Allergic response to food triggers cardiovascular changes

Acute food-induced allergic reactions appear to substantially impact cardiovascular factors, such as stroke volume, heart rate, and peripheral blood flow, regardless of reaction severity, a recent study has found.

Fifty-seven adults participated in the double-blind, placebo-controlled food challenge, conducted over 2 separate days, at least 7 days apart. Participants were given increasing doses of peanut protein or placebo, concealed as dessert base matrix. Doses were 3, 30, and 300 µg, followed by 3, 30, 100, 30, and 1,000 mg; each administration was taken every 30 minutes.

Cardiovascular responses—heart rate, blood pressure, stroke volume, and peripheral blood flow, among others—were measured using validated and approved methods.

Stroke volume dropped from 54.6 mL/beat/m² at baseline to 52.3 mL/beat/m² after the challenge, corresponding to a statistically significant mean decrease of 4.2 percent (p=0.02). The change was also significant when compared to placebo (p=0.03).

Simultaneously, there was a significant 19.7-percent increase in peripheral blood flow (p<0.0001), accompanied by similar spikes in systolic and diastolic blood pressure, and in heart rate (p<0.0001 for all). All changes were significant relative to placebo. In turn, cardiac output jumped by a significant 0.23 L/min/m² (p=0.012) relative to placebo.

A repeat open peanut challenge was performed including 26 participants 3–12 months after. Similar cardiovascular responses were observed in this sample.

“These data provide a sound rationale for optimizing venous return during anaphylaxis through postural manoeuvres and fluid resuscitation in the management of refractory reactions, even in the absence of apparent cardiovascular compromise,” the researchers said.