Plasma N-terminal pro-brain natriuretic peptide and brain natriuretic peptide in assessment of acute dyspnea.

We examined the analytical correlation between non-radioimmunometric plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) and B-type natriuretic peptide (BNP) and evaluated whether NT-proBNP or BNP was superior in the emergency diagnosis of heart failure and whether this was influenced by age, gender, body mass index (BMI) and renal function. Data were collected prospectively from patients admitted to the emergency department for acute dyspnea. Plasma BNP (Triage, Biosite) and NT-proBNP (Elecsys, Roche diagnostic(R)) were measured at admission in addition to other standard biological parameters and clinical variables. Reference diagnosis was adjudicated by two independent cardiologists using the European society of cardiology guidelines. We evaluated the influence of creatinine clearance, age, gender and BMI on plasma BNP and NT-proBNP levels. One hundred and sixty consecutive patients were included: 84 females and 76 males, mean age 80.1 + 13.5 (16-98). The analytical correlation between the automated electro-chemiluminescence immunoassay for NT-proBNP and the single use fluorescence immunoassay for BNP was satisfactory using the equation: NT-proBNP = 1.1 BNP + 0.57 and a correlation r = 0.93. This was established over a wide range of concentration (5-6400 pg/ml for BNP). Areas under receiver operating characteristic (ROC) curve for BNP and NT-proBNP as a diagnostic marker for heart failure were 0.82 and 0.84, respectively and a BNP level of 150 pg/ml has similar sensitivity and specificity that NT-proBNP level of 1000 pg/ml. The correlation was not influenced by age, gender and BMI of patients. Renal dysfunction did not affect significantly this correlation (r = 0.93). We conclude that NT-proBNP, as assayed in the present study, correlates closely with BNP. This correlation is only slightly modulated by creatinine clearance values. The NT-proBNP appears as accurate as BNP according to area under ROC curve. Used in conjunction with other clinical information, rapid measurement of BNP or NT-proBNP is useful in establishing or excluding the diagnosis of congestive heart failure in patients with acute dyspnea.

Analytical correlation between plasma N-terminal pro-brain natriuretic peptide and brain natriuretic peptide in patients presenting with dyspnea.

OBJECTIVES: We examined the analytical correlation N-terminal pro-brain natriuretic peptide (NT-proBNP) and brain natriuretic peptide (BNP). DESIGN AND METHODS: Electrochemiluminescence and fluorescence immunoassays were used to measure NT-proBNP and BNP levels, respectively. RESULTS: The analytical correlation was satisfactory using the equation: NT-proBNP = 8.56 x BNP + 91.7 and a correlation r = 0.85. The correlation was not influenced by age, gender and BMI of patients. CONCLUSIONS: We conclude that NT-proBNP correlates with BNP.

Iron metabolism in patients with anorexia nervosa: elevated serum hepcidin concentrations in the absence of inflammation.

BACKGROUND: Only a few studies based on small cohorts have been carried out on iron status in anorexia nervosa (AN) patients. OBJECTIVE: The aim of this study was to evaluate the role of hepcidin in hyperferritinemia in AN adolescents. DESIGN: Twenty-seven adolescents hospitalized for AN in the pediatric inpatient unit of Ambroise Paré Academic Hospital were enrolled in the study. The control group comprised 11 patients. Hematologic variables and markers of iron status, including serum hepcidin, were measured before and after nutritional rehabilitation. RESULTS: The mean age of patients was 14.4 y. Except for 2 AN patients and 1 control patient, all patients presented normal hemoglobin, vitamin B-12, and folate concentrations. Markers of inflammation and cytokines were normal throughout the study. None of the muscular lysis markers were elevated. Most AN patients had normal serum iron concentrations on admission. Serum ferritin concentrations were significantly higher in patients than in control subjects (198 compared with 49 µg/L, respectively; P < 0.001). The median hepcidin concentration was significantly higher in AN patients than in the control group (186.5 compared with 39.5 µg/L, respectively; P = 0.002). There was a highly significant correlation between ferritinemia and serum hepcidin concentrations (P < 0.0001). After nutritional rehabilitation, a significant reduction was observed (P = 0.004) in serum ferritin. Serum hepcidin analyzed in a smaller number of patients also returned to within the normal range. CONCLUSIONS: Hepcidin and ferritin concentrations were higher in the serum of AN patients, without any evidence of iron overload or inflammation. These concentrations returned to normal after nutritional rehabilitation. These results suggest that nutritional stress induced by malnourishment in the hepatocyte could be yet another mechanism that regulates hepcidin.