Предикторы начальной стадии хронической сердечной недостаточности при сахарном диабете 2-го типа

Abstract

Introduction. Type 2 diabetes mellitus (T2DM) is considered to be the equivalent of cardiovascular disease due to its micro- and macrovascular complications. Insulin resistance and hyperinsulinemia, impaired glucose tolerance and fasting glucose, and their subsequent maladaptive responses lead to myocardial dysfunction several years before the onset of T2DM. Pathological changes in the cardiovascular system in T2DM can progress without any symptoms for a long time. Aim. To identify clinical, laboratory, echocardiographic predictors of the early manifestations of chronic heart failure (CHF) in patients with T2DM. Materials and methods. The study included 94 patients with T2DM with and without initial symptoms of CHF at the age of 40 to 65 years. All patients had obesity or excess body weight and arterial hypertension (AH), 37 patients had stable coronary heart disease (CHD). Patients underwent general clinical and laboratory examination, a 6-minute walk test (6MWT), echocardiography. The concentration of N-terminal pro-B-type natriuretic peptide (NT-proBNP ) was also determined. The patients were divided into 2 groups: without CHF symptoms (group 1, n = 54) and with initial symptoms of CHF (group 2, n = 40) and then these groups were compared. Results. Differences were revealed between the second and first groups in the duration of T2DM (10.5 vs 7.5 years, p = 0.02) and AH (15 vs 10 years, p = 0.009); the incidence of stable CHD (70 vs 16.7%, p < 0.0001); distance covered during 6MWT (375 vs 425 m, p < 0.0001); the median level of NT-proBNP (38.5 vs 27.2 pg/ml, p = 0.031); the left atrium (LA) size (4.4 vs 4.2 cm, p = 0.044); the left ventricular posterior wall thickness (PWT) (1.05 vs 0.95 cm, p = 0.02); the level of triglycerides (2.3 vs 1.6 mmol/l, p = 0.03) and the glomerular filtration rate (GFR) (74.1 vs 79.1 ml/min/1.73 m2, r = 0.04). The discriminant analysis revealed combination of factors associated with initial symptoms of CHF: the duration of CHD (taken as 0, if absent, p < 0.00001), PWT of the LV (p = 0.000007), GFR (p = 0.0009), the LA size (p = 0.005), the level of triglycerides (p = 0.03), the duration of T2DM (p = 0.046). The NT-proBNP level > 125 pg/ml was detected in 16% of patients with T2DM and correlated with the duration of diabetes over 10 years (p = 0.0085), the presence of stable CHD (p < 0.0001), and left ventricular mass index (p = 0.0005) and the ejection fraction of the LV (p < 0.0001). Conclusion. Predictors of the initial manifestations of chronic heart failure in patients with type 2 diabetes mellitus were the presence and duration of stable CHD, an increase in the PWT of the LV, the LA size, the level of triglycerides, and the duration of diabetes. An elevated level of NT-proBNP (more than 125 pg/ml) in patients with T2DM was detected in 16% of cases and was associated with the duration of diabetes for more than 10 years, presence of stable CHD, initial symptoms of CHF, left ventricular myocardial hypertrophy, and a lower left ventricular ejection fraction according to echocardiography.