Glucose tolerance in Canadian and French cystic fibrosis adult patients

ESPEN-ESPGHAN-ECFS guideline on nutrition care for cystic fibrosis

BACKGROUND

Nutritional status is paramount in Cystic Fibrosis (CF) and is directly correlated with morbidity and mortality. The first ESPEN-ESPGHAN-ECFS guidelines on nutrition care for infants, children, and adults with CF were published in 2016. An update to these guidelines is presented.

METHODS

The study was developed by an international multidisciplinary working group in accordance with officially accepted standards. Literature since 2016 was reviewed, PICO questions were discussed and the GRADE system was utilized. Statements were discussed and submitted for on-line voting by the Working Group and by all ESPEN members.

RESULTS

The Working Group updated the nutritional guidelines including assessment and management at all ages. Supplementation of vitamins and pancreatic enzymes remains largely the same. There are expanded chapters on pregnancy, CF-related liver disease, and CF-related diabetes, bone disease, nutritional and mineral supplements, and probiotics. There are new chapters on nutrition with highly effective modulator therapies and nutrition after organ transplantation.

Insulinogenic index and early phase insulin secretion predict increased risk of worsening glucose tolerance and of cystic fibrosis-related diabetes

OBJECTIVE

Measures of stimulated insulin secretion are emerging as important predictors of diabetes mellitus in at-risk populations. We analyzed the utility of clinical estimates of insulin secretion in a prospective cohort at risk for cystic fibrosis-related diabetes (CFRD).

METHODS

We divided the profiles of 189 people with CF (pwCF) followed longitudinally in the Montreal CF cohort (mean follow up 6.6 ± 1.2 years) according to quartiles of the insulinogenic index (IGI; (I₃₀-I₀)/(G₃₀-G₀)); area under the curve for insulin normalized for glucose (AUC_ins/glu), and HOMA-B at baseline to compare clinical characteristics and risk of CFRD according to quartiles for each measure. We also compared characteristics of 40 pwCF found to have de novo CFRD at baseline.

RESULTS

At baseline, IGI and AUC_ins/glu were lower in subjects with de novo CFRD and those who later developed CFRD than those who never developed CFRD (p < 0.0001 for each). Subjects with the lowest quartiles of IGI, AUC_ins/glu, and AUC_{ins/glu 0-30} had increased risk of developing CFRD by Kaplan-Meier analysis (p = 0.0244, p = 0.0024, and p = 0.0338, respectively). There was no significant difference in risk between quartiles of HOMA-B. Subjects in the lowest quartile of IGI showed a significant increase in 2-hour OGTT glucose and AUC_glu between the initial and final study visits (p = 0.0027 and p = 0.0044, respectively).

CONCLUSION

IGI is easily measured in a clinical setting and needs to be validated in prospective studies as a potential tool to improve risk stratification in CFRD with direct relevance to pathogenesis.

Glycemic indices at night measured by CGM are predictive for a lower pulmonary function in adults but not in children with cystic fibrosis

INTRODUCTION

In patients with cystic fibrosis (CF), it is still unclear to which extent glucose abnormalities - preceding the diagnosis of cystic fibrosis related diabetes (CFRD) - are associated with pulmonary and nutritional outcome parameters. This study related circadian glycemic patterns to clinical outcomes in a group of CF patients not previously diagnosed with diabetes.

METHODS

Continuous glucose monitoring (CGM) readings (7 days) of 47 CF patients (26 children, 21 adults) with an impaired oral glucose tolerance test (OGTT) (n = 25) and/or increased Hb1Ac (> 5.5%) were analyzed. Biometric, pulmonary function and clinical parameters were retrospectively collected over a period of 1 year before (T-1) and 1 year after (T + 1) CGM (T0).

RESULTS

96% (45/47) of CGM readings showed glucose values > 140 mg/dL ≥ 4.5% of the time and at least one ≥ 200 mg/dL. In the pediatric cohort, no significant associations were found between CGM parameters and pulmonary and nutritional outcome parameters. In the adult cohort, an area under the curve (AUC) > 140 mg/dL and%-time > 140 mg/dL during the night were associated with a lower forced expiratory volume in 1 s (FEV1)% predicted (pp) at time of evaluation but not with change in FEV1pp.

CONCLUSION

This is the first study reporting the circadian glycemic pattern in children and adults at risk for CFRD. In the adult cohort an association between detection of abnormal glucose exposure and a lower FEV1pp was found. Our results support continued screening for glucose intolerance in patients with CF.

Combined Indeterminate and Impaired Glucose Tolerance Is a Novel Group at High Risk of Cystic Fibrosis-Related Diabetes

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; n = 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); n = 144/105] are prospective observational cohorts.

RESULTS

In the MCFC and DIAMUCO cohorts, mean age was 25.5 ± 7.7 and 25.0 ± 8.6 years; body mass index, 21.7 ± 3.0 and 20.2 ± 2.2 kg/m2; percentage of forced expiratory volume expired in 1 sec, 73.2 ± 22.1 and 62.5 ± 21.9; and follow-up, 6.9 ± 3.8 and 2.4 ± 1.2 years, respectively. In the MCFC cohort, the IGT only and combined INDET and IGT (INDET + IGT) groups had greater risk of CFRD (P = 0.0109). In the DIAMUCO cohort, there was lower diabetes-free survival in the INDET + IGT group (P = 0.0105). In both cohorts, CFRD risk ranged from 17% in normal glucose tolerance patients up to 42% to 56% in patients with INDET + IGT.

