Body composition in patients on home parenteral nutrition

Oxygen utilisation in patients on prolonged parenteral nutrition; a case-controlled study

BACKGROUND

Parenteral nutrition (PN) deficient in mitochondrial substrates and thiamine may lead to acidosis. This, combined with fatigue seen in patients with intestinal failure (IF), may suggest suboptimal oxidative metabolism. We therefore studied oxygen utilisation in otherwise apparently well-nourished individuals with intestinal failure receiving long term PN.

METHODS

This was a retrospective analysis conducted in a tertiary IF institution, from 2010 to 2019, comparing treadmill/bicycle cardiopulmonary exercise test (CPET) derived variables including peak oxygen consumption (VO_{2 peak}), anaerobic threshold (AT) and ventilatory efficiency (minute ventilation (VE)/CO₂ output (VCO₂) of patients with IF (cases) to those without (controls), matched in a 1:2 ratio for age ( ± 3 years), gender, use of beta-blockers and physiology parameters of p-POSSUM score ( ± 5). All subjects were free of sepsis and metastatic malignancy. Mann-Whitney or Student's t-test for continuous and Fisher's exact or chi-squared test for categorical variables were used as appropriate. Data shown represent mean or median values.

RESULTS

Participants (31 cases, 62 controls) were comparable in age (65.4 vs. 65.3, p = 0.98); p-POSSUM parameters (18.0 vs. 17.0, p = 0.45); gender (p = 1.00); smoking status (p = 0.52); use of beta-blockers (p = 1.00) and ≤10 mg/day of oral steroids (p = 0.34). Participants had been on PN for 11.0 (6.0-24.0) months and were adequately nourished (requirements 27.6 kcal/kg/day, replacement 23.5 kcal/kg/day). No differences were found between VO_{2 peak} (15.2 vs. 14.6 ml/kg/min, p = 0.96), AT (10.4 vs. 11.0 ml/kg/min, p = 0.44) and VE/VCO₂ (33.0 vs. 33.0, p = 0.96) of the examined groups.

CONCLUSION

Patients with intestinal failure receiving PN who are apparently well-nourished also appear to have normal oxygen utilisation, suggesting alternative causes for fatigue. More studies will be required to determine whether CPET could reliably be used to assess perioperative risk in this group of patients.

Body composition in paediatric intestinal failure patients receiving long-term parenteral nutrition

OBJECTIVE

Outcome of children with intestinal failure (IF) has improved on treatment with parenteral nutrition (PN). The effects of PN and IF on body composition (BC) are unknown. The aim was to review BC in PN-treated children and those weaned off and to compare with reference data.

DESIGN

Children on long-term/home PN underwent measurement of regional fat mass (FM) and lean mass (LM) using dual energy X-ray absorptiometry. Underlying diseases were intestinal enteropathy, n=15, short bowel syndrome (SBS), n=8 and intestinal dysmotility, n=11. PN duration was median 10 years. Fat Mass Index (FMI) and Lean Mass Index (LMI) were compared in children with and without intestinal inflammation, steroid treatment and according to PN dependency.

RESULTS

34 children aged 5-20 years were studied. They were short, mean height SD score (SDS) -1.8 (p<0.001) and light (mean weight SDS -0.86, p<0.001) with high body mass index (BMI) SDS: mean 0.4 (p=0.04) and low Limb LMI SDS -0.9 (p<0.001). Children with SBS had low FMI SDS -0.8 (p=0.01). BC did not significantly differ between diagnostic groups or with steroid treatment. Patients with intestinal inflammation (n=20) had higher BMI SDS than those without, p=0.007. Totally, PN-dependent children, n=11 had higher BMI SDS, p=0.004, total body FMI SDS, p=0.008 and trunk FMI SDS, p=0.001 compared with patients partially dependent and off PN.

CONCLUSIONS

Significantly low limb LM was seen in all patient groups with high FM in children on total PN. Children with IF requiring PN treatment >27 days may benefit from BC monitoring and PN adjustment according to results in order to maximise linear growth and health in later life.

Bone deficits in parenteral nutrition-dependent infants and children with intestinal failure are attenuated when accounting for slower growth

OBJECTIVE

The aim of the present study was to determine whether bone mineral content (BMC) and density (BMD) of infants and children with parenteral nutrition (PN)-dependent intestinal failure (IF) is lower than healthy controls, and investigate potential causes of lower BMC and BMD.

METHODS

We performed a cross-sectional study comparing infants and children with PN-dependent IF with duos of age-, sex-, and race-matched controls. Lumbar spine BMC and BMD were measured by dual-energy x-ray absorptiometry, and serum cytokines, aluminum, insulin-like growth factor-1 (IGF-1), IGF-binding protein 3 (IGF-BP3), parathyroid hormone, 25-hydroxy vitamin D, and 1,25-dihydroxy vitamin D were measured. Generalized estimating equation models accounting for matching were used for comparisons.

