Obesity phenotypes and the risk of myocardial infarction: a prospective cohort study

Aim . To study the dynamics of obesity phenotypes and risk of myocardial infarction (MI) during 13-year follow-up period. Material and methods . The study was performed based on the material of the international project HAPIEE (population sample of men and women 45-69 years old, n=9360, basic survey 2003-2005). The analysis included persons with a body mass index (BMI) >30 kg/m2: 3197 people; 857 men (26,8%) and 2340 women (73,2%). To analyze the incidence of MI, a sample of 3008 subjects free from baseline history of MI was selected (752 men and 2256 women). New cases of myocardial infarction have been collected according to the data of the WHO “Register of Acute Myocardial Infarction” program, held at the Research Institute of Therapy and Preventive Medicine; the results of two repeated examinations (2006-2008 and 2015-2017) and repeated postal interview of cohort during 13-year follow-up. The analysis was carried out in individuals with a metabolically phenotype of healthy obesity (MHO). The MHO is defined according to various classifications: NCEPATPIII 2001 — in the presence of 2 and/or less components of the metabolic syndrome; IDF 2005 — waist circumference (WC) >94 cm in men and >80 cm in women and one or no risk factor; Russian Society of Cardiology (RSC) — the index of waist circumference/hip circumference (WC/HC) <0,9 in men and <0,85 in women. Statistical analysis was performed using the SPSS (V. 13.0) package. Results . The frequency of MHO in studied sample was 20% (by IDF); 45% (by NCEPATPIII); — 31% (by RSC criteria). During 13-year prospective follow-up among participants with MHO 51-59% of subjects developed metabolically unhealthy obesity phenotype (MUH). Women were more likely to retain MHO according to NCEP ATP III and RSC criteria, and more frequently transited, to MUH, according to IDF and RSC criteria than men during 13 years. The relative risk of MI in subjects with MHO was 2,5 times lower than in those with MUO: OR=1,9 (95% CI: 1,2; 2,9) by NCEPATP III; OR=3,2 (95% CI: 1,7; 6,1) by RSC; no significant difference was found in the incidence of MI by IDF criteria, p>0,05. Conclusion . MHO is unstable condition accompanied by transition to the MUH among more than half of men and women during 13 years of observation. In studied population cohort the 13-years risk of incident MI in subjects with MUO was higher compared to MHO: OR=1,9 (95% CI: 1,2; 2,9) by NCEPATP III; OR=3,2 (95% CI: 1,7; 6,1) by RSC criteria.