Funding informationWe are grateful to the Brazilian agencies Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) -Finance Code 001, CAPES (CAPES-PNPD -23038007200/11-08) and Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq) for financial support. PDL, AP, and PRTR also thank CNPq for fellowships.This study investigated the peripheral frequency of monocytes, CD4 + T cell subsets and the systemic levels of cytokines in lean and obese men with different levels of cardiorespiratory fitness (CRF). Mononuclear cells were obtained from 45 lean and 45 obese men who were assigned into six groups according to their body mass index and CRF (low, moderate, or high VO 2Peak ) to analyze the frequency of monocyte subsets and subpopulations of CD4 + T cells (Treg cells, CD4 + CD25 high CD127 low ; mTeff, CD4 + CD25-CD39+; mTreg, CD4 + CD25+CD39+). The systemic levels of interleukin (IL)-6, IL-10, IL-17a, IL-33, leptin, and tumor necrosis factor-alpha (TNF-α) were also evaluated. Seven sedentary obese men performed one week of high-intensity interval training (HIIT, 3 sessions/week), and blood samples were collected before and 24 hours after the last session for phenotypic analysis of T cells and monocytes. Obese individuals presented an inflammatory profile characterized by lower frequencies of Treg and mTreg cells and higher proportions of proinflammatory monocytes. However, higher CRF status increased the frequencies of Treg cells and mTreg cells and decreased the percentage of CD4 + mTeff cells and intermediate and non-classical monocytes in the peripheral blood from lean and obese men. Systemic lower levels of proinflammatory (IL-6 and TNF-) cytokines and higher concentrations of IL-10 and IL-33 were observed in moderate and higher CRF in all subjects. HIIT increased the proportions of circulating mTreg and Treg cells in sedentary obese individuals. The immunoregulatory role of CRF contributes to the maintenance of low levels of inflammatory mediators. K E Y W O R D S CD39, CD73, exercise, inflammation, monocyte subsets, obesity, T cells, Treg cells, VO 2 peak 1756 | DORNELES Et aL.
SUPPORTING INFORMATIONAdditional supporting information may be found online in the Supporting Information section at the end of the article. How to cite this article: Dorneles GP, da Silva I, Boeira MC, et al. Cardiorespiratory fitness modulates the proportions of monocytes and T helper subsets in lean and obese men. Scand J Med Sci Sports.