Decline in Locomotor Functions over Time in HIV-infected Patients

Objectives: To assess changes in locomotor function in HIV-infected patients and to evaluate the determinants of variations in lower limb muscle performance.

Design: Longitudinal study within the ANRS CO3 Aquitaine Cohort.

Methods: Standardized locomotor tests, including global functional capacity [6-min walk distance (6MWD)] and lower limb muscle performance tests [five times sit-to-stand (5STS) test], were performed in HIV-infected adults at baseline and 2-year follow-up. Evolution of performances and determinants of 5STS time were studied in linear mixed-effects models.

Results: At baseline (354 patients, 90% on antiretroviral treatment), median 5STS time was 9.8 s and 6MWD 549 m. Poorer performances were associated with falls, reported by 12% of 178 patients at follow-up. Estimated mean deterioration was +0.24 s/year (P < 10) for 5STS time and -11 m/year (P < 10) for 6MWD. In multivariable analyses, older age was associated with worse baseline 5STS time (+0.47 s/10-year age increase; P = 10), but not with further deterioration. Deterioration was greater in prior injecting drug users compared to others (difference in slope +0.62 s/year; P = 0.04). 5STS time at any time point was worse in patients with history of cerebral AIDS conditions (+2.47 s; P < 10) and diabetes (+0.95 s; P = 0.02) than in others. No significant associations were found for antiretroviral treatment type, viral load or CD4 cell count.

Conclusion: Compared to published data from healthy persons of similar age, baseline 5STS time and 6MWD were poorer in HIV-infected adults and associated with subsequent falls. Test performances deteriorated further over time. Age, diabetes, neurologic complications and injection drug use, rather than virologic factors, contribute to variations in lower limb muscle performance.