Association of cumulative excess weight and waist circumference exposure with transition from metabolically healthy obesity to metabolically unhealthy

Background and aims: The association between obesity severity and duration with the transition from metabolically healthy obese/overweight (MHO) phenotype to metabolically un-healthy obese (MUO) phenotype is not well understood.Methods and results: This study includes the Tehran Lipid and Glucose Study participants who were initially classed as MHO. Cumulative excess weight (CEW) and cumulative excess waist circumference (CEWC) scores, which represent the accumulation of body mass index and waist circumference deviations from expected values over time (kg/m2 * y and cm ) y, respectively), were calculated until the transition from MHO to MUO or the end of follow-up. The sex -stratified association of CEW and CWEC with the transition from MHO to MUO was investigated by time-dependent Cox models, adjusting for confounders. Out of 2525 participants, 1732 (68.5%) were women. During 15 years of follow-up, 1886 (74.6%) participants transitioned from MHO to MUO. A significant association was found between CEW and CEWC quartiles with the develop-ment of MUO among women participants (fully adjusted hazard ratios in the fourth quartile of CEW and CEWC [95% (CI)]:1.65 [1.37-1.98] and [95% CI]: 1.83 [1.53-2.19]). There was no signif-icant association between CEW and CEWC with the MHO transition to MUO among men partic-ipants.Conclusion: Over 15 years of follow-up in TLGS, general and central obesity accumulation was associated with the increased transition from MHO to MUO among women participants. More research with a larger sample size is needed to confirm and explain why the results are different for men and women.(c) 2022 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Ital-ian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.