RESUMO
Objective:To analyze levels of oral Streptococcus sanguinis( Ss)in middle-aged and elderly patients with primary microvascular angina(PMVA)and changes in vascular endothelial function. Methods:In this case-control study, 21 middle-aged and elderly patients diagnosed with PMVA at the Department of Cardiology, Hangzhou Red Cross Hospital between January 2019 and July 2022(the PMVA group)were recruited, with ages ranging from 45 to 80(63.4±12.3)years, while 23 healthy individuals receiving health checkups during the same period served as the control group, with ages ranging from 48-76(62.5±6.5)years.The 21 middle-aged and elderly PMVA patients underwent tests for the measurement of subgingival plaque Ss levels of the oral cavity and levels of plasma vascular von Willebrand factor(VWF)and homocysteine(Hcy). Pearson linear regression analysis was conducted.Results:Ss was not found in subgingival plaque of the oral cavity in the control group, but low levels of Ss were detected in patients from the PMVA group(percentage: 1.754×10 -4; 6.218×10 -5, 4.450×10 -4). The VWF level in the PMVA group was higher than in the control group[(20.22 ± 4.44)μg/L vs.(12.00 ± 6.60)μg/L, t=4.890, P<0.01]. There was no statistical difference in the Hcy level between the PMVA group and the control group[(15.28±6.40)μmol/L vs.(12.86±2.63)μmol/L, t=1.615, P>0.05]. There was no significant correlation between Ss levels and VWF levels in the PMVA group( r=0.038, P>0.05). Conclusions:Ss can be detected in subgingival plaque of the oral cavity in PMVA patients, but not in healthy middle-aged and elderly people.The VWF level in PMVA patients is significantly higher than in healthy people, indicating that vascular endothelial function is impaired in middle-aged and elderly PMVA patients.However, there is no correlation between subgingival plaque Ss levels of the oral cavity and VWF levels in PMVA patients.