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.

Resumo O objetivo deste estudo foi verificar a cinética de lactato sanguíneo (CLS) e a sua resposta ao treinamento físico combinado (TFC) bem como avaliar os efeitos sobre os aspectos bioquímicos, imunológicos, cardiorrespiratório e composição corporal de pessoas vivendo com HIV/AIDS. Doze voluntários HIV+ realizaram o TFC, por um período de 16 semanas, e foram submetidos às avaliações nos momentos pré, oito e 16 semanas de TFC. Ao final, houve um aumento das células TCD4+ e manutenção da carga viral, aumento do consumo máximo de oxigênio e da força muscular e, ainda, aumento do HDL-c e diminuição dos triglicerídeos e glicemia de jejum. Ainda, ocorreu aumento da CLS após o período de treinamento. Concluímos que o TFC influenciou positivamente os parâmetros imunológicos, bioquímicos, cardiorrespiratório e muscular, no entanto, a questão relacionada à CLS necessita de estudos futuros para maiores esclarecimentos.

Abstract The aim of the study was to verify the blood lactate kinetics (BLK) and the response to combined physical training (CPT) as well as to evaluate the effects on markers related to biochemical, immunological, cardiorespiratory and body composition in HIV + people. Twelve HIV+ volunteers performed CPT during 16 weeks, and were subjected to evaluations in 3 moments: pre, 8 and 16 weeks of CPT. At the end, there was improvement in immune and cardiorespiratory parameters, muscular strength and of glycemic and lipid profiles. Concerning BLK, the concentrations were increased after the CPT. We conclude that CPT improved the measured variables, nevertheless, the issue related to the BLK requires further studies in order to clarify this occurrence.

ResumoO objetivo deste estudo foi determinar a intensidade no lactato mínimo (ILM) pelo LACminteste usando três estágios incrementais (LACminteste3) e avaliar sua sensibilidade às alterações do condicionamento aeróbio (CA). Vinte ratos realizaram: LACminteste3 (1): indução da hiperlactacidemia e fase incremental (4%, 5% e 6,5% do pc); Testes de cargas constantes equivalentes (2) e acima (3) da ILM. Metade dos animais foi submetida ao treinamento físico na ILM individual e os testes foram efetuados novamente. A sobrecarga média no LACmintest3foi 5,04 ± 0,13% pc à 5,08 ± 0,55 mmol L-1 de lactato sanguíneo mínimo (LSM). Houve estabilização e aumento desproporcional do lactato sanguíneo nos testes 2 e 3, respectivamente. Após o período de treinamento, o LSM médio foi menor no grupo treinado. O LACminteste3 parece ser um bom indicador da ILM e responsivo às mudanças no CA em ratos treinados por natação.

AbstractThe purpose of this study was to determine the lactate minimum intensity (LMI) by swimming LACmintest using three incremental stages (LACmintest3) and to evaluate its sensitivity to changes in aerobic fitness (AF). Twenty Wistar rats performed: LACmintest3 (1): induction of hyperlactacidemia and incremental phase (4%, 5% and 6.5% of bw); Constant loads tests on (2) and above (3) the LMI. Half of the animals were subjected to training with the individual LMI and the tests were performed again. The mean exercise load in LACmintest3 was 5.04 ± 0.13% bw at 5.08 ± 0.55 mmol L-1 blood lactate minimum (BLM). There was a stabilize and disproportionate increase of blood lactate in tests 2 and 3, respectively. After the training period, the mean BLM was lower in the trained animals. The LACmintest3 seems to be a good indicator of LMI and responsive to changes in AF in rats subjected to swim training.

ResumenDeterminar la intensidad del lactato mínimo (ILM) por LACmintest incremental mediante tres etapas graduales (LACmintest3) y evaluar su sensibilidad a los cambios en condiciones aerobias (CA). Veinte ratas realizaron: LACmintest3 (1): inducción de hiperlactacidemia y fase incremental (4 %, 5% y 6,5 % de pc); pruebas de cargas constantes equivalente (2) y arriba (3) de la ILM. Mitad de los animales fueron sometidos a entrenamiento físico con la persona carga equivalente a la ILM y las pruebas se realizaron nuevamente. La carga media en LACmintest3fue 5,04 ± 0,13 % pc a 5,08 ± 0,55 mmol L-1 de lactato mínimo en la sangre (LMS). Se observó una estabilización y desproporcionado aumento de lactato sanguíneo en las pruebas 2 y 3, respectivamente. Después del período de entrenamiento físico, la media fue menor en el grupo entrenado. LACmintest3resultó ser un buen indicador de la ILM y sensible a los cambios que se producen en el CA en ratas entrenadas por nadar.