The paradox of the positive effect of overweight and obesity on the results of coronary artery bypass grafting depending on the age and sex of patients

Objective. To determine the presence of the "obesity paradox" and to establish its impact on the results of coronary artery bypass grafting on a working heart in patients of different ages and sexes. Materials and methods. The study involved 3674 patients with coronary heart disease, 3061 men and 613 women who underwent coronary artery bypass grafting on a beating heart. The average age of the study participants was (60.6 ± 0.8) years. The data of clinical and anthropometric studies with the determination and interpretation of body mass index were analysed. The study design was based on the age and sex of the patients. Results. The highest body mass index was in geriatric patients – 30.9 kg/m2 and in young patients – 29.7 kg/m2 , and the lowest – in young patients – 24.9 kg/m2 (p=0.01, χ2 =5.78) and in geriatric patients – 28.0 kg/m2 (p≥0.05). Among men, the highest frequency of normal body weight (24.7%) was observed in the geriatric age, and the lowest (8.7%) – in the young age (p=0.0001, χ2 =45.02); among women – in the young age (25.0%) and in the geriatric age (7.1%), p≥0.05. The proportion of overweight patients was highest (51.2%) in the elderly, and lowest (42.3%) in the young (p=0.0001, χ2 =19.55). Regarding the prevalence of overweight in patients, the highest proportion (53.6%) of patients with such a body weight was recorded in the elderly, and the lowest (25.0%) – in the young (p≥0.05). Overweight was statistically significantly (p=0.0001, χ2 =38.14) more common in men than in women. In patients, the incidence of obesity was highest at a young age and lowest at an older age (p=0.0001, χ2 =143.28). In women, the highest (59.0%) prevalence of obesity was observed in middle age, and the lowest (39.3%) in old age (p=0.0001, χ2 =65.15). The prevalence of obesity was statistically significantly higher in women (50.9%) than in men (38.0%) (p=0.0001, χ2 =42.49). Early postoperative mortality was statistically significantly (p=0.017, χ2 =5.68) higher in patients, with the highest rate recorded in the elderly. The early postoperative mortality rate in patients with normal body weight was statistically significantly (p=0.018, χ2 =5.63) higher than in patients with overweight. Conclusions. There were more elderly patients with overweight and fewer young patients (p=0.0001, χ2 =19.55). Overweight patients were statistically significantly (p=0.0001, χ2 =38.14) more common than female patients. In men, the incidence of obesity was highest in young age and lowest in old age (p=0.0001, χ2 =143.28), and in women, respectively, in middle age and old age (p=0.0001, χ2 =65.15). There were statistically significantly more obese women (p=0.0001, χ2 =42.49) than men. The early postoperative mortality rate in patients with normal body weight was statistically significantly (p=0.018, χ2 =5.63) higher than in patients with overweight.