RESULTS

BMC was 15% and BMD was 12% lower in IF participants than in controls (P ≤ 0.004). Group differences were attenuated to 3% and 7% and were not statistically significant (P = 0.40 and P = 0.07) when adjusted for length and weight; length- and weight-for-age were lower in IF than in control participants (12.5% vs 63%; 29.5% vs 54%, P ≤ 0.03). IF participants had higher serum aluminum (23 vs 7 μg/L, P < 0.0001), IGF-1 (97 vs 64 ng/mL, P = 0.04), and 25-hydroxy vitamin D concentrations (40 vs 30 ng/mL, P = 0.0005), and lower IGF-BP3 (1418 vs 1812 ng/mL, P < 0.0001) and parathyroid hormone concentrations (51 vs 98 pg/mL, P = 0.0002) than controls. There was no difference in serum cytokine concentrations (P ≥ 0.09).

CONCLUSIONS

Growth retardation is a significant problem for patients with PN-dependent IF. Additional investigation is needed to elucidate the cause and its effect on bone mass and density, especially the role of IGF-1 resistance and aluminum toxicity.

[Clinical practice guidelines for evaluation and treatment of osteoporosis associated to endocrine and nutritional conditions. Bone Metabolism Working Group of the Spanish Society of Endocrinology]

OBJECTIVE

To provide practical recommendations for evaluation and treatment of osteoporosis associated to endocrine diseases and nutritional conditions.

PARTICIPANTS

Members of the Bone Metabolism Working Group of the Spanish Society of Endocrinology, a methodologist, and a documentalist.

METHODS

Recommendations were formulated according to the GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation) to describe both the strength of recommendations and the quality of evidence. A systematic search was made in MEDLINE (Pubmed), using the following terms associated to the name of each condition: AND "osteoporosis", "fractures", "bone mineral density", and "treatment". Papers in English with publication date before 18 October 2011 were included. Current evidence for each disease was reviewed by two group members, and doubts related to the review process or development of recommendations were resolved by the methodologist. Finally, recommendations were discussed in a meeting of the Working Group.

CONCLUSIONS

The document provides evidence-based practical recommendations for evaluation and management of endocrine and nutritional diseases associated to low bone mass or an increased risk of fracture. For each disease, the associated risk of low bone mass and fragility fractures is given, recommendations for bone mass assessment are provided, and treatment options that have shown to be effective for increasing bone mass and/or to decreasing fragility fractures are listed.

Genetics of osteoporosis

Osteoporosis is a common multifactorial disorder of reduced bone mass. The disorder in its most common form is generalized, affecting the elderly, both sexes, and all racial groups. Multiple environmental factors are involved in the pathogenesis. Genes also play a major role as reflected by heritability of many components of bone strength. Quantitative phenotypes in bone strength in the normal population do not conform to a monogenetic mode of inheritance. The common form of osteoporosis is generally considered to be a polygenic disorder arising from the interaction of common polymorphic alleles at quantitative trait loci, with multiple environmental factors. Finding the susceptibility genes underlying osteoporosis requires identifying specific alleles that coinherit with key heritable phenotypes in bone strength. Because of the close correspondence among mammalian genomes, identification of the genes underlying bone strength in mammals such as the mouse is likely to be of major assistance in human studies. Identification of susceptibility genes for osteoporosis is one of several important approaches toward the long-term goal of understanding the molecular biology of the normal variation in bone strength and how it may be modified to prevent osteoporosis. As with all genetic studies in humans, these scientific advances will need to be made in an environment of legal and ethical safeguards that are acceptable to the general public.

Serum leptin concentrations in patients with short-bowel syndrome

BACKGROUND

Short-bowel syndrome is a state of severe malabsorption resulting from absence or removal of the small bowel for several causes. A number of short-bowel patients develop hyperphagia. Leptin, a protein secreted from adipose tissue, signals the amount of energy stores to the brain.

OBJECTIVE

To study body composition and leptin regulation in short-bowel patients and to determine whether or not leptin concentrations are linked with hyperphagia.

DESIGN

We studied 25 short-bowel patients (remnant bowel less than 150 cm) and 31 controls and 10 oral nutrition. Fifteen patients received total parenteral nutrition and 10 oral nutrition. Anthropometric measurements, body composition (by bioelectrical impedance), and cholesterol, triacylglycerol and leptin concentrations were studied in all subjects.

RESULTS

There were no differences between short-bowel patients and controls in anthropometric variables, body composition, or leptin concentrations. Leptin concentrations were higher in short-bowel women than men (9.21+/-8.54 vs. 3.22+/-1.86 ng/ml, P=0.01). Leptin concentrations correlated positively with age (r=0.4, P=0.045), body mass index (r=0.52, P=0.007), fat mass (r=0.67, P=0.001) and body fat (r=0.68, P=0.0001); there were no correlations with other body composition parameters. We found no correlations between parenteral or oral nutrition and body composition parameters, or between leptin concentrations and the presence of hyperphagia. Logistic regression analysis showed that body fat correctly identified leptin concentrations in 60% of patients.

CONCLUSIONS

Body composition, leptin concentrations and leptin regulation in patients with short-bowel syndrome are similar to those of controls. Leptin concentrations do not correlate with hyperphagia in short bowel-patients.

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.