Weight loss effect on inflammation and LDL oxidation in metabolically healthy but obese (MHO) individuals: low inflammation and LDL oxidation in MHO women

OBJECTIVE: Recently, a subtype of obesity characterized as a metabolically healthy but obese (MHO) individual has been identified. However, limited data are available on these MHO individuals' metabolic and inflammatory profiles, and the effect of weight loss on these profiles. We investigated metabolic and inflammatory markers in MHO women to determine the effects of a 12-week weight loss on those markers. SUBJECTS: One hundred and twenty-nine overweight-obese Korean women participated for 12 weeks in a clinical intervention study involving a 300 kcal/day intake reduction. The subjects were divided into two groups: MHO and metabolically abnormal obese (MAO) individuals. METHODS: Computed tomography was performed. C-reactive protein (CRP), interkeukin-6 (IL-6) and oxidized low-density lipoprotein (LDL), as well as blood lipids, glucose and insulin concentrations were determined at baseline and after weight loss. RESULTS:At baseline, plasma CRP (P<0.001), IL-6 (P<0.05) and oxidized LDL (P<0.001) levels were significantly lower in the MHO group than in the MAO group. Visceral fat at L1 (P<0.005) and visceral fat at L4 (P<0.001) were significantly lower in the MHO group than in the MAO group. The treatment induced weight loss averaging 3.11% of initial body weight, and the degree of weight loss between the two groups was similar. Visceral fat at L1 and L4 was reduced from its initial values by 3.2 and 5.4%, respectively, after weight loss. The levels of CRP (P<0.05) and oxidized LDL (P<0.01) were significantly reduced in the MAO group after the 12-week weight loss, whereas these effects were not seen in the MHO group. CONCLUSIONS: Our results showed that MHO individuals exhibited lower visceral fat accumulation and more favorable metabolic and inflammatory states than MAO individuals. After a 12-week weight loss program, significant reductions in blood lipids, CRP and oxidized LDL levels were observed in MAO individuals. However, there was no measurable effect of weight loss on lipid profiles and inflammation in MHO individuals, indicating differing effects of weight loss on these markers between MAO and MHO groups.