ABSTRACT: Pancreatic exocrine insufficiency (PEI) impairs fat absorption, but few data are available on protein absorption. We investigated this question in patients with chronic pancreatitis, both in the absence and presence of enzyme therapy, using a stable isotope sensitive method.
Eleven patients with sustained PEI and regular enzyme substitution were investigated at hospital, after a washout period without enzyme substitution, and later after reintroduction of substitution. The digestibility and postprandial metabolism of dietary protein were characterized after the ingestion of a semi-synthetic single meal containing 20 g (15)N-labeled casein.
At baseline, 20 ± 8% of dietary nitrogen was transferred to the metabolic pools vs. 24.5 ± 7% under enzyme treatment (P = 0.04). After treatment, the transfer of dietary nitrogen tended to increase in plasma amino acids, and increased significantly in plasma proteins and the deamination pool. In contrast, the fecal excretion of dietary nitrogen did not demonstrate any treatment effect. In patients not receiving insulin for diabetes, the treatment stimulated insulin secretion.
Protein malabsorption was mostly undetectable using standard fecal tests. The study of the postprandial fate of dietary protein revealed a moderate increase of its transfer to metabolic pools after enzyme substitution.
Clinical nutrition (Edinburgh, Scotland) 07/2011; 30(6):831-7. · 3.27 Impact Factor
ABSTRACT: Colonic response to food (CRF) is abnormal in irritable bowel syndrome (IBS) patients.
The aim of this study was to compare CRF in patients who complain of abnormal defecation pattern according to the presence or absence of abdominal pain.
One hundred forty-nine patients and 50 controls were studied: 96 IBS patients (46 IBS-C, 13 IBS-D, 15 IBS-M, and 22 IBS-U not included), 43 patients with functional constipation (group C) and ten with functional diarrhea (group D). Clinical evaluation and visual analog scales about four items (constipation, diarrhea, abdominal bloating and abdominal pain) were filled by all subjects. Colonic transit time (CTT) was measured in fasting conditions and after eating a standard 1,000-cal test meal. CRF was quantified by calculating the variation in number of markers between the two films.
The frequency of meal-related symptoms did not vary among the different groups of patients but was significantly higher than in controls. Compared to IBS-C patients, constipated patients of the group C had longer total and segmental colonic transit time, and compared to IBS-D patients, diarrheic patients of the group D had shorter oro-anal and segmental colonic transit time except in the recto-sigmoid area. CRF was different in patients and controls, and differed between IBS and non IBS patients with similar transit abnormalities. Stool output was greater in patients of the group D than in patients of the IBS-D group.
The different subgroups of IBS patients have different CRF patterns, distinct from subjects with constipation and diarrhea, but without abdominal pain.
Digestive Diseases and Sciences 04/2011; 56(10):2947-56. · 2.12 Impact Factor
ABSTRACT: Wasting can occur at an early stage of HIV infection. Both reduced energy intake and increased resting energy expenditure (REE) have been considered as factors in wasting with predominant lean body mass loss, suggesting disturbances of protein metabolism. Our aim was to study protein-energy metabolism in relation to body composition and oral energy intake in asymptomatic patients with HIV infection but receiving no active antiretroviral therapy. Stable-weight asymptomatic male patients (n = 8) at stage A of HIV infection with a detectable viral load were compared with 9 healthy control men. Protein metabolism was studied in the postabsorptive state using a primed constant infusion of l-[1-(13)C]leucine and l-[2-(15)N]glutamine. REE was studied by indirect calorimetry, body composition by bioelectrical impedance, and energy intake by dietary records. BMI and lean body mass did not differ between patients and controls. In HIV-infected subjects, energy intake, protein breakdown, protein synthesis, and REE were 57% (P < 0.05), 18% (P < 0.05), 22% (P < 0.05) and 14% (P < 0.05) greater than in controls, respectively. REE and protein breakdown were correlated (r = 0.73, P < 0.05). The hormonal profile was normal in HIV-infected subjects with the exception of low urinary C-peptide and plasma reverse triiodothyronine. Plasma interleukin-6 and tumor necrosis factor-alpha were greater than in controls, but energy intake was 1.53 times the REE in the HIV-infected men. Thus, at the asymptomatic stage of HIV infection, increased protein turnover contributes to the increase in the REE. Moderate hyperphagia, which occurred despite increased levels of cytokines, in conjunction with increased protein synthesis maintains a normal body composition, without significant loss of lean body mass.
Journal of Nutrition 09/2004; 134(9):2301-6. · 3.92 Impact Factor