N-terminal pro-brain natriuretic peptide (NT-proBNP) is considered a marker of poor cardiovascular prognosis in patients with diabetes1 . Increased resting heart rate is also associated with increased cardiovascular complications and mortality in patients with diabetes2 . There is evidence that BNP modulates the autonomic nervous system3 . This study aimed to investigate the relationship between NT-proBNP and 24h haemodynamic parameters in patients with type 1 and type 2 diabetes.
Clinical characteristics, serum NT-proBNP level and 24h ambulatory blood pressure were collected in 141patients with type 1 and type 2 diabetes who attended diabetes clinics at Austin Health, a tertiary referral centre in Melbourne. A multiple regression model was generated to predict log10(NT-proBNP), with the following variables as potential predictors: 24h systolic, diastolic and mean arterial blood pressure; morning blood pressure surge; night-to-day systolic blood pressure ratio; 24h heart rate; age; sex and BMI.
The mean age was 64±13 years, 65% were males, and 74% had type 2 diabetes. The mean 24h systolic, diastolic and mean arterial pressure was 130±13, 70±9, and 91±8 mmHg, respectively. The mean 24h heart rate was 73±10 bpm. In a multiple regression model, night-to-day systolic blood pressure ratio, age, and 24h heart rate significantly predicted log10(NT-proBNP) (R2=0.4, p<0.001, Figures 1a-c).
In patients with diabetes, lack of nocturnal blood pressure dipping is associated with increased NT-proBNP level. Further studies are needed to define the relationship between heart rate and NT-proBNP.