Serum and fecal pancreatic enzymes in beta-thalassemia major

CONCLUSION

This study, using indirect tests, demonstrated that exocrine pancreatic function is impaired in a proportion of patients with beta-thalassemia major (TM), though this impairment is generally mild or moderate.

BACKGROUND

Impaired structure and function of the exocrine pancreas has been reported in patients with Beta-thalassemia major.

METHODS

In this study we measured fecal fats and serum and fecal pancreatic enzymes in 30 patients (13 M, 17 F) with TM, mean age 22.1 yr (range 14-39) and compared them with those of a matched group of healthy controls. Results were correlated with age, serum ferritin, blood transfusion, and various nutritional parameters. Enzymes assays included: serum pancreatic amylase (PA), lipase (L), trypsin (T), fecal chymotrypsin (FCT), and fecal elastase (FE).

RESULTS

No patient was positive for steatorrhea. Comparison of the mean values showed a significant difference only for FE (p < 0.002). Using only the fecal tests as a reference, we found that 12 patients had FE values below the cutoff limit; of these, five had values between 100 and 185 micrograms/g, three between 50 and 99 micrograms/g and four below 50 micrograms/g. Ten patients had FCT values below the cutoff limit; seven presented impairment in both tests and six of them had FE values below 100 micrograms/g (including four diabetics). No correlations were found between enzyme values and mean serum ferritin values or mean blood consumption over the previous 3 yr. No correlation was found between FE and FCT levels or between enzymes and age.

Postprandial glucose-dependent insulinotropic polypeptide and insulin responses in patients with chronic pancreatitis with and without secondary diabetes

OBJECTIVE

To study GIP and insulin release after a test meal in patients with chronic pancreatitis with and without secondary diabetes mellitus.

METHODS

28 patients with chronic pancreatitis were classified in groups I and II according to the presence or absence of secondary diabetes mellitus. Twelve healthy subjects were included as controls. After a test meal plasma GIP levels and serum insulin levels were determined at 0, 30, 60, 120 and 180 min.

RESULTS

A significant diminished GIP response was found in the groups of patients with respect to the control group. No association could be detected with severity of pancreatic insufficiency. Higher values of GIP were demonstrated at 60 and 120 min in patients without diabetes than in patients with it.

CONCLUSIONS

An abnormal GIP response is present in cases of chronic pancreatitis irrespective of the presence or severity of pancreatic insufficiency. This response is further affected if secondary diabetes mellitus is present.

Exocrine pancreatic insufficiency: accuracy and clinical value of the uniformly labelled 13C-Hiolein breath test

BACKGROUND AND AIMS

The 13C-Hiolein breath test (98% [U-13C] labelled long chain triglyceride mixture (highly labelled triolein) was evaluated as a non-invasive, non-radioactive test for exocrine pancreatic insufficiency. Accuracy and clinical validity were examined with reference to both the secretin pancreozymin test and faecal fat analysis.

METHODS

A secretin pancreozymin test and faecal fat analysis were performed in 46 patients, 30 with exocrine pancreatic insufficiency and 16 with normal pancreatic function. In all of these patients and in seven healthy volunteers (controls), a 13C-Hiolein breath test was performed using 2 mg/kg [U-13C] labelled Hiolein with a standard risk snack (1.5 g/kg; 25% fat). 13CO2/12CO2 enrichment in the exhaled breath was measured by isotope ratio mass spectrometry.

RESULTS

In patients with pancreatic steatorrhoea the 13CO2 response was below the 95% confidence interval of 13CO2 exhalation in the controls. These responses were also diminished (p < 0.001) compared with patients with impaired lipase output but normal fat excretion and with disease as well as healthy controls. There was a linear correlation between stimulated lipase output and the ratio of lipase output/13CO2 response (r = 0.95). Among the 40 patients in whom direct pancreatic function testing was clinically indicated, the sensitivity of the 13C-Hiolein test for detecting steatorrhoea was 91.7%, with a specificity of 85.7%.

CONCLUSIONS

In patients with pancreatic disease the 13C-Hiolein breath test reflects impaired lipase output and indicates decompensated lipolysis. The 13C-Hiolein breath test is a convenient alternative to faecal fat analysis.

Gastric emptying of pancreatin granules and dietary lipids in pancreatic insufficiency

AIM

To investigate the emptying of enzyme granules and dietary lipids in patients with pancreatic insufficiency secondary to chronic pancreatitis.

