70岁及以上人群收缩压与认知障碍的相关关系:一项以西安市鄠邑区农村人群为基础的横断面调查

Objective: To study the relationship between blood pressure and cognitive impairment in people aged ≥70 years. Methods: From October 2014 to March 2015, blood pressure and global cognitive function information were collected from the participants aged ≥70 years who lived in a village in the suburbs of Xi'an, China, during in-person interviews. Mini-mental State Examination (MMSE) was used to evaluate global cognitive function. Cognitive impairment was defined as the MMSE score lower than the cutoff value. Specifically, the cutoff value was ≤17 for the illiterate, ≤20 for the primary school educated, and ≤24 for those educated at the junior high school level and above. Multivariate Logistic regression was performed to correct confounding factors. Results: A total of 236 permanent residents aged ≥70 lived in the village. Of them 217 subjects (92.0%) completed blood pressure measurement and MMSE examination and 31 subjects were excluded because of previous stroke. A total 186 subjects were enrolled in the analysis, including 87 males (46.8%). The age ranged from 70 to 85 years (mean 74.17±3.97 years), and 64 people (34.4%) were diagnosed with cognitive impairment. The mean systolic blood pressure (SBP) was (143.45±20.25)mmHg. Totally 69 subjects had SBP of ≤139 mmHg, 66 subjects had SBP of 140-159 mmHg, and 51 subjects had SBP of ≥160 mmHg. Univariate analysis showed that both subjects with SBP ≤139 mmHg and those with SBP ≥160 mmHg had a higher prevalence of cognitive impairment compared with the subjects with SBP of 140-159 mmHg (≤ 139 mmHg vs. 140-159 mmHg vs. ≥160 mmHg, 40.6% vs. 25.8% vs. 37.3%, P=0.171). Multivariate Logistic regression analysis showed that compared with the reference group (140-159 mmHg), both subjects with a lower SBP (OR=2.99, 95% CI 1.19-7.53, P=0.020) and those with a higher SBP (OR=2.66, 95% CI 0.97-7.28, P=0.057) had a higher risk of cognitive impairment. The mean diastolic blood pressure (DBP) was (82.48±10.34)mmHg. 136 (73.1%) subjects had DBP of ≤89 mmHg, 29 (15.6%) subjects had DBP of 90-99 mmHg, and 21 (11.3%) ones had DBP of ≥100 mmHg. There was no significant difference in the prevalence of cognitive impairment among the three groups (≤89 mmHg vs. 90-99 mmHg vs. ≥100 mmHg, 35.3% vs. 34.5% vs. 28.6%, P=0.833). Multivariate Logistic regression analysis showed no significant correlation between cognitive impairment and DBP (P=0.714). Conclusion: In this cross-sectional survey, SBP below 140 mmHg or above 160 mmHg is associated with an increased risk of cognitive impairment in people aged 70 years or above. However, no significant correlation was found between DBP and cognitive impairment.