Effect of anthropometric factors on the reproducibility of Doppler echocardiographic measurements during stationary bicycle exercise in healthy males
The effect of selected anthropometric indices on the reproducibility of continuous wave (CW) Doppler echocardiographic recordings in exercise were studied in 42 healthy males between 18 and 43 years of age. Each subject was measured and rank ordered in reference to four anthropometric Indices: sum of 3 skinfolds (SK); chest girth-waist girth ratio (CW); biacromial width-chest depth ratio (WD); and peak exercise ventilationâ forced vital capacity ratio (VV). Each subject then performed two maximal bicycle exercise tolerance tests on nonconsecutive days wherein the CW Doppler variables of peak acceleration (pKA), peak velocity (pKV) and stroke velocity integral (SVI) were measured along with heart rate (HR), blood pressure (BP) and respiratory gas analysis data including oxygen consumption (V0₂). Statistical analyses were then conducted to determine if subject groups with high vs. low values on any anthropometric index differentiated with regard to testâ retest reliability between bicycle exercise test trials. Statistical differences were noted between ( the high and a low groups for each index at the .05 alpha level. Pearson's Product Moment correlational analyses revealed that across all subjects the highest test-retest reliability occurred during the moderate intensity of exercise. The average test-retest correlation coefficients for the high and low groups within each index are as follows: SKH, = .52, SKL = 62, CWH = .64, CWL = .60, WDH. = 62,WDL = 58, VVh. = 61, VVL = .67. Inspection of test-retest correlations between the high vs. low groups for the anthropometric indicies revealed a trend in the skinfold index. For each dependent measure at all levels of exercise intensity, the low group exhibited higher correlation coefficients than the high group except for pKA at the peak level of exercise. The other three indicies exhibited no such trends. lt was concluded that since The other three indicies exhibited no such trends. lt was concluded that since the overall correlation coefficients (average = .65) were within the ranges of those computed for HR. BP and VO₂; (average = .50) the test-retest reliability with the CW Doppler was acceptable; but only during moderate levels of exercise. It was also determined from the correlation coefficients generated by the skinfold index data that measures obtained on lean individuals may be moree reproducible than measures obtained from obese individuals (See Table 2).