PATIENTS AND METHODS

Seven patients with chronic pancreatitis and exocrine pancreatic insufficiency ingested a test meal including colloidal 99m-technetium-radiolabelled liver paté, and swallowed two pancreatin capsules, in which half of the granules had been replaced with 111-indium-radiolabelled plastic particles of comparable physical dimensions. The passage of the two isotopes was followed simultaneously by gamma camera imaging for direct visual judgement and calculation of mean gastric emptying time.

RESULTS

Pancreatin granules and dietary lipids were observed to empty simultaneously. In the duodenum the particles and the test meal were well mixed. Mean gastric emptying time of radiolabelled liver paté and radiolabelled plastic particles could be calculated in six patients. The median of these values were 47 and 43 min, respectively (P = 0.69).

CONCLUSION

Pancreatin granules sized 1.0-1.5 mm seem to empty together with dietary lipids.

Fat-soluble vitamins in patients with chronic pancreatitis (pancreatic insufficiency)

The fat-soluble vitamin contents in the blood (vitamins A, D, E, and K) were determined in 12 patients with chronic pancreatitis (exocrine pancreatic insufficiency) and in 20 healthy adults by the HPLC and CPBA methods. In addition, 9 g (3 g x 3 times) of high potency pancreatin was given to 11 patients with chronic pancreatitis (CP) for approximately 1 month and changes in the blood fat-soluble vitamin levels were evaluated before and after the treatment. The major component of vitamin E was alpha-tocopherol. The mean alpha-tocopherol level in normal individuals was 0.97 mg/dl, while it was significantly reduced in CP patients (p < 0.01). The vitamin A, D, and K levels had also been reduced in patients with CP, but the differences were not significant (although some patients in this group exhibited significant reductions from the levels of normal individuals). Only the blood vitamin E level showed a significant correlation with the fecal fat excretion or the fat absorption rate. None of the patients with CP exhibited an overt fat-soluble vitamin deficiency (i.e., the deficiency of fat-soluble vitamins was at a subclinical level). These results indicated that CP patients suffer from a latent fat-soluble vitamin deficiency and that the vitamin E level is closely related to a dysfunction of fat digestion. It was suggested that the dietary intake of each fat-soluble vitamin should be evaluated further.

Medium-chain triglyceride absorption in patients with pancreatic insufficiency

BACKGROUND

The role of medium-chain triglycerides (MCTs) in the management of patients with pancreatic insufficiency is controversial. The aim of the study was to evaluate the absorption of MCTs in the presence of pancreatic insufficiency and the effect of pancreatic extracts on MCT absorption so as to clarify whether the replacement of usual dietary fats with MCTs is cost-effective.

METHODS

Six patients with severe pancreatic steatorrhea were for 5 days fed a low-fat diet to which butter (long-chain triglycerides (LCTs)) or MCT oil was added, with and without pancreatic extracts, in a crossover design.

RESULTS

Fecal weight and nitrogen losses were the same during MCT and LCT intake. Steatorrhea was substantial during both periods but was significantly lower during MCT than LCT intake. Fecal weight and nitrogen and fat losses were reduced by pancreatic extracts in both diets. Steatorrhea was the same when MCTs and LCTs were consumed together with pancreatic extracts.

CONCLUSIONS

MCTs are absorbed better than LCTs in the presence of pancreatic insufficiency but require pancreatic extracts for optimal absorption. No advantage is to be expected from replacing usual dietary fats with MCTs if pancreatic supplements are used.

Absorption of triglycerides with defined or random structure by rats with biliary and pancreatic diversion

