Near infrared spectrometry for faecal fat measurement: comparison with conventional gravimetric and titrimetric methods.

Abstract

SUMMARY This investigation was aimed at comparing a new method for measuring faecal fat excretion, carried out with a semi-automated instrument by using near infrared analysis (NIRA), with the traditional titrimetric (Van de Kamer) and gravimetric (Sobel) methods. Near infrared analysis faecal fat was assayed on the three day stool collection from 118 patients (68 chronic pancreatitis, 19 organic diseases of the gastrointestinal tract, 19 alcoholic liver disease, 12 functional gastrointestinal disorders). A strict linear correlation was found between NIRA and both the titrimetric (r=0.928, p<00001) and the gravimetric (r=0.971, p<00001) methods. On homogenised faeces, a mean coefficient of variation of 2.1 (SD 171)% was found. Before homogenisation (where a mean coefficient of variation of 7% was found) accurate results were obtained when the mean of five measurements was considered. In conclusion, the assay of faecal fat excretion by the near infrared refiessometry appears a simple, rapid and reliable method for measuring steatorrhoea.Fat malabsorption represents a sign of several pancreatic, intestinal and biliary diseases. Its quantification is important in the follow up and in the therapy monitoring of such patients, and many methods (gravimetric,' titrimetric,' colorimetric,4 spectrophotometric,5 with nuclear magnetic resonance6) have been suggested. They are, however, not widely used in clinical practice because they require prolonged manipulation of stools and are rather complex and time consuming. Fat, starch, and nitrogen have recently been measured in stools by near infrared reflectance analysis, a method increasingly used in clinical chemistry for direct measurement of composite materials. Results are obtained in less than one minute from small quantities (2-3 g) of unprocessed faeces. The aim of this study was to evaluate the efficiency of this method, and to compare it with the most widely used titrimetric and gravimetric methods.

Near infrared spectroscopy—a potentially useful method for rapid determination of fat and protein content in homogenized diets

“…The necessary analytical procedures are, however, often complex and time consuming. Recently, near-infrared re¯ec-tance (NIR) spectroscopy has been introduced as an alternative to or even a replacement for the traditional chemical methods for nutrient measurements in stools (Benini et al, 1989(Benini et al, , 1992 and foods (Lanza, 1983). NIR spectroscopy is a rapid, non-destructive method, which has found widespread use in compositional analyses such as fat, protein, water and carbohydrates (Osborne & Fearn, 1986;Williams & Norris, 1987).…”

Fecal Fat Concentration in the Screening of Steatorrhea

“…To measure the fecal fat concentration, five small samples were obtained from different parts of a single movement. We have already shown that the mean of at least five fat measurements from a single movement is always within ± 10% of the results found after its homogenization [23]. To calculate the mean daily fat excretion, the stool collections of the 3 days were weighed and accurately mixed.…”

Delayed release pancrelipase for treatment of pancreatic exocrine insufficiency associated with chronic pancreatitis

“…Despite an adequate clinical response of malabsorption and steatorrhea in patients receiving PES, malnutrition may persist. Fecal fat estimation is considered the most reliable measure of fat malabsorption and various techniques ranging from clinical observation 106 to the gold standard measures such as the van de Kramer method, 107 the near infrared spectrometry 108 and Nuclear magnetic Resonance (NMR) spectrometric fecal fat analysis 109 have been described. Indices such as the coefficient of fat absorption ((ingested fat -excreted fat)/ingested fat *100), and daily fat excretion (excreted fat/ingested fat * 100) can be derived from dietary and fecal fat estimation.…”