Elevated resting heart rate is associated with several cardiovascular disease risk factors in urban-dwelling black South Africans

This study determined the associations of resting heart rate (RHR) with cardiovascular disease risk factors (CVDRF) in 25-74-year-old black South Africans. This cross-sectional study determined CVDRF by administered questionnaires, clinical measurements and biochemical analyses, including oral glucose tolerance tests. Multivariable linear regression models determined the associations of rising RHR with CVDRF. The basic model comprised age, gender, urbanisation, problematic alcohol use, daily cigarette smoking, physical activity and waist circumference. Glucose, blood pressure and cholesterol variables were entered separately and individually in the above model. Among the 1054 participants (382 men and 672 women, mean age 42.8 years), mean RHR was 70.6 beats per minute (bpm) and significantly higher in women (73.6 bpm) compared with men (65.3 bpm). RHR peaked in 45-54-year-old men (69.3 bpm) and 25-34-year-old women (75.3 bpm). Prevalence of RHR < 60 bpm and ≥90 bpm was 24.3% and 6.2%. In the regression model, female gender, problematic alcohol use, decreasing physical activity and increasing waist circumference were significantly associated with rising RHR. All glycaemic variables (diabetes, fasting glucose and 2-hour glucose) and diastolic blood pressure were significantly associated with RHR. The use of RHR in daily primary healthcare settings to identify increased risk for CVDRF should perhaps be encouraged.