Reproducibility of pulse contour analysis in children before and after maximal exercise stress test: The Physical Activity and Nutrition in Children (PANIC) Study

Summary Objective: Arterial stiffness index (SI) and reflection index (RI) from digital pulse contour analysis have been shown to be good measures of arterial stiffness and may be useful in the evaluation of endothelial function. Finger skin temperature (FST) is also considered to reflect peripheral circulatory functions. We evaluated the reproducibility of SI, RI and FST before and after the exercise stress test. Methods: The subjects were 36 children (16 boys, 20 girls) 6–8 years of age. We measured SI, RI and FST at rest both before and after the exercise stress test on a cycle ergometer and repeated these measurements within 5–14 days. The reproducibility of SI, RI and FST was evaluated by calculating intraclass correlation coefficients (ICC), coefficients of variation (CV%) and 95% limits of agreements. Results: SI had a greater reproducibility after the exercise stress test than before it (CV% 4·8 versus 6·3%, ICC 0·548 versus 0·438). RI had a better ICC (0·689 versus 0·416) but a higher CV% (28·6 versus 18·7%) after the exercise stress test than before it. Relative change in response to the exercise stress test in SI (−1·5% at first visit and 0·4% at second visit) was not as dramatic as in RI (−49·3% at first visit and −46·5% at second visit). The reproducibility of FST was also better after the exercise test than before it (CV% 5·7 versus 10·0%, ICC 0·509 versus 0·503). Conclusion: In healthy children, the reproducibility of SI, RI and FST was relatively good, especially after the exercise stress test.