Biomarkers and subclinical left ventricular dysfunction in patients with type 2 diabetes without clinical manifestations of cardiovascular diseases

Abstract

Aim. To study the relationship between the structural and functional left ventricular (LV) parameters and N-terminal pro-brain natriuretic peptide (NT-proBNP) and inflammatory markers in patients with type 2 diabetes (T2D) without clinical manifestations of cardiovascular diseases, as well as to evaluate the possibility of their use for early diagnosis of subclinical LV dysfunction.Material and methods. Data from 120 patients of both sexes aged 45-75 years (57,11±7,9 years) were analyzed. They were divided into three following groups: 1st — with T2D (n=47), 2nd — with prediabetes (n=20), 3rd — control (n=53). All participants underwent transthoracic echocardiography with assessment of the linear and volumetric heart dimensions, systolic and diastolic LV function. Speckle tracking echocardiography was analyzed with calculation of LV global longitudinal strain (GLS). The blood levels of NT-proBNP and inflammatory markers were determined (high-sensitivity C-reactive protein (hsCRP), fibrinogen, interleukin-6).Results. According to echocardiography, patients with carbohydrate metabolism disorders revealed significantly higher LV mass values, LV posterior wall thickness, and relative wall thickness in comparison with the control group. Transmitral flow parameters, as well as tissue Doppler sonography, in the T2D and prediabetes groups were significantly different from those in the control group. GLS in the groups of patients with carbohydrate metabolism disorders was lower than in the control group (p=0,001). The level of NT-proBNP was significantly higher in the T2D and prediabetes groups compared to the control group, while in all three groups it did not exceed normal values (p<0,001). A higher level of NT-proBNP was associated with hypertension — odds ratio (OR) 3,64 [1,02-13,04] (p=0,005), a decrease in LV ejection fraction — OR 1,25 [1,06-1 ,47] (p=0,007), concentric hypertrophy — OR 4,84 [1,43-16,41] (p=0,011) and decreased GLS — OR 1,85 [1,62-2,06] (p=0,005), an increase in the ratio of early and late diastolic transmitral flow (E/A) — OR 0,01 [0,008-0,416] (p=0,024) and isovolumic relaxation time (IVRT) — OR 1,08 [1,03-1,14] (p=0,03). The sensitivity and specificity of NT-proBNP as a test for predicting GLS reduction <-18% were 86 and 27%, respectively. The hsCRP level, within the reference values, was significantly higher in the T2D and prediabetes groups compared to the control group (p<0,001) and demonstrated a direct linear relationship with E/A, IVRT, early diastolic deceleration time (p<0,05). A higher level of hsCRP was significantly associated with diastolic dysfunction — OR 1,16 [1,02-1,32] (p=0,023), as well as with a GLS decrease <-18% — OR 1,58 [1,12-4,65] (p=0,03).Conclusion. In patients with T2D without clinical manifestations of cardiovascular disease, the presence of concentric LV myocardial hypertrophy, LV diastolic dysfunction and decreased GLS (<-18%) is associated with higher blood levels of NT-proBNP and hsCRP. However, in all cases, the levels of biomarkers do not exceed the reference values, which does not allow their use in the early diagnosis of subclinical LV dysfunction in T2D.