Fecal Fat Determination Research Articles

Is the remnant pancreas still working over a year after surgery in patients undergoing pancreaticoduodenectomy with reconstruction by pancreaticogastrostomy?

BackgroundPancreaticogastrostomy (PG) has been widely used as an alternative to pancreatojejunostomy (PJ) in patients undergoing pancreaticoduodenectomy (PD), but its long-term exocrine function remains unclear. The present study aimed to measure the secretion of pancreatic α-amylase (p-AMY) into the gastric cavity in patients who underwent PG reconstruction after PD over 1 year after surgery and to evaluate the relationship between gastric p-AMY level and clinically available indirect tests. MethodsClinical records of 39 patients who underwent PG reconstruction after PD were reviewed. Pancreatic exocrine function was evaluated over 1 year after surgery using the following methods: 1) Measurement of p-AMY level in gastric fluids (gastric p-AMY level) during routine gastrointestinal endoscopy, 2) Qualitative faecal fat determination by Sudan III staining on faeces and 3) Pancreatic function diagnostic (PFD) test using oral administration of N-benzoyl-l-tyrosyl-p-aminobenzoic acid. ResultsGastric p-AMY level was detectable in 31 of 39 patients (79%), and 12 patients (30.8%) had steatorrhea over a year after surgery. Patients with steatorrhea had significantly lower gastric p-AMY level, larger diameter of remnant main pancreatic duct (MPD) and larger pancreatic duct to parenchymal thickness ratio than those without steatorrhea (84 IU/L vs 7979 IU/L, respectively; P < 0.001, 5.3 mm vs 3.2 mm, respectively; P = 0.001, and 0.38 vs 0.23, respectively; P = 0.007). Receiver operating characteristic analysis showed that the cut-off value of the diameter of the remnant MPD to predict steatorrhea was 3.5 mm (sensitivity, 92.3%; specificity, 70.4%). PFD test was not associated with any clinical data. ConclusionsPancreatic enzyme was detected in 79% of patients having PG reconstruction. Diameter of remnant MPD >3.5 mm and pancreatic parenchymal atrophy may be surrogate markers of postoperative exocrine insufficiency following PD.

Diagnosis of Exocrine Pancreatic Insufficiency.

The accurate diagnosis of exocrine pancreatic insufficiency (EPI) helps identify those in need of pancreatic enzyme replacement therapy. Conversely, ruling out EPI identifies those in which additional evaluation should be pursued to explain their symptoms. There are many available tests that can be used to diagnose EPI; however, the tests must be tailored to each clinical scenario. Tests that are convenient but less accurate (e.g., fecal elastase-1, qualitative fecal fat determination) are best suited for patients with a high pretest probability of EPI. In contrast, tests that are highly accurate but more cumbersome (e.g., endoscopic pancreatic function testing, 72-h fecal fat collection) are favored in patients suspected to have mild EPI or an early stage of chronic pancreatitis. Additional research is needed to identify a more convenient means of accurately diagnosing at all stages of EPI.

Determinación cuantitativa de lípidos fecales. Valores Normales

La determinación cuantitativa de lípidos fecales es de valor diagnóstico en la pancreatitis, sprue tropical y no tropical, y en las demás condiciones de esteatorrea; sirva, además, para evaluar la severidad del trastorno metabólico y para medir la eficacia terapéutica. Pero, para afirmar cuándo hay eliminación excesiva, es necesario conocer la eliminación normal.

Fecal fat determination with a modified titration method

Objective. Intestinal malabsorption is a serious condition which unfortunately may remain unrecognized due to methodological problems. The old titration method of van de Kamer is still the gold standard. We present a modification of the method, pointing out practical improvements and pitfalls. Material and methods. Our method uses less than one tenth of the amount of feces originally described, which implies proper mixing and homogenization of all feces collected over 72 hrs. Validation is performed by measuring fat concentration in commercial milk products. Results. Reproducibility and validity were satisfactory. Concentration and output of fecal fat was poorly correlated, indicating that fecal output is required for diagnosing intestinal malabsorption. Our experiments also highlight the importance of using a non-polar extraction agent because polar agents take up water-soluble short chain fatty acids which are derived from fermentation of carbohydrates and give erroneous results. Conclusion. The modified method is reliable and robust and minimizes the aesthetical problems associated with fecal fat determination.