Fat absorption may be compromised by pancreatic or bile insufficiency, resulting in low uptake of essential fatty acid and energy. Using a rat model of malabsorption, we examined the absorption of defined triglycerides with medium-chain fatty acids (MCFA) in the sn-1,3 positions and essential fatty acids in the sn-2 position (MLM) compared to other fats. The thoracic duct was cannulated for collection of lymph, and the common bile and pancreatic duct was cannulated to divert both the pancreatic juice and bile. The rats were given a single bolus of triglyceride as a taurocholate emulsion. Fat absorption was measured from collected lymph samples. The triglycerides administered were a defined triglyceride, MLM [mainly (8:0/10:0)-(18:2n-6)-(8:0/10:0)], a similar triglyceride subjected to chemical randomization, a mixture of medium-chain triglycerides and soybean oil, and soybean oil, respectively. The first three triglycerides had approximately 36 wt% linoleic acid (18:2n-6) content. Administration of defined triglyceride was followed by significantly higher lymphatic level (wt%) of 18:2n-6 (P < 0.01) as well as a relative enhancement in mol% of 18:2n-6 (P < 0.05) compared to the other triglycerides. Lymphatic absorption of MCFA was similar in the three first groups but not as efficient as for long-chain fatty acids. Our results indicate that defined triglycerides thus may provide a means to increase absorption of essential fatty acids in fat malabsorption, such as that seen in cystic fibrosis, or for pre-term infants.

No negative feedback regulation between plasma CCK levels and luminal tryptic activities in patients with pancreatic insufficiency

The study was conducted on five healthy subjects and six patients with calcifying pancreatitis (CP) and steatorrhea. Following overnight fasting, one tube each was placed in the stomach and the upper of the small intestine, respectively. Through the gastric tube, a test meal that included 30 g of fat (total calories, 625 kcal, 500 mL) was infused over a span of 30 min. Every 30 min (up to 150 min), fluid samples in the upper small intestine were collected and chilled, and the amylase, trypsin, and lipase levels were determined. In addition, in the case of the CP patients, a high-potency pancreatin preparation was infused into the stomach together with the test meal. In order to determine the plasma CCK level, blood sample were collected before test meal infusion and at 10, 20, 30, 45, 60, 90, 120, and 150 min subsequent to infusion. The plasma CCK was extracted using a Sep-Pak C-18 cartridge and analyzed with radioimmunoassay using an OAL-656 antibody. The result was converted to the CCK-8 level and expressed in pg/mL. The enzyme activities in the upper small intestine of the CP patients after test meal administration amounted to 22.8 (amylase), 10.8 (trypsin), and 16.9% (lipase) compared with the corresponding figures for the normal subjects. Following administration of a high-potency pancreatin in patients with CP, enzyme activities in the upper small intestine increased to 132.2 (amylase), 38.7 (trypsin), and 45.3% (lipase) compared with levels in the normal subjects. However, the healthy subjects and the CP patients, both with and without treatment with supplementary exogenous enzymes, all exhibited similar profiles in the plasma CCK response to stimuli. Based on these findings, we concluded that a negative feedback mechanism does not exist between the tryptic activity of the upper small intestine and the CCK secretory response in patients with chronic pancreatitis.

Faecal triglycerides and fatty acids in the differential diagnosis of pancreatic insufficiency and intestinal malabsorption in patients with low fat intakes

To investigate possible parameters for the differential diagnosis of steatorrhoea in patients with low fat intakes, faecal specimens were analysed from 15 patients with steatorrhoea due to chronic pancreatitis and seven patients with steatorrhoea due to intestinal malabsorption. The fat intakes of the patients ranged from 30.1 to 60 g, less than the average in American and European patients. The group with pancreatic steatorrhoea showed a significantly lower faecal output than the group with intestinal steatorrhoea but the two groups did not differ significantly in their total faecal fat excretion or concentration. The percentage triglycerides and the molecular ratio of triglycerides to fatty acids in the faeces were significantly higher (P < 0.01) in the group with pancreatic steatorrhoea than in those with intestinal steatorrhoea. The molecular percentage ratio of triglycerides to fatty acids was 6.8 +/- 2.2 for the chronic pancreatitis group and 2.4 +/- 1.0 for the intestinal malabsorption group; while the respective faecal hydroxy fatty acid contents were 3.1 +/- 3.6% and 10.1 +/- 3.3% (means +/- SDs). These latter two parameters appeared to be the most valuable for distinguishing the two forms of steatorrhoea.

