Use of Anthropometric Indices to Identify Appropriate Cuff Shapes for Blood Pressure Measurement: Normative Data for Adults

BACKGROUND: Published evidence has shown that troncoconical cuffs improve blood pressure measurement accuracy in subjects with obesity. However, the exact shape of these cuffs according to arm size is unknown. The aim of the present study was to investigate the anthropometric characteristics of the arm in a large population in order to identify the appropriate shape of the cuff for each arm. METHODS: The anthropometric characteristics were assessed in 729 adults with middle arm circumference ranging from 16 to 55 cm. Subjects were divided into classes of arm size and the upper-arm slant angle of the truncated cone was calculated. RESULTS: In the whole sample, the conical shape of the arm progressively increased with increasing arm circumference (r = 0.61, P < 0.0001). Independent predictors of the conical shape were arm circumference (P < 0.0001) and length (negative relationship, P < 0.0001), and female sex (P = 0.048). Women had a slightly more pronounced conical shape of the arm (P = 0.007) than men. However, the decrease in the slant angle across the arm-size classes showed a similar trend in men and women, and in a 2-way analysis of variance there was no interactive effect between arm size and sex on the conical shape of the arm (P = 0.11). On the basis of the slant angle calculated in each arm-size class, we provide dimensions for bladders that would appropriately fit the arm within a given circumference range. CONCLUSIONS: To properly fit the upper arm in patients with obesity cuffs should have a troncoconical shape. This study provides reference data according to arm size.