Effects of precise determination of body mass index in patients with lower limb amputation

Background: About 7000 limb amputation is done in Hungary per year. According to the database of “Gyógyinfok” approximately 65 amputations can be expected for 100,000 inhabitants per year in Hungary, 57 of them is lower limb amputation. The most frequent cause of lower limb amputation is infection caused by poor peripheral circulation. The group of diabetic patients is a specific high-risk group. Due to the neuropathy patients do not sense the injuries on the leg, and also damages the blood vessels. Poor sensation and circulation make the cure of infections more difficult. Risk factors of peripheral vascular disease are diabetes, high blood pressure, high cholesterol level and smoking. Exact determination of body weight is very important to the preparation of appropriate prosthesis.

Aims: To determine the total body weight and the body mass index (BMI) of amputees, methodology that can be used in practice.

Methods: Calculation of total body weight from measured or estimated body weight and body height, determination of BMI that is needed to (nutritional) rehabilitation.

Subjects: adult lower limb amputees. Calculation of BMI from measured body weight and body height without correction is often an incorrectly applied method in the practice. Authors represent the distorting results of this incorrect practice in 49 (31 males and 18 females) unilateral amputees and in 10 (8 male and 2 female) both legs (femur) amputees. In the absence of both lower limbs estimation of the body height from the length of the ulna, considering age and sex, is a reliable method. We can include people in the screening who were previously dropped out or “produced” false results.

Results: according to the BMI values calculated from the “original” data only one third of these patients belonged to the optimal category and one third have BMI≥30.0. Considering the weight of the missing limb 45 patients belonged to other category.

Conclusions: Authors are aware of the limited usability of BMI (especially regarding people older 65), however, draw attention to the incorrect classification that results form false – routine – use and the opportunities for practical use.