Heart rate variability and its postural adaptation to postural changes in HIV cART-treated patients

Aim. The aim of this study was to evaluate presence of an autonomic dysfunction in HIV patients compared to healthy controls and its relationships with body fat and Protease Inhibitors (PI) treatment. Methods. Twenty-for HIV cART-treated, non-hypertensive and non-smoker patients (M/F 19/5; 48±6 yrs; BMI 24±4 kg/m2) and 24 healthy controls matched for gender, age and anthropometric features (M/F 13/7; 51±12 yrs; BMI 24±3 kg/m2) were recruited. Heart rate variability (HRV) indexes of parasympathetic tone in time (RMSSD, pNN50) frequency (High Frequency [HF] and Low Frequency [LF] in absolute and normalized units [nu]) domains, and a HRV index of sympathovagal balance (LF/HF ratio), and complexity (α1DFA) were calculated in basal condition both in supine and standing position for 5 min each, by an ECG recording. Results. In supine position HIV patients have a lower parasympathetic tone respect to healthy controls (HR: 72±9 vs 64±10 bpm, p<0.05; LnRMSSD: 1.27±0.21 vs 1.45±0.25 ms, p<0.05; LnpNN50: 0.47±0.59 vs 0.73±0.69 %, p<0.05; LnHF: 1.49±0.20 vs 1.56±0.25 ms2). The postural change in standing position significantly improved the α1DFA of HIV patients (1.27±0.21 vs 1.51±0.15, p<0.05), significantly reduced LnpNN50 (0.73±0.69 vs 0.49±0.63, p<0.05) and improved α1DFA (1.11±0.28 vs 1.27±0.32) in healthy controls. LFnu and HFnu did not show significant difference in basal condition for HIV and control group, and both react significantly to the postural change. LF/HF showed an increased activation in the HIV group, with significant interaction between position and pathology (p=0.0476). In supine position LnHF power significantly correlated with the superficial fat and α1DFA significantly correlated with visceral fat. Total fat mass and trunk fat mass were significantly higher in patients taking PI. Conclusions. HIV HAART-treated patients showed and impaired parasympathetic controls respect to healthy controls, which is more evident in the postural change. The PI-treatment was related to superficial and visceral fat, probably connected to an excess of body fat.