The acid steatocrit: a much improved method

Elexacaftor/tezacaftor/ivacaftor and gastrointestinal outcomes in cystic fibrosis: Report of promise-GI

BACKGROUND

Elexacaftor/tezacaftor/ivacaftor (ETI) improves pulmonary disease in people with cystic fibrosis (PwCF), but its effect on gastrointestinal symptoms, which also affect quality of life, is not clear.

METHODS

PROMISE is a 56-center prospective, observational study of ETI in PwCF >12 years and at least one F508del allele. Gastrointestinal symptoms, evaluated by validated questionnaires: Patient Assessment of Upper Gastrointestinal Disorders-Symptom (PAGI-SYM), Patient Assessment of Constipation-Symptom (PAC-SYM), Patient Assessment of Constipation-Quality of Life (PAC-QOL)), fecal calprotectin, steatocrit and elastase-1 were measured before and 6 months after ETI initiation. Mean difference and 95% confidence intervals were obtained from linear regression with adjustment for age and sex.

RESULTS

438 participants fully completed at least 1 questionnaire. Mean (SD) for baseline PAGI-SYM, PAC-SYM, and PAC-QOL total scores were 0.56 (0.59), 0.47 (0.45), and 0.69 (0.53) out of maximum 5, 4, and 5, respectively (higher score indicates greater severity). Corresponding age- and sex-adjusted 6 months mean changes (95% CI) in total scores were -0.15 (-0.21, -0.09) for PAGI-SYM, -0.14 (-0.19, -0.09) for PAC-SYM, and -0.15 (-0.21, -0.10) for PAC-QOL. While statistically significant, changes were small and unlikely to be of clinical importance. Fecal calprotectin showed a change (95% CI) from baseline of -66.2 µg/g (-86.1, -46.2) at 6 months, while fecal elastase and steatocrit did not meaningfully change.

CONCLUSIONS

After 6 months of ETI, fecal markers of inflammation decreased. Gastrointestinal symptoms improved, but the effect size was small. Pancreatic insufficiency did not improve.

Coefficient of Fat Absorption to Measure the Efficacy of Pancreatic Enzyme Replacement Therapy in People With Cystic Fibrosis: Gold Standard or Coal Standard?

OBJECTIVES

We sought data on the validity, reliability, responsiveness, and feasibility of the coefficient of fat absorption (CFA) as a measure of pancreatic enzyme replacement therapy (PERT) efficacy in people with cystic fibrosis (pwCF) and reviewed the literature for alternative measures.

METHODS

We searched PubMed for the Medical Subject Heading cystic fibrosis and the key words cystic fibrosis, fat absorption, CFA, and fecal fat imbalance; historical articles; and citations in bibliographies.

RESULTS

The lower the CFA, the greater its variability; thus, it is less variable in healthy individuals who have higher CFA than pwCF. In addition, the test-retest values for CFA are more variable in pwCF than the general population. There is no correlation between CFA and body mass index or PERT dose but CFA is related to gastrointestinal signs and symptoms. Research-quality CFA studies are expensive, time consuming, and odious to pwCF and research staff. Sparse stool tests, breath tests, and blood tests of fat absorption have been studied as potential alternatives to CFA to measure PERT efficacy.

CONCLUSIONS

Based on the evidence, we conclude that CFA as a measure of the efficacy of PERT is more of a "coal standard" than a gold standard; developing suitable alternatives should be a priority.

Assessment of exocrine pancreatic function in children and adolescents with direct and indirect testing

The exocrine pancreas plays an important role in digestion. Understanding of the physiology and regulation of exocrine function provides insight into disease processes and basis of functional testing. Specifically, exocrine pancreatic insufficiency (EPI) can cause maldigestion and thus a proper assessment of exocrine pancreatic function is important. There are indirect and direct methods for evaluating pancreatic function. Indirect methods are varied and include stool, serum, urine, and breath tests. Fecal elastase is a commonly used indirect test today. Direct methods involve stimulated release of pancreatic fluid that is collected from the duodenum and analyzed for enzyme activity. The most used direct test today is the endoscopic pancreatic function test. Indirect pancreatic function testing is limited in identifying cases of mild to moderate EPI, and as such in these cases, direct testing has higher sensitivity and specificity in diagnosing EPI. This review provides a comprehensive guide to indirect and direct pancreatic function tests as well as an in-depth look at exocrine pancreatic function including anatomy, physiology, and regulatory mechanisms.

Rice (Oryza sativa L.) bran preserves cardiac function by modulating pro-inflammatory cytokines and redox state in the myocardium from obese rats

Purpose

This study aimed to evaluate the effect of rice bran (RB) supplementation to a high-sugar fat (HSF) diet on cardiac dysfunction in an experimental obesity model.

Methods

Male Wistar rats were distributed into three groups: control, high-sugar fat, and high-sugar fat supplemented with 11% RB for 20 weeks.

Results

HSF diet promoted obesity and metabolic complications. Obese rats showed cardiac structural and functional impairment associated with high levels of interleukin-6, tumoral necrosis factor alpha, and malondialdehyde, and decreased activity of superoxide dismutase and catalase in the myocardium. RB supplementation was able to mitigate obesity and its metabolic alterations in HSF diet-fed animals. Moreover, the RB also prevented structural and functional damage, inflammation, and redox imbalance in the heart of these animals.

Conclusion

This study suggests that RB supplementation prevents cardiac dysfunction in rats fed on HSF by modulating systemic metabolic complications and inflammation and oxidative stress in the myocardium, representing potential alternative therapy.

