Low prevalence of glucose intolerance in racially mixed children with cystic fibrosis.
OBJECTIVE
To evaluate glucose tolerance in racially mixed Brazilian youth with cystic fibrosis (CF).


METHODS
Cross-sectional study conducted between August and September 2007, at a reference service for CF, evaluating: glycated hemoglobin (HbA1c), blood glucose, and insulin levels, before and 2 h after a glucose overload.


RESULTS
There were 46 patients aged between 6 yr and 16 yr and 2 months (median: 9 yr and 10 months) of whom 64% were boys. Of these, 26% were Whites; 54.4% Mulattoes; and 19.6% Blacks. HbA1c was normal in all patients. Only one participant (12-yr old) had glucose intolerance. Insulin levels ranged from 1 to 23 µIU/mL (median: 4.5 µIU/mL) at baseline and from 3.2 to 192.1 µIU/mL (median: 11 µIU/mL) after a glucose overload. Insulin resistance evaluated by the HOMA index, stratified by sex and age, was present in three patients. The ΔF508 mutation was present in only 4.3% of the sample, all of them being heterozygous.


CONCLUSIONS
The low prevalence of carbohydrate intolerance in this population is probably a result of their young age. Another possibility is the low frequency of the ΔF508 mutation. Although not conclusive, these data suggest that in addition to age, the genotype:phenotype ratio may influence the development of glucose intolerance in patients with CF.
Alves
Crésio
C
Federal University of Bahia, Salvador-Bahia, Brazil. cresio.alves@uol.com.br
Lima
Daniela S
DS
Cardeal
Mauricio
M
Santana
Angelica
A
D000293:Adolescent; D044383:Black People / Q000235:genetics; D001786:Blood Glucose / Q000378:metabolism; D001938:Brazil / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000097:blood* / Q000150:complications / Q000453:epidemiology; D005260:Female; D018149:Glucose Intolerance / Q000097:blood / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D044465:White People / Q000235:genetics
D001786:Blood Glucose; D007328:Insulin