Effect of replenished lipase on postcibal absorption of fat in a canine model of pancreatic insufficiency

Clinical studies indicate that as little as 10% of pancreatic secretory capacity is needed to ensure normal digestion; but we found previously that supplying lipase to the postcibal duodenum at > or = 10% of normal rates did not normalize fat absorption in pancreatic insufficiency. Therefore, we examined the dose-response of endogenous lipase on fat absorption. Pancreatic juice was excluded and returned in varied amounts to the postcibal duodenum in dogs with pancreatic fistulas. Meals contained margarine labeled with digestible [14C]triolein and indigestible [3H]glyceroltriether. With an isotope ratio method, we estimated the amount of radiotriolein absorbed hourly from chyme collected for 6 h after a meal from midgut fistulas. When all pancreatic juice was excluded, there was almost no absorption. When 10 or 20% of pancreatic juice was returned, approximately 80% of triolein was absorbed by the midgut, compared with 90% absorption when all pancreatic juice was instilled. However, we observed that at 10 and 20% replenishments, the amount of triolein absorbed in the first hour was much less than in subsequent hours, and thus that absorptive efficiency varied with the fraction of fat emptied from the stomach during the first hour. At rates of 10 or 20% of normal, lipase was equally effective, whether from endogenous juice or exogenous pancreatin.

Oral absorption of omega-3 fatty acids in patients with cystic fibrosis who have pancreatic insufficiency and in healthy control subjects

Dietary supplementation with fish oils high in the omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, may have an antiinflammatory effect. We determined whether patients with cystic fibrosis (CF) could incorporate omega-3 fatty acids into their plasma and cell membrane phospholipids without adverse effects. In this double-blind study, 12 patients with pancreatic insufficiency who have CF (mean age, 12.2 +/- 5.4 (SD) years) and 13 subjects without CF (mean age, 13.4 +/- 6.3 (SD) years) were randomly assigned to ingest 8 gm daily of either encapsulated fish oil (3.2 gm of eicosapentaenoic acid and 2.2 gm of docosahexaenoic acid daily) or olive oil ethyl esters for 6 weeks. Two of seven and two of five patients with CF who received fish and olive oils, respectively, and one of eight and none of five subjects without CF discontinued taking the capsules before 6 weeks because of eructation or diarrhea. Significant incorporation of omega-3 fatty acids into plasma and erythrocyte membrane phospholipids was observed in subjects with and those without CF randomly assigned to the fish oil treatment. For example, in subjects randomly assigned to receive fish oil, the eicosapentaenoic acid/arachidonic acid ratio in plasma increased 9.8-fold, from 0.04 +/- 0.02 (mean +/- SEM) to 0.39 +/- 0.11 (p = 0.02), in the patients with CF (n = 7) and 23.0-fold, from 0.04 +/- 0.01 to 0.92 +/- 0.17 (p = 0.001), in the subjects without CF (n = 8) who received fish oil (p = 0.02, patients with CF vs subjects without CF at 6 weeks). No clinically or statistically significant changes from baseline were observed in platelet aggregation or levels of vitamin E or A in subjects who received fish oil. Future studies are indicated to determine whether omega-3 fatty acid enrichment provides a clinically beneficial antiinflammatory effect in patients with CF.

Comparative in vitro and in vivo studies of enteric-coated pancrelipase preparations for pancreatic insufficiency

We evaluated three acid-resistant pancreatic enzyme preparations by in vitro assays, and by comparing degree of steatorrhea, creatorrhea, fecal wet weight, and stool energy losses in a randomized crossover study of patients with pancreatic insufficient cystic fibrosis. Aims of the study were to assess (a) the most practicable and reliable indicator of malabsorption; (b) the variation in enzyme batch potency; (c) the decline in enzyme batch potency with prolonged shelf life; and (d) the relative bioefficacy of the different preparations. In the in vivo study, absorption of energy, nitrogen, and fat did not differ when comparing the three preparations at roughly pharmaceutically equivalent doses, but when expressed per capsule of pancreatic supplement ingested, absorption reflected relative enzyme content, favoring the higher potency preparations. Although steatorrhea was reasonably controlled by these preparations, stool energy losses varied from 800 to 1,100 kJ per day, suggesting greater attention be paid to overall energy absorption rather than absorption of individual nutrients. In addition, fecal energy loss correlated more closely with fecal wet weight (r = 0.81; p < 0.05) than with steatorrhea (r = 0.40; ns), such that 1 g wet feces = 8.37 kJ (+/- 0.14). In vitro enzyme potency varied markedly between batches of the same brand, and also a decline of up to 20% in amylase, lipase, and trypsin activity was noted over an 8-month period for each batch. Both observations have clinical implications at times of represcription. Finally, the higher potency preparations were more effective per capsule and reduced capsule dosage is therefore attainable.

