Resting energy expenditure in cancer patients: Agreement between predictive equations and indirect calorimetry.

BACKGROUND/OBJECTIVES: Disorders of energy metabolism is a common phenomenon in cancer patients. Changes in resting energy expenditure (REE) combined with inadequate nutrition support appear to be causes of nutritional depletion in cancer patients. In clinical practice, REE is typically calculated using predictive equations. The aim of this study was to determine the agreement between REE estimated by predictive equations and REE measured by IC in Portuguese cancer patients. Differences in measured REE between patients with different types of digestive cancers were also assessed. SUBJECTS/METHODS: REE was measured by indirect calorimetry (IC) in 61 patients with cancer diagnosis (gastric cancer, cholangiocarcinoma, pancreatic cancer, liver cancer and colorectal cancer). Measured REE values were compared with those estimated by equations of Harris-Benedict, Schofield, Ireton-Jones, Mifflin-St.Jeor and Barcellos I and II. RESULTS: Mean Respiratory Quotient (RQ) was 0.77 ± 0.09, which indicates high lipids utilization as substrate. No statistically significant differences between REE or RQ from patients with different cancer types were observed. All equations underestimate REE: Harris-Benedict, mean difference -648 kcal (limits of agreement +627 to -1923 kcal); MifflinSt.Jeor, mean difference -694 kcal (limits of agreement +544 to -193 kcal); Schofield, mean difference -531 kcal (limits of agreement +662 to -1723 kcal); and Ireton-Jones, mean difference -556 kcal (limits of agreement +774 to -1887 kcal). Barcellos I and II showed lower mean difference when compared to measured REE, +59 and + 52 kcal, respectively, although presenting wide limits of agreement, +1542 to -1424 kcal and +1429 to -1326, respectively. CONCLUSIONS: Although Barcellos Equations underestimate less and enable more accurate average REE prediction in cancer patients, still present wide limits of agreement and therefore clinically important differences in REE estimation may be found at individual level. Our results support the appropriateness of measuring REE by IC to better adequate the nutrition support to cancer patients. Further research is needed to improve the current knowledge base of energy expenditure in cancer patients, and to improve the accuracy of existing predictive equations.

Calystegines are Potential Urine Biomarkers for Dietary Exposure to Potato Products.

SCOPE: Metabolites derived from specific foods present in urine samples can provide objective biomarkers of food intake (BFIs). This study investigated the possibility that calystegines (a class of iminosugars) may provide BIFs for potato (Solanum tuberosum L.) product exposure. METHODS AND RESULTS: Calystegine content is examined in published data covering a wide range of potato cultivars. Rapid methods are developed for the quantification of calystegines in cooked potato products and human urine using triple quadrupole mass spectrometry. The potential of calystegines as BFIs for potato consumption is assessed in a controlled food intervention study in the United Kingdom and validated in an epidemiological study in Portugal. Calystegine concentrations are reproducibly above the quantification limit in first morning void urines the day after potato consumption, showing a good dose-response relationship, particularly for calystegine A3 . The design of the controlled intervention mimicks exposure to a typical UK diet and showed that neither differences in preparation/cooking method or influence of other foods in the diet has significant impact on biomarker performance. Calystegine biomarkers also perform well in the independent validation study. CONCLUSION: It is concluded that calystegines have many of the characteristics needed to be considered as specific BFIs for potato product intake.

New equation to estimate resting energy expenditure in non-critically ill patients.

BACKGROUND: Correct measurement of resting energy expenditure (REE) is essential to offer a proper nutritional management during hospital stay. Dietitians are not able to perform an effective dietary treatment if predicted REE values are obtained from invalid equations. OBJECTIVE: The aim of this study was to develop a more valid method to estimate REE in non-critically ill Portuguese patients. DESIGN: In this cross-sectional study, REE was measured by indirect calorimetry (IC) in 180 non-critically patients during hospital stay (50 participants were allocated to the validation group by simple randomization and the remaining 130 were allocated to the derivation group). The best accurate equations were derived by multiple linear regression analysis (stepwise) based on anthropometric variables. The equations were tested on the validation group and compared with published predictive equations. RESULTS: Data was collected from 130 patients, 68 women (52.3%) and 62 men (47.7%), mean age was 58.9 ± 16.8 years and REE-IC was 1918 ± 721 kcal/day. The new best-fit equation REE (kcal/day) = 14.4 (Height) + 52.7 (MUAC) + 453.4 (1 if male, 0 if female) - 371.2 (if Obese) - 2138.3 showed strength of evidence decisive (BF10 = 8008), when compared by Bayesian model, and r2 = 0.315. Only estimated REE values obtained using new equations did not present significant difference when compared with measured REE values (kcal/kg). CONCLUSIONS: In this study, new equations derived from a non-critically ill population showed higher validity in estimating REE than currently used equations. A better estimation of REE may lead to a better nutritional intervention and a decreased risk of undernutrition in hospitalized patients.

Galacto-Oligosaccharides: Production, Properties, Applications, and Significance as Prebiotics.

Galacto-oligosaccharides (GOS) have now been definitely established as prebiotic ingredients after in vitro and animal and human in vivo studies. Currently, GOS are produced by glycoside hydrolases (GH) using lactose as substrate. Converting lactose into GOS by GH results in mixtures containing GOS of different degrees of polymerization (DP), unreacted lactose, and monomeric sugars (glucose and galactose). Recent and future developments in the production of GOS aim at delivering purer and more efficient mixtures. To produce high-GOS-content mixtures, GH should not only have good ability to catalyze the transgalactosylation reaction relative to hydrolysis, but also have low affinity for the GOS formed relative to the affinity for lactose. In this article, several microbial GH, proposed for the synthesis of GOS, are hierarchized according to the referred performance indicators. In addition, strategies for process improvement are discussed. Besides the differences in purity of GOS mixtures, differences in the position of the glycosidic linkages occur, because different enzymes have different regiochemical selectivity. Depending on oligosaccharide composition, GOS products will vary in terms of prebiotic activity, as well as other physiological effects. This review focuses on GOS production from synthesis to purification processes. Physicochemical characteristics, physiological effects, and applications of these prebiotic ingredients are summarized. Regulatory aspects of GOS-containing food products are also highlighted with emphasis on the current process of health claims evaluation in Europe.