Mediating Effect of the NLR on the Relationship Between HbA1c and Left Atrial Stiffness in Overweight Patients With Hypertension.

Background: We aimed to investigate the association between hemoglobin A1c (HbA1c) and left atrial (LA) stiffness in patients with hypertension and to explore the mediating effect of the neutrophil/lymphocyte ratio (NLR) on this association.

Methods: Essential hypertensive patients (n = 292) aged 18-83 years were enrolled and divided into two groups based on the LA stiffness index (LASI): Group I (LASI ≤ 0.32, n = 146) and Group II (LASI > 0.32, n = 146). The LASI was defined as the ratio of early diastolic transmitral flow velocity/lateral mitral annulus myocardial velocity (E/e') to LA reservoir strain. Multivariate linear regression analysis was performed to determine the independent predictors of the LASI.

Results: Age, BMI, SBP, HbA1c, CRP, and NLR were significantly greater in Group II than in Group I (P < 0.05). Additionally, Group II had a greater LA volume index (LAVI), left ventricular mass index (LVMI), and early diastolic transmitral flow velocity/lateral mitral annulus myocardial velocity (E/e') and lower LA reservoir, conduit, and booster pump strains than Group I (P < 0.001). Univariate and multivariate linear regression models revealed that age, SBP, HbA1c, and the NLR were independently associated with the LASI. Further mediation analysis was performed to determine the mediating effect of the NLR on the association between HbA1c and the LASI and revealed that the NLR had a mediating role only in overweight hypertensive patients, and the proportion of the mediating effect was 21.9%.

Conclusions: The NLR was independently correlated with the LASI and played a mediating role in the relationship between HbA1c and the LASI in overweight hypertensive patients.