Glucose Fluctuations are Not Modulated by the Proportion of Calories from Macronutrients or Spontaneous Total Energy Expenditure in Adults with Cystic Fibrosis

The effect of a pre-meal snack and/or postprandial exercise on breakfast glycemic excursion in adults with cystic fibrosis: A pilot study

BACKGROUND & AIMS

Cystic fibrosis (CF)-related diabetes (CFRD), a common comorbidity in CF, is often preceded and characterized with elevated postprandial glycemic (PPG) excursions. In the general population, the consumption of a pre-meal protein snack and/or physical activity (PA) hinder the elevation of PPG levels. Our objective is to evaluate the effect of a pre-meal snack and/or post-meal PA on PPG excursions in CF.

METHODS

This is a double-blinded randomized controlled crossover interventional study in 14 adults with CF, with 4 interventions: placebo pre-meal snack + no PA (control: CTL), pre-meal soy snack + no PA (SK), placebo pre-meal snack + PA (PA), and pre-meal soy snack + PA (SK + PA). The pre-meal soy snack or placebo beverage (vanilla flavoured water) is served at 8 AM, followed by a standardized breakfast at 9 AM and, postprandially, 5 repeated bouts of 3-min walk every 30 min or sedentary activity. Blood glucose and insulin were measured every 15-30 min during the interventions.

RESULTS

Plasma glucose (PG) was higher 30 min after snack consumption compared to placebo beverage. One-hour post-breakfast, PG levels were lower during both PA interventions than with sedentary behavior. However, the overall 3 h post-breakfast glucose area under the curve (AUC) was similar between interventions. Post-breakfast 3 h insulin AUC was significantly lower during the SK + PA intervention compared to the sedentary behavior interventions.

CONCLUSION

Repeated short bouts of post-meal physical activity may positively impact PPG control in adults with CF, with or without the addition of a pre-meal soy snack. A pre-meal snack alone does not improve PPG.

Safety and tolerability of a low glycemic load dietary intervention in adults with cystic fibrosis: a pilot study

Introduction

To achieve and maintain adequate weight, people with cystic fibrosis (CF) May often consume energy-dense, nutrient-poor foods high in added sugars and refined carbohydrates; however, little is known about the glycemic and metabolic effects of dietary composition in this patient population. The objective of this pilot study was to investigate the safety and tolerability of a low glycemic load (LGL) diet in adults with CF and abnormal glucose tolerance (AGT).

Methods

Ten adults with CF and AGT completed this prospective, open-label pilot study. Mean age was 27.0 ± 2.1 years, 64% were female, and all had pancreatic insufficiency. Each participant followed his/her typical diet for 2 weeks, then transitioned to a LGL diet via meal delivery service for 8 weeks. The primary outcome was change in weight from baseline to study completion, with safety established if no significant decline was noted. Other key safety outcomes included change in hypoglycemia measured by patient report and continuous glucose monitoring (CGM). Exploratory outcomes included changes in other CGM measures, body composition by dual energy X-ray absorptiometry (DXA), and patient reported outcomes.

Results

There were no significant changes in weight or in subjectively-reported or objectively-measured hypoglycemia. Favorable non-significant changes were noted in CGM measures of hyperglycemia and glycemic variability, DXA measures of fat mass, and gastrointestinal symptom surveys.

Discussion

A LGL dietary intervention was safe and well tolerated in adults with CF and AGT. These results lay the groundwork for future trials investigating the impact of low-glycemic dietary interventions on metabolic outcomes in the CF population.

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.

Acute soluble fibre supplementation has no impact on reducing post-prandial glucose excursions in adults with cystic fibrosis and glucose intolerance

BACKGROUND

Cystic fibrosis (CF)-related diabetes (CFRD) is a common comorbidity in CF. In CFRD, fasting blood glucose level is often normal, but post-prandial glycaemia (PPG) is problematic. Elevated PPG has been associated to a higher risk of developing CFRD, a worst clinical state and a lower pulmonary function. Interventional studies in type 2 diabetes have demonstrated a beneficial impact of fibre supplement on PPG.

METHODS

Our objective is to evaluate the efficiency of 2 doses of a soluble fibre supplement to lower PPG in CF patients with glucose intolerance (pre-diabetic or CFRD patients). This is a double-blinded crossover interventional study with three interventions: placebo or psyllium fibre (5.1g or 7.7g) of soluble fibre consumed before breakfast. A second meal (lunch) is also eaten four hours later to evaluate a second meal effect. Blood glucose and insulin were measured during the interventions.