Fecal dysbiosis in infants with cystic fibrosis is associated with early linear growth failure

Most infants with cystic fibrosis (CF) have pancreatic exocrine insufficiency that results in nutrient malabsorption and requires oral pancreatic enzyme replacement. Newborn screening for CF has enabled earlier diagnosis, nutritional intervention, and enzyme replacement for these infants, allowing most infants with CF to achieve their weight goals by 12 months of age¹. Nevertheless, most infants with CF continue to have poor linear growth during their first year of life¹. Although this early linear growth failure is associated with worse long-term respiratory function and survival^2,3, the determinants of stature in infants with CF have not been defined. Several characteristics of the CF gastrointestinal (GI) tract, including inflammation, maldigestion and malabsorption, could promote intestinal dysbiosis^4,5. As GI microbiome activities are known to affect endocrine functions^6,7, the intestinal microbiome of infants with CF might also impact growth. We identified an early, progressive fecal dysbiosis that distinguished infants with CF and low length from infants with CF and normal length. This dysbiosis included altered abundances of taxa that perform functions important for GI health, nutrient harvest, and growth hormone signaling, including decreased Bacteroidetes and increased Proteobacteria. Thus, the GI microbiota represent a potential therapeutic target to correct linear growth defects among infants with CF.

Effectivity of microscopic test as a simple diagnostic method to detect fat malabsorption in children

BACKGROUND Lipid malabsorption causes many health problems, for example stunting, a major worldwide issue. There has not been any assessment on the effectivity of lipid microscopic test in diagnosing lipid malabsorption. This research was aimed to study the effectivity of lipid microscopic test in detecting lipid malabsorption in children. METHODS This was a cross-sectional diagnostic study that evaluated the effectivity of lipid microscopic test using Sudan III against steatocrit test as the gold standard in diagnosing lipid malabsorption. The study was done in 68 children aged 6–60 months in Cipto Mangunkusumo Hospital, Jakarta. Results of lipid microscopic test were compared with that of steatocrit test among children with lipid malabsorption and normal children. The primary endpoints of this study are the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS A total of 68 children consisting of 41 boys and 27 girls were included, with a median age of 14.3 months. The most frequently found stool consistency was mushy (50%). The most common result of microscopic test, found in 42% of subjects, was positive 1. Sensitivity, specificity, PPV, and NPV of lipid microscopic test were 49.15%, 66.67%, 90.63%, and 16.67%, respectively. CONCLUSIONS Lipid microscopic test has a moderate sensitivity in diagnosing fat malabsorption and needs to be complemented with other methods such as steatocrit.

Poor diagnostic values of stool analysis and steatocrit test in detecting exocrine pancreatic insufficiency

BACKGROUND Exocrine pancreatic insufficiency (EPI) is one of the most challenging cases to be diagnosed accurately in Indonesia because of the unavailability of the fecal elastase-1 (FE-1) test, which is the primary indirect diagnostic tool till date. Stool analysis and steatocrit test are feasible alternatives as they can detect nutrient malabsorption, a consistent feature in EPI. Despite the common practice of using both tests, no study has ever been conducted in Indonesia to evaluate their accuracy. METHODS This cross-sectional diagnostic study was conducted in 182 children aged 6–60 months. Study subjects were divided into children with persistent diarrhea (PD), those with malnutrition, and healthy children. Children with PD and malnutrition were selected on the basis of clinical criteria and the WHO z-score. FE-1 test was used as the gold standard to detect EPI. Primary endpoints of this study were sensitivity and specificity of the stool analysis and the steatocrit test. The accuracy of both tests, represented by area under the curve (AUC) values, was also evaluated individually and in combination. RESULTS Each component of stool analysis and steatocrit test in each subgroup of patients generally had higher specificity than sensitivity. The specificity of both tests among healthy and malnourished children was good (≥70%), but among children with PD, the specificity of some components was <70%. The individual and combined AUC values of both tests in each subgroup of subjects were poor (<0.7). CONCLUSIONS Stool analysis and steatocrit test cannot be used as alternative methods for FE-1 to detect EPI.

Comparing acid steatocrit and faecal elastase estimations for use in M-ANNHEIM staging for pancreatitis

AIM

To compare two tests for exocrine pancreatic function (EPF) for use in M-ANNHEIM staging for pancreatitis.

METHODS

One hundred and ninety four consecutive patients with acute pancreatitis (AP; n = 13), recurrent acute pancreatitis (RAP; n = 65) and chronic pancreatitis (CP; n = 116) were enrolled. EPF was assessed by faecal elastase-1 (FE-1) estimation and stool fat excretion by the acid steatocrit method. Patients were classified as per M-ANNHEIM stages separately based on the results of the two tests for comparison. Independent Student's t-test, χ² test, Kruskal-Wallis test, Mann-Whitney U test and McNemar's test were used as appropriate.

RESULTS

Sixty-one (52.5%) patients with CP had steatorrhoea when assessed by the acid steatocrit method; 79 (68.1%) with CP had exocrine insufficiency by the FE-1 test (χ² test, P < 0.001). The results of acid steatocrit and FE-1 showed a significant negative correlation (Spearman's rho = -0.376, P < 0.001). A statistically significant difference was seen between the M-ANNHEIM stages as classified separately by acid steatocrit and the FE-1. Thirteen (6.7%), 87 (44.8%), 89 (45.8%) and 5 (2.5%) patients were placed in M-ANNHEIM stages 0, I, II, and III respectively, with the use of acid steatocrit as against 13 (6.7%), 85 (43.8%), 75 (38.6%), and 21 (10.8%) respectively by FE-1 in stages 0, I, II, and III thereby altering the stage in 28 (14.4%) patients (P < 0.001, McNemar's test).

CONCLUSION

FE-1 estimation performed better than the acid steatocrit test for use in the staging of pancreatitis by the M-ANNHEIM classification since it diagnosed a higher proportion of patients with exocrine insufficiency.

