RESUMO
OBJECTIVES: The classical glycosylated hemoglobin A1c threshold of 6.5% is an insensitive screening test for cystic fibrosis-related diabetes (CFRD). We sought to identify CF-specific A1C thresholds associated with 1) risk of progression to CFRD and 2) changes in body mass index (BMI) and forced expiratory volume (FEV1). METHODS: We studied the cross sectional and longitudinal associations between A1c, BMI, and FEV1 in 2 cohorts of 223 children (followed for up to 8 years) and 289 adults (followed for a mean of 7.5 ± 4.3 years) with CF but without diabetes at baseline and undergoing regular assessments including Oral Glucose Tolerance Test (OGTT). RESULTS: For the onset of OGTT-defined CFRD optimal A1c threshold was 5.9% in adults (sensitivity: 67% and specificity: 71%) and 5.7% for children (sensitivity: 60% and specificity: 47%). Kaplan-Meier analysis of progression to CFRD according to baseline A1C showed increased the risk of developing CFRD for A1c ≥ 6.0% in adults (P = 0.002) and ≥ 5.5% in children (p = 0.012). Temporal changes in BMI and FEV1 according to baseline A1C in adults were assessed with a linear mixed-effect model, BMI significantly increased over time in subjects with a baseline A1c < 6%, but those with a A1C ≥ 6.0% gained significantly less weight over time (P = 0.05). There was no difference in FEV1 according to baseline A1c category. CONCLUSION: An A1C above 6% may be associated with a high risk of developing CFRD and a lower probability of weight gain in both adults and children with CF.
Assuntos
Fibrose Cística , Diabetes Mellitus , Intolerância à Glucose , Humanos , Adulto , Criança , Hemoglobinas Glicadas , Fibrose Cística/complicações , Fibrose Cística/epidemiologia , Fibrose Cística/diagnóstico , Glicemia , Estudos Transversais , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/diagnóstico , Aumento de Peso , Intolerância à Glucose/complicaçõesRESUMO
BACKGROUND: Indeterminate glycemia (INDET) and impaired glucose tolerance (IGT) are independently associated with cystic fibrosis-related diabetes (CFRD) risk. We determined whether patients meeting both criteria have increased risk of diabetes in 2 separate adult cohorts. METHODS: The Montreal Cystic Fibrosis Cohort (MCFC; nâ =â 293 baseline and 198 for prospective analysis excluding subjects identified with incident CFRD at baseline) and the Lyon cystic fibrosis cohort [Determination of the Predictive Factors in the Reversibility or the Aggravation in the Disorders of the Glucose Metabolism in Cystic Fibrosis Patients (DIAMUCO); nâ =â 144/105] are prospective observational cohorts. RESULTS: In the MCFC and DIAMUCO cohorts, mean age was 25.5â ±â 7.7 and 25.0â ±â 8.6 years; body mass index, 21.7â ±â 3.0 and 20.2â ±â 2.2 kg/m2; percentage of forced expiratory volume expired in 1 sec, 73.2â ±â 22.1 and 62.5â ±â 21.9; and follow-up, 6.9â ±â 3.8 and 2.4â ±â 1.2 years, respectively. In the MCFC cohort, the IGT only and combined INDET and IGT (INDETâ +â IGT) groups had greater risk of CFRD (Pâ =â 0.0109). In the DIAMUCO cohort, there was lower diabetes-free survival in the INDETâ +â IGT group (Pâ =â 0.0105). In both cohorts, CFRD risk ranged from 17% in normal glucose tolerance patients up to 42% to 56% in patients with INDETâ +â IGT. CONCLUSION: Patients who meet combined criteria have a higher risk of developing diabetes probably justifying closer follow-up.
Assuntos
Fibrose Cística , Diabetes Mellitus , Intolerância à Glucose/epidemiologia , Adolescente , Adulto , Doenças Assintomáticas , Estudos de Coortes , Fibrose Cística/complicações , Fibrose Cística/diagnóstico , Fibrose Cística/epidemiologia , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/etiologia , Feminino , Seguimentos , França/epidemiologia , Intolerância à Glucose/complicações , Intolerância à Glucose/diagnóstico , Intolerância à Glucose/patologia , Humanos , Masculino , Quebeque/epidemiologia , Fatores de Risco , Índice de Gravidade de Doença , Adulto JovemRESUMO
OBJECTIVES: Our aims in this study were to document the screening rate for cystic fibrosisârelated diabetes (CFRD) in children followed at a cystic fibrosis (CF) clinic in Canada and to evaluate the accuracy of various glycated hemoglobin (A1C) cutoffs to screen for CFRD and impaired glucose tolerance (IGT) in a pediatric CF population. METHODS: The CFRD screening rate was calculated over a follow-up period of up to 8 years among children who attended the CF clinic between 1993 and 2018. Test performance of A1C at various thresholds ranging from 5.5% to 6.2% was compared with the oral glucose tolerance test (OGTT) as the reference method. Children with CF aged ≥10 years with an OGTT performed within 120 days of A1C measurement were included in the analysis. RESULTS: The overall CFRD screening rate was 53.0%. A total of 256 children were included for the A1C performance analysis, of whom 8.6% had an OGTT-confirmed CFRD diagnosis. An A1C threshold of 5.8% demonstrated an optimal balance between sensitivity (90.9%) and specificity (60.7%) for CFRD screening, leading to a potential reduction of 56.3% of the annual required OGTTs. A1C demonstrated poor accuracy for identifying children with IGT. CONCLUSIONS: An A1C threshold ≥5.8% allows for identification of children requiring further CFRD investigations, which may reduce the clinical burden of children with CF without compromising the ability of early CFRD diagnosis.