Nocturnal saturation and glucose tolerance in children with cystic fibrosis
- Dharmeshkumar Suratwala1,
- June S H Chan2,
- Andrea Kelly3,
- Lisa J Meltzer1,
- Paul R Gallagher4,
- Joel Traylor1,
- Ronald C Rubenstein1,
- Carole L Marcus1,4
- 1Division of Pulmonary Medicine, Cystic Fibrosis and Sleep Center, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
- 2Department of Paediatrics and Adolescent Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong
- 3Division of Endocrinology, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
- 4Clinical and Translational Research Center, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
- Correspondence to Carole L Marcus, Children's Hospital of Philadelphia, Pulmonary Division, 9NW50, 34th Street & Civic Center Boulevard, Philadelphia, PA 19104, USA;
Contributors All authors contributed to aspects of study design, data collection, data interpretation and manuscript review.
- Received 6 May 2010
- Accepted 16 December 2010
- Published Online First 27 January 2011
Background Glucose intolerance is common in cystic fibrosis (CF), and is associated with worsening pulmonary function and nutritional status, and increased mortality. As sleep-disordered breathing is associated with disorders of glucose metabolism, it was hypothesised that recurrent episodes of hypoxaemia during sleep, and sleep disruption, would be associated with inflammation and glucose intolerance in CF.
Methods 25 children (aged 14±4 (mean±SD) years) with CF underwent polysomnography, actigraphy, measurement of serum inflammatory markers and oral glucose tolerance testing. Blood glucose area under the curve (AUC), as a cumulative measure of glucose response, was determined. Polysomnography data were compared with retrospective data from 25 healthy controls.
Results Forced expiratory volume in 1 s was 92±14% predicted. 24 subjects underwent glucose tolerance testing, of whom 29% had impaired glucose tolerance and 4% had diabetes. The mean nocturnal oxygen saturation correlated negatively with glucose AUC at 120 min (r=−0.49, p=0.015). Partial correlations and regression models including age, body mass index, nocturnal saturation and pulmonary function indicated that nocturnal saturation accounted for the majority of the predictive power for glucose AUC (R2=0.24, p=0.001). There were no meaningful relationships between sleep quality, inflammation and glucose tolerance.
Conclusions Lower oxyhaemoglobin saturation is associated with worse glucose regulation in children with CF. Further studies are needed to determine whether lower saturation negatively impacts glucose regulation or, alternatively, whether abnormalities in glucose metabolism are an early sign of pulmonary dysfunction.
DS and JSHC contributed equally to this work.
Funding This study was supported by the National Institutes of Health: Junior Investigator Pilot Grant Program from UL1 RR024134; R01 HL58585.
Competing interests None.
Ethics approval This study was conducted with the approval of the Institutional Review Board of the Children's Hospital of Philadelphia.
Provenance and peer review Not commissioned; externally peer reviewed.