Simple and noninvasive method for assessment of digestive efficiency: Validation of fecal steatocrit in greenfinch coccidiosis model

Animals’ capability to absorb energy and nutrients from food poses a major internal constraint that affects the amount of resources available for allocation to maintenance, growth, signaling, and reproduction. Intestinal surface is the largest area of contact between immune system and microbial antigens; gut thus appears the main arena where trade‐offs between immune function and other components of fitness arise. Assessment of the integrity of digestive machinery should therefore be of high priority in ecophysiological research. Traditional methods of digestive physiology, however, appear unsuitable for most ecological applications due to lethality or complexity of the procedure.

Here, we test the reliability of a simple, cheap, and noninvasive procedure, an acid steatocrit that assesses fat content in feces. It is based on centrifugation of a fecal sample, diluted in acid medium, in hematocrit capillary tube and quantifying the percentage of fat in fecal matter. The method has been previously validated in humans and mice; here, we apply it for the first time in birds.

When applied to captive wild‐caught greenfinches, the method showed reasonable internal consistency (r_s = 0.71 for steatocrit values, sampled from the same fecal aliquot in duplicate but processed separately). Individual steatocrit values were significantly repeatable in time in different intervals from eight to at least 20 days (r_s = 0.32–0.49). The relationship between intestinal health and steatocrit values was tested by experimental manipulations. Medication against coccidiosis (a naturally pervasive intestinal infection) reduced, and experimental infection with heterologous coccidian strains increased steatocrit. Individual changes in steatocrit correlated negatively with changes of two markers of nutritional state—plasma triglyceride levels and body mass.

Findings of this study suggest that steatocrit has a wide application potential as a marker of intestinal health in ecophysiological research. In particular, we see the perspective of this method for increasingly popular immunoecological research, conservation medicine, and studies of animal coloration.

ESPGHAN and NASPGHAN Report on the Assessment of Exocrine Pancreatic Function and Pancreatitis in Children

The purpose of this clinical report is to discuss several recent advances in assessing exocrine pancreatic insufficiency (EPI) and pancreatitis in children, to review the array of pancreatic function tests, to provide an update on the inherited causes of EPI, with special emphasis on newly available genetic testing, and to review newer methods for evaluating pancreatitis.

Diagnosing malabsorption with systemic lipid profiling: pharmacokinetics of pentadecanoic acid and triheptadecanoic acid following oral administration in healthy subjects and subjects with cystic fibrosis

Objective: A Malabsorption Blood Test (MBT) is proposed as an alternative method to the 72-hour stool and dietary collection for assessing the degree of fat malabsorption in people with pancreatic insufficiency. The MBT consists of a simultaneous oral dose of pentadecanoic acid (PA), a free fatty acid, and triheptadecanoic acid (THA), a triglyceride with three heptadecanoic (HA) saturated fatty acids requiring hydrolysis by pancreatic lipase before HA can be intestinally absorbed. The aim of this study is to demonstrate the ability of MBT to detect fat malabsorption in healthy adult subjects using the pancreatic lipase (PL) inhibitor Orlistat (Xenical^®), and in subjects with CF and PI while on and off routine pancreatic enzyme doses. Materials and methods: The MBT with the PA and THA were delivered in a breakfast test meal (2.5 g PA and either 5 g or 8 g THA) to healthy adult subjects (ages 18 – 50 years, BMI 21 – 30) and to subjects with CF (> 12 years, FEV_1% predicted > 40%), after a 12-hour fast and 24 hours without dairy foods. Serum levels of PA and HA were assessed by gas-liquid chromatography, from blood samples drawn prior to MBT and then hourly for 8 hours. For healthy subjects, the MBT was administered before and after Orlistat treatment, and in subjects with CF, both with subjects receiving routine pancreatic lipase treatment (“on enzyme”) and also “off enzyme” treatment. Treatment groups were compared for baseline (C₀) and maximum (C_max) plasma concentrations of PA and HA over 8 hours: area under the curve (AUC) was calculated using linear trapezoid method. The ratio of HA to PA C_max and AUC was also calculated and compared. Results: For the healthy subjects (n = 15, 60% female, ages 21 – 49 years), absorption of HA was reduced 71% for C_max (p < 0.001) and 65% for AUC (p = 0.001) after Orlistat treatment, and absorption of PA was unchanged. For subjects with CF (n = 6, 50% female, ages 13 – 19 years), absorption of HA was minimal with subjects “off enzymes” and increased significantly with subjects “on enzymes” while absorption of PA did not differ between groups. Enzyme administration resulted in increased C_max HA/PA ratios from 0.02 to 0.92 and from 0.05 to 0.73 in subjects with CF receiving 5.0 g and 8.0 g of THA, respectively. AUC HA/PA ratios showed similar increases. Conclusions: In this pilot and feasibility proof-of-concept study, the MBT, utilizing the relative absorption of HA to PA, two odd-chained fatty acids, responds to changes in fat absorption in healthy subjects using a lipase inhibitor and in subjects with CF while on or off enzyme therapy. The MBT holds promise to provide a more accurate, specific and acceptable alternative to the 72-hour stool collection to quantify pancreatic-based fat malabsorption in a variety of clinical and research contexts.

