Method for estimating body weight in persons with lower-limb amputation and its implication for their nutritional assessment.

BACKGROUND Body weight is a good indicator of a person's size and is widely used in clinical assessment. However, health-status assessment based on observed body weight (W(O)) is incorrect for persons with limb amputation. OBJECTIVES The objectives were 1) to develop a more accurate and generalized method for estimating body weight in persons with limb amputation, 2) to determine whether corrected body weight can be used to assess nutritional status in persons with limb amputation, and 3) to test the validity of the estimation by using empirical data. DESIGN Anthropometric data were collected from men from Calcutta and adjoining areas with unilateral lower-extremity amputation (n = 102). Mathematic formulas were developed for determining estimated body weight (W(E)) and body mass index (BMI) calculated from both W(O) and W(E) (ie, BMI(O) and BMI(E), respectively). We assessed nutritional status by using BMI(O) and BMI(E) and tested the validity of each by considering the result of nutritional assessment from midupper arm circumference as the gold standard. We also compared the nutritional status results for the subjects with limb amputation with those for a similar sample size of healthy control subjects. RESULTS BMI(E) had a stronger association with midupper arm circumference and a higher efficiency (ie, proportion of correct results given by any test method) than did BMI(O). Moreover, the results obtained with BMI(E) were similar to those obtained with BMI in healthy control subjects. However, the nutritional assessments made with BMI(O) and BMI(E) did not differ significantly from one another. CONCLUSION For persons with limb amputation, W(E) provides a better basis for appropriate nutritional evaluation than does W(O).