Obesity in the Russian population: contribution to survival and cardiovascular events. Data from ESSE-RF and ESSE-RF2

Aim. To study the contribution of obesity, including abdominal obesity (AO), to the risk of all-cause death and cardiovascular events (CVE) in the Russian population. Material and methods . The representative samples of the Russian population aged 25-64 years from the ESSE-RF (2012-2014) and ESSE-RF2 (2017) studies were analyzed (n=22869). A modular questionnaire and standard epidemiological methods for assessing risk factors were used. The body mass index (BMI) was calculated using the following equation: BMI=body mass (kg)/height (m 2 ). Overweight was defined as 25,0≤ BMI ≤29,9 kg/m 2 , while obesity — as BMI ≥30,0 kg/m 2 , and AO — as waist circumference ≥102 cm in men and ≥88 cm in women. High blood pressure (BP) was defined as systolic BP ≥140 mm Hg and/or diastolic BP ≥90 mm Hg. The presence of diabetes with type indication was assessed by a questionnaire. In this analysis, carbohydrate metabolism disorders were defined as fasting glucose ≥6,1 mmol/l and/or a history of diabetes. The prospective observational cohort was formed from 14 regions included in ESSE-RF and ESSE-RF2. Every 2 years, the following were assessed: causes of death, non-fatal CVD, new cases of cardiovascular diseases and cardiovascular events. Statistical analysis was performed using the statistical programming language and the R environment (version 4.1) with open source code. To assess survival, Kaplan-Meier survival curves were used with the log-rank test with Holm's adjustment. Associations with endpoints were assessed using Cox models. The differences for all tested hypotheses were considered significant at p<0,05. Results . The presence of obesity, including AO, significantly worsens survival in the Russian cohort (p<0,001), and is also significantly associated with fatal and non-fatal CVD (p<0,001). The significance of obesity is preserved in multivariate analysis adjusted for sex, age and region of residence. The lowest all-cause death risk is shifted towards overweight. The risk of fatal and non-fatal cardiovascular diseases increases with increasing BMI. In the Russian cohort, the combination of obesity with carbohydrate metabolism disorders and elevated blood pressure significantly worsens the prognosis (p<0,001) compared to each condition separately. Conclusion . Obesity, including AO, is associated with worsening survival in the Russian population. Despite the obesity paradox, in which the lowest all-cause death risk is shifted towards overweight, the risk of CVD increases with increasing BMI in the Russian cohort. To control obesity, it is important to improve the detection of obesity, including through medical check-ups and preventive examinations, as well as the choice of treatment tactics for obese patients according to clinical guidelines.