Resting energy expenditure in females with cystic fibrosis: is it affected by puberty?

OBJECTIVE: The aims of this study were to determine the effect of puberty and the menstrual cycle on resting energy expenditure (REE) in females with cystic fibrosis (CF). DESIGN: Cross-sectional study. All participants had measurements of REE, anthropometry and pubertal staging. The measurements in the postmenarche group were carried out both in the follicular and luteal phases of their menstrual cycle. SETTING: CF outpatient clinic at the Children's Hospital at Westmead. SUBJECTS: Fifty-six females with CF and pancreatic insufficiency (13 postmenarche) were recruited from the hospital clinic and 63 controls (21 postmenarche) were recruited through families and friends of hospital staff. RESULTS: Females with CF had a higher REE than controls (111.6+/-12.8% of predicted from controls P<0.001). There was a significant effect of menarche on REE with a decrease in the postmenarche -470 kJ/24 h compared with premenarche after adjustment for fat-free mass, fat mass and group (control or CF). There was no difference in REE between the follicular and luteal phases for either CF or controls. CONCLUSIONS: Females with CF had raised REE that appeared to be independent of menarche. This study implies all females with CF and pancreatic insufficiency may need more intensive dietary management, owing to raised REE, to maintain growth and nutritional status, and possibly improve survival.