Excreção de gordura fecal de ratos (Rattus norvegicus, Wistar), submetidos a dietas hiperlipídicas e hipercolesterolêmicas suplementadas com quitosana

Investigou-se o efeito de duas marcas comerciais de quitosana na excreção de gordura fecal, em ratos submetidos a dietas hipercolesterolêmicas e hiperlipídicas. Utilizou-se 32 ratos Wistar, distribuídos aleatoriamente em quatro grupos (n=8): grupo controle (GC), recebeu dieta AIN-93G, grupo hiperlipídico (GH): dieta AIN-93G modificada no teor de lipídios (12%) e suplementada com colesterol (1%), e os grupos hiperlipídico quitosana 1 (GHQ1) e hiperlipídico quitosana 2 (GHQ2), que receberam a mesma dieta do GH, suplementados com suas respectivas quitosanas (5%). Realizou-se coleta de fezes nos dias 0, 14º e 28º do experimento. A determinação da gordura fecal (g) foi realizada através do método de Soxhlet. Não foram observadas diferenças estatísticas significativas (p>0,05) entre os 4 grupos quanto ao teor de gordura fecal no início do experimento. No 14º dia, o grupo GHQ1 teve aumento significativo na excreção de gordura fecal quando comparado aos outros três grupos (p<0,05). No 28º dia, no grupo GHQ1, a excreção de gordura fecal foi maior que nos demais grupos (p<0,05), enquanto que o grupo GHQ2 não diferiu estatisticamente do grupo GH. Os resultados sugerem que as diferenças entre estes dois grupos podem ser devidas ao grau de pureza, viscosidade e grau de desacetilação das quitosanas.

The NBT-PABA test in the diagnosis of exocrine pancreatic insufficiency (author's transl)

The NBT-PABA test, an oral pancreatic function test, was performed in 67 patients with proven chronic pancreatitis (secretin pancreozymin test or intraoperatively) and was pathological in 60 (89.6%). Prolongation of urinary collection period from 6 to 9 hours did not improve the diagnostic value. In comparison with the NBT-PABA test the sensitivity of trypsin and chymotrypsin determination in stool was 40.6% and 62.2%, respectively. In severe exocrine pancreatic insufficiency when pathological fecal fat excretion was demonstrable (steathorrhea) the accuracy of fecal enzyme determination was clearly higher (59.1% and 91.8%, respectively). Thus the NBT-PABA test is an alternative diagnostic tool for exocrine pancreatic insufficiency when the secretin-pancreozymin test, and fecal enzyme and fecal fat determination are too complicated. However, as intact absorption of NBT-PABA is possible, the test only provides a qualitative and limited quantitative evaluation of pancreatic function.

Indirect Pancreatic Function Tests in Children

Indirect Pancreatic Function Tests in Children

Effect of Chitin-Chitosan Treatment on Fatty Liver in Rats with a High Fat Diet

The present study was designed to investigate the hepatoprotective effect of 2% chitin-chitosan mixture on high fat diet-induced fatty liver, an experimental model for non-alcoholic fatty liver disease, in Wistar strain male rats. The hepatoprotective property was determined based on the following criteria: total lipid in liver, concentrations of total cholesterol, triglycerides, free fatty acids and phospholipids of serum and liver tissue; liver lipid/protein ratio; serum and tissue activities of aspartate amino transferase (AST) and alanine amino transferase (ALT); fecal fat determination and activity of pancreatic lipase. Chitin-chitosan fed animals gained less weight compared to the controls. A significant (p < 0.001) reduction in the liver lipid/protein ratio was observed in chitin-chitosan mixture supplemented rats as compared to that of control animals. Also the blood and liver fat, cholesterol, triglycerides, free fatty acids and phospholipid concentrations, decreased significantly by chitin-chitosan supplementation. Serum levels of aspartate aminotransferase and alanine aminotransferase showed significant (p < 0.001) reduction while tissue levels exhibited a concomitant increase upon chitin-chitosan treatment. Enhanced fat excretion (p < 0.001) was observed in the chitin-chitosan supplemented group. In the present study, supplementation of chitin-chitosan mixture did not induce any significant change in the activity of pancreatic lipase as compared to normal animals. This indicates that the antilipidaemic effect of chitin-chitosan mixture supplementation was mainly due to the interference in the gastrointestinal absorption of dietary fat rather than the mixture having any direct role on lipid metabolism. In conclusion, dietary supplementation of chitin-chitosan mixture can alleviate the high fat diet-induced aberrations related to lipid metabolism in fatty liver of experimental animals by their antilipidaemic property.

