Orthostatic Hypotension Guidelines Called into Question
Modifications should be made to the current guidelines for assessing orthostatic hypotension, say researchers from Johns Hopkins University School of Medicine. A new report highlighting the study findings has been published in JAMA Internal Medicine.
Current guidelines recommend that patients be assessed for orthostatic hypotension three minutes after rising from supine to standing positions, however, whether measurements taken immediately after standing can predict adverse events has yet to be established. The researchers, led by Stephen P. Juraschek, MD, PhD, set out to compare early vs. later orthostatic hypotension measurements and their correlation with history of dizziness and longitudinal adverse outcomes.
The team conducted a prospective cohort study of adults aged 44–66 years who participated in the Atherosclerosis Risk in Communities Study (1987–1989). Orthostatic hypotension was defined as a drop in blood pressure (systolic ≥20mmHg or diastolic ≥10mmHg) from supine to standing, measured up to five times every 25 seconds. They measured the link between each of the five measurements with history of dizziness on standing and the risk of fall, fracture, syncope, motor vehicle crashes, and all-cause mortality over a median 23 years of follow-up.
Of the total 11,429 patients with ≥4 measurements after standing, the authors found that measurement 1 (mean 28 seconds; range 21–62 seconds) was the only one associated with a higher likelihood of dizziness (odds ratio [OR] 1.49, 95% CI: 1.18–1.89). Specifically, measurement 1 was linked to the highest rates of fracture (18.9 per 1000 person-years), syncope (17.0 per 1000 person-years), and death (31.4 per 1000 person-years).
In contrast, measurement 2 (mean 53 seconds; range 43–83 seconds) was associated with the highest rate of falls (13.2 per 1000 person-years) and motor vehicle crashes (2.5 per 1000 person-years).
After adjustments, measurement 1 was significantly associated with risk of fall (HR 1.22, 95% CI: 1.03–1.44), fracture (HR 1.16, 95% CI: 1.01–1.34), syncope (HR 1.40, 95% CI: 1.20–1.63), and death (HR 1.36, 95% CI: 1.23–1.51). Measurement 2 was associated with all long-term outcomes, including motor vehicle crashes (HR 1.43, 95% CI: 1.04–1.96).
Orthostatic hypotension measurements taken after the first minute were not associated with dizziness; no consistent ties were seen with individual long-term outcomes.
The study authors concluded that orthostatic hypotension should be assessed within 1 minute of standing position, as data showed the strongest correlation to dizziness and individual adverse events. Dr. Juraschek added, "These results show that assessing OH within the first minute not only is OK, but also makes a lot of sense because it's more predictive of future falls."
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