[Measurement of selective intestinal permeability using a new, simple sugar absorption test]

OBJECTIVE

To study the clinical value of the sugar absorption test (SAT) as a function test of the selective permeability of the small intestine in various intestinal diseases.

DESIGN

Inventory of the results of the SAT in a number of patient groups and controls.

SETTING

Beatrix Children's Hospital, Groningen and Rijnstate Hospital, Arnhem.

METHODS

The SAT was performed in 51 controls (25 children, 26 adults) and in a number of diseases: (suspected) allergy to cow's milk albumin (30 children), (suspected) coeliac disease (86 children and 35 adults), Crohn's disease (25 patients) with ulcerative colitis (9), and pancreatic insufficiency (31) due to cystic fibrosis or chronic pancreatitis. For the SAT, the fasting patient is given a solution of mannitol (M) and lactulose (L) following which the L/M ratio, as an indicator of the selective intestinal permeability, is determined in 5-hour urine by means of gas chromatography.

RESULTS

In cow's milk protein allergy, the L/M ratio showed a statistically significant increase in clinically positive cow's milk provocation results, unlike that in clinically negative results. After pretreatment with cromoglycate this difference decreased to non-significant values. The L/M ratio was increased in active coeliac disease (with villous atrophy), first-degree relatives of coeliac disease patients, Crohn's disease, clinically active ulcerative colitis and pancreatic insufficiency. The L/M ratio was not increased in inactive coeliac disease (with normal villi), suspicion of coeliac disease because of short stature, dystrophy and/or aspecific gastrointestinal symptoms with normal villi, and in clinically inactive ulcerative colitis.

CONCLUSION

The selective intestinal permeability can be determined by means of the SAT. This could be an important tool for diagnosis and evaluation of therapy in gastrointestinal disorders.

Comparison of net protein utilization of milk protein mild enzymatic hydrolysates and free amino acid mixtures with a close pattern in the rat

The nutritive value of two nitrogen-containing mixtures, one formed from small peptides (milk protein mild enzymatic hydrolysates) and the other consisting of a mixture of free amino acids having the same pattern except for glutamine, was measured in rats with and without experimental liver and exogenous pancreas dysfunction. For this purpose, 30 animals (group N) were fitted with an indwelling duodenal catheter; 36 animals (group L) also underwent ligation and resection of the biliopancreatic duct. After a 3-day recovery period, the animals in each group, divided into three equivalent batches, were given, for 10 days, a protein-free diet ad libitum and a twice-daily duodenal infusion (5 mL) of either saline, the small peptides, or the free amino acid mixture. The nitrogen-containing mixtures provided 0.32 g of nitrogen per day. A blood sample (left side of the heart) was collected 1 hour before (five to six animals per batch) and after (five to six animals per batch) the last infusion for determination of glucose, insulin, and amino acids. After the animals were killed, their carcasses were freeze-dried, ground, and analyzed for nitrogen content. Under these conditions, the net protein utilization (the gain in body nitrogen in the animals infused with one of the two nitrogen-containing solutions in comparison with the animals infused with saline only divided by the nitrogen ingested) was calculated.(ABSTRACT TRUNCATED AT 250 WORDS)

Complex carbohydrate malabsorption in exocrine pancreatic insufficiency

The magnitude of complex carbohydrate malabsorption in exocrine pancreatic insufficiency has not been well quantified in the past. The quantity of carbohydrate malabsorbed after a rice starch (100 g) meal in 20 patients with chronic pancreatitis (n = 10) or pancreatic cancer (n = 10) was therefore estimated. Patients had a three day stool fat collection (80 g/24 hour fat intake), a lactulose (20 g), and a rice flour (100 g) breath hydrogen test. Normal controls (n = 29) had a postprandial H2 increase < or = 14 ppm and malabsorbed (mean (SEM)) 1.12 (0.44) (range 0-11.10) g of the 100 g of carbohydrate ingested. Patients malabsorbed significantly more carbohydrate (11.36 (2.23) (range 8.90-32.60) g, F1.47 = 29.92, p < 0.001). The number of patients with fat (> 7 g, n = 8) or carbohydrate (increase in H2 > or = 20 ppm, n = 10) malabsorption was not different (chi 2 = 0.10, p = 0.75). There was a significant correlation between faecal fat and amount of malabsorbed carbohydrate (r = 0.60, F1.17 = 9.70, p = 0.006) and faecal fat and stool wet weight (r = 0.57, F1.18 = 8.67, p < 0.009), but not between stool wet weight and amount of malabsorbed carbohydrate (r = 0.28, F1.17 = 1.45, p = 0.25). Although patients with exocrine pancreatic insufficiency malabsorb 10%-30% of the ingested complex carbohydrate, the main determinant of stool wet weight could be faecal fat.

