US demographic trends in mid-arm circumference and recommended blood pressure cuffs: 1988-2002

Mid-arm circumference (AC) measurement is a prerequisite for the selection of properly sized blood pressure (BP) cuffs and accurate BP readings. This study examined trends in the frequency distribution of mid-AC and corresponding recommended BP cuff sizes using National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 1999-2002 data. Both surveys used a complex sample design to obtain nationally representative samples of the civilian noninstitutionalized US population. The sample consisted of 7453 men and 8372 women from NHANES III and 4295 men and 4838 women from NHANES 1999-2002. Mean mid-AC (cm) and associated American Heart Association-defined cuff sizes were assessed. Variables were analysed by gender, age, race/ethnicity, and by hypertension or diabetic co-morbidity. Mid-AC increased significantly between surveys for all age groups; the greatest increase in mid-AC occurred in the 20-39 year age group. Data from NHANES 1992-2002 show that among nonHispanic white and nonHispanic black men aged 20-59 years, the mean mid-AC was >34 cm. Among NHB women aged 40 years and above, the mean mid-AC was greater than or equal to 34 cm. In all, 42% of all men and 26% of all women aged 40-59 years required large BP cuffs. In all, 39% of individuals classified as hypertensive and 47% of self-reported diabetics required a BP cuff greater than the standard adult size. In conclusion, mean mid-AC has increased across many demographic subgroups in the US with implications for the accuracy of BP measurement in clinical practice.