Characteristics of multi-organ lymphangiectasia resulting from temporal deletion of calcitonin receptor-like receptor in adult mice

Adrenomedullin (AM) and its receptor complexes, calcitonin receptor-like receptor (Calcrl) and receptor activity modifying protein 2/3, are highly expressed in lymphatic endothelial cells and are required for embryonic lymphatic development. To determine the role of Calcrl in adulthood, we used an inducible Cre-loxP system to temporally and ubiquitously delete Calcrl in adult mice. Following tamoxifen injection, Calcrl^fl/fl/CAGGCre-ER™ mice rapidly developed corneal edema and inflammation that was preceded by and persistently associated with dilated corneoscleral lymphatics. Lacteals and submucosal lymphatic capillaries of the intestine were also dilated, while mesenteric collecting lymphatics failed to properly transport chyle after an acute Western Diet, culminating in chronic failure of Calcrl^fl/fl/CAGGCre-ER™ mice to gain weight. Dermal lymphatic capillaries were also dilated and chronic edema challenge confirmed significant and prolonged dermal lymphatic insufficiency. In vivo and in vitro imaging of lymphatics with either genetic or pharmacologic inhibition of AM signaling revealed markedly disorganized lymphatic junctional proteins ZO-1 and VE-cadherin. The maintenance of AM signaling during adulthood is required for preserving normal lymphatic permeability and function. Collectively, these studies reveal a spectrum of lymphatic defects in adult Calcrl^fl/fl/CAGGCre-ER™ mice that closely recapitulate the clinical symptoms of patients with corneal, intestinal and peripheral lymphangiectasia.

Evaluation of stool collections to measure efficacy of PERT in subjects with exocrine pancreatic insufficiency

OBJECTIVE

The standard measure of pancreatic enzyme replacement therapy (PERT) efficacy in treating exocrine pancreatic insufficiency (EPI) is the coefficient of fat absorption (CFA). CFA measurement involves 72-hour stool collection, which presents a logistical challenge because, although the test may be performed on an outpatient basis in clinical practice, hospitalization is needed if assurance of complete collection and 100% compliance is required, for example, in controlled situations such as clinical trials. Our aim was to investigate sparse stool sample collection as an alternative to complete 72-hour collection for measurement of stool fat in subjects with EPI.

SUBJECTS AND METHODS

Prospective data analysis from a previously published, double-blind, randomized, placebo-controlled, 2-period crossover trial in subjects ages 7 to 11 years with EPI caused by cystic fibrosis. Percentage fat (PF) data from sparse stool samples were compared with 72-hour CFA values as a dichotomous variable (<80%, ≥80%), with evaluation of sensitivity, specificity, and positive predictive value. Area under the curve values were obtained from receiver operating characteristic plots of sensitivity versus 1-specificity.

RESULTS

Twelve subjects provided samples for this analysis. Multiple-sample PF values ≤30% were greatly predictive for CFA values ≥80%, as shown by positive predictive value, sensitivity, and specificity values ≥0.89, with high accuracy (AUCs ≥0.93).

CONCLUSIONS

Sparse stool sampling for PF analysis appears to be a valid, practical alternative to 72-hour CFA determination and has potential as a screening tool in clinical practice to identify both suboptimal dosing in subjects with EPI receiving PERT and substantial fat malabsorption in subjects not receiving PERT.

Fat malabsorption in cystic fibrosis: comparison of quantitative fat assay and a novel assay using fecal lauric/behenic acid

OBJECTIVES

The gold standard for the diagnosis of fat malabsorption, the 72-hour fat balance study, requires a 3-day collection to generate a coefficient of fat absorption (CFA). We hypothesized that a new test using behenic acid (behenate test) as a nonabsorbable lipid marker may provide a facile means to assess fat absorption. The study proposed to answer 2 questions: first, whether the behenate test correlated with the gold standard and, second, whether the CFA improved when taking pancreatic enzymes during meals instead of taking them before meals.

PATIENTS AND METHODS

The study compared the behenate test with the gold standard in 15 patients with cystic fibrosis during 3 arms that require 3- to 4-day hospitalization: first, taking pancreatic enzymes before meals; second, taking it during meals; and third, without taking it.

RESULTS

The mean CFA was 78.3% when pancreatic enzymes were taken during meals and 80.4% when these enzymes were taken before meals. Correlation between the CFA and the behenate test for collections during all 3 arms was r = 0.219 (P = 0.001).

CONCLUSIONS

Timing of ingestion of pancreatic enzymes does not significantly alter the CFA. Although the CFA correlates with the behenate test, the correlation is not robust enough to justify replacement of the gold standard by this test. It is unclear whether the poor correlation between tests relates to intermeal variability in fat excretion or other factors; however, the behenate test may be suitable as a screening test for the detection of fat malabsorption.

Acid steatocrit determination is not helpful in cystic fibrosis patients without or with mild steatorrhea

BACKGROUND

Most methods used for the assessment of severe steatorrhea in cystic fibrosis (CF) are sensitive. In fact, the tests show their usefulness in a borderline zone of the results. Yet, the existing data related to acid steatocrit (AS) are still contradictory. Therefore, in the present study we have aimed to assess CF patients without or with mild steatorhea (<10 g/day) and evaluate the applicability of AS in such a subset of patients.

PATIENTS AND METHODS

In fifty-five CF patients, AS, fecal fat concentration (FFC) and fecal fat excretion (FFE) in 1-day stool collection were assessed from one to three times (149 samples). In 50 subjects, FFC, FFE, and AS were available for 3 subsequent days. It allowed for the calculations based upon 3-day fecal fat balance study.

RESULTS

The correlations between FFE/FFC and AS based upon 1-day stool collection, although statistically significant, were rather weak (r = 0.208, P < 0.011; r = 0.362, P < 0.000006, respectively). The correlations between FFE/FFC and AS based upon the 3-day stool collection, although stronger, did not show values a linear relationship (r = 0.394, P < 0.005; r = 0.454, P < 0.001, respectively). With no regard to the cut-off level for AS (10% and 20%), sensitivity, specificity, negative, and positive predictive values in the determination of abnormal FFC and FFE were not satisfactory. The flow charts describing the accuracy of AS to determine FFE and FC revealed a high level of uncertainty.

CONCLUSIONS

AS does not reflect in a reliable way FFE in CF patients without or mild steatorrhea. Its applicability in the assessment of FFC in such patients has therefore limited practical value.

