Optimising nutrition in cystic fibrosis

Vitamin E supplementation in people with cystic fibrosis

BACKGROUND

People with cystic fibrosis are at an increased risk of fat-soluble vitamin deficiency, including vitamin E. Vitamin E deficiency can cause a host of conditions such as haemolytic anaemia, cerebellar ataxia and cognitive difficulties. Vitamin E supplementation is widely recommended for people with cystic fibrosis and aims to ameliorate this deficiency. This is an updated version of the review.

OBJECTIVES

To determine the effects of any level of vitamin E supplementation on the frequency of vitamin E deficiency disorders in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Group's Cystic Fibrosis Trials Register and also searched international online trial registries for any ongoing clinical trials that were not identified during our register search. Date of last search of the Register: 11 August 2020. Date of last search of international online trial registries: 20 July 2020.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials comparing any preparation of vitamin E supplementation to placebo or no supplement, regardless of dosage or duration.

DATA COLLECTION AND ANALYSIS

Two authors extracted outcome data from each study (published information) and assessed the risk of bias of each included study. They assessed the quality of the evidence using GRADE.

MAIN RESULTS

Four studies with a total of 141 participants were included in the review, two of these were in children (aged six months to 14.5 years), and two did not specify participants' age. All studies used different formulations and doses of vitamin E for various durations of treatment (10 days to six months). Two studies compared the supplementation of fat-soluble as well as water-soluble formulations to no supplementation in different arms of the same study. A third study compared a water-soluble formulation to a placebo; and in the fourth study a fat-soluble formulation of vitamin E was assessed against placebo. There was limited detail about randomisation and blinding in the included studies which compromises the quality of the evidence base for the review. The heterogeneous mix of the formulations with differing biovailabilities among these studies also limits the generalisability of the data to the wider cystic fibrosis population. None of the studies in either comparison report the review's primary outcomes of vitamin E total lipid ratio or the incidence of vitamin E-specific deficiency disorders, or the secondary outcomes lung function or quality of life. Water-soluble vitamin E Water-soluble vitamin E may improve serum vitamin E levels compared with control at six months, one study (45 participants), mean difference (MD) 19.74 umol/L (95% confidence interval (CI) 13.48 to 26.00) (low-quality evidence). Similar results were also seen at one month, two studies (32 participants), MD 17.66 umol/L (95% CI 10.59 to 24.74) and at three months, one study (45 participants), MD 11.61 umol/L (95% CI 4.77 to 18.45). Only one study (45 participants) reported weight (secondary outcome of growth and nutritional status) at one and six months, but showed no difference between treatment and control at either time point. Fat-soluble vitamin E Two studies (36 participants) reported higher levels of serum vitamin E at one month with fat-soluble vitamin E compared with control, MD 13.59 umol/L (95% CI 9.52 to 17.66); however, at three months one study (36 participants) showed no difference between treatment and control. No studies in this comparison reported on growth or nutritional status.

AUTHORS' CONCLUSIONS

Vitamin E supplementation may lead to an improvement in vitamin E levels in people with cystic fibrosis, although evidence we assessed was low quality. No data on other outcomes of interest were available to allow conclusions about any other benefits of this therapy. In future, larger studies are needed, especially in people already being treated with enteric-coated pancreatic enzymes and supplemented with vitamin E, to look at more specific outcome measures such as vitamin E status, lung function and nutritional status. Future studies could also look at the optimal dose of vitamin E required to achieve maximal clinical effectiveness.

[Nutritional status in patients with cystic fibrosis: Possibilities of correction]

The major risk factor for death in cystic fibrosis (CF) is a progressive lung injury; however, low nutritional status (NS) remains an important and underestimated problem in the management of these patients. The NS of a patient with CF is impaired by many factors, such as chronic malabsorption, pancreatic failure, chronic inflammation, and recurrent pulmonary infection - they all lead to higher energy demand in the presence of lower intake of nutrients. The NS of those with CF plays an important role in maintaining lung function. The patients with higher NS have longer life expectancies. According to the Russian National Registry, both pediatric and adult patients with CF have shorter life expectancies. The article discusses various nutritional support regimens and their impact on lung function parameters.

