OBJECTIVETo investigate the correlation of the onset time of sudden deafness and blood rheology using a large-scale retrospective study.

METHODSOne hundred and ninety-eight patients of sudden deafness were examined with blood rheology and compared with 60 healthy people. Thirty patients were as subjects to study the circadian of blood rheology in order to search whether the blood rheology of morning was the highest. By divided 24 hours into twelve groups, each group contained two hours. Then the 198 patients were separated into twelve groups according to the time of onset. The blood rheology of each group was analyzed and compared with each other to observe which group was the highest.

RESULTSMost blood rheology index of the patients were higher than that of the healthy people. The onset time in most of the patients was during 4 am-8 am, but 45 patients during 4 am-6 am and 40 patients during 6 am-8 am. By analyzing and comparing the blood rheology of each group, the results showed that the blood rheology index in the group of 4 am-8 am was highest. And the blood rheology index of sudden deafness was highest in the morning.

CONCLUSIONSThere was a close relation between blood rheology and sudden deafness. The peak time of onset was 4 am-8 am, and the patients whose blood rheology were the highest should be more predisposed to sudden deafness than the other patients.