RESULTS

In 14 adult CF patients with impaired glucose tolerance (IGT; n=10) or CFRD (n=4), we observed no beneficial effect of fibre supplementation on PPG for both meals. However, all blood glucose levels were lower after the lunch compared to breakfast in spite of the higher carbohydrate content.

CONCLUSION

An acute treatment with fibre supplementation had no effect on blood glucose control in patients with CF-IGT or CFRD.

What do people with cystic fibrosis eat? Diet quality, macronutrient and micronutrient intakes (compared to recommended guidelines) in adults with cystic fibrosis-A systematic review

BACKGROUND

Treatment advancements have improved life expectancy and nutritional status of people with cystic fibrosis (CF). Alongside reductions in malnutrition, incidences of overweight, obesity and risk factors for diet-related chronic diseases have increased in recent years. This study aimed to synthesise the available literature on diet quality, macronutrient and micronutrient intakes compared to the recommended guidelines in adults with CF, an essential step in deducing the optimal dietary pattern and intakes for CF adults.

METHODS

A systematic search of five electronic databases from inception until April 2023 was conducted using keywords related to CF, diet quality and nutrient intakes.

RESULTS

Twenty-one studies were included comprising 18 cross-sectional, one cohort and two case control studies, reporting data from 724 adults with CF. Energy and / or macronutrient intake data was reported across 17 cohorts, eight studies provided micronutrients data, and diet quality was determined for four CF cohorts by using a diet quality score, and / or categorising food intake into servings per day for food groups and comparing findings to national dietary guidelines. Although energy intake recommendations were met, and most micronutrient requirements were achieved through supplementation, total energy intake from fat was above recommendations and diet quality was poor.

CONCLUSION

This is the first systematic review comprehensively evaluating literature on dietary intakes of adults with CF. Energy-dense, nutrient-poor foods contribute to intakes which pose risk in developing diet-related chronic diseases. Revision of dietary guidelines and practice change in CF nutritional therapy is warranted to optimise nutrition and health outcomes.

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.

Brazilian Guidelines for Nutrition in Cystic Fibrosis

OBJECTIVE

To develop a scientific consensus on nutrition in cystic fibrosis.

METHODS

Sixteen coordinators elaborated relevant questions on nutritional therapy in cystic fibrosis, which were divided into six sections: nutritional assessment, nutritional recommendations, nutritional intervention, dietary counseling, special situations and enzyme replacement, and gastrointestinal manifestations. Two to three specialists in the field were responsible for each section and obtaining answers formulated based on standardized bibliographic searches. The available literature was searched in the PubMed®/MEDLINE database, after training and standardization of search strategies, to write the best level of evidence for the questions elaborated. Issues related to disagreement were discussed until a consensus was reached among specialists, based on the current scientific literature.

RESULTS

Forty-two questions were prepared and objectively answered, resulting in a consensus of nutritional therapy in cystic fibrosis.

CONCLUSION

This work enabled establishing a scientific consensus for nutritional treatment of cystic fibrosis patients.

Academy of Nutrition and Dietetics: 2020 Cystic Fibrosis Evidence Analysis Center Evidence-Based Nutrition Practice Guideline

The Academy of Nutrition and Dietetics Evidence Analysis Center conducted a systematic review of the literature to develop an evidence-based practice guideline for primary nutrition issues in cystic fibrosis (CF). This guideline is designed to complement and build upon existing evidence-based CF nutrition guidelines. The objective of this guideline was to provide recommendations for registered dietitian nutritionists in the United States delivering medical nutrition therapy to individuals with CF and their families that fill gaps in current evidence-based guidelines on topics that are crucial in order to improve health and prevent disease progression. This guideline provides 28 nutrition recommendations to guide medical nutrition therapy, including nutrition screening, nutrition assessment, and dietary intake. For topics outside the scope of this guideline, practitioners are referred to external, evidence-based recommendations. The CF landscape is evolving rapidly with breakthroughs in cystic fibrosis transmembrane regulator modulators changing CF at a cellular level. Medical nutrition therapy for individuals with CF from infancy through advanced age requires novel and individualized approaches. The Academy Evidence Analysis Library CF guidelines provide a framework for expanding upon current knowledge to determine effective nutrition strategies for individuals with CF through long and healthy futures.