Quantitative determination of faecal fatty acids and triglycerides by Fourier transform infrared analysis with a sodium chloride transmission flow cell.

We studied the applicability of Fourier transform infrared (FTIR) spectroscopy to determine the amount of faecal fatty acids and triglycerides in faeces. For this, we have optimised a simple hexane extraction procedure of stool. After extraction, an aliquot of the hexane layer is directly injected into the measurement cell of the spectrophotometer and absorbance at 1714 cm(-1) and 1751 cm(-1) is read for quantitation of fatty acids and triglycerides, respectively. Comparison of the FTIR spectrophotometric method with the traditional titrimetric Van de Kamer method for faecal fat determination showed a good correlation. The advantage of our method over the previously described FTIR and near-infrared spectroscopy (NIR) methods is that it allows a combined measurement of both fatty acids and triglycerides in one run, using a simple and rapid hexane extraction procedure. Clinical validation of this method was performed by reviewing the medical records of 24 patients with steatorrhoea: patients with pancreatic steatorrhoea showed highly increased faecal triglyceride excretion, but a normal faecal fatty acid and faecal weight when compared with patients with non-pancreatic intestinal steatorrhoea.

HIV-related diarrhea is multifactorial and fat malabsorption is commonly present, independent of HAART

OBJECTIVE: Highly active antiretroviral therapy (HAART) has significantly decreased the incidence of infectious diarrhea affecting HIV-infected patients. Still, diarrhea remains a common symptom in HIV. We sought to determine the incidence of fat malabsorption as a cause of diarrhea in HIV patients receiving non-HAART (nucleoside analog only) and HAART (protease inhibitor-containing) antiretroviral regimens. METHODS: From June, 1995, to April, 1999, 88 HIV-infected patients underwent evaluation for diarrhea, which included endoscopy. We examined the incidence of fat malabsorption with a 24-h stool collection for fecal fat in a cohort of these patients (N = 33). Patients were divided into two groups, those receiving protease inhibitor-containing HAART and those receiving less intensive, nucleoside analog-only, non-HAART regimens. RESULTS: Thirty of 33 patients (90.9%) had fat malabsorption. Twenty of 21 patients not receiving HAART (95.2%) had fat malabsorption with a mean of 34 ± 38 g of stool fat and a mean stool weight of 797 ± 454 g. Ten of 12 patients receiving HAART (83.3%) had fat malabsorption with a mean of 46 ± 86 g of stool fat and a mean stool weight of 800 ± 647 g. Stool weight correlated with the degree of fat malabsorption ( R = 0.77). CONCLUSION: Fat malabsorption represents a commonly undiagnosed entity in HIV-infected patients with diarrhea, whether or not they are receiving HAART therapy. Fecal fat determination should be considered a routine part of the diagnostic workup of HIV-infected patients experiencing diarrhea.

Enhanced Time-saving Extraction Procedure for the Analysis of Fecal Fat by Fourier Transform Infrared Spectroscopy

Recently, we presented an improved procedure for the determination of fecal fat by means of Fourier transform infrared spectroscopy (1). This method can be used in laboratories equipped with a mid-infrared spectrometer. With this method, fecal fat was extracted from stool samples with petroleum ether-ethanol. After extraction, the petroleum ether was dried, and the fatty acids were redissolved in chloroform before measurement. Because the extraction procedure in the previously described analytical method (1) was still rather time-consuming, we replaced the petroleum ether-ethanol extraction with a single chloroform extraction. In the new extraction procedure, 1 g of homogenized …

New method for faecal fat determination by mid-infrared spectroscopy, using a transmission cell: an improvement in standardization.

