Revisiting the association of blood pressure with mortality in oldest old people in China: community based, longitudinal prospective studyBMJ 2018; 361 doi: https://doi.org/10.1136/bmj.k2158 (Published 05 June 2018) Cite this as: BMJ 2018;361:k2158
- Yue-Bin Lv, assistant research fellow1,
- Xiang Gao, professor2,
- Zhao-Xue Yin, associate research fellow3,
- Hua-Shuai Chen, professor4,
- Jie-Si Luo, assistant research fellow3,
- Melanie Sereny Brasher, associate professor5,
- Virginia Byers Kraus, professor6,
- Tian-Tian Li, research fellow1,
- Yi Zeng, director and professor4 7,
- Xiao-Ming Shi, director and research fellow1
- 1National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
- 2Nutritional Epidemiology Lab, Pennsylvania State University, Philadelphia, PA, USA
- 3Division of Non-Communicable Disease Control and Community Health, Chinese Center for Disease Control and Prevention, Beijing, China
- 4Center for the study of Aging and Human Development and the Geriatric Division of School of Medicine, Duke University, Durham, NC, USA
- 5Department of Sociology and Anthropology and Department of Human Development and Family Studies, University of Rhode Island, Kingston, RI, USA
- 6Duke Molecular Physiology Institute and Division of Rheumatology, Department of Medicine, Duke University School of Medicine, Durham, NC, USA
- 7Center for Study of Healthy Aging and Development Studies, Peking University, Beijing, China
- Correspondence to: X-M Shi
- Accepted 17 April 2018
Objective To examine the associations of blood pressure with all cause mortality and cause specific mortality at three years among oldest old people in China.
Design Community based, longitudinal prospective study.
Setting 2011 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey, conducted in 22 Chinese provinces.
Participants 4658 oldest old individuals (mean age 92.1 years).
Main outcome measures All cause mortality and cause specific mortality assessed at three year follow-up.
Results 1997 deaths were recorded at three year follow-up. U shaped associations of mortality with systolic blood pressure, mean arterial pressure, and pulse pressure were identified; values of 143.5 mm Hg, 101 mm Hg, and 66 mm Hg conferred the minimum mortality risk, respectively. After adjustment for covariates, the U shaped association remained only for systolic blood pressure (minimum mortality risk at 129 mm Hg). Compared with a systolic blood pressure value of 129 mm Hg, risk of all cause mortality decreased for values lower than 107 mm Hg (from 1.47 (95% confidence interval 1.01 to 2.17) to 1.08 (1.01 to 1.17)), and increased for values greater than 154 mm Hg (from 1.08 (1.01 to 1.17) to 1.27 (1.02 to 1.58)). In the cause specific analysis, compared with a middle range of systolic blood pressure (107-154 mm Hg), higher values (>154 mm Hg) were associated with a higher risk of cardiovascular mortality (adjusted hazard ratio 1.51 (95% confidence interval 1.12 to 2.02)); lower values (<107 mm Hg) were associated with a higher risk of non-cardiovascular mortality (1.58 (1.26 to 1.98)). The U shaped associations remained in sensitivity and subgroup analyses.
Conclusions This study indicates a U shaped association between systolic blood pressure and all cause mortality at three years among oldest old people in China. This association could be explained by the finding that higher systolic blood pressure predicted a higher risk of death from cardiovascular disease, and that lower systolic blood pressure predicted a higher risk of death from non-cardiovascular causes. These results emphasise the importance of revisiting blood pressure management or establishing specific guidelines for management among oldest old individuals.
Contributors: Y-BL, XG, and Z-XY contributed to the concept and data analysis of the manuscript. H-SC and J-SL helped to implement the survey. X-MS and YZ designed the survey. MSB, VBK, and T-TL helped to conduct the data analysis. X-MS was responsible for accuracy of data analysis. All authors contributed to the framework construction, results interpretation, manuscript revision, and approved the final version of the manuscript. XMS is guarantor. The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.
Funding: The Chinese Longitudinal Healthy Longevity Survey, which provided the data analysed in this article, is jointly supported by National Natural Sciences Foundation of China (71233001, 71490732, and 81573247), US National Institute of Ageing (2P01AG031719), United Nations Fund for Population Activities, and a grant from the Claude D Pepper Older Americans Independence Center (5P30 AG028716 from the National Institute of Ageing to VBK). The funders had no role in the study design or implementation; the data collection, management, analysis, and interpretation; the manuscript preparation, review, or approval; or the decision to submit the manuscript for publication.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: support from the National Natural Sciences Foundation of China, US National Institute of Ageing, United Nations Fund for Population Activities, and Claude D Pepper Older Americans Independence Center for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: The biomedical ethics committee of Peking University approved the study (IRB00001052-13074), and all participants or their proxy respondents provided written informed consent.
Data sharing: No additional data available.
The lead author affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.
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