Arterial Stiffness, Submaximal Heart Rate and Predicted Cardiovascular Fitness in College-Aged Mexican-American Males

Abstract

Increased arterial stiffness is a known predictor for cardiovascular disease. One population that is at a known greater risk for increased arterial stiffness is the Hispanic population. Additionally, little is reported on the association of heart rate response during and after submaximal exercise on individuals classified with borderline large artery elasticity (LAE). PURPOSE: The purpose of this study was to examine the differences in heart rate during a submaximal exercise test between individuals who have normal arterial stiffness and individuals who have borderline arterial stiffness within a Mexican-American (MA) college-aged population. METHODS: Arterial waveform was measured on 45 college-aged (24.07, +6.7) MA males. Standardized protocols for arterial waveform analysis were followed. Participants were also measured for height, weight, BMI, body fat, and blood pressure. Immediately following the arterial stiffness measurement each participant was asked to perform a three-minute submaximal cardiovascular step test (Queen's College Step Test [QCST]). Heart rate (HR) was recorded at the beginning of the test and at each ten second interval during the test and for two minutes post exercise to examine heart rate recovery (HRr). RESULTS: The results indicate 22 participants had normal LAE (17.52 ml/mmHg × 10 +2.58) and 23 with borderline LAE arterial elasticity (12.82 ml/mmHg × 10 +1.91). ANOVA results show no significant differences between the groups in height, weight, BMI, body fat, or initial QCST HR. Analysis of variance revealed significant HR differences (p<0.05) between LAE normal and borderline groups during the QCST at each ten second interval. The ANOVA also revealed HR differences during HRr at 10s, 20s, and 30s post exercise. Predicted VO2 for the normal LAE group (47.19 ml/kg/min +6.48) and borderline LAE group (42.44 ml/kg/min +6.08) was significantly different (p<0.05). CONCLUSIONS: The majority of the MA males in this sample are diagnosed with borderline LAE. The results indicate that although the two groups show a predicted healthy VO2, there are underlying arterial mechanisms attributed to arterial stiffness exhibited during submaximal exercise that may already be indicative of cardiovascular disease that a submaximal field test may not reveal.