CONCLUSION

Patients who meet combined criteria have a higher risk of developing diabetes probably justifying closer follow-up.

The impact of the high emergency lung transplantation program in cystic fibrosis in France: insight from a comparison with Canada

INTRODUCTION

France implemented a high emergency lung transplantation (HELT) program nationally in 2007. A similar program does not exist in Canada. The objectives of our study were to compare health outcomes within France as well as between Canada and France before and after the HELT program in a population with Cystic Fibrosis (CF).

METHODS

This population-based cohort study utilised data from the French and Canadian CF registries. A cumulative incidence curve assessed time to transplant with death without transplant as competing risks. The Kaplan-Meier method was used to estimate post-transplant survival.

RESULTS

Between 2002 and 2016, there were 1075 (13.0%) people with CF in France and 555 (10.2%) people with CF in Canada who underwent lung transplantation. The proportion of lung transplant increased in France after the HELT program was initiated (4.5% versus 10.1%) whereas deaths pre-transplant decreased from 85.3% in the pre-HELT to 57.1% in the post-HELT period. Between 2008-2016, people in France were significantly more likely to receive a transplant (Hazard Ratio (HR) 1.56, 95% CI 1.37-1.77, p<0.001) than die (HR 0.55, 95% CI 0.46-0.66, p<0.001) compared to Canada. Post-transplant survival was similar between the countries and there was no difference in survival when comparing pre- and post-HELT period in France.

CONCLUSION

Following the implementation of the HELT program, people living with CF in France were more likely to receive a transplant than die. Post-transplant survival in the post-HELT period in France did not change compared to the pre-HELT period, despite potentially sicker patients being transplanted, and is comparable to Canada.

Impact of 1h oral glucose tolerance test on the clinical status of adult cystic fibrosis patients over a 4-year period

OBJECTIVE

To report the clinical profile associated with G60 and I60 over a 4-year prospective observational period in 2 large cohorts of adult patients with CF.

METHODS

319 patients were included (210 Canadian and 119 French) and classified according to their inclusion G60 (≥ or < 11.1 mmol/L) and the median inclusion I60 (≥ or < 24 mU/I). Forced expiratory volume in 1 second (FEV1), body mass index (BMI) were collected on OGTT days. Linear mixed regression models were used to assess the effect of G60 and I60.

RESULTS

High G60 was not associated to a lower FEV1 at inclusion and the follow-up decline was not higher in the high G60 group (Coefficient [95% CI]: -3.4 [-7.4;0.6], p = 0.0995.). There was no significant association between BMI and G60. Patients with high I60 tended to have a higher mean BMI (+0.5 kg/m2 [0.0 to 1.1], p = 0.05) but no interaction over time was observed.

CONCLUSIONS

High G60 is not associated with a lower lung function at inclusion nor its decline over a 4-year follow-up. High I60 is slightly associated to a higher weight at inclusion, but not with BMI evolution over time in adult patients.

Influence of pre-diabetic and pancreatic exocrine states on pulmonary and nutritional status in adults with Cystic Fibrosis

BACKGROUND

In 1992, a landmark study demonstrated clinical deterioration in respiratory function and nutritional status prior to the onset of cystic fibrosis-related diabetes (CFRD). We re-evaluated this outcome.

METHODS

The Montreal Cystic Fibrosis Cohort is a prospective CFRD screening study. We performed a 6-year retrospective analysis of nutritional parameters and FEV₁ (%) in subjects who developed incident CFRD and in controls who maintained normoglycemia (NG). In the former group, data was collected over 6 years prior to diabetes onset.

RESULTS

Subjects (n = 86) had a mean age of 31.7 ± 8.1 years, BMI of 23.0 ± 4.0 kg/m2, and FEV1% of 70.1 ± 24.2%. Eighty-one percent had pancreatic insufficiency (PI). Patients were grouped as follows: NG+PS (pancreatic sufficient) (n = 16), NG+PI (pancreatic insufficient) (n = 21), CFRD+PS (n = 3) and CFRD+PI (n = 46). At their most recent screen NG+PS subjects had significantly greater BMI, as compared to NG+PI and CFRD+PI groups (26.2 ± 3.6 kg/m² vs 22.6 ± 4.2 kg/m² vs 22.1 ± 3.5 kg/m², p = 0.0016). FEV₁ was significantly greater in the NG+PS group (91.5 ± 16.8% vs 67.8 ± 25.3% vs 63.5 ± 22.2%, p = 0.0002). The rates of change in weight, BMI, fat mass (%), and FEV₁ prior to the most recent visit (NG+PS, NG+PI groups) or to the diagnosis of de novo CFRD were similar between groups.

CONCLUSION

In a contemporary context, CFRD onset is not preceded by deterioration in BMI, fat mass, or pulmonary function. Low BMI and FEV₁ are more closely associated with PI than a pre-diabetic state.