Elevated NT-proBNP levels should be interpreted in elderly patients presenting with dyspnea.
BACKGROUND
B-type natriuretic peptide (BNP) assay is a useful tool in order to diagnose dyspnea due to congestive heart failure (CHF). On the other hand many other diseases could affect BNP levels. The aim of this study was to investigate a group of elderly patients admitted to an Internal Medicine unit because of dyspnea.


METHODS
NT-proBNP was assessed in 132 consecutive patients aged 80±6 years because of dyspnea. History data, anthropometric, clinical and biochemical parameters were collected. Renal function was assessed by the CKD-EPI formula. Diagnosis of pulmonary disease such as infections and chronic obstructive disease was considered and was analyzed as a single parameter. Statistical analysis was carried out dividing patients with high NT-proBNP from those with normal NT-proBNP according to the Januzzi cut-off.


RESULTS
NT-proBNP was higher than the normal reference values in 68.7% of patients and its levels increased in the 5 different stages of chronic kidney disease. Subjects with high NT-proBNP had lower haemoglobin levels (11.6±2.1 vs 12.8±1.9 g/dl, p=0.003), higher prevalence of atrial fibrillation (54.3 vs 25%, p=0.001), and lower prevalence of pulmonary diseases (29.7 vs 57.5%, p=0.005). Logistic regression analysis showed that NT-proBNP levels were independently associated with haemoglobin (OR 1.307 95% CI 1.072-1.593, p=0.008) and pulmonary diseases (OR 3.069 95% CI 1.385-6.801, p=0.006).


CONCLUSIONS
A disease different from CHF appears to affect NT-proBNP plasma levels. Therefore, determination of its levels does not seem to help clinicians in the definition of dyspnea in elderly people with different comorbidities.
Department of Clinical and Experimental Medicine, University Hospital St. Anna, Corso Giovecca, 203, I-44100 Ferrara, Italy. f.fabbian@ospfe.it
Fabio
F
Fabbian
Alfredo
A
De Giorgi
Marco
M
Pala
Ruana
R
Tiseo
Francesco
F
Portaluppi
D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015415:Biomarkers / Q000097:blood; D003937:Diagnosis, Differential; D004417:Dyspnea / Q000097:blood* / Q000209:etiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008171:Lung Diseases / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood; D012044:Regression Analysis; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity
D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain