New insights into the effects of irisin levels in HIV-infected subjects: correlation with adiposity, fat-free mass, and strength parameters

ABSTRACT Objective Patients infected with the human immunodeficiency virus (HIV) have an increased risk of metabolic disorders and alterations on irisin levels. Therefore, the purpose of the current investigation was to quantify the circulating irisin concentration in HIV-infected subjects under highly active antiretroviral therapy and to determine possible correlations between irisin levels with fat mass, fat-free mass, body mass index (BMI), and muscle strength. Subjects and methods Cross-sectional study of 10 men (36.7 ± 11.3 years) and 10 women (42.5 ± 10.3 years) infected with HIV, recruited from the Specialized Service Center in the State Center of Reference for High and Medium Complexity. Blood samples were collected to determine plasma irisin levels, glucose, HDL, total cholesterol, triglycerides, and LDL. Body composition (fat mass, fat-free mass) and anthropometrics (body mass index; BMI) were measured by bioelectrical impedance. Muscle strength was assessed using a mechanic hand dynamometer and one maximum repetition tests. Results Irisin levels correlated positively with fat mass (r = 0.67; p = 0.001) and BMI (r = 0.48; p = 0.036). In contrast, there was an inverse correlation between irisin levels and fat-free mass (r = -0.41; p = 0.008) and five strength parameters: right hand grip (r = -0.46; p = 0.044); left hand grip (r = -0.50; p = 0.027), relative hand grip (r = -0.79; p = 0.001), bench press (r = -0.58; p = 0.009), leg press (r = -0.40; p = 0.085), and biceps curl (r = -0.059; p = 0.009). Conclusion Irisin levels correlated positively with body fat and negatively with fat-free mass and strength parameters in HIV-infected patients. Female patients infected with HIV receiving highly active antiretroviral therapy have higher levels of irisin compared with men in a similar circumstance.

Cinética de lactato de sujeitos HIV+ após 20 semanas de treinamento físico combinado / Lactate kinetics of hiv+ subjects after 20 weeks of combined physical training

O objetivo do presente estudo foi analisar os efeitos do treinamento físico combinado (TFC) sobre a cinética de lactato sanguíneo (LS) e a aptidão cardiorrespiratória de pacientes HIV+. Antes e após 20 semanas de TFC, 10 pacientes HIV+ (5 homens + 5 mulheres; 44,7±9,0 anos de idade) em tratamento pela HAART (Terapia Antirretroviral Altamente Ativa) foram avaliados quanto a cinética do LS (LS; mmol/L) durante o teste ergoespirométrico (ERGO) na esteira (para determinação do VO2max [ml.kg-1.min-1]. O TFC consistiu de 40min de exercícios de força seguidos de 30min de caminhada (3x/semana; duração total = 20 semanas). Os níveis de LS foram determinados durante a ERGO em 6 diferentes condições: repouso, 4min de exercício e imediatamente após o exercício (fadiga) (isto é, M0, M1, M2, respectivamente) bem como após os minutos, 1, 4, e 6 durante a recuperação passiva (isto é, R0, R1, e R2 respectivamente). A cinética de LS foi alterada durante a recuperação passiva (principalmente em R1 e R2), denotando que a remoção do LS foi melhorada nesses períodos (LS [pré-TFC/post-TFC]: M0: 2,9±0,6/2,3±0,5; M1: 4,7±1,3/3,3±0,8; M2: 6,3±2,0/8,9±1,9; R0: 9,3±2,3/8,5±2,5; R1: 10,1±2,2/ 7,6±2,0; R2: 9,4±2,5/7,5±1,8). Os valores de VO2max também foram melhorados após TFC (VO2max [pré-TFC/post-TFC]: 29,0±7,1/41,4±7,2). Os resultados denotaram, hipoteticamente, aumento da metabolização intra-tecido de LS no músculo e/ou fígado durante a recuperação passiva, os quais podem ser associados ao VO2max superior pós-TFC. A melhora na remoção do LS em repouso é uma importante ocorrência no que tange à restauração do metabolismo ao seu estado de normalidade.

The purpose of the present study was to verify the effects of combined physical training (CPT) on blood lactate (BL) kinetics as well as the cardiorespiratory aptitude of HIV+ patients. Before and after 20 weeks of CPT, 10 HIV+ patients (5 men + 5 women; 44.7±9.0 years old) under HAART (Highly Active Antiretroviral Therapy) treatment were evaluated for BL (LAC; mmol/L) kinetics during ergospirometric test (ERGO) on the treadmill (to determine VO2max [ml.kg-1.min-1]). The CPT was composed by 40min of resistance exercise followed by 30min of walking exercise (3x/week; total duration=20 weeks). The BL levels were determined at 6 different times during ERGO: at rest, 4min of exercise and immediately after exercise (fatigue) (i.e., M0, M1 and M2, respectively) as well as at the minutes 1, 4, and 6 during passive recovery (i.e., R0, R1, and R2, respectively). The BL kinetics was altered during passive recovery (R1 and R2 times), denoting that the BL disappearance was enhanced in this particular stage (BL [pre-CPT/post-CPT]: M0: 2.9±0.6/2.3±0.5; M1: 4.7±1.3/3.3±0.8; M2: 6.3±2.0/8.9±1.9; R0: 9.3±2.3/8.5±2.5; R1: 10.1±2.2/7.6±2.0; R2: 9.4±2.5/7.5±1.8). The VO2max values were also improved after CPT (VO2max [pre-CPT/post-CPT]: 29.0±7.1/41.4±7.2). The findings show that occurred, hypothetically, an increase of intra-tissue metabolization of BL in the muscle and/or liver of the HIV+ patients during passive recovery, which can be strongly associated to higher VO2máx values post-CPT. The enhanced BL disappearance at rest is an important metabolic occurrence in order to restore the organic systems to their normal states.

