Glucose intolerance in cystic fibrosis as a determinant of pulmonary function and clinical status.
BACKGROUND
Cystic fibrosis related diabetes (CFRD) is associated with a decrease in pulmonary function and nutritional status. We investigated the clinical significance of impaired glucose tolerance (IGT) in cystic fibrosis (CF) patients.


METHODS
Fifty-five CF patients (aged 22.8 ± 9.2 years, 29 males, mean FEV1 67.9 ± 22% predicted, mean BMI-SDS -0.23 ± 1.1) underwent a 2-h Oral Glucose Tolerance Test (OGTT) with 30-min interval measurements of glucose and insulin. Additional clinical and laboratory data were obtained from the medical charts.


RESULTS
Thirty-eight participants (69%) had normal glucose tolerance (NGT), 13 (23.7%) had IGT, and 4 (7.3%) had newly diagnosed CFRD. Compared to patients with NGT, patients with IGT had significantly lower BMI-SDS (-1.1 ± 0.8 vs. 0.1 ± 1.1, p<0.001), mean FEV1 (57 ± 19 vs. 74 ± 21% predicted, p<0.01), and albumin (3.9 ± 0.3 vs. 4.3 ± 0.2g/dl, p=0.004), and higher fibrinogen (376 ± 56 vs. 327 ± 48 g/dl, p=0.02). Patients with IGT had impaired β-cell function, with reduced first phase insulin secretion, a delayed insulin peak, and significantly lower total insulin secretion, HOMA-%B and insulinogenic index. Seven patients had HbA1c in the "diabetic" range (≥6.5%; 47.5 mmol/mol), however, HbA1c was not a sensitive or specific marker of glucose tolerance status.


CONCLUSIONS
IGT in CF patients is associated with increased inflammation and decreased nutritional status and pulmonary function.
Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel Hashomer, Israel(1). Electronic address: moran.lavie@sheba.health.gov.il.
Moran
M
Lavie
Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel Hashomer, Israel(1).
Dor
D
Fisher
Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel Hashomer, Israel(1).
Daphna
D
Vilozni
Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel Hashomer, Israel(1).
Rinat
R
Forschmidt
Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel Hashomer, Israel(1).
Ifat
I
Sarouk
Institute of Endocrinology, Chaim Sheba Medical Center, Tel Hashomer, Israel(1).
Hannah
H
Kanety
Institute of Endocrinology, Chaim Sheba Medical Center, Tel Hashomer, Israel(1).
Rina
R
Hemi
Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel Hashomer, Israel(1).
Ori
O
Efrati
Pediatric Endocrinology and Diabetes Unit, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel Hashomer, Israel(1).
Dalit
D
Modan-Moses
D052242:Adiponectin / Q000097:blood; D000293:Adolescent; D000328:Adult; D000418:Albumins / Q000032:analysis; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D003550:Cystic Fibrosis / Q000150:complications* / Q000175:diagnosis; D003920:Diabetes Mellitus; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D018149:Glucose Intolerance / Q000150:complications*; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D012129:Respiratory Function Tests; D055815:Young Adult
D052242:Adiponectin; D000418:Albumins; D001786:Blood Glucose; D007328:Insulin; D008055:Lipids; D005340:Fibrinogen
Adiponectin; Cystic fibrosis; Cystic fibrosis related diabetes (CFRD); Impaired glucose tolerance (IGT); Insulin resistance