EUR-1008 pancreatic enzyme replacement is safe and effective in patients with cystic fibrosis and pancreatic insufficiency

BACKGROUND

EUR-1008 (Zenpep [pancrelipase]) is a new, enteric-coated, porcine-derived pancreatic enzyme product (PEP) developed for the treatment of cystic fibrosis (CF) patients with malabsorption associated with exocrine pancreatic insufficiency (EPI). Unlike currently marketed PEPs, EUR-1008 contains the label-claimed lipase content. Safety and efficacy were assessed in younger (<7 years) and older (> or =7 years) CF patients with EPI.

METHODS

Two multicenter studies were conducted: a randomized, double-blind, placebo-controlled, crossover trial in patients > or =7 years of age (N=34) and a supplemental, open-label study in children <7 years of age (N=19). Use of any medications altering gastric pH/motility was prohibited during the studies. Outcome measures in the randomized trial included changes in the coefficient of fat absorption (CFA), coefficient of nitrogen absorption (CNA), and signs/symptoms of malabsorption for EUR-1008 vs. placebo. Outcome measures in the supplemental study included safety and response (defined as no steatorrhea and no overt signs/symptoms of malabsorption) to EUR-1008 vs. previous enzyme treatment.

RESULTS

In the randomized trial, EUR-1008 treatment compared to placebo resulted in a significantly higher mean CFA (88.3% vs. 62.8%, respectively) and CNA (87.2% vs. 65.7%, respectively) (both p<0.001) and reduced the incidence of malabsorption signs and symptoms in 32 evaluable patients. In the supplemental study, 11 of 19 patients met the criteria for responder with EUR-1008 at the end of the study vs. 10 of 19 patients at screening (previous PEP), and improvements in clinical symptoms were reported with EUR-1008 treatment. EUR-1008 was safe and well tolerated, and no serious drug-related AEs were reported in either study.

CONCLUSIONS

EUR-1008 was safe, well tolerated, and effective in CF patients of all ages with EPI-associated malabsorption in two clinical trials. Treatment led to clinically and statistically significant improvements in CFA and CNA in the randomized study, and control of malabsorption and clinical symptoms in both studies.

Fecal elastase1 and acid steatocrit estimation in chronic pancreatitis

BACKGROUND

Measurement of pancreatic exocrine function and steatorrhea in chronic pancreatitis in the clinical setting has not received much attention.

AIM

To assess pancreatic exocrine function and fecal fat excretion in a cohort of patients with chronic pancreatitis.

METHODS

Stool elastase1 levels were measured in 101 patients using polyclonal ELISA and acid steatocrit was measured in 86 chronic pancreatitis patients. Associations with etiology, clinical and radiological features, and diabetic status were examined.

RESULTS

Low pancreatic stool elastase1 (<200 microg/g stool) was observed in two-thirds of chronic pancreatitis patients and correlated with ductal dilatation, pancreatic atrophy and calcification (p<0.05). Diabetes was more prevalent in chronic pancreatitis patients with low elastase1 (p=0.045). There was no difference in mean acid steatocrit between diabetics and non-diabetics (p=0.069). Elastase1 levels had a negative correlation with acid steatocrit (r=-0.606, p<0.001), and a positive correlation (r=0.412) with body mass index (p=0.013). Fifty-three percent of chronic pancreatitis patients with normal BMI had low elastase1.

CONCLUSIONS

Fecal elastase1 levels correlated with fecal fat excretion and BMI. Fecal elastase1 estimation may be helpful in early detection of malabsorption in chronic pancreatitis.

Increased energy expenditure, dietary fat wasting, and resistance to diet-induced obesity in mice lacking renin

An overactive renin-angiotensin system is associated with obesity and the metabolic syndrome. However, the mechanisms behind it are unclear. Cleaving angiotensinogen to angiotensin I by renin is a rate-limiting step of angiotensin II production, but renin is suggested to have angiotensin-independent effects. We generated mice lacking renin (Ren1c) using embryonic stem cells from C57BL/6 mice, a strain prone to diet-induced obesity. Ren1c(-/-) mice are lean, insulin sensitive, and resistant to diet-induced obesity without changes in food intake and physical activity. The lean phenotype is likely due to a higher metabolic rate and gastrointestinal loss of dietary fat. Most of the metabolic changes in Ren1c(-/-) mice were reversed by angiotensin II administration. These results support a role for angiotensin II in the pathogenesis of diet-induced obesity and insulin resistance.

[Fat absorption after total gastrectomy in rats submitted to Roux-en-Y or Rosanov-like double-transit technique]

PURPOSE

Steatorrhea is one of the most common complications in reconstruction after total gastrectomy. Many reconstruction techniques after total gastrectomy have been developed in order to avoid these undesirable effects, but each one of them has some inconvenience. In this experiment, a modified Rosanov technique that keeps duodenal transit, evaluation of fat absorption after gastrectomy was tested.

METHODS

Three groups of rats with the same characteristics were used. Total gastrectomy was performed in two groups: one was operated on and transit was reestablished by the Roux-en-Y technique (group Y), while the other was submitted to the modified Rosanov technique (group R). Following surgery, a handmade hyper fatty diet (11% of fat) was offered. A third group (control - group C) was not operated but was submitted to the same conditions of the other groups, and used for reference steatocrit values. The animals underwent laparotomy 14 days after surgery and had their feces collected from cecum to determine their steatocrit by analysis of their values.

RESULTS

Steatocrit values for groups R and C (mean 5.16% and 4.15% respectively) were similar (p > 0.1), while group Y had significantly higher values (mean = 28.18%, p = 0.0001 - p < 0,05). This was attributed to the fact that group R animals had their duodenal transit patent, decreasing the complications expected in the Roux-en-Y reconstruction.

