Abstract:

Objective To discuss the association between hemodynamic patterns and the risk of ischemic stroke in the people with chronic orthostatic intolerance （OI）， and to provide the basis for the early assessment of the onset of ischemic stroke. Methods A total of 638 residents aged ≥40 years from three streets/townships in Changchun City of Jilin Province were selected as the subjects by multistage random sampling method. Transcranial Doppler （TCD） combined with head-up tilt test （HUTT） were used to evaluate the hemodynamic patterns of the people with OI， and the OI research cohort was established. The patients were divided into orthostatic hypotension （OH） group， orthostatic hypertension （OHT） group， postural tachycardia syndrome （POTS） group， and orthostatic cerebral hypoperfusion syndrome （OCHOs） group according to the changes of hemodynamics. The subjects were followed up once every six months for two years， and the first incidence of ischemic stroke of the subjects was regarded as the observation endpoint；the baseline data and incidence of ischemic stroke of the subjects during the follow-up period were collected； Cox proportional hazards model was used to analyze the association factors with the risk of ischemic stroke. Results A total of 121 subjects were diagnosed with OI， including 80 subjects （66.12%） in OH group， 35 subjects （28.93%） in OHT group， 5 （4.13%） subjects in POTS group， and 1 subject （0.82%） in OCHOs group. During the follow-up period， the overall people had 43 confirmed new cases of ischemic stroke. After controlling the related confounding factors， compared with non-OI individuals， the risk of ischemic stroke in the entire OI people， as well as in the OH and OHT patients， was increased by 1.527 times ［hazard ratio （HR）=2.527， 95% confidence interval （CI）： 1.269－5.032， P<0.01）］， 2.268 times （HR=3.268， 95% CI： 1.603－6.663， P=0.001）， and 2.153 times （HR=3.153， 95% CI： 1.213－8.916， P=0.008）， respectively. Conclusion OI is associated with the increased risk of ischemic stroke， particularly in the patients in OH and OHT groups.

Key words: Orthostatic intolerance, Orthostatic hypotension, Orthostatic hypertension, Ischemic stroke, Transcranial doppler, Head-up tilt test