Peak OGTT glucose is associated with lower lung function in young children with cystic fibrosis

Bernadette J Prentice; Avinesh Chelliah; Chee Y Ooi; Shihab Hameed; Charles F Verge; Leanne Plush; John Widger

doi:10.1016/j.jcf.2019.05.005

Peak OGTT glucose is associated with lower lung function in young children with cystic fibrosis

J Cyst Fibros. 2020 Mar;19(2):305-309. doi: 10.1016/j.jcf.2019.05.005. Epub 2019 May 22.

Authors

Bernadette J Prentice¹, Avinesh Chelliah², Chee Y Ooi³, Shihab Hameed⁴, Charles F Verge⁵, Leanne Plush⁶, John Widger⁷

Affiliations

¹ Department of Respiratory Medicine, Sydney Children's Hospital, Randwick, NSW, Australia; School of Women's and Children's Health, Medicine, The University of New South Wales, Randwick, NSW, Australia; Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), Sydney, Australia. Electronic address: bernadette.prentice@health.nsw.gov.au.
² School of Women's and Children's Health, Medicine, The University of New South Wales, Randwick, NSW, Australia.
³ School of Women's and Children's Health, Medicine, The University of New South Wales, Randwick, NSW, Australia; Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), Sydney, Australia; Department of Gastroenterology, Sydney Children's Hospital, Randwick, NSW, Australia.
⁴ School of Women's and Children's Health, Medicine, The University of New South Wales, Randwick, NSW, Australia; Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), Sydney, Australia; Department of Endocrinology, Sydney Children's Hospital, Randwick, NSW, Australia; University of Sydney, Faculty of Medicine, NSW, Australia.
⁵ School of Women's and Children's Health, Medicine, The University of New South Wales, Randwick, NSW, Australia; Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), Sydney, Australia; Department of Endocrinology, Sydney Children's Hospital, Randwick, NSW, Australia.
⁶ Department of Respiratory Medicine, Sydney Children's Hospital, Randwick, NSW, Australia.
⁷ Department of Respiratory Medicine, Sydney Children's Hospital, Randwick, NSW, Australia; School of Women's and Children's Health, Medicine, The University of New South Wales, Randwick, NSW, Australia; Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), Sydney, Australia.

PMID: 31126898
DOI: 10.1016/j.jcf.2019.05.005

Abstract

Background: Screening for Cystic Fibrosis-related diabetes is recommended in patients with CF <10 years old when there are concerns about growth and lung function. The Oral Glucose Tolerance Test (OGTT) is recommended but has not been validated in this cohort. We sought to determine whether the 2-h OGTT, the gold standard diagnostic test for CFRD, detects clinical decline in children with CF <10 years old.

Methods: We analysed blood glucose(BG) levels collected every 30 min during OGTT in 27 children with CF < 10 years old, comparing the 2-hour BG (BG_120min), peak BG (BG_max) and Area Under the Curve(AUC) for glucose and the association with lung function and nutritional status. We also compared the OGTT results with results from Continuous Glucose Monitoring (CGM) performed in 11 participants.

Results: The BG_max was higher than the BG_120min in 25/27 (93%) participants. There was a significant inverse correlation between BG_max and weight z-score (r_s = -0.56, p = .002) and between BG_max and FEV₁ (r_s = -0.54, p = .014) that was not present for BG_120min. A significant inverse correlation was also identified between fasting insulin level and elevated glucose on CGM, defined as AUC >7.8 mmol/L (r_{s =} - 0.69, p = .027) or as % time > 7.8 (r_s = - 0.76, p = .011).

Conclusions: Children with CF < 10 years of age with higher BG_max on OGTT have lower lung function and weight z- scores that may not be identified using the 2 h OGTT BG_120min. CGM also identifies glucose excursions in young children with CF.

Keywords: Abnormal glucose tolerance; CFRD; CGM; Child; Cystic fibrosis-related diabetes; Growth.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Blood Glucose / analysis*
Blood Glucose Self-Monitoring / methods
Child
Child Development
Correlation of Data
Cystic Fibrosis* / blood
Cystic Fibrosis* / complications
Cystic Fibrosis* / physiopathology
Diabetes Mellitus* / blood
Diabetes Mellitus* / diagnosis
Diabetes Mellitus* / etiology
Female
Glucose Intolerance* / blood
Glucose Intolerance* / diagnosis
Glucose Intolerance* / etiology
Glucose Tolerance Test / methods*
Humans
Insulin / blood*
Male
Mass Screening / methods
Nutritional Status
Respiratory Function Tests / methods

Substances

Blood Glucose
Insulin