CONCLUSIONS

Steatorrhea in the modified Rosanov technique was similar to the control group, while Roux-en-Y reconstruction presented higher steatorrhea and fat malabsorption.

Diagnosis and treatment of intestinal malabsorption in cystic fibrosis

Intestinal malabsorption is severe and of early onset in virtually all people who have cystic fibrosis. The main cause is deficiency of pancreatic enzymes. Bicarbonate deficiency, abnormal bile salts, mucosal transport problems, motility differences, and anatomical structural changes are other contributory factors. Effective treatment should allow a normal to high-fat diet to be taken, control symptoms, correct malabsorption, and achieve a normal nutritional state and growth. Appropriate pancreatic enzyme replacement therapy will achieve normal or near-normal absorption in most people with cystic fibrosis. Early identification and treatment of intestinal malabsorption is critical to achieving optimal nutritional status. The occurrence of fibrosing colonopathy in a few patients on very high doses of those enzymes which have the copolymer Eudragit L30 D55 in their covering resulted in guidelines in the UK to avoid doses equivalent to more than 10,000 IU lipase per kg per day, and also to avoid preparations containing this copolymer in children and adolescents. For patients not responding to 10,000 IU lipase per kg per day review of adherence to treatment, change of enzyme preparation, variation in time of administration, and reduction in gastric acid may improve absorption. The importance of early investigation to exclude other gastrointestinal disorders as a cause of the patient's symptoms, rather than merely increasing the dose of enzymes, is stressed. With modern pancreatic enzymes in doses up to or only slightly in excess of 10,000 IU lipase per kg per day, adequate control of gastrointestinal symptoms and absorption can be achieved, and a normal nutritional state and growth rate maintained in most people with cystic fibrosis.

Enteral feeding of premature infants with Saccharomyces boulardii

BACKGROUND

Saccharomyces boulardii (SB) is a yeast that acts both as a probiotic and as a polyamine producer. Probiotics prevent the overgrowth of pathogens in the gut while polyamines enhance intestinal maturation. The aim of this randomized study was to investigate the ability of SB to modify the gut microbial ecology and its function.

METHODS

A total of 87 healthy babies with gestational age 28-32 weeks were studied. They were randomly assigned to receive a preterm formula to which SB or maltodextrins was added for 30 days. Evaluations were made on the following: SB tolerance and weight gain, faecal flora analysis, intestinal D-xylose absorption and faecal lipid excretion.

RESULTS

SB was well tolerated by the infants. There was no difference in weight gain between the two groups. Median log of colony forming units per gram of faeces for Escherichia coli and enterococci was significantly lower in the SB group [E. coli: 2.67 (0.045) vs. 2.75 (0.058), P<0.001; enterococci: 2.14 (0.359) vs. 2.19 (0.138), P<0.05]. On the other hand, the number of bifidobacteria and staphylococci in the stools was significantly higher in the SB group [bifidobacteria: 2.65 (0.083) vs. 2.27 (0.075), P<0.001; staphylococci: 1.23 (0.869) vs. 0.6 (0.281), P<0.001]. D-Xylose and lipid absorption was not improved by SB [median blood D-xylose: 1.5 (0.4) mmol/l vs. 1.35 (0.3) mmol/l, P>0.1; median stool steatocrit: 64% (3.05%) vs. 65% (2.72%) P>0.5].

CONCLUSIONS

An SB-supplemented formula is well tolerated by preterm infants, it has a beneficial effect on stool flora bringing it closer to that of breast fed babies but it does not improve D-xylose or lipid gut absorption.

Comparison of steatocrit and fat absorption in persons with cystic fibrosis

BACKGROUND

Exocrine pancreatic insufficiency is a common problem in persons with cystic fibrosis causing malabsorption and poor growth. The 72-hour fecal fat study is the best qualitative measure of fat malabsorption used in clinical practice. This test has several drawbacks, which include cost and logistics. The steatocrit has been proposed as a rapid method to assess fat malabsorption.

OBJECTIVES

The objective of this study was to determine whether the steatocrit is an accurate estimation of fat malabsorption in persons with cystic fibrosis.

METHODS

Forty-nine stool samples for steatocrit processing were obtained from 72-hour fecal fat collections performed on twenty-seven persons with cystic fibrosis. Stools were weighed and homogenized with sand and water. The emulsified specimen was pipetted into heparinized capillary tubes and centrifuged for 15 minutes. The length of the fatty layer was compared to the length of the solid layer plus the fatty layer in each tube to determine the steatocrit value. Four steatocrit mixtures were evaluated: (1) standard steatocrit, (2) dilute steatocrit, (3) acid steatocrit, (4) dilute acid steatocrit. Steatocrit values were compared with the coefficient of fat absorption determined from the 72-hour fecal fat collection.

RESULTS

The correlation coefficient of the steatocrit and the coefficient of fat absorption ranged from -.045 to -.491. Only the coefficient of fat absorption and the acid steatocrit had a significant correlation ( = 0.033).

CONCLUSION

The steatocrit is an imprecise measure of fat absorption and not clinically useful in estimating steatorrhea.

Comparison of near infrared reflectance analysis of fecal fat, nitrogen and water with conventional methods, and fecal energy content

OBJECTIVES

To evaluate Near-Infrared Analysis (NIRA) method for determining fecal fat, water and nitrogen.

DESIGN AND METHODS

The results of fecal fat, water and nitrogen by NIRA were compared with results of van de Kamer and Acid Steatocrit (AS), Dumas and vacuum drying methods for fat, nitrogen and water respectively. Results of fat determining methods were also compared with total fecal energy as obtained by bomb calorimeter.