Fate of oral enzymes in pancreatic insufficiency

Oral pancreatic enzyme supplements, including those protected from gastric acidity by enteric coating, often achieve only partial correction of pancreatic steatorrhoea. To characterise the mechanisms involved in vivo, eight patients with steatorrhoea due to advanced pancreatic insufficiency and nine healthy controls were studied. Two sets of studies (small bowel intubation and five day faecal fat quantification) were randomly performed while patients were either on enteric coated pancreatin or equivalent placebo. A 260 cm long multilumen tube was used for double marker perfusion of two 20 cm segments located in the duodenum and in the ileum respectively. Luminal pH, flow, and trypsin and lipase activity outputs were measured at each segment for four hours postcibally. Placebo treated patients with pancreatic steatorrhoea had low enzyme outputs in the duodenal test segment and even lower outputs in the ileal segment. Pancreatin treatment significantly decreased steatorrhoea (p < 0.05) and increased luminal enzyme outputs (p < 0.05). The increase was much greater in the ileal than in the duodenal segment. Thus enteric coated pancreatin treatment abolished the normal gradient between postcibal duodenal and ileal lipase output. The results suggest that enteric coated pancreatin nearly corrects severe pancreatic steatorrhoea. The ingested lipase was utilised inefficiently, however, as luminal enzyme activity in the ileum was enhanced to a greater extent than in the duodenum, and consequently the absorptive potential of the small bowel was only partially utilised.

Use of famotidine in severe exocrine pancreatic insufficiency with persistent maldigestion on enzymatic replacement therapy. A long-term study in cystic fibrosis

In patients with pancreatic exocrine insufficiency, the use of pancreatic enzyme does not abolish steatorrhea in some cases. We carried out a long-term prospective study in an attempt to clarify the effectiveness of the associated use of famotidine to enzymatic supplementation on fat absorption and nutritional parameters of patients with pancreatic insufficiency due to cystic fibrosis. We studied 10 patients, mean age 12.5 years, with persistent steatorrhea on enzymatic supplementation. A double-blind crossover design was used and famotidine (1 mg/kg/day) or placebo was given as adjuvant to enzymatic preparations for either of two six-month periods. A statistically significative reduction in fecal wet weight (P less than 0.0001), an improvement in the coefficient of fat absorption (P less than 0.01) and in the steatocrit values (P less than 0.028) were found on famotidine. Moreover, the weight and the height increases were greater after famotidine than after placebo period (respectively, P less than 0.012 and P less than 0.01); also the serum calcium and triglycerides levels were higher after the period on famotidine (respectively, P less than 0.0025 and P less than 0.025). No adverse effects of famotidine were noted. These data suggest that famotidine is a useful adjuvant to pancreatic enzyme therapy in patients with severe pancreatic insufficiency and persistent maldigestion on large doses of pancreatic supplements; in fact, famotidine improves not only fat absorption but the nutritional status of the patients.

Evaluation of vitamin A absorption by using oil-soluble and water-miscible vitamin A preparations in normal adults and in patients with gastrointestinal disease

We evaluated vitamin A absorption in 50 healthy adults and 26 gastrointestinal-disease patients by measuring the postabsorptive response in plasma retinyl esters after oral doses of the vitamin. On 3 consecutive days, two physiologic-dose tests of 2000-2400 retinol equivalents (RE) and one pharmacologic-dose test (84,000 RE) were administered. The physiologic doses were given as an oil-soluble or a water-miscible preparation. In gastrointestinal-disease patients the physiologic-dose test was highly correlated with the pharmacologic-dose test for the oil-soluble preparation as determined by peak rise (r = 0.50, P less than 0.05) and area under the curve (r = 0.56, P less than 0.01), suggesting that the physiologic dose is valid for investigating vitamin A absorption. Intestinal-disease or resection patients absorbed preparations poorly. Pancreatic-disease patients absorbed the oil-soluble preparation poorly. Physiologic rather than pharmacologic doses of vitamin A can be used to study vitamin A absorption.

