Association between sleep-disordered breathing, aminoterminal pro-brain natriuretic peptide (NT-proBNP) levels and insulin resistance in morbidly obese young women

ObjectiveSleep-disordered breathing (SDB) is often encountered in morbid obesity (MO) in conjunction with insulin resistance (IR) and several cardio-vascular risk factors. Aminoterminal pro-brain natriuretic peptide (NT-proBNP) is a promising marker for left ventricular dysfunction (LVD) in MO. The aim of this study was to look for possible correlations between SDB, IR, heart structure and function indexes and NT-proBNP levels in MO female subjects.Materials and methodsCross-sectional study involving 110 MO (44.5 ± 0.7 kg m− 2) apparently healthy, young (37.8 ± 1.0 y.o.) female patients. NT-proBNP was measured using an ELISA kit (Roche). Echo-cardiograms were performed to quantify left ventricular ejection fraction values (LVEF), cardiac output (CO), left ventricular mass (LVM), left atria size (LA) and left ventricular filling pressures (the E/Em ratio). The Berlin Questionnaire (BQ) was used to assess the risk of SDB. IR and sensitivity were assessed using the HOMA index and adiponectin measurements, respectively.ResultsAll patients had a normal LVEF (> 50%). Hypertension and Type 2 diabetes mellitus prevalences were 34.5 and 4.5% (respectively). Log-transformed NT-proBNP levels correlated with BQ categories (P < 0.0005), creatinine (P < 0.001), age (P < 0.05), LVM (P < 0.001), CO (P < 0.001), LA (P < 0.0005) and E/Em (P < 0.01). NT-proBNP levels, LVD and LVM increased significantly along with BQ scores (P < 0.0001). Stepwise multiple regression analysis identified BQ and log-transformed HOMA as independent variables predicting as much as 48.0% of log-transformed NT-proBNP's variability (dependent variable).ConclusionsNT-proBNP levels are independently predicted by SDB and IR in asymptomatic MO women. Additionally, SDB worsens along with LVH and diastolic dysfunction. Larger prospective studies are warranted.