Gender differences in diastolic function among youth.

BACKGROUND: Youth were studied to determine the influence of gender on diastolic function, which has been shown to express abnormalities early in the course of congestive heart failure.
METHODS: The study participants were 121 normotensive individuals (53 girls, 68 boys) ages 14 to 18 years. Demographics, hemodynamics, and Doppler-derived indices of diastolic function were collected. Dependent measures of diastolic function were the ratio of early (E) to late (A) peak filling velocities and the isovolumetric relaxation time (IVRT).
RESULTS: The girls had a higher relative wall thickness (RWT) (36.58% +/- 4.59% vs 34.60% +/- 4.01%; p < 0.02), higher A (48.40 +/- 8.47 cm/s vs 42.36 +/- 10.43 cm/s; p < 0.001), a lower E/A ratio (1.96 +/- 0.40 vs 2.38 +/- 0.68; p < 0.01), and a shorter IVRT (51.80 +/- 11.14 ms vs 59.00 +/- 14.36 ms; p < 0.01) than the boys. The differences in deceleration time were not significant (181.30 +/- 81.33 ms vs 170.30 +/- 31.06 ms). Hierarchical stepwise regression analysis predicting E/A ratio found gender (male > female) to be the best predictor (R (2 )= 0.09) followed by heart rate (R (2) increase = 0.07; total R (2 )= 0.15; p < 0.01) and by RWT (R (2) increase = 0.05; total R (2 )= 0.21; p < 0.015). For IVRT prediction, gender (male > female) was the best predictor (R (2 )= 0.11), followed by total peripheral resistance (R (2) increase = 0.06; total R (2 )= 0.17; p < 0.017).
CONCLUSION: The study data indicate that gender differences in diastolic function exist already in youth. Girls show a higher RWT, a lower E/A ratio, and a shorter IVRT. The implications of these differences for cardiovascular morbidity and mortality of the two genders require attention.