Current techniques used in clinical laboratories for faecal fat determination, such as the Van de Kamer method, are not very accurate or precise. This became apparent when results obtained by different laboratories were compared, and could explain the disappointing performance of near-infrared and mid-infrared spectroscopy since the accuracy of these techniques depends upon the accuracy of the calibration used (i.e. inaccurate wet chemical analysis). In order to improve standardization, we developed and tested a new quantitative method in three laboratories, based on Fourier transform infrared (FT-IR) spectroscopy. Fatty acids were extracted from faecal samples with acidified petroleum ether-ethanol and the extracts were dried and dissolved in chloroform. An infrared spectrum of the extracts was recorded in the range 4000-650 cm(-1), using an infrared transmission cell. Standard mixtures of stearic and palmitic acids (65:35) were used for calibration. Quantification was based on the absorbance band of the CH2 group (2855 cm(-1)) of free fatty acids and fatty acid glycerol esters. The calibration curve showed excellent linearity. The correlation coefficient between the titrimetric Van de Kamer and FT-IR methods was 0.96 (y = 1.12x-0.02, standard error of prediction = 0.89 g% fat). No significant difference was found when the FT-IR results of 28 faecal samples from patients were compared between two different university hospital laboratories. The new FT-IR method, using primary standards, is simple and rapid, and provides satisfactory intra- and inter-laboratory precision for the diagnosis and monitoring of steatorrhoea.

Simultaneous Determination of Fecal Fat, Nitrogen and Water by Fourier Transform near Infrared Reflectance Spectroscopy through a Polyethylene/Polyaminde Film

The determination of fecal fat, nitrogen and water is important to get evidence for malassimilation and for estimating the efficacy of treatment with pancreatic enzymes. Standard methods for the determination of these parameters (van-de-Kamer method for fat determination, Kjeldahl method for nitrogen determination) are expensive, time-consuming and cumbersome for laboratory assistants. Near infrared (NIR) reflectance spectroscopy was evaluated as a potentially attractive alternative method, especially because the simultaneous measurement of fat, nitrogen and water content is possible. After homogenisation parts of stool samples were packed and thermowelded in a bag of polyethylene/polyamide (PE/PA) film to optimize the handling in the laboratory. Two optical systems were tested: 1. Fiber optic, In-Ga-As-detector, weavelength range 1000–2500 nm, area of measurement diameter 4–mm; 2. Integrating sphere, Ge-detector, wavelength range 1000–1800 nm, area of measurement diameter 10 mm. Forty stool samples were used for calibration, another 20 for validation from both healthy children and patients with cystic fibrosis in an age range from 5 to 18 years. The concentrations of fecal compounds were calculated using the chemometric Partial Least Square (PLS) method with the NIR reflectance spectroscopy measurement data. The calibration were carried out based on results of chemical analysis with standard methods. The regression equations of the external NIR reflectance spectroscopy validations were as follows:1. for the fiber optic system: fat determination y = 0.9737x + 5.7261r = 0.989, nitrogen determination y = 1.0092x+0.0731 r = 0.933, water determination y = 0.9699x+2.0703 r = 0.993;2. for the integrating sphere system: fat determination y = 1.0308x–1.6797 r = 0.998, nitrogen determination y = 0.9529x+0.5302 r = 0.959, water y = 1.0301x–1.8193 r = 0.993.The NIR reflectance spectroscopy method is a precise and alternative method for the determination of fecal fat, nitrogen and water. Moreover, handling is simple, time of analysis is short (4 minutes on average) and all calibrated constituents can be analyzed simultaneously. Therefore, we conclude that NIR reflectance spectroscopy is a reliable and useful method for analysis of fecal components in laboratory medicine.

Simultaneous determination of fecal fat, nitrogen, and water by near-infrared reflectance spectroscopy.

