Abstract
Aims: Plasma concentrations of the heart failure (HF) biomarker N-terminal B-type natriuretic peptide (NT-proBNP) vary by ethnicity. We investigated whether NT-proBNP concentrations differed in HF between Pacific peoples, Māori (the Indigenous people), and New Zealand (NZ) Europeans, in patients with HF.
Methods: Plasma NT-proBNP was measured in patients with HF participating in two prospective NZ based multicentre studies [PEOPLE: n = 836, 30% female, median age 71, interquartile interval (IQI) 60, 80; IMPERATIVE-HF: n = 413, 30% female, median age 66, IQI 55, 76]. Regression analyses were used to understand predictors of NT-proBNP taking into account age, sex, body mass index (BMI), estimated glomerular filtration rate (eGFR), left ventricular ejection fraction (LVEF) and presence of atrial fibrillation (AF).
Results: Median NT-proBNP concentrations were significantly lower in both Pacific (930 pg/mL; P < 0.001, IQI 409-1,473; n = 127) and Māori (1,387 pg/mL, IQI 685-2,393; P < 0.001; n = 221) compared with NZ Europeans (2,055 pg/mL, IQI 973-3,865; n = 901) in unadjusted comparisons. NT-proBNP was independently associated with ethnicity, age, sex, BMI, eGFR, LVEF and presence of AF. The significant differences in plasma NT-proBNP between Pacific peoples, but not Māori, and NZ Europeans remained after adjusting for these clinical and demographic factors. The effect of age on NT-proBNP concentrations differed significantly between Pacific peoples and NZ Europeans, but not between Māori and NZ European (Pinteraction = 0.0109). For each decade of life over 60 years, plasma NT-proBNP in patients with HF was on average, 67% lower in a Pacific person than that of an aged-matched NZ European.
Conclusions: In HF, Pacific and Māori people had significantly lower median plasma concentrations of NT-proBNP than NZ Europeans. This difference remained after adjusting for clinical and demographic factors in patients with Pacific ethnicity. Pacific peoples also had a significantly lower rate of increase of NT-proBNP with age compared with NZ Europeans and Māori.