Hot flashes, core body temperature, and metabolic parameters in breast cancer survivors

Objective: To examine core body temperature, energy expenditure, and respiratory quotient among breast cancer survivors experiencing hot flashes and compare these data to published studies from healthy women. Design: In an observational study, nine breast cancer survivors with daily hot flashes who met specified criteria spent 24 hours in a temperature- and humidity-controlled whole-room indirect calorimeter (ie, metabolic room). Demographic and disease/treatment information were obtained and the following were measured: hot flashes via sternal skin conductance monitoring (sampled every second); core body temperature via an ingested radiotelemetry pill (sampled every 10 seconds); and energy expenditure and respiratory quotient via a whole-room indirect calorimeter (calculated every minute). Results: Circadian analysis of core temperature indicated wide variability with disrupted circadian rhythm noted in all women. Core temperature began to rise 20 minutes pre-flash to 7 minutes pre-flash (0.09degreesC increase). Increases in energy expenditure and respiratory quotient increased with each hot flash. Conclusions: Findings are comparable to published data from healthy women and warrant replication in larger, more diverse samples of women treated for breast cancer.