Physical Fitness Can Partly Explain the Metabolically Healthy Obese Phenotype in Women

To investigate whether physical fitness and/or fat distribution and inflammation profile may explain why approximately 30% of the women with obesity are protected against obesity-related disorders.10 metabolically healthy obese women and 10 age- and weight-matched women with the metabolic syndrome were enrolled. Physical fitness (VO2max), daily physical activity levels (METs, steps per day), insulin sensitivity (clamp), body fat distribution (DXA scan) and, inflammation markers and adipokines were determined.The metabolically healthy obese women had a 17% higher VO2max (25.1±3.9 vs. 21.5±3.1 ml ∙ min-1 ∙ kg-1, p=0.04) and tended to take more steps per day (7 388±1 440 vs. 5 927±1 301, p=0.06) than women with the metabolic syndrome. Despite equivalent levels of fat mass, metabolically healthy obese women had significantly lower circulating TNF-α levels compared to women with the metabolic syndrome (3.55±3.83 vs. 0.43±0.97 ng/ml, p=0.03). No differences were seen in insulin sensitivity, adipokines, and inflammatory markers between both groups.Metabolically healthy obese women have a higher cardio-respiratory fitness and lower TNF-α levels, which may partly explain why these women are protected from the detrimental effects of obesity compared to obese women with the metabolic syndrome.