Author(s): Bowden Davies K.A.; Sprung V.S.; Norman J.A.; Wilding J.P.H.; Kemp G.J.; Cuthbertson D.J.; Thompson A.; Mitchell K.L.; Harrold J.O.A.; Finlayson G.; Gibbons C.; Hamer M.
Source: Medicine and Science in Sports and Exercise; Jun 2019; vol. 51 (no. 6); p. 1169-1177
Publication Date: Jun 2019
Publication Type(s): Article
Abstract:INTRODUCTION/PURPOSE: To investigate whether (a) lower levels of daily physical activity (PA) and greater sedentary time accounted for contrasting metabolic phenotypes (higher liver fat/presence of metabolic syndrome [METS+] vs lower liver fat/absence of metabolic syndrome [METS-]) in individuals of similar body mass index and (b) the association of sedentary time on metabolic health and liver fat. METHOD(S): Ninety-eight habitually active participants (53 female, 45 male; age, 39 +/- 13 yr; body mass index 26.9 +/- 5.1 kg.m), underwent assessments of PA (SenseWear armband; wear time ~98%), cardiorespiratory fitness (VO2 peak), body composition (magnetic resonance imaging and magnetic resonance spectroscopy) and multiorgan insulin sensitivity (oral glucose tolerance test). We undertook a) cross-sectional analysis comparing four groups: nonobese or obese, with and without metabolic syndrome (METS+ vs METS-) and b) univariate and multivariate regression for sedentary time and other levels of PA in relation to liver fat. RESULT(S): Light, moderate, and vigorous PA did not account for differences in metabolic health between individuals, whether nonobese or obese, although METS+ individuals were more sedentary, with a higher number, and prolonged bouts (~1-2 h). Overall, sedentary time, average daily METS and VO2 peak were each independently associated with liver fat percentage. Each additional hour of daily sedentary time was associated with a 1.15% (95% confidence interval, 1.14%-1.50%) higher liver fat content. CONCLUSION(S): Greater sedentary time, independent of other levels of PA, is associated with being metabolically unhealthy; even in habitually active people, lesser sedentary time, and higher cardiorespiratory fitness and average daily METS is associated with lower liver fat.