Total body potassium, fat and water during total parenteral nutrition in Crohn's disease

Nutrition and inflammatory bowel disease: an update

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammatory process, the aetiology of which remains unknown. Nutrition may play an important role in the pathogenesis and treatment of IBD. The evidence regarding the role of specific dietary components in the pathogenesis of IBD is still inconclusive. Many studies have been subject to methodological limitations; studies of better design are necessary to confirm the hypothesis that nutritional factors may indeed play a role in the development of IBD. Several studies have reported nutritional and functional deficiencies in IBD patients, especially in Crohn's disease. It is, however, hard to discriminate between disease-induced and malnutrition-induced changes in nutritional parameters. Maintaining adequate nutritional status has been suggested to be beneficial to the course of the disease in IBD. Studies have provided further insight into the possible beneficial effects of nutritional supplementation as primary and adjunctive therapy in IBD. The effects of specific nutritional therapy may be caused by alterations in intestinal flora and hence in the production of intraluminal proinflammatory substances. Immunonutrients such as n-3 fatty acids and antioxidants may also play a role in the treatment of IBD. In this paper, the relation between nutritional aetiological factors, nutritional status and nutritional therapy is discussed in detail.

Body composition changes measured by dual-energy X-ray absorptiometry in patients receiving home parenteral nutrition

BACKGROUND

To monitor changes in body composition in patients receiving home parenteral nutrition (HPN) and to ascertain whether changes were related to the amount of energy supplied by HPN, we studied prospectively patients with gut failure maintained on HPN.

METHODS

Patients were subjected to repeated measurement of body composition by dual-energy X-ray absorptiometry (DXA), the second investigation being performed after a mean period of 20 (range, 11-26) months. Thirty-two patients were included, one patient was excluded, and five patients died during the study period. At inclusion, the patients had received HPN for a mean period of 30 (range, 6-216) months. The indication for HPN was inflammatory bowel disease (n = 16), abdominal cancers (n = 5), and scleroderma and others (n = 11). The fat-free mass (FFM), fat mass (FM), and total body mineral content (TBMC) were measured by DXA.

RESULTS

Mean body mass index decreased from 21.18 to 20.96 kg/m2 (P = 0.36). The mean FFM showed a small, insignificant increase to 37.68 kg (P = 0.71). Mean TBMC was unchanged at 2.28 kg, and mean FM decreased from 19.25 to 18.17 kg (P = 0.055). During the study period the mean daily energy supply by HPN was reduced from kcal 1195 to kcal 959 (P = 0.004). There was a direct positive correlation between the individual changes in HPN energy supply and body weight and FFM (r = 0.437, r = 0.410, P < 0.05).

CONCLUSION

The body composition of HPN patients was stable, with no change in mean FFM, FM, or TBMC. Individual changes in body weight and FFM correlated with change in HPN energy supply.

Total enteral nutrition support improves body composition of patients with active Crohn's disease

BACKGROUND

Previous studies using indirect calorimetry in Crohn's disease have suggested that with weight loss there is a proportionally greater decrease in body fat along with a spring of lean mass. This study analyzed body composition (compared with that of controls) by direct methods in a group of 30 patients with active Crohn's disease and further evaluated the effects of nutrition support on body composition.

METHODS

Total body protein was assessed by neutron activation, fat was assessed by dual energy x-ray absorptiometry, water was assessed by bioelectric impedance analysis, and potassium was assessed by gamma-ray technique. These measurements were repeated in patients with Crohn's disease after 3 weeks of enteral nutrition by feeding tube that provided 35 nonprotein kcal/kg of ideal body weight.

RESULTS

Compared with age- and sex-matched controls, patients had lost (on average) 11.3 kg (16%) of body weight (p < .0005), including 5.1 kg (30%) of fat (p < .0005), 2.2 kg (19%) of protein (p < .025), 3.7 kg (10%) of water (p = NS), and 24.9 g (21%) of total body potassium (p < .01). After enteral feeding, body weight increased by 1.9 +/- 0.3 kg (p < .0005). Weight gain was accompanied by an increase in body protein (0.3 +/- 0.1 kg), fat (0.3 +/- 0.1 kg), and water (1.1 +/- 0.4 kg) (all p < .025), and by a nonsignificant increase in total body potassium. The weight gain of approximately 2 kg consisted of 65% water, 18% fat, and 18% protein, thus comprising a normal proportion of body composition.

CONCLUSIONS

Reduced body weight in patients with Crohn's disease compared with that in controls was due to less fat tissue. With modest nutritional repletion, proportionate gains in all body compartments are possible.

Comparison of amino acid v peptide based enteral diets in active Crohn's disease: clinical and nutritional outcome

Elemental diets are considered an effective primary treatment for active Crohn's disease. This study examined the hypothesis that improvement occurs because of the presence of amino acids or the low fat content, or both. A randomised, controlled trial was undertaken in 40 patients with active Crohn's disease to evaluate clinical and nutritional outcomes after an amino acid based diet containing 3% fat was given by a feeding tube compared with a peptide based diet containing 33% fat. After three weeks' treatment, clinical remission occurred in 84% of patients who were given the amino acid diet and 75% of patients who received the peptide diet (p = 0.38). Plasma linoleic acid concentration was reduced after the amino acid but not the peptide diet. An increase in total body nitrogen was associated with the magnitude of nutritional depletion before treatment and at six months' follow up, only patients who showed gains in total body nitrogen after enteral nutrition had a sustained clinical remission. This study shows that peptide based high fat diets are as effective as amino acid low fat diets for achieving clinical remission in active Crohn's disease. Improved total body protein stores but not essential fatty acid depletion may be an important indicator of a sustained remission.

Crohn's disease and nutrition

Malnutrition was included by Crohn as one of the features of the new disease he described. Most patients with Crohn's disease are malnourished even if their disease is not active. Nutritional factors may be implicated in the aetiology of the disease, but this remains unproven. The role of nutritional support and therapy is discussed and it is suggested that improving the patient's nutritional status may have a primary therapeutic as well as a supportive role in the treatment of the disease.