Association between dehydration and stroke, a retrospective cohort study of a large database

Aging changes contribute to higher rates of dehydration in older adults. We searched a large database to see if there is an association between stroke and dehydration.

A retrospective cohort design utilizing TriNetX, an electronic health record database from 55 United States healthcare organizations with >85 million patients. The study population consisted of adults aged 80 years and older who had healthcare encounters between January 1, 2018 and December 31, 2019, before the pandemic. The dehydration cohort was identified using ICD-10 diagnosis codes and laboratory test results. Outcome measures included one of three stroke types: intracerebral hemorrhage, ischemic stroke, and transient ischemic attack, based on ICD-10 codes. A sub analysis of individuals with diabetes was undertaken.

Of 3,125,610 adults, 80 and older, 563,476 were dehydrated. Individuals with diabetes numbered 443,450 and 101,661 were dehydrated. The dehydration cohorts in both populations had a greater percentage of females, non-Hispanic, white individuals, and were slightly older (82.7 vs. 82.4, p <0.001). After controlling for common confounders in propensity score matching, individuals with dehydration were 1.98-3.99 times more likely to develop stroke: intracerebral hemorrhage (OR=3.99, 95% CI=3.41-4.67), ischemic stroke (OR=1.98, 95% CI=1.9-2.07), and TIA (OR=2.88, 95% CI=2.74-3.28). The diabetes group showed: intracerebral hemorrhage (OR=6.76, 95% CI=4-11.42), ischemic stroke (OR=1.97, 95% CI=1.81-2.16), and TIA (OR=2.81, 95% CI=2.33-3.39).

A strong association between dehydration and stroke was found. The largest association was with intracerebral hemorrhage. Both physiologic changes of normal aging and medications used to treat cardiovascular stroke risk factors increase older adults' risk for dehydration. The strength of this study is the propensity risk management of over 3 million older adults (≥80 years). Limitations of this study include the retrospective nature of database evaluation. Future studies should evaluate whether increased hydration status leads to decreased stroke.