Cuff size influences blood pressure measurement in obese children and adolescents.

Introduction: Recently, we established that a group of obese children and adolescents had a higher blood pressure (BP) than a healthy control group. In the present study, we investigate whether the higher BP in the obese group was influenced by BP cuff sizes. Methods: A total of 104 obese patients aged 10-18 years were compared with 50 controls. BP was measured with a validated oscillometric device using an appropriate cuff size depending on each person's arm circumferences (AC) according to the manufacturer's recommendation; small (AC < 23 cm), medium (23 <= AC <= 32 cm) and large (AC >= 32 cm). Results: Cuff sizes had a significant impact on BP measurements. Despite the influence of cuff size, multiple regression analyses revealed that systolic BP was 6.8 mmHg higher and diastolic BP 3.2 mmHg higher in the obese group than in the control group. A step function, i.e. a sudden fall in BP, was seen at the point of switching from small to medium cuff size in the control group, which suggests that systolic BP was overestimated when using small cuff size and underestimated when using medium cuff size in subjects with an AC near 23 cm. Conclusions: BP was higher in the obese group than in the control group although BP was influenced by BP cuff sizes.