Cholesterol malabsorption in pancreatic insufficiency: effects of enzyme substitution

Defective lipolysis, steatorrhea, and hypocholesterolemia characterize pancreatic insufficiency. Lipid metabolism in pancreatic insufficiency was studied by measuring serum lipoproteins, cholesterol absorption with double labels and serum plant sterols, and bile acid and cholesterol synthesis with fecal and dietary steroid analysis and cholesterol precursor sterols before and during exogenous pancreatic enzyme substitution. Baseline fecal fat, masses, bile acids and neutral steroids, and cholesterol synthesis were increased, whereas cholesterol absorption was markedly reduced. In fact, the present data suggest that sterol absorption may be disturbed more sensitively than fat absorption in pancreatic insufficiency. Enzyme substitution significantly reduced fecal fat, masses, bile acids and neutral steroids, and synthesis of cholesterol and improved cholesterol absorption in relation to serum cholesterol, although normal values were not obtained. Serum level of high-density lipoprotein cholesterol was significantly elevated by exogenous enzymes, whereas levels of cholesterol or triglycerides in other lipoproteins remained unchanged. Improved sterol absorption increased also serum levels of plant sterols and reduced levels of cholesterol precursors and cholesterol synthesis and precursor sterol-plant sterol ratios. Thus, reduced intestinal lipolysis with expanded oil phase appears to be a major reason for impaired cholesterol absorption, causing enhanced cholesterol and, consequently, bile acid synthesis and reduced serum cholesterol level. Exogenous enzyme substitution seems partly to correct these abnormalities, improvements of which can be monitored by the gas-liquid chromatographic determination of serum plant sterols or cholesterol precursor-plant sterol ratios.

[Effect of pellet size of a pancreas enzyme preparation on duodenal lipolytic activity]

Release of lipolytic activity from enteric coated microspheres occurs after emptying from the stomach. Gastric emptying of the spheres is strongly influenced by their size, as several studies indicate. In the present study 10 patients with exocrine pancreatic insufficiency received two types of enzyme substitution (Kreon) and were investigated using the cholesterol-14C-octanoate breath test. Preparation A with microspheres of the size 1.0-1.2 mm and B with the size 1.8-2.0 mm. All patients showed an obvious delay in intraduodenal lipolytic activity using the 1.8-2.0 mm preparation. In 3 out of 10 patients lipolytic activity increased much more early using the 1.0-1.2 mm preparation, in the other patients differences were not as clear. The effectiveness of enzyme substitution was 25% greater for the 1.0-1.2 mm preparation for the time of testing (mean values, p less than 0.10).

Fate of orally ingested enzymes in pancreatic insufficiency: comparison of two pancreatic enzyme preparations

The effect on steatorrhoea of a pH-sensitive enteric-coated pancreatic preparation (Eurobiol 25,000) was compared with a conventional pancreatic enzyme preparation (Eurobiol) in six adult patients with exocrine pancreatic insufficiency. In addition, the fate of orally ingested pancreatic enzymes in the upper digestive tract was evaluated by measuring gastric and duodenal pH, amount of enzymes in the stomach, duodenal enzyme output, and fat absorption at the angle of Treitz for the 4 hours following a standard meal. When compared with placebo, Eurobiol and Eurobiol 25,000 reduced daily faecal fat excretion by 24% (not significant) and 43% (P less than 0.05), respectively. With the conventional preparation, enzyme output and fat absorption at the duodeno-jejunal flexure were significantly improved (P less than 0.05). Marked inter-individual differences in duodenal enzyme recovery (lipase 3% to 80%; chymotrypsin 26% to 100%) and, consequently, in the reduction of steatorrhoea (0% to 67%) were observed, with the gastric emptying rate emerging as a key determinant factor. With the enteric-coated preparation, enzyme output and fat absorption at the duodenojejunal flexure were not significantly improved. Discrepancy between the marked reduction of faecal fat excretion and the low duodenal enzyme recovery could indicate that enzyme delivery from microtablets occurs further down in the small bowel. Efficacy of enteric-coated preparations could be enhanced by adding unprotected enzymes, especially in patients with rapid gastric emptying.

