Background N-terminal pro-brain natriuretic peptide (NT-proBNP) is a recognized myocardial injure marker, a known predictor of heart failure and cardiovascular death. Rheumatoid arthritis (RA) patients (pts) were shown to have higher than in general population NT-proBNP concentrations, positively correlating with IL-6 levels. Adipose tissue is considered be one of the sources of this pro-inflammatory cytokine. But on the other hand, metabolic syndrome (MS) and obesity, which also occur in RA pts, are usually associated with lower NT-proBNP levels in general population.
Objectives To find out whether overweight/obesity or MS may modify NT-proBNP levels in RA pts.
Methods A total of 68 early RA pts (72% females, 28% males) was enrolled in the study. Mean disease duration was 6 [4;8] months, and RA activity using DAS28 calculator was 5,6 [5,1;6,4] scores. The majority of pts had positive RF (87%) and ACPA (88%). All pts were glucocorticoids and disease-modifying antirheumatic drugs - naïve prior to inclusion. The overweight/obesity was determined by WHO criteria in patients with body mass index (BMI) ≥25 kg/m2. National Cholesterol Education Program/Adult Treatment Panel III criteria were used to confirm MS. Serum levels of NT-proBNP (pg/mL) were measured using electrochemiluminescence test Elecsys proBNP II (Roche Diagnostics, Switzerland). NT-proBNP levels >125,0 pg/mL were considered as elevated.
Results Overweight and obesity were established in 54,4% RA pts. Overweight/obese RA pts were older than pts with normal BMI (57 [53;61] years vs 48 [34;61] years, p=0,02), had higher DAS28 scores (5,85 [5,20;6,57] vs 5,28 [4,76;5,69], p<0,01), higher CRP (38,8 [14,3; 47,9] mg/L vs 12,8 [2,2;28,8] mg/L, p<0,01). Elevated NT-proBNP concentrations were found in 62,2% overweight/obese pts vs 29,0% pts with normal weight (p<0,01), median NT-proBNP concentrations were 153,4 [87,3;236,9] pg/mL vs 75,2 [40,2;147,4] pg/mL, respectively (p=0,02). MS was established in 62,2% pts with BMI ≥25kg/m2 and in 25,8% pts with BMI<25kg/m2 (p<0,01). Median NT-proBNP concentrations did not vary significantly in pts with and without MS, whether they were overweight/obese (p=0,75), or had normal BMI (p=0,27). Although higher rates of elevated NT-proBNP concentrations were documented in pts with MS (61,3% vs 35,1%, p=0,03). NT-proBNP levels positively correlated with waist circumference (r=0,33, p<0,01), ESR (r=0,25, p=0,04), and CRP (r=0,3, p=0,01).
Conclusions Overweight and obesity in RA pts were associated with increased NT-proBNP levels. Abdominal obesity was identified as the only MS component, influencing NT-proBNP levels, presumably via up-regulation of the inflammatory process.
Disclosure of Interest None declared