Short-term (5-day) changes in food intake alter daily hemodynamics in rabbits

In humans, particularly among individuals trying to lose weight, cycles of hypophagia followed by cycles of hyperphagia are quite common and may lead to an increased cardiovascular morbidity. The aim of the present study was to evaluate the alterations in daily mean arterial pressure (MAP) and heart rate (HR) during short-term (5-day) changes in food intake.

Adult male rabbits instrumented for continuous (24 h/day) telemetric recording of blood pressure (BP) and HR were subjected to five 14-day periods of altered food intake. Each period consisted of 5 days in which food intake was set to -50%, -25%, +25%, +50%, or +100% (food ad libitum) per day followed by 9 days at 150 g/day of maintenance diet.

The increase in food intake induced an immediate and significant increase in HR and a less pronounced increase in MAP. Similarly, a 25% and 50% decrease in food intake induced a decrease in HR and MAP. Unlike the increase in HR during hyperphagia, which reached a plateau after 1 day, the decrease in HR during hypophagia was progressive. The effect of hyperphagia on MAP and HR was reversible within 1 day, whereas hypophagia induced changes were persistent over several days.

A highly significant linear relationship can be established across the alterations in food intake (from -50% to +100%) and the respective changes in blood pressure (BP) or HR. These data suggest that prompt changes in hemodynamics induced by alterations in food intake might be implicated in the early events during weight gain or during weight loss.