Vitamin E supplementation in people with cystic fibrosis

BACKGROUND

People with cystic fibrosis are at an increased risk of fat-soluble vitamin deficiency including vitamin E. Vitamin E deficiency can cause a host of conditions such as haemolytic anaemia, cerebellar ataxia and cognitive difficulties. Vitamin E supplementation is widely recommended in cystic fibrosis and aims to ameliorate this deficiency. This is an updated version of the review.

OBJECTIVES

To determine the effects of any level of vitamin E supplementation on the frequency of vitamin E deficiency disorders in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Group's Cystic Fibrosis Trials Register and also searched international trial registers for any ongoing clinical trials that were not identified during our register search.Date of last search of the Register: 10 October 2016. Date of last search of international trial registers: 15 February 2017.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials comparing any preparation of vitamin E supplementation to placebo or no supplement, regardless of dosage or duration.

DATA COLLECTION AND ANALYSIS

Two authors extracted outcome data from each study (published information) and assessed the risk of bias of each included study.

MAIN RESULTS

Four studies with a total of 141 participants were included in the review, two of these were in children (aged six months to 14.5 years), and the other two did not specify participants' age. All studies used different formulations and doses of vitamin E for various durations of treatment (10 days to six months). Two studies compared the supplementation of fat-soluble as well as water-soluble formulations to no supplementation in different arms of the same study. A third study compared a water-soluble formulation to a placebo; and in the fourth study a fat-soluble formulation of vitamin E was assessed against placebo.At one month, three months and six months, water-soluble vitamin E significantly improved serum vitamin E levels compared with control: at one month, two studies, mean difference 17.66 (95% confidence interval 10.59 to 24.74); at three months, one study, mean difference 11.61 (95% confidence interval 4.77 to 18.45); and at six months, one study, mean difference 19.74 (95% confidence interval 13.48 to 26.00). At one month fat-soluble vitamin E significantly improved serum vitamin E levels compared with control: one month, two studies, mean difference 13.59 (95% CI 9.52 to 17.66). The findings at three months were imprecise; one study; mean difference 6.40 (95% confidence interval -1.45 to 14.25).None of the studies report the review's primary outcomes of vitamin E total lipid ratio or the incidence of vitamin E-specific deficiency disorders, or the secondary outcomes lung function or quality of life. Only one study, comparing water-soluble vitamin E with placebo, reported the secondary outcome of growth and nutritional status (weight), but the results are uncertain due to imprecision around the effect estimate.There was limited detail about randomisation and blinding in the included studies which compromises the quality of the evidence base for the review. The heterogeneous mix of the formulations with differing biovailabilities among these studies also limits the generalisability of the data to the wider cystic fibrosis population.

AUTHORS' CONCLUSIONS

Vitamin E supplementation led to an improvement in vitamin E levels in people with cystic fibrosis, although the studies may have been at risk of bias. No data on other outcomes of interest were available to allow conclusions about any other benefits of this therapy.In future, larger studies are needed, especially in people already being treated with enteric-coated pancreatic enzymes and supplemented with vitamin E, to look at more specific outcome measures such as vitamin E status, lung function and nutritional status. Future studies could also look at the optimal dose of vitamin E required to achieve maximal clinical effectiveness.

Vitamin E supplementation in people with cystic fibrosis

BACKGROUND

People with cystic fibrosis are at an increased risk of fat-soluble vitamin deficiency including vitamin E. Vitamin E deficiency can cause a host of conditions such as haemolytic anaemia, cerebellar ataxia and cognitive difficulties. Vitamin E supplementation is widely recommended in cystic fibrosis and aims to ameliorate this deficiency.

OBJECTIVES

To determine the effects of any level of vitamin E supplementation on the frequency of vitamin E deficiency disorders in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Group's Cystic Fibrosis Trials Register and also searched international trial registers for any ongoing clinical trials that were not identified during our register search.Date of last search of the Register: 10 February 2014. Date of last search of international trial registers: 30 August 2014.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials comparing any preparation of vitamin E supplementation to placebo or no supplement, regardless of dosage or duration.

DATA COLLECTION AND ANALYSIS

Two authors extracted outcome data from each study (published information) and assessed the risk of bias of each included study.

