Objective: To study the reference range of cerebrovascular hemodynamics indexes (CVHI) in a sampling population.
Methods: Fourteen thousand, four hundred and eighty participants without history of stroke or exposure to risk factors were screened from 26 cities in Northeast China, North China, East China, Northwest China, South China, and Southwest China in the prospective study on stroke intervention. CVHI were checked and 95% confidence intervals were calculated using normal distribution methods, which were grouped by age, sex, area, and check positions.
Results: Characteristics of CVHI 95% confidence intervals showed that low limit of carotid blood velocity as V(max), V(min), V(mean) decreased, but upper limit of cerebral RV, Zcv, WV, DR and CP increased with the increase of age. However, Q(mean) and DP did not show significant trends of age difference. Low limit of Q(mean), V(max) and upper limit of RV, DR, CP and DP in males were higher than that in females while upper limit of WV and Zcv in females were higher than that in males. Left carotid low limit of Q(mean), V(mean), V(max), V(min), and upper limit of WV, Zcv and CP were higher than that of the right but upper limit of RV, DR and DP were lower than that of the right. There were no obvious differences between areas.
Conclusion: Obvious differences of CVHI 95% confidence intervals ranges were found between age groups, sex, and checking positions, respectively, suggesting that the reference ranges of CVHI to be estimated by every subgroup.