Impact of sex on insulin secretion in cystic fibrosis.
BACKGROUND
Cystic fibrosis-related diabetes is primarily due to a defect in insulin secretion. Women with cystic fibrosis (CF) are at higher risk of developing CF-related diabetes.


OBJECTIVE
The objective of the study was to examine sex differences in insulin and glucose homeostasis. We hypothesized that in CF, women would display lower insulin secretion than men.


METHODS
This was a study based on an ongoing observational CF cohort with a mean follow-up of 19.9 ± 5.2 months.


METHODS
The study was conducted at the CF clinic of the Centre Hospitalier de l'Université de Montréal (Québec, Canada).


METHODS
From 230 adults with CF (123 men, 107 women) of similar age and functional pulmonary status, 104 retested after the follow-up. Age-matched healthy individuals (25 men, 19 women) were included in the study.


METHODS
Participants underwent a 2-hour oral glucose tolerance test with 30-minute interval sample measurements.


METHODS
Plasma insulin and glucose levels were measured.


RESULTS
Women with CF had higher overall insulin secretion as compared with men with CF (P ≤ .05) but similar to healthy women (P = .606). Men with CF had lower overall insulin secretion than healthy men (P = .020) and higher insulin sensitivity (P = .009) than women with CF. PATIENTS with CF displayed higher overall glucose excursions than healthy patients. Sex-related differences were still observed in the CF cohort after follow-up.


CONCLUSIONS
Surprisingly, in CF, adult women presented higher insulin secretion than adult men at a comparable level with what is observed in healthy individuals. Potential implications of this sex dimorphism in CF remain to be established.
Platform for Research on Obesity, Metabolism, and Diabetes (A.C., L.B., S.Z., E.H., M.-S.G., L.C., Y.B., R.R.-L.), Metabolic Unit laboratory, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada H2W 1R7; Department of Nutrition (A.C., L.B., S.Z., E.H., M.-S.G., G.M., R.R.-L.), Université de Montréal, Montréal, Québec, Canada H3T 1A8; Endocrinology Division (R.R.-L.), Department of Medicine, Université de Montréal, Montréal, Québec, Canada H3T1J4; Department of Medicine (L.C., Y.B., R.R.-L.), Université de Montréal, Montréal, Québec, Canada H3T1J4; Research Center (G.M.), Centre Hospitalier de l'Université Sainte-Justine, Université de Montréal, Montréal, Québec, Canada H3T 1C5; and Cystic Fibrosis Clinic (Y.B., R.R.-L.) of the Centre hospitalier de l'Université de Montréal, Montréal, Québec, Canada H2W1T8; and Montreal Diabetes Research Center (R.R.-L.), Montréal, Québec, Canada H1W4A4.
Adèle
A
Coriati
Linda
L
Belson
Sophie
S
Ziai
Eleonore
E
Haberer
Marie-Soleil
MS
Gauthier
Geneviève
G
Mailhot
Lise
L
Coderre
Yves
Y
Berthiaume
Rémi
R
Rabasa-Lhoret
D000328:Adult; D001786:Blood Glucose; D003550:Cystic Fibrosis / Q000097:blood* / Q000503:physiopathology; D005260:Female; D018149:Glucose Intolerance / Q000097:blood* / Q000503:physiopathology; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D012737:Sex Factors
D001786:Blood Glucose; D007328:Insulin