Absence of fluctuation and inverted circadian rhythm of blood pressure increase the risk of cognitive dysfunction in cerebral small vessel disease patients

BACKGROUND AND PURPOSE: Cerebral small vessel disease (CSVD) is a common cause of stroke and senile vascular cognitive impairment, imposing a heavy burden on public health care systems worldwide. Hypertension and 24-hour blood pressure variability (BPV), known to be significant risk factors for cognitive dysfunction, have been found to be associated with cognitive function in CSVD patients in previous studies. However, as a derived part of BPV, there are few studies on the relationship between circadian rhythm of blood pressure and cognitive dysfunction in CSVD patients, and the relationship between them is still unclear. Thus, this study aimed to investigate whether the disturbance of circadian rhythm of blood pressure can affect the cognitive function of patients with CSVD. METHODS: A total of 383 CSVD patients hospitalized in the Geriatrics Department of the Lianyungang Second People’s Hospital between May 2018 and June 2022 were enrolled in this study. The clinical information and parameters of 24-hour ambulatory blood pressure monitoring were compared between the cognitive dysfunction group (n = 224) and the normal group (n = 159). Finally, a binary logistic regression model was used to assess the relationship between circadian rhythm of blood pressure and cognitive dysfunction in patients with CSVD. RESULTS: (1) Patients in the cognitive dysfunction group were older, had lower blood pressure on admission, and had a greater number of previous cardiovascular and cerebrovascular diseases (P < 0.05). (2) More patients in the cognitive dysfunction group had circadian rhythm abnormalities in blood pressure, especially the non-dipper and reverse-dipper types (P < 0.001). (3) In the elderly, there was a statistical difference in the circadian rhythm of blood pressure between the cognitive dysfunction group and the normal group, but this phenomenon did not exist in the middle-aged. (4) Binary logistic regression analysis showed that after adjusting for confounding factors, the risk of cognitive dysfunction in CSVD patients with non-dipper type was 4.052 times higher than that of dipper type (95% CI, 1.782–9.211; P = 0.001), and reverse-dipper type was 8.002 times higher than those with dipper type (95% CI, 3.367–19.017; P<0.001). CONCLUSIONS: The disturbance of circadian rhythm of blood pressure may affect the cognitive function of patients with CSVD, and the risk of cognitive dysfunction in non-dipper and reverse-dipper types are higher.