RESULTS

NIRA results correlated significantly (p < 0.001) with standard methods for nitrogen (r = 0.79), fat (r = 0.84 and r = 0.88 for van de Kamer and AS respectively) and water (r = 0.91). The limits of agreement for nitrogen and fat results were too wide for the methods to be used interchangeably. The fecal fat results correlated significantly (p < 0.001) with fecal energy results.

CONCLUSION

NIRA may be valuable for monitoring malabsorption but the diagnostic value remains to be determined.

Effects of therapy with lansoprazole on intestinal permeability and inflammation in young cystic fibrosis patients

BACKGROUND

Defective pancreatic bicarbonate secretion with low intestinal pH or intestinal inflammation of any origin increase intestinal permeability in cystic fibrosis (CF).

METHODS

In this open study, the authors evaluated the effect of a proton-pump inhibitor on intestinal permeability and inflammation in 14 young, pancreatic-insufficient CF patients. Permeability was measured by a three-sugar permeability test before and after 1 year of lansoprazole use, and urinary nitric oxide (NO) oxidation products were assessed before and during that year as a marker of inflammation.

RESULTS

After 1 year of lansoprazole use, median urinary recovery percentages changed from 2.5% to 1.7% (P = 0.064), from 24.9% to 24.5% (no significance), and from 10.5% to 11.1% (no significance) for lactulose, mannitol, and L-rhamnose, respectively. Despite the fact that the median urinary excretion ratios decreased from 0.108 to 0.083 (P = 0.03) and from 0.246 to 0.176 (P = 0.016) for lactulose and mannitol and for lactulose and rhamnose, respectively, they both remained increased. Median urinary NO products-to-creatinine ratios were 0.287 for CF patients before lansoprazole and 0.130 for healthy control participants (P = 0.002). Although there was a tendency toward a decrease in the NO products-to-creatinine ratio during treatment, this was not significant at the end point.

CONCLUSIONS

Intestinal permeability is considerably increased in CF patients and is partly corrected after the use of a proton-pump inhibitor for 1 year, which may point to a harmful effect of the acid luminal contents on the tight junctional related paracellular permeability pathway. The start and end values for the NO products-to-creatinine ratio in CF patients were not significantly different, but were considerably increased when compared with control participants (P = 0.002).

13C mixed triglyceride breath test: a noninvasive method to assess lipase activity in children

BACKGROUND

Results from the 13C mixed triglyceride (MTG) breath test correlate with duodenal lipase activity in adults. This noninvasive test is a potential screening and diagnostic tool for children with fat malabsorption. The aim of this study was to adapt the methodology of the MTG breath test to study test meals and sampling methods and to define normal values for healthy children of all age groups; premature and full-term infants have similar pancreatic lipase deficiencies.

METHODS

After parental consent was obtained, 12 premature infants (< 37 weeks gestation and with body weights > 2 kg), 12 full-term infants (1-6 months old), 20 children (3-10 years old), and 20 teenagers (11-17 years old) were tested. All children were thriving well, had no gastrointestinal or respiratory problems, and had not received any medication that contained natural 13C. For the premature and full-term infants, a formula was prepared that had a low and stable natural 13C content mixed with 100 mg 13C-labeled MTG (1,3-distearyl, 2-[13C-carboxyl] octanoyl glycerol) and 1 g polyethylene-glycol 3350. The best accepted test meal for children over 3 years old was a slice of white bread with 5 g butter and 15 g chocolate paste, mixed with 250 mg 13C-labeled MTG, and a glass of 100 mL whole-fat milk. Children over 3 years old were able to blow through a straw in a vacutainer for collecting the breath samples. In children under 3 years old, expired air was collected by aspirating breath via a nasal prong. Carbon dioxide production was calculated according to weight, age, and sex.

RESULTS

For healthy pediatric control participants, the mean values for cumulative excretion of 13CO2 as a percentage of the administered dose after 6 hours were 23.9 +/- 5.2% in premature infants, 31.9 +/- 7.7% in full-term infants, 32.5 +/- 5.3% in children, and 28.0 +/- 5.4% in teenagers. The mean value for healthy adults is 35.6% with a lower reference limit of 22.8%.

CONCLUSIONS

Age-specific test meals and breath-sampling techniques for the MTG breath test were defined. The mean values for different age groups may serve as guidelines for normal values in the pediatric population. The cumulative values for expired 13CO2 were above the lower limit for adults, which suggests that preduodenal lipases compensates for pancreatic lipase deficiency in premature and full-term infants.

The eye in cystic fibrosis

PURPOSE

To investigate modifications of ocular surface and lens transparency in patients with cystic fibrosis in relation to the stage of digestive insufficiency.

METHODS

Forty consecutive patients with cystic fibrosis and 24 age- and sex-matched healthy volunteers were examined. The tear tests (Schirmer's basic test, tear film break-up time) and conjunctival exfoliative cytology (CC) were used to study the ocular surface. The lens transparency was measured with the Opacity Lens Meter 701 (OLM 701, Interzeag AG, Switzerland). Digestive insufficiency was evaluated by the steatocrit method.

RESULTS

Significant changes in conjunctival cytology and lens opacity, and abnormal tear tests were detected in CF patients; the alterations were more pronounced in patients with severe digestive insufficiency.

CONCLUSIONS

Cystic fibrosis patients present ocular surface abnormalities and lens transparency modifications and their severity is related to the digestive insufficiency. Simple, rapid and non-invasive tear tests and cytological procedures might be used as additional tests for assessing the severity of cystic fibrosis.

