Objective  To investigate the relationship between cerebral microbleeds (CMBs) and blood pressure variability (BPV) in patients with asymptomatic lacunar infarction (LI).

Methods  The asymptomatic LI patients were selected as the research objects. A total of 50 patients with CMBs displayed by magnetic sensitivity imaging (SWI) were designed as study group, and 50 patients without CMBs were selected as control group. The clinical materials were collected in both groups, the parameters related to BPV were collected by ambulatory blood pressure monitoring (ABPM), and the rhythm was classified.

Results  The 24 h mean systolic blood pressure (24 h SBP), nighttime mean systolic blood pressure (NSBP), nighttime mean diastolic blood pressure (NDBP), 24 h coefficient of variation of systolic blood pressure (24 h SBP-CV) and 24 h coefficient of variation of diastolic blood pressure (24 h DBP-CV) in the study group were significantly higher than those in the control group (P < 0.05 or P < 0.01). There were 44 cases (88.00%) with abnormal rhythm in the study group and 35 cases (70.00%) with abnormal rhythm in the control group, and the difference was statistically significant (P < 0.05). The incidence rates of CMBs in patients with abnormal rhythms of non-dipper type, anti-dipper type and super-dipper type in the study group were 29.55% (13/44), 43.18% (19/44) and 27.27% (12/44) respectively, which showed significant differences when compared to 42.86% (15/35), 17.14% (6/35) and 40.00% (14/35) respectively in the control group (P=0.047). Spearman analysis showed that 24 h DBP-CV and 24 h SBP-CV were positively correlated with the grading of CMBs number (r=0.561, 0.435, P < 0.01).

Conclusion  Both meanblood pressure and BPV are correlated with CMBs, and the higher the mean blood pressure and BPV are, the higher the incidence of CMBs is; abnormal rhythm is an important risk factor for CMBs; CV is positively correlated with the severity of CMBs.