Relationship between Nonspecific ST-T Changes in Exercise ECG and Predicted Maximal Oxygen Intake in Japanese Females

Abstract

This study was designed to clarify the relationship between aerobic power level, nonspecific ST-T changes in exercise ECG and coronary heart disease (CHD) risk factors in Japanese females.
Oxygen intake per kilogram of body weight (VO₂max/wt), nonspecific ST-T change in exercise ECG (horizontal and sagging depression ≥1mm) and CHD risk factors were examined in 317 middleaged healthy females.
The findings were as follows:
1) The mean value of VO₂max/wt in the nonspecific ST-T changes in exercise ECG group (ST group) was significantly lower than that found in the normal ECG group (N group) (p<0.05). However, the higher the mean values of the risk factors (SBP, TC, LDL-c, TC/HDL-c) in the ST group after adjusting for the effects of age and percent body fat (% fat) (all p<0.01). There were no significant differences between the ST group and the N group in the mean values of DBP, HDL-c, and TG.
2) Significant correlations were observed between VO₂max/wt and CHD risk factors (each p<0.0001 except for TG<0.001).
From these results, it was concluded that VO₂max/wt may be closely related to CHD risk factors and nonspecific ST-T changes in exercise ECG. Also these results suggest that it may be necessary to maintain the VO₂max/wt to a high level for coronary heart disease prevention.