Changes in pulmonary hyperinflation and bronchial hyperresponsiveness following treatment with lansoprazole in children with cystic fibrosis

SUMMARY. In this prospective open study of 14 children with cystic fibrosis (CF), we evaluated the effect of 1 year adjuvant therapy with lansoprazole, a proton pump inhibitor (PPI), on growth, fecal fat loss, body composition and lung function. Only stable patients with pancreatic insufficiency were included, and their data were compared to those of a large Dutch pediatric normal reference population. During the use of the PPI, mean weight and height did not change significantly, while body mass index improved (P < 0.05). An immediate significant and persistent reduction of fecal acid steatocrit (P < 0.05) was demonstrated. Compared to normal Dutch children, the CF patients showed significantly decreased standard deviation scores (SDS) for total body fat (TBF, -0.966) and fat-free mass (FFM, -1.826). Under lansoprazole, TBF improved significantly (P < 0.05), while mean FFM remained unchanged. A significant improvement in total lung capacity (P < 0.05), residual volume (P = 0.055), and maximal inspiratory mouth pressure (P = 0.002) was also demonstrated. Hyperinflation tended to decrease during the use of a PPI. Daily recordings of peak expiratory flow (PEF) showed a maximal diurnal variability of 28% of recent best PEF and minimal morning PEF of 72% of recent best PEF, confirming that bronchial hyperresponsiveness is increased in CF. We conclude that adjuvant therapy with lansoprazole in young CF patients with persistent fat malabsorption, decreased fat losses and improved total body fat. Lung hyperinflation decreased, which may partly explain the improvement in inspiratory muscle performance. The simultaneous improvements in body composition and lung hyperinflation suggest a relationship between these two parameters. Further research is necessary to confirm such a relationship and to elucidate the mechanisms involved.

Control of malabsorption in cystic fibrosis

Intestinal malabsorption is severe and of early onset in virtually all people who have cystic fibrosis. The main cause is deficiency of pancreatic enzymes, but bicarbonate deficiency, abnormalities of bile salts, mucosal transport and motility, and anatomical structural changes are other contributory factors. Appropriate pancreatic replacement therapy will achieve normal or near normal absorption in many patients. It is important to identify both malabsorption and evidence of a pancreatic lesion in all patients who are to receive pancreatic enzymes. All who have evidence of fat malabsorption are deemed pancreatic insufficient and candidates for enzyme replacement therapy. Effective treatment should allow a normal diet to be taken, control symptoms, correct malabsorption and achieve a normal nutritional state and growth. The occurrence of fibrosing colonopathy in some patients receiving very high doses of those enzymes that have the copolymer Eudragit L30 D55 in their covering has resulted in guidelines in the UK to avoid dosages greater than the equivalent of 10,000 IU lipase/kg/day for all patients and also to avoid preparations containing this copolymer in children and adolescents. For patients not responding to 10,000 IU lipase/kg/day, review of adherence to treatment, change of enzyme preparation, variation of the time of administration and reduction in gastric acid may improve absorption. The importance of excluding other gastrointestinal disorders as a cause of the patient's symptoms and the need for early investigations, rather than merely increasing the dosage of enzymes, is stressed. With modern enzymes, adequate control of gastrointestinal symptoms and absorption can be achieved at dosages of 10,000 IU lipase/kg/day or only slightly more, and a normal nutritional state and growth rate maintained in most patients with cystic fibrosis.

Clinical use of acid steatocrit

Malabsorption of fat is an important gastrointestinal cause of malnutrition and growth retardation in childhood. The gold standard for the evaluation of fat malabsorption is the faecal fat balance method. The acid steatocrit method has recently been introduced as a simple method to evaluate faecal fat. The present study was aimed at evaluating the acid steatocrit in clinical practice. Faecal fat excretion and acid steatocrit results were determined in 42 children, half with and half without fat malabsorption. Acid steatocrit results correlated significantly with both faecal fat excretion (p < 0.01) and faecal fat concentration (p < 0.001). Sensitivity and specificity of the acid steatocrit for the diagnosis of malabsorption were 90% and 100%, respectively. We consider the acid steatocrit method useful for the screening and monitoring of patients with steatorrhoea.

Acid steatocrit during infancy

The faecal acid steatocrit is an improved steatocrit method for the evaluation of faecal fat. The present study was set up in order to establish reference values during the first year of life. Faecal acid steatocrit values were determined in 58 healthy full term and in 16 healthy prematurely born infants. Very high acid steatocrit results (above 60%) were found in all premature and many formula-fed term infants during the first 6 months of age, thereafter with values below 10%. In 40- to 120-day-old infants acid steatocrit results of human milk-fed infants were significantly lower than those of formula-fed infants (p < 0.01). We conclude that high acid steatocrit results after the age of 6 months are indicative of fat malabsorption, while before this age high values can be due to "physiological steatorrhoea". The acid steatocrit should be useful for the evaluation of milk fat absorption in infants.

Improved steatocrit results obtained by acidification of fecal homogenates are due to improved fat extraction

Conflicting results have been reported on the value of the steatocrit as a screening test for steatorrhea. We recently modified the test procedure by fecal acidification with the hope of improving fat extraction and consequently the sensitivity of the test. The aim of the present study was to ascertain whether or not fecal acidification led to improved fat extraction by comparing the fat content of both fatty and solid layers obtained by centrifugation of 12 acidified (acid steatocrit) and unacidified (classical steatocrit) steatorrheal stool samples. The fat content of fatty and solid layers was evaluated using the semiquantitative (+ = 1, +2 = 2, +3 = 3) scoring system described by Drummey for the interpretation of the Sudan microscopic method for fecal fat. The fatty layers sum of scores for the 12 samples examined was 31 and 16 for the acid and classical steatocrit, respectively. The solid layers sum of scores for the 12 samples was 13 and 24 for the acid and classical steatocrit, respectively. Fat extraction from stool samples was significantly improved after fecal sample acidification (p < 0.005). Acid steatocrit results agreed better with chemically measured fecal fat than classical steatocrit results. We conclude that fecal acidification, by improving fat extraction, increases the reliability of the steatocrit method for the detection of steatorrhea.