Factors associated with inspiratory muscle weakness in patients with HIV-1

Abstract

Background: the impact of human immunodeficiency virus type 1 (HIV-1) on lung function is well known and associated with a reduction in pulmonary ventilation. Moreover, the use of highly active antiretroviral therapy has been associated with mitochondrial dysfunction and decreased muscle strength. However, there is scarce information about the factors associated with inspiratory muscle weakness in these patients.

Objective: the purpose of the present study was to investigate the factors associated with inspiratory muscle weakness in patients with HIV-1.

Methods: two-hundred fifty seven patients with HIV-1 were screened and categorized into two groups: (1) IMW+ (n=142) and (2) IMW- (n=115). Lung function (FEV1, FVC and FEV1/FVC), maximum inspiratory pressure, distance on the six-minute walk test and CD4 cell count were assessed.

Results: the mean duration of HIV infection was similar in the two groups. The following variables were significantly different between groups: mean duration of highly active antiretroviral therapy (81±12 in IMW+ versus 38±13 months in IMW-; p=0.01), and CD4 cell count (327±88 in IMW+ versus 637±97cells/mm(3) in IMW-; p=0.02). IMW+ presented reduced lung function (FEV1, FVC, FEV1/FVC).

Conclusion: patients with IMW+ had lower distance on the six-minute walk test in comparison to the IMW- group. The duration of highly active antiretroviral therapy, distance traveled on the 6MWT and CD4 count were determinants of IMW in patients with HIV.

Keywords: Diaphragm muscle; Exercise tolerance, highly active antiretroviral therapy; Inflammatory response; Inspiratory muscle; Lung function.

Fig. 1

The CONSORT-flow diagram of patients in the study.

Fig. 2

Scattergram of the association between maximum inspiratory pressure (MIP) and CD4 count (cells/mm³) for all subjects. Open circles represent patients without inspiratory muscle weakness. Filled circles represent patients with inspiratory muscle weakness. r = Pearson's correlation coefficient.