Determinations of fecal fat and nitrogen reveal evidence of malabsorption and assist in estimating the efficacy of pancreatic enzyme treatment. Seventy-two-hour stool collection, with chemical analysis of fecal fat, and Kjeldahl's method for measurement of fecal nitrogen are generally accepted as standard methods for making these determinations. However, these traditional methods are expensive, time-consuming, and cumbersome. This study evaluated the efficiency and validity of an alternative method, using near-infrared reflectance spectroscopy (NIRS) and compared results with those of the standard methods. Near-infrared reflectance spectroscopy is a secondary method: The instrument first has to be calibrated with samples analyzed by the standard method. Sixty-three stool samples with known fat content (range 4.79-292.5 mg/g), 24 samples with known nitrogen content (range 5.36-19.38 mg/g), and 24 samples with known water concentration (range 60.1-82.22%) served for calibration. A further 69 samples were analyzed to validate the procedure. There was a satisfactory correlation between the measurements produced by near-infrared reflectance spectroscopy and those produced by standard methods: fat r = 0.97; nitrogen r = 0.94; water r = 0.96. Near-infrared reflectance spectroscopy appears to be a reliable, simple, and rapid method of measuring different fecal components-as precise and accurate as the standard methods. Stool samples should be analyzed immediately after collecting or stored only a few days before analyzing.

Rapid determination of fecal fat by Fourier transform infrared analysis (FTIR) with partial least-squares regression and an attenuated total reflectance accessory

Fecal lipid content is usually determined by titrimetric or gravimetric methods, but these methods are time consuming and involve dangerous solvents. We have developed a new method of measuring fecal lipids by Fourier transform infrared spectrometry (FTIR) with an attenuated total reflectance accessory that is fast and requires no solvents. The spectra of stools from 4000 to 750 cm-1 were analyzed, and the lipid concentrations were measured by using a calibration curve prepared by partial least-squares analysis of data from 34 stools. The linearity of the method was tested by mixing low-lipid stools with lipid-overloaded stools to give a range of 0.5-15% lipid. The prediction residual values were -0.49-0.78% for calibrators, and -2.55-2.34% for unknown samples. There was good agreement between the fecal lipids measured by gravimetric (x) and FTIR(y) methods: y = 0.87x + 5.5. The standard error of prediction was 1.07%.

Steatorrhea: A common manifestation in patients with HIV/AIDS

Multiple infectious causes of diarrhea are known in patients with HIV/AIDS. Maldigestion and malabsorption have been reported in patients with HIV/AIDS and may be independent of infectious etiologies. Among ambulatory patients with HIV/AIDS, we examined the prevalence of fat malabsorption (steatorrhea). Sixty-one patients with unexplained diarrhea (defined as > 2 stools/d) and/or weight loss despite adequate caloric intake (and without clinical evidence of chronic pancreatitis) were evaluated in our outpatient Gastroenterology-Nutrition Clinic between March 1, 1993, and July 1994. Patients were instructed by a dietitian to follow a ≥100 g/d fat diet for 24 h before submitting a stool sample for qualitative (or quantitative) fecal fat determination. Forty-five patients, 32 with ongoing diarrhea and 13 without diarrhea, submitted stool samples. Twenty-two of 45 patients (49%) had qualitative or quantitative steatorrhea, 16 32 with diarrhea (50%) and 6 13 patients without diarrhea (46%). Thirty of 32 patients with diarrhea had had extensive microbiologic and/or endoscopic evaluations. Only 9 patients had a detectable intestinal pathogen, 5 patients had cytomegalovirus (4 treated), 4 patients had cryptosporidia (3 treated), and 1 patient had microsporidia. Steatorrhea, as determined by abnormal qualitative fecal fat, is detectable in nearly 50% of patients with HIV/AIDS. Fat malabsorption appears to be a primary defect in these patients independent of detectable pathogens. Assessment of fat malabsorption should be considered in patients with unexplained weight loss or diarrhea before extensive evaluation for opportunistic infections.

FECAL FAT EVALUATION METHODS AND FECAL ENERGY CONTENT. † 752

Introduction:Fecal fat balance with chemical determination of fecal fat according to the method of van de Kamer is considered the gold standard for the diagnosis of fat malabsorption.Rapid and easier methods are:the acid steatocrit method and the near-infrared reflectance analysis (NIRA).

