Background: Hypertension is a major risk factor of coronary artery disease therefore, an accurate diagnosis is required. For an accurate blood pressure measurement, an appropriately sized arm cuff should be used. This study attempted to examine the problems associated with misdiagnosis of hypertension caused by using a regular size adult arm cuff in overweight patients.
Methods: We selected 201 overweight patients who visited the obesity clinic at an university hospital. Blood pressure was measured with both a regular adult cuff and a large adult cuff according to the 1999 WHO/ISH Hypertension Guidelines. These data were analysed using paired t-test and Pearson’s correlation.
Results: 1) The average age was 48.0 years, the average BMI was 27.4 kg/m2 and the average arm circumference was 29.0 cm. 2) Significant association was found between arm circumference and BMI. 3) For men, mean differences of systolic and diastolic blood pressure were 4.8 mmHg and 3.6 mmHg. For women, the results were 5.5 mmHg and 3.3 mmHg. 4) We categorized BMI into three groups, 23≤ BMI<25, 25≤BMI<30 and BMI≥30 kg/m². greater discrepancy in blood pressure was noted between the two cuffs in correlation to increasing BMI. 5) When an inappropriate sized cuff was used 20∼25% of the subjects were misclassified.
Conclusion: We recommend the use of an appropriate size of arm cuff to accurately measure blood pressure. Application of a large size adult arm cuff should be considered in patients with BMI ≥25kg/ ㎡especially when the arm circumference is greater than 30 cm.

Keywords: Overweight, Blood Pressure, Cuff, Measurement, Arm circumference