiautomatic oscillometric Omron i-C10 BP device in patients with or without hypertension in three different settings: (a) when used by a doctor or a nurse at the office (OBP); (b) when used for self-measurement by the patient at the office (SMOBP); and (c) when used for 7 consecutive days at home (HBP).

Materials and methods

A total of 247 individuals were invited to participate, but 78 of these individuals declined and a further seven were excluded, leaving a final cohort of 162 participants.

Results

The mean OBP was higher than HBP (difference 8.1±14/3.1±8.8 mmHg, P<0.0001) and so was SMOBP compared with HBP (difference 7.0±13/4.2±7.3 mmHg, P<0.0001). Sixteen participants (9.9%) had at least 10 mmHg higher systolic SMOBP than OBP and 28 (17%) participants had at least 10 mmHg lower systolic SMOBP than OBP. Participants who were current smokers had a larger mean difference between systolic OBP and SMOBP than nonsmokers (OBP−SMOBP in smokers: 6.6±9.4 mmHg, OBP−SMOBP in nonsmokers: 0.5±9.2 mmHg, P=0.011 between groups).

Conclusion

Self-measurement of BP in the office does not preclude an increase in BP when levels in the individual patients are compared with HBP using the same equipment. Thus, SMOBP with a semiautomatic device does not lead to a reduction in the white-coat effect in the same manner as fully automatic devices.