Dietary Macronutrient Distribution and Nutrition Outcomes in Persons with Cystic Fibrosis: An Evidence Analysis Center Systematic Review

Cystic fibrosis (CF) increases risk for undernutrition and malabsorption. Individuals with CF traditionally have been counseled to consume a high-fat diet. However, a new era of CF care has increased lifespan and decreased symptoms in many individuals with CF, necessitating a re-examination of the high-fat CF legacy diet. A literature search was conducted of Medline (Ovid), Embase, and CINAHL (EBSCO) databases to identify articles published from January 2002 to May 2018 in the English language examining the relationships between dietary macronutrient distribution and nutrition outcomes in individuals with CF. Articles were screened, risk of bias was assessed, data were synthesized narratively, and each outcome was graded for certainty of evidence. The databases search retrieved 2,519 articles, and 7 cross-sectional articles were included in the final narrative analysis. Three studies examined pediatric participants and 4 examined adults. None of the included studies reported on outcomes of mortality or quality of life. Very low certainty evidence described no apparent relationship between dietary macronutrient distribution and lung function, anthropometric measures, or lipid profile in individuals with CF. The current systematic review demonstrates wide ranges in the dietary macronutrient intakes of individuals with CF with little to no demonstrable relationship between macronutrient distribution and nutrition-related outcomes. No evidence is presented to substantiate an outcomes-related benefit to a higher fat-diet except in the context of achieving higher energy intakes in a lesser volume of food.

Dietary intake in cystic fibrosis and its role in glucose metabolism

BACKGROUND

Dietary intervention in cystic fibrosis (CF) has historically focused on high-energy diets to address malnutrition, with little attention on diet quality. With increased survival, CF complications such as impaired glucose tolerance (IGT) and cystic fibrosis related diabetes (CFRD) have increased in prevalence. In the absence of consensus on the management of IGT, the role of dietary intake, specifically carbohydrate quality, requires consideration.

AIMS

The aims of this study were to: 1) determine nutritional quality of dietary intake at an adult CF clinic and compare this to the Australian Dietary Guidelines 2) explore relationships between dietary intake, including glycaemic index (GI) and glycaemic load (GL), and glucose response variables using continuous glucose monitoring (CGM).

METHODS

Adults attending a Sydney hospital were recruited to undergo CGM for five-seven days and record dietary intake using a food record over the CGM period. The relationship between variables of dietary intake, including GI and GL and variables of glycaemic response, including mean amplitude of glycaemic excursions (MAGE), percentage of time in hyperglycaemic and euglycaemic range, were determined.

RESULTS

Eighteen participants completed the study with 87 full days of dietary and CGM data. Dietary intake was higher than recommendations in the Australian Dietary Guidelines in relation to grains and protein foods and only slightly higher in saturated fat. Bivariate correlations showed dietary GI was significantly positively associated with percentage of time in hyperglycaemic range. Dietary GL was significantly associated with SD, MAGE and percentage of time in euglycaemic range on CGM. Results remained significant when controlled for energy intake in partial correlation analyses.

CONCLUSIONS

This study suggests GI and GL may be important dietary factors influencing glucose metabolism in CF. Further studies exploring low GI or GL diets as a dietary intervention in CF are the next step.

Physical activity and associations with clinical outcome measures in adults with cystic fibrosis; a systematic review

BACKGROUND

Physical activity (PA) is important in the management of Cystic Fibrosis (CF) and is associated with a number of beneficial effects. PA assessment is not commonplace or consistent in clinical practice, therefore understanding of PA in adults with CF remains limited. The purpose of this review was to evaluate PA levels in this population and compare PA to global recommendations and non-CF peers.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were utilised to inform the review process. Original research was identified and screened against inclusion/exclusion criteria. Quality was assessed, data extracted and a narrative synthesis undertaken to describe the findings.

RESULTS

Adults with CF did not achieve recommended PA guidelines and step count targets in 5/8 studies where assessment was possible. No significant differences in PA were found between CF and non-CF peers in 3/5 studies. Associations between PA and improved lung function were inconsistent with 4/9 studies finding a positive association. Evidence for an association between PA and higher exercise capacity was stronger with all 4 studies reviewed reporting a positive association. Quality ratings were low across all studies.

CONCLUSIONS

PA in adults with CF is largely comparable to their non-CF peers, despite being insufficiently active to achieve PA recommendations. Assessment tools used and outcomes reported are variable, many of which do not provide sufficient information to assess relevant components of PA. There is a requirement for high quality studies designed specifically to explore PA in adults with CF, ideally employing standardised PA assessment methods.