Fat absorption and gastroenteric pH profile in postsurgical pancreatic insufficiency: role of the association of H2-receptor antagonists with pancreatic enzymes.

The complete control of steatorrhea in post-surgical exocrine pancreatic insufficiency is difficult. The aim of this study was to evaluate the effect of the association of ranitidine with pancrelipase om fecal fat excretion in patients who had undergone a pancreatoduodenectomy with suppression of the exocrine pancreatic secretion by Neoprene injection. Ten patients were studied 1 year after surgery. Steatorrhea was measured as an integrated test of 3-day stools, while patients were kept on a diet of 100 g lipid/day, with their usual enzyme supplementation therapy (16,050 USP units of lipase/meal). A basal 24-h gastroenteric pH profile was also obtained. In the following month, patients had ranitidine (150 mg twice a day) in addition to pancrelipase. Then steatorrhea and gastroenteric pH were reassessed. Mean fecal fat was 26.9 (SD 13.7) g/day without ranitidine and 30.5 (SD 13.9) g/day during combined treatment. Body weight and nutritional parameters did not show any significant variation after ranitidine administration. Even in the absence of ranitidine, postprandial gastroenteric pH values were always > 4; the H2-receptor antagonist only reduced fasting gastric acidity. In conclusion, the gastroenteric pH and fecal fat determinations showed that ranitidine is not useful in patients with total postsurgical exocrine pancreatic insufficiency.

Determination of Faecal Chymotrypsin Concentration and 72-Hour Faecal Chymotrypsin Output in the Detection of Pancreatic Steatorrhoea

In 96 consecutive patients who underwent a 72-h faecal fat determination because of suspected nutrient malassimilation (maldigestion and/or malabsorption) faecal chymotrypsin (F-Chym) was estimated with a commercial photometric test (Monotest Chymotrypsin), comparing F-Chym concentrations in the first 24-h stool with the total 72-h F-Chym output. In the first 24-h faeces, the F-Chym concentration, calculated as a mean of three random samples, did not significantly differ from a single value obtained after homogenization. In known pancreatic disease, a F-Chym concentration less than 3.0 U/g wet faeces distinguished well between steatorrhoic patients (n = 12) and nonsteatorrhoic (n = 13) (positive predictive value (PV), 91%; negative PV, 86%) but was less suitable as a screening test for pancreatic steatorrhoea in the unselected patient group (positive PV, 61%; negative PV, 98%). Although the estimation of 72-h F-Chym output could differentiate between various subgroups of patients to a certain extent, the positive PV for discovery of pancreatic steatorrhoea in a single patient was low. Four patients had excessively high F-Chym output and increased bile acid excretion after ileal resection (n = 3) and radiation ileitis (n = 1), respectively, possibly indicating the removal of an inhibitory mechanism of pancreatic and biliary secretion in these conditions.

Assessment of pancreatic function in screened infants with cystic fibrosis

Previously we have reported that 37% of infants with cystic fibrosis diagnosed by neonatal screening with the dried blood spot immunoreactive trypsin assay have pancreatic sufficiency. However, 34 of the 78 infants had pancreatic function tests an average 2.3 years after diagnosis, thus it was possible that the percentage with neonatal pancreatic sufficiency was underestimated, due to the loss of pancreatic function with time in some infants. To assess this hypothesis we have assessed pancreatic function at the time of diagnosis in a further 20 infants since the completion of the previous study. Results of fecal fat determinations and/or pancreatic stimulation tests indicate that 10 (50%) of these infants have pancreatic sufficiency. Combining these results with those of the previous study, 31 of 64 patients (48%) have pancreatic sufficiency at this early age. We have also monitored the progression of pancreatic disease in the 39 patients with pancreatic sufficiency recognized to date. Eleven have developed pancreatic insufficiency and require enzyme replacement therapy. Five others have shown further improvement of colipase secretion with age. We conclude that the dried blood immunoreactive trypsin screening program for cystic fibrosis does recognize patients with pancreatic sufficiency, and at diagnosis nearly half the patients are in this category. To date, 28% of patients with pancreatic sufficiency have demonstrated a variable decline in pancreatic function with age.