Introduction: A subset of adults with obesity may be classified as having metabolically healthy obesity (MHO). There is a high conversion rate from the MHO condition to a metabolically unhealthy obesity (MUO) condition over time. The insulin sensitizing effects of exercise across these metabolic states has not been established and may inform more precise obesity treatment.
Methods: Sedentary adults (n=43) with obesity, but not diabetes, underwent inpatient testing (anthropometric measurements, blood chemistries, aerobic capacity (VO2MAX), and insulin sensitivity (euglycemic clamp) before and after 12 weeks of aerobic exercise training (5x/week, 60 min/session, ∼85% HRMAX). A metabolic health score (MetScore) was calculated using baseline values (BMI, VO2MAX, HOMA-IR, triglycerides, and cholesterol) to stratify participants with MHO (n= 21; MetScore ≤ 237) or MUO (n=22; MetScore > 237). Linear mixed models determined group differences over time.
Results: MHO and MUO groups differed by MetScore at baseline (202 and 325; P<0.01) and after 12 weeks of exercise (181 and 261; P<0.01), but MHO had lower fasting glucose, insulin, HOMA-IR, and higher HDL-C along with superior M/I, than MUO participants. MetScore improved in the group with MUO (-64; P<0.01) compared to MHO (-20; p=0.06)(P<0.01, between groups). Both groups (MHO v. MUO) experienced similar improvements in VO2MAX (+6.8 and +9.3 ml/kg/min), body weight (-8.8 and -7.5 kg), body fat (-4.2 and -2.9%), triglyceride concentrations (-31.7 and -25.8 mg/dl), and M/I (0.0183 and 0.0166 mg/kg/min/μU/ml) (P>0.20, all between groups). Insulin (-2.62 μU/ml; P=0.0185) and HOMA-IR (-0.71; P=0.022) decreased in the group with MUO with no between group differences (P=0.75 and P=0.52, respectively).
Conclusion: Aerobic exercise enhances individual components of health similarly in persons with MHO and MUO after 12 weeks. However, those with MUO experienced the greatest collective improvement, thus presenting an opportunity for intervention.
K.K. Hoddy: None. C.L. Axelrod: None. J.T. Mey: None. A. Hari: None. R.A. Beyl: None. J.P. Kirwan: None.
National Institute on Aging (AG012834); National Institute of General Medical Sciences (GM104940); Louisiana Clinical & Translational Science Center (U54-GM104940)