Resting Heart Rate and Its Relationship with General and Abdominal Obesity in Young Male Saudi University Students

Background: An elevated resting heart rate (RHR) has been linked with adverse cardiovascular outcomes. Obese people have altered autonomic balance that could lead to elevated RHR and altered responses to postural changes. As no comparative data are available on RHR in young normal weight (NW) and obese (OB) adults in Saudi Arabia, the present study was aimed at finding out the effect of adiposity on RHR and RHR response to change in posture. Methods: Second-year male students (n=231; age:19–20 years), were recruited from the Dammam University, Dammam, Saudi Arabia, during the period September 2008 to October 2009. Anthropometric measures were obtained and indices of obesity (body mass index [BMI], waist circumference [WC], waist-to-hip ratio [WHR], waist-to-stature ratio [WSR]) were calculated. RHR in standing and supine positions were obtained from radial pulse. Pearson’s correlation (r) between obesity indices and RHR as well as the differences between RHR in NW and OB groups were calculated. Results: General obesity (BMI≥25.0 kg/m) was found in 45.5% students. Central obesity (WC>85 cm or WSR>50.0) was found in 36.8% students. RHR was significantly correlated with BMI, WC and WSR (r=0.305, 0.300, 0.299 respectively, p<0.01). Subjects above the obesity indices cut-off points had significantly higher values of RHR in both standing and supine positions compared to NW individuals (p<0.05). There was a greater reduction in RHR on changing the posture to supine state in OB group. Conclusion: A significantly higher RHR and a greater change in RHR on changing the posture point towards an altered autonomic balance in OB group of young adolescent males. This underscores the need to implement health education program to combat obesity at school and college levels.