Association of cardio-metabolic risk factors with elevated basal heart rate in South African Asian Indians

The aim of this study was to determine the association of increasing basal heart rate (BHR) with cardio-metabolic risk in a community sample of Asian Indians from South Africa, due to lack of population-based data on the interaction between heart rate and cardiovascular factors.

Data drawn from 1349 randomly selected participants was collected using the WHO STEPS questionnaire. Anthropometry, blood pressure, physical examination and laboratory analyses of venous blood samples and definition of cardiometabolic derangements were performed according to established guidelines. BHR classified into three categories, i.e., <60 bpm; 60-89 bpm and ≥90 bpm. Stepwise backward regression models were constructed for determination of association between increasing BHR and cardiometabolic parameters. A ROC was constructed to determine the AUC and to determine their sensitivity and specificity for discriminating increasing BHR levels.

In 379 men (mean age 42±15 years; mean HR 79±13 bpm) and 970 women (mean age 46±12 years; mean HR 87±7.8 bpm), with BHR significantly higher in women (P<0.0001). The distribution of HR was: <60 bpm (2.7%); HR 60-89 bmp (75.8%); HR≥90 bpm (20.1%). In the adjusted logistic regression model fasting plasma glucose (P=0.02; OR 95% CI: 1.18 [1.02-1.4]); age (P=0.01 OR 95% CI: 0.97 [0.96-0.99]); systolic blood pressure (P<0.001 OR 95% CI: 0.95 [0.9-0.97]), and diastolic blood pressure (P≤0.001 OR 95% CI: 1.1 [1.06-1.1]) emerged as independently associated with increasing BHR. The highest AUC for discriminating increasing BHR was for mean diastolic blood pressure (AUC=0.618; P<0.001), and fasting blood glucose (AUC=0.595; P<0.0001).

Increasing BHR was independently associated with derangements in fasting blood glucose and blood pressure.