Influence of traumatic lower-limb amputation on physical activity, body composition and cardiometabolic risks: a descriptive preliminary study

Introduction: Following traumatic lower-limb amputation (LLA), humans are predisposed to numerous unfavourable changes in health, including the development of secondary chronic health conditions, including metabolic disorders and cardiovascular disease.

Objective: To determine within and between group differences in cardiometabolic component risks, body composition and physical activity (PA) in individuals with traumatic unilateral and bilateral LLA, compared to non-injured controls.

Design: Prospective observational cohort study.

Setting: A military complex trauma rehabilitation centre.

Participants: Sixteen males with traumatic LLA (8 unilateral, mean age 30±5yrs and 8 bilateral, mean age 29±3yrs). Thirteen active age-matched males with no LLA (28±5yrs) acted as controls and performed habitual activities of daily living.

Intervention: Participants with LLA attended two 4-week periods of in-patient rehabilitation, separated by two 6-week periods of home-based recovery.

Main Outcome Measures: Venous blood samples were taken prior to and following a 75g oral glucose load, for determination of biomarkers, including insulin and glucose, at baseline and 20-weeks. Body composition (dual X-ray absorptiometry) was measured at baseline, 10 and 20-weeks. Daily PA was recorded using a triaxial accelerometer for 7-days during in-patient rehabilitation and whilst at home. Energy expenditure was estimated using population-specific equations.

Results: Bilateral-LLA demonstrated more unfavourable mean body composition values, lower PA and increased cardiometabolic health risk compared to control. Cardiometabolic syndrome was identified in 63% of bilateral-LLA. No statistically significant differences in cardiometabolic component risk factors, body composition and estimated daily PA were reported between unilateral-LLA and control (p>0.05). Whilst at home, mean PA counts.day-1 reduced by 17% (p=0.018) and 42% (p=0.001) in the unilateral and bilateral-LLA groups, respectively.

Conclusions: Despite extensive in-patient rehabilitation, cardiometabolic component risks are elevated in bilateral-LLA, but are comparable between unilateral-LLA and active non-injured controls. Innovative strategies that improve/support the long-term PA and cardiometabolic health of severely injured bilateral-LLA are warranted.