MAIN RESULTS

Four studies with a total of 141 participants were included in the review, two of these were in children (aged six months to 14.5 years), and the other two did not specify participants' age. All studies used different formulations and doses of vitamin E for various durations of treatment (10 days to six months). Two studies compared the supplementation of fat-soluble as well as water-soluble formulations to no supplementation in different arms of the same study. A third study compared a water-soluble formulation to a placebo; and in the fourth study a fat-soluble formulation of vitamin E was assessed against placebo.At one month, three months and six months, water-soluble vitamin E significantly improved serum vitamin E levels compared with control: at one month, two studies, mean difference 17.66 (95% confidence interval 10.59 to 24.74); at three months, one study, mean difference 11.61 (95% confidence interval 4.77 to 18.45); and at six months, one study, mean difference 19.74 (95% confidence interval 13.48 to 26.00). At one month fat-soluble vitamin E significantly improved serum vitamin E levels compared with control: one month, two studies, mean difference 13.59 (95% CI 9.52 to 17.66). The findings at three months were imprecise; one study; mean difference 6.40 (95% CI -1.45 to 14.25).None of the studies report the review's primary outcomes of vitamin E total lipid ratio or the incidence of vitamin E-specific deficiency disorders, or the secondary outcomes lung function or quality of life. Only one study, comparing water-soluble vitamin E with placebo, reported the secondary outcome of growth and nutritional status (weight), but the results are uncertain due to imprecision around the effect estimate.There was limited detail about randomisation and blinding in the included studies which compromises the quality of the evidence base for the review. The heterogeneous mix of the formulations with differing biovailabilities among these studies also limits the generalisability of the data to the wider cystic fibrosis population.

AUTHORS' CONCLUSIONS

Vitamin E supplementation led to an improvement in vitamin E levels in people with cystic fibrosis, although the studies may have been at risk of bias. No data on other outcomes of interest were available to allow conclusions about any other benefits of this therapy.In future, larger studies are needed, especially in people already being treated with enteric-coated pancreatic enzymes and supplemented with vitamin E, to look at more specific outcome measures such as vitamin E status, lung function and nutritional status. Future studies could also look at the optimal dose of vitamin E required to achieve maximal clinical effectiveness.

Avaliação e recomendações nutricionais para crianças e adolescentes com fibrose cística

OBJETIVO: Revisar e discutir evidências sobre a avaliação do estado nutricional e as recomendações para o tratamento nutricional de crianças e adolescentes com fibrose cística. FONTES DE DADOS: Bancos de dados MEDLINE (versão PubMed) e Latin American and Caribbean Center on Health Sciences Information (LILACS), entre 1984 a 2009. Aplicou-se a combinação dos seguintes descritores: fibrose cística, estado nutricional, criança e adolescente - em inglês e português. SÍNTESE DOS DADOS: A fibrose cística é uma doença genética, de evolução crônica, progressiva e fatal. Resulta do defeito na proteína reguladora transmembrana que regula a condução de cloro e, consequentemente, o fluxo de sódio e água através da membrana apical das células epiteliais. Pacientes fibrocísticos são vulneráveis à desnutrição, que resulta do desequilíbrio entre ingestão alimentar, gasto e perdas energéticas. Novos conhecimentos sobre a fisiopatologia da doença, adquiridos nas últimas décadas, resultaram em mudanças significativas nas atuais recomendações energéticas e principalmente de lipídeos. A importância da nutrição no bem-estar e sobrevida dos fibrocísticos está bem estabelecida, assim como a associação entre a desnutrição e a deterioração da função pulmonar. Existem múltiplos fatores inter-relacionados que afetam o estado nutricional, tais como, mutação genética, insuficiência pancreática, ressecção intestinal, perda de sais e ácidos biliares, refluxo gastroesofágico, inflamação e infecções pulmonares, diabetes e condições emocionais. CONCLUSÕES: O monitoramento nutricional e o aconselhamento dietético são elementos chave no manejo de crianças e adolescentes com fibrose cística com o intuito de controlar a sintomatologia e a progressão da doença, proporcionando melhor qualidade de vida.

