title: Elevation of one hour plasma glucose during oral glucose tolerance testing.
abstract: OBJECTIVE
  In cystic fibrosis (CF) patients, elevations in 1 hr plasma glucose (PG1) during a 75 g oral glucose tolerance test are common, but of unclear long-term clinical relevance. Thus, we examined associations of PG1 with percent-predicted forced expiratory volume in 1 sec (FEV1 % predicted), CF exacerbations, and CF related diabetes (CFRD) development.
  
  
  METHODS
  We conducted a retrospective cohort study of 80 pediatric patients with CF (43 males) followed over 5 years in a single CF center. We considered the association between elevated versus normal PG1 (greater vs. no greater than 160 mg/dl) and linear changes in FEV1 % predicted over time for males and female, as well as the odds of a CF exacerbation and the odds of developing CFRD.
  
  
  RESULTS
  No significant difference in FEV1 % predicted between normal versus elevated PG1 was found at baseline, or over time in males or females. However, males with elevated PG1 tended to have worse FEV1 % predicted over time than those with normal PG1 (reduction of 0.9 FEV1 % predicted/year, 95%CI: -2.5, 0.6). Subjects with PG1 > 160 mg/dl were more likely to develop CFRD (OR 4.5, 95%CI: 1.7, 18.7, P = 0.04) but CF exacerbation risk was similar in both groups.
  
  
  CONCLUSIONS
  The risk of CFRD increases with PG1 > 160 mg/dl. No statistically significant evidence of an association between elevated PG1 and pulmonary function was found, yet our results do not exclude the possibility that in males, elevated PG1 may signal adverse changes in FEV1 % predicted over time. This possibility requires further study with a larger sample size.
authors.affiliation: Division of Pulmonary Medicine and Cystic Fibrosis Center, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.|Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Saba
authors.initials: S
authors.lastname: Sheikh
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Putt
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.|Division of Gastroenterology, Hospital of University of Pennsylvania and Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Forde
authors.affiliation: Division of Pulmonary Medicine and Cystic Fibrosis Center, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.|Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Rubenstein
authors.affiliation: Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.|Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Andrea
authors.initials: A
authors.lastname: Kelly
mesh_terms: D000293:Adolescent; D001786:Blood Glucose / Q000032:analysis*; D002648:Child; D015331:Cohort Studies; D003550:Cystic Fibrosis / Q000097:blood / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology*; D005951:Glucose Tolerance Test; D006801:Humans; D008297:Male; D012189:Retrospective Studies
chemical_list: D001786:Blood Glucose
keywords: cystic fibrosis; cystic fibrosis related diabetes; oral glucose tolerance test