Short report: lipid and vitamin B12 malassimilation in pancreatic insufficiency

Patients with exocrine pancreatic insufficiency have steatorrhoea as well as vitamin B12 malassimilation. To investigate whether this is caused by the pancreatic insufficiency per se or whether intestinal bacterial overgrowth contributes to the condition, 10 patients with pancreatic steatorrhoea were studied. Intestinal culture was done. Lipid and vitamin B12 assimilation was estimated from faecal spot tests, using 14C-triolein and 58Co-vitamin B12 as tracers and 51CrCl3 as marker. Out of the 10 patients, 9 had either vitamin B12 malassimilation (n = 8), and/or bacterial overgrowth (n = 5). These 9 patients were retested with pancreatic enzyme therapy, with and without addition of the antibiotics metronidazole and cefalexin. The lipid assimilation was significantly increased by enzyme therapy but did not improve further on additional antibiotic treatment. The vitamin B12 assimilation did not improve significantly on enzyme therapy nor with additional antibiotic treatment.

Monitoring the effect of substitution therapy in patients with exocrine pancreatic insufficiency

Twenty-three outpatients with chronic pancreatitis and severe exocrine insufficiency were studied for the purpose of comparing the effect of Pancrease, Pankreon, and Pankreatin by estimation of duodenal enzyme activity, the faecal fat excretion, and the faecal 14C-triolein-3H-oleic acid test and, at the same time, to evaluate these tests when monitoring outpatients. The three preparations did not disclose any significant difference in treating steatorrhoea. Pankreatin increased the meal-stimulated duodenal enzyme activity (p less than 0.01) and caused reduction in the faecal fat excretion (p less than 0.05), whereas no change in these variables were observed with Pankreon or Pancrease. The faecal 14C-triolein-3H-oleic acid test showed significant improvement in the 14C-triolein digestion with all three preparations (p less than 0.01). The faecal 14C-triolein-3H-oleic acid test was the most reliable when monitoring outpatients.

Georges Brohee Prize 1988-1989. Assimilation of nutritional carbohydrates: influence of hydrolysis

The influence of hydrolysis on the assimilation rate of important nutritional carbohydrates was studied in healthy subjects and patients with intestinal diseases, mainly by means of 13CO2 breath test techniques. All substrates were "naturally enriched" with carbon-13. The studies showed that hydrolysis is the rate limiting step for the assimilation of lactose, starch and even maltose, but not for the assimilation of sucrose. The degree of gelatinisation and the degree of side-branching of starch molecules were two important parameters, influencing starch hydrolysis in normal subjects. Addition of wheat bran had no influence on the digestion rate of starch. A comparative study between normal subjects and patients with pancreatic disease, showed that starch digestion may be impaired in patients with pancreatic disease. However, this occurs only if amylase output is extremely low. The effect of lactase deficiency on lactose absorption was studied in patients with a history suggestive of lactase deficiency. For this purpose a lactose 13CO2 and H2 breath test were compared with lactase activity in a jejunal biopsy. The results showed that the relation between lactase activity in the biopsy and lactose assimilation takes the form of a saturation curve. The 13CO2 breath test was found to be a reliable test for the diagnosis of lactase deficiency. Finally, the effect of acarbose on starch digestion was studied in normal subjects, ileostomy patients, and a fecal incubation system. These experiments showed that acarbose may induce an important degree of starch malabsorption. If administered in high doses, the effect is not only related to inhibition of brush border enzymes, but also to the inhibition of alpha-amylase.

Pearson's marrow-pancreas syndrome. A multisystem mitochondrial disorder in infancy

Pearson's marrow-pancreas syndrome (McKusick No. 26056) is a fatal disorder of hitherto unknown etiology involving the hematopoietic system, exocrine pancreas, liver, and kidneys. The observation of high lactate/pyruvate molar ratios in plasma and abnormal oxidative phosphorylation in lymphocytes led us to postulate that Pearson's syndrome belongs to the group of mitochondrial cytopathies. Since rearrangements of the mitochondrial genome between direct DNA repeats were consistently found in all tissues tested, our results show that this disease is in fact a multisystem mitochondrial disorder, as suggested by the clinical course of the patients. Based on these observations, we would suggest giving consideration to the hypothesis of a defect of oxidative phosphorylation in elucidating the origin of other syndromes, especially those associated with an abnormal oxidoreduction status in plasma.