NMR spectrometry. A new method for total stool fat quantification in chronic pancreatitis

Abstract

In the present investigation, suitability of nuclear magnetic resonance (NMR) spectrometry for total stool fat quantification in patients with normal or impaired exocrine pancreatic function (chronic pancreatitis) has been analyzed in comparison with a conventional chloroform-methanol extraction technique. Basic temperature-dependence studies of NMR spectrometry (90 degrees/180 degrees radiofrequency pulse sequence) on 21 chloroform-methanol extracted pure total stool lipid standards (weight range: 0.05-1.6 g) revealed significantly (P less than 0.05) improving correlations between NMR signal amplitudes and corresponding weights at increasing temperatures (r = 0.952/40 degrees C, r = 0.965/60 degrees C, r = 0.988/80 degrees C), thus indicating 80 degrees C as optimal temperature for NMR spectrometric total stool fat quantification. In subsequent comparative measurements of lyophilized stool samples, NMR spectrometry (at 80 degrees C) and conventional chloroform-methanol extraction provided significantly (P less than 0.001) correlated results with respect to total fecal fat contents/day of quantitatively collected and homogenized stools in 93 patients with known exocrine pancreatic function (secretin-pancreozymin test), irrespective of whether correlations were determined for all 93 patients (r = 0.983) or separately for patients with normal (N = 45; r = 0.867), moderately reduced (N = 31; r = 0.946), or highly reduced (N = 17; r = 0.992) exocrine pancreatic function and correspondingly increased total fecal fat excretions.