The following is a summary of “Hemodynamic Effects of the Osmopressor Response: A Systematic Review and Meta‐Analysis,” published in the November 2023 issue of Cardiology by Oyewunmi et al.

Rapid water intake has been proposed as a potential therapy for orthostatic hypotension, but its efficacy across various conditions remains uncertain. This study aimed to evaluate the effects of rapid consumption of 350 to 500 mL of water on systolic and diastolic blood pressure (BP) and heart rate (HR) through a comprehensive systematic review and meta-analysis.

A systematic review encompassed MEDLINE and Embase databases until June 2023, focusing on randomized controlled trials and prospective cohort studies. Employing random-effects meta-analysis, pooled mean differences (MDs) were calculated for the maximum hemodynamic effects following the rapid ingestion of 350 to 500 mL of water. Among individuals with orthostatic hypotension, there was an increase in systolic BP (MD, 24.18 [95% CI, 15.48–32.88]) and diastolic BP (MD, 11.98 [95% CI, 8.87–15.09]) alongside a decrease in HR (MD, −3.46 [95% CI, −5.21 to −1.71]). These effects were similarly observed in subgroup analyses of multiple system atrophy and pure autonomic failure. In contrast, healthy individuals exhibited modest increases in systolic BP (MD, 2.33 [95% CI, 1.02–3.64]) and diastolic BP (MD, 2.73 [95% CI, 1.15–4.30]) with non-significant HR changes (MD, −2.06 [95% CI, −5.25 to 1.13]). Notably, in patients with seated or supine postural tachycardia syndrome, water intake did not significantly affect hemodynamics, although the effects while standing were not evaluated. This study did not address the potential impact of water intake on postural tachycardia syndrome in a standing position.

Rapid water consumption was associated with elevated short-term systolic and diastolic BP and a mild reduction in HR among individuals with orthostatic hypotension, while the effects were milder in healthy participants. However, no significant changes in seated or supine positions were observed in patients with postural tachycardia syndrome. Further research is necessary to explore the potential benefits of rapid water ingestion in standing positions for individuals with postural tachycardia syndrome, an aspect not covered in this study.

Source: ahajournals.org/doi/10.1161/JAHA.122.029645