Efeitos do treinamento físico combinado realizado na intensidade do limiar anaeróbio sobre a composição corporal e sistema imune de sujeitos com HIV / Effects of combined physical training performed at anaerobic threshold intensity on the body composition and immune system of subjects with HIV

O objetivo do presente estudo foi avaliar os efeitos do treinamento físico combinado (TC) de 16 semanas sobre a composição corporal e o sistema imune, bem como velocidade e inclinação da esteira rolante obtidos na intensidade do limiar anaeróbio (LAn) em indivíduos com HIV. Participaram do estudo10 indivíduos, sendo 5 homens e 5 mulheres (44,7±8,97 anos; Tempo de Terapia Antirretroviral Altamente Ativa [HAART]: 8,89±6,21 anos; Tempo Portador: 9,14±5,37 anos; Carga Viral: indetectável), os quais foram submetidos a 16 semanas de TC. Os dados foram expressos como média±desvio padrão (p≤0,05). Foram observadas melhoras em relação à massa magra relativa (MMR; %) (Pré: 45,5 [32,8 – 63,0]; Pós: 47,9 [33,7 – 66,3]) e massa magra absoluta (MMA; %) (Pré: 67,0 [55,0 – 75,2]; Pós: 68,8 [56,6 – 75,7]). O índice de massa corporal (IMC; kg/m2 ) não sofreu alteração pós TC (Pré: 24,2 [21,3 – 28,7]; Pós: 23,7 [21,8 – 30,0]). A carga viral permaneceu indetectável, sendo que houve aumento no número delinfócitos T CD4+ (Pré: 529 [426,0 – 900,0]; Pós: 694 [381,0 – 1175,0]). Além disso, houve melhora nosvalores de VO2 (ml.kg.min-1) (Pré: 16,2±4,9; Pós: 21,2±3,2), velocidade (km/h) (Pré: 5,7±0,9; Pós: 6,3±1,0) e inclinação (%) (Pré: 3,8±1,2; Pós: 4,9±1,0) obtidos na intensidade do LAn. Conclui-se que oTC melhorou o VO2 na intensidade do LAn e induziu a aumentos de MMR e de MMA. Finalmente, o TC promoveu aumento no número de linfócitos T CD4+, sem efeito negativo sobre a carga viral. Estes resultados são de extrema importância para a qualidade de vida dos pacientes com HIV.

The aim of the present study was to evaluate the effects of combined physical training (CT) on body composition and immune system, as well as, speed and inclination obtained at the intensity of anaerobic threshold (AT) in subjects with HIV. Ten individuals, 5 men and 5 women, united in a single group (44.7±8.97 years of age; Highly Active Antiretroviral Therapy [HAART] time: 8.89±6.21 years; HIV-Bearer Time: 9.14±5.37 years; Viral Load: undetectable), were subjected to 16 weeks of CT. Data were expressed as mean±standard deviation (p ≤ 0.05). Both relative lean mass (RLM; %) (Pre: 45.5 [32.8-63.0]; Post: 47.9 [33.7-66.3]) and absolute lean mass (ALM; %) (Pre: 67.0[55.0-75.2]; Post: 68.8 [56.6-75.7]) were improved after CT. The body mass index (BMI; kg/m2 ) did not change post-CT (Pre: 24.2 [21.3 – 28.7]; Post: 23.7 [21.8 – 30.0]). The viral load remained undetectable, while the number of CD4+ T lymphocytes was increased (Pre: 529 [426.0-900.0]; Post: 694 [381.0-1175.0]). In addition, VO2(ml.kg.min-1) (Pre: 16.2 ± 4.9; Post: 21.2 ± 3.2), speed (km/h) (Pre: 5.7 ± 0.9; Post: 6.3 ± 1.0) and inclination (%) (Pre: 3.8 ± 1.2; Post: 4.9 ± 1.0), obtained at AT intensity, were improved. It was concluded that CT was able to improve the VO2 at the intensity of AT and induced increases in RLM and ALM. Finally, the CT increased the number of CD4 + T lymphocytes, with no negative effect on the viralload. These results are extremely important for the quality of life of patients with HIV.