Growth and nutritional status in children and adolescents with cystic fibrosis

BACKGROUND

Growth retardation, delayed puberty and malnutrition are frequently observed in children suffering from cystic fibrosis.

AIM

The aim of this study was to estimate growth and nutritional status in children with cystic fibrosis on the basis of body proportions and body mass index.

SUBJECTS AND METHODS

Anthropometric data were collected from the medical histories of 62 patients treated in three cystic fibrosis treatment centers in Poland. Anthropometric parameters were expressed in terms of standard deviations away from age-specific and sex-specific reference means reported for the population of Poland. Two-way analysis of variance was used to determine whether the type of cystic fibrosis transmembrane conductance regulator (CFTR) mutation is correlated with age at the time of diagnosis and with body proportions.

RESULTS

The type of mutation was significantly correlated with height, weight and transverse chest width. Growth retardation was greater in subjects diagnosed before they were 3 years old than in subjects diagnosed later. The children had infantile body proportions. Their legs were short and their trunks were long in comparison to their height. Almost 40% of the subjects suffered from malnourishment.

CONCLUSION

Further study is needed to determine how growth in children with cystic fibrosis is affected by clinical practice and socio-economic factors.

Vitamin A levels in patients with CF are influenced by the inflammatory response

BACKGROUND

Serum vitamin A, normally depressed in inflammatory conditions, is frequently low in people with CF. Vitamin A is important in respiratory epithelial regeneration and repair. We hypothesised that serum vitamin A would be associated with inflammation and disease severity.

METHODS

Serum vitamin A (as retinol), C-reactive protein (CRP), vitamin E, 25-hydroxy vitamin D (25OHD), 1,25-dihydroxy vitamin D (1,25(OH)(2)D), weight, and lumbar spine bone mineral density (LSBMD) were measured in 138 subjects with CF (5-56 years) and 138 control subjects (5-48 years). FEV(1), presence of CF liver disease (CFLD) and hospital admissions were recorded in those with CF.

RESULTS

Serum vitamin A level was lower in CF subjects than in controls (mean, 95% CI: 1.29, 1.0-1.37 vs. 1.80, 1.7-1.87 micromol/l, p < 0.0001), and inversely correlated with CRP (r(s) = -0.37, p < 0.0001). CF subjects with low vitamin A (45%) level had poorer FEV(1), weight z-score, LSBMD z-score, and higher CRP compared with those with normal levels. In the CF group CRP, vitamin E, 1,25(OH)(2)D, presence of CFLD, admissions, and age were associated with vitamin A level.

CONCLUSIONS

Serum vitamin A is negatively associated with CRP in subjects with CF, consistent with normal population studies. It is important to distinguish between low serum vitamin A associated with the inflammatory response and that due to poor nutritional stores. The role of vitamin A in CF warrants further study, in the contexts both of chronic recurrent inflammatory disease and acute pulmonary exacerbation.

Is there a case for n-3 fatty acid supplementation in cystic fibrosis?

PURPOSE OF REVIEW

This review evaluates our current knowledge on the association of fatty acid abnormalities in cystic fibrosis with the disease process, and makes a case for a well-designed clinical trial to evaluate the clinical efficacy of long chain n-3 fatty acids.

RECENT FINDINGS

It has long been known that cystic fibrosis patients exhibit fatty acid abnormalities, but these have not been well investigated in tissues affected by the disease. Recent studies have demonstrated that such tissues do indeed show abnormalities in the proportions of linoleic, arachidonic and docosahexaenoic acids, and have demonstrated alterations in fatty acid and phospholipid metabolism in cystic fibrosis. Work in other areas has identified novel anti-inflammatory actions of long chain n-3 fatty acids that might be relevant to cystic fibrosis. A recent systematic review of fish oil supplementation in cystic fibrosis did not allow firm conclusions to be drawn, but suggested that there may be some benefits.

SUMMARY

The restoration of abnormal fatty acid profiles may be beneficial in cystic fibrosis, but this approach has not been evaluated in studies with a suitable design to permit firm conclusions to be drawn. There is a need for a long-term randomized controlled study to evaluate the therapeutic benefit of fish oil supplementation in cystic fibrosis.