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Postprandial haemodynamic changes: a source of bias in cardiovascular research affected by its own methodological
C de Mey1, S Hansen-Schmidt, D Enterling
1SK&F Institute for Applied Clinical Pharmacology, Goettingen, Federal Republic of Germany.
Insights
Eating a cold meal significantly impacts heart rate and blood pressure, potentially skewing cardiovascular study results. Methodological choices in blood pressure measurement can introduce bias, affecting postprandial data interpretation.
Area of Science:
- Cardiovascular Physiology
- Human Nutrition
- Biomedical Engineering
Background:
- Postprandial physiological changes can influence cardiovascular measurements.
- Accurate blood pressure monitoring is crucial for clinical and research settings.
- Different blood pressure measurement techniques may yield varying results.
Purpose of the Study:
- To investigate the cardiovascular effects of consuming a cold meal.
- To compare different blood pressure measurement methods during postprandial state.
- To identify potential biases in cardiovascular data interpretation due to eating.
Main Methods:
- Randomized, balanced crossover study involving eight healthy young subjects.
- Assessment of heart rate and blood pressure (systolic and diastolic) after a 3100 kJ cold meal.
- Simultaneous blood pressure measurement using auscultation (Korotkoff I, IV, V) and an automated device with graphical analysis.
Main Results:
- Eating induced increases in mean heart rate and systolic blood pressure, with a decrease in diastolic blood pressure.
- Diastolic blood pressure decrease was overestimated using Korotkoff V compared to Korotkoff IV endpoints.
- Automated and graphical methods showed overall agreement with auscultation but less optimal quantitative agreement for postprandial effects.
Conclusions:
- Consuming food can alter cardiovascular parameters, potentially confounding study interpretations.
- Methodological bias in blood pressure measurement can affect the accuracy of postprandial cardiovascular assessments.
- Careful consideration of measurement techniques is necessary to avoid bias in studies involving eating.
Abstract:
The effects of heart rate and systolic and diastolic blood pressure of eating a 3100 kJ cold meal were assessed in eight young normal subjects studied in a randomised and balanced crossover study. Blood pressure was measured simultaneously and in the same arm by auscultation of the fossa cubitalis (Korotkoff I, IV, and V), by an automated device with a microphone over the brachial artery (equivalent to Korotkoff I and V), and by graphical analysis of these microphone signals (equivalent to Korotkoff I and IV). Eating caused a rise in mean heart rate, a small rise in systolic blood pressure, and a decrease in diastolic blood pressure, which was overestimated when Korotkoff V rather than Korotkoff IV endpoints were considered. Both the automated device and the graphical analysis yielded acceptable overall quantitative agreement with the auscultatory method. Both alternative methods allowed similar postprandial blood pressure trends to be detected, but the quantitative agreement in estimating the postprandial effects was far less optimal. Eating therefore was shown to cause changes that might distort and confuse the interpretation of cardiovascular data in studies in which subjects are allowed to eat. This source of bias itself appeared to be affected by its own methodological bias.