Nutrition in Clinical Practice

Inflammatory bowel disease (IBD), which primarily includes Crohn’s disease and ulcerative colitis, involves chronic inflammation of the gastrointestinal tract. The mechanisms of IBD pathogenesis are not well understood at this time, but likely involve an interaction between genetic, gut microbial, immune, and environmental factors. Emerging epidemiologic studies have suggested a relationship between specific dietary nutrients as an environmental factor and IBD risk. Clinical trials have also shown oral diets to have variable efficacy in affecting clinical outcomes for IBD. This review discusses the key studies that evaluated the use of various oral diets as well as nutrition support in the management of IBD.

Malnutrition is prevalent in individuals with chronic liver disease and occurs as a result of inadequate nutrient intake, altered metabolism, and malabsorption. Although limited data show benefits of enteral nutrition (EN) in this population, patients with chronic liver disease often have inadequate oral intake and are potential candidates for EN. The goals of the EN, type and severity of liver disease, and access for EN will influence the decision to initiate EN. This paper summarizes EN studies in patients with liver disease and provides practical tips regarding patient selection, EN access, and EN formula choices. Two case studies illustrate the principles and challenges of providing EN to patients with cirrhosis. The paper concludes with suggested parameters for an EN feeding protocol and recommendations for future research.

Despite significant advancements made in life expectancy over the past century, cystic fibrosis remains a life-threatening genetic disease that affects the gastrointestinal tract, and it has significant impact on the nutrition status of those with the disease. Nutrition management includes a high-calorie/high-fat diet, pancreatic enzyme replacement therapy, vitamin and mineral replacement, and enteral support as needed. As patients are living longer, clinicians may encounter patients with cystic fibrosis in obstetrician offices, endocrine clinics, or hospital settings, owing to lung transplantation or for treatment for distal intestinal obstruction syndrome.

The introduction of newborn screening and the development of new therapies have led to an expanding population of patients with inherited metabolic disorders, and these patients are now entering adulthood. Dietary therapy is the mainstay of treatment for many of these disorders, and thus, trained metabolic dietitians are critical members of the multidisciplinary team required for management of such patients. The main goals of dietary therapy in inborn errors of metabolism are the maintenance of normal growth and development while limiting offending metabolites and providing deficient products. Typically, the offending metabolite is either significantly reduced or removed completely from the diet and then reintroduced in small quantities until blood levels are within the normal range. Such treatment is required in infancy, childhood, and adulthood and requires careful monitoring of micronutrient and macronutrient intake throughout the life span. The goal of this review is to highlight the basic principles of chronic nutrition management of the inborn errors of protein, carbohydrate, and fat metabolism.

Duchenne muscular dystrophy (DMD) is a serious degenerative muscular disease affecting males. Diagnosis usually occurs in childhood and is confirmed through genetic testing and/or muscle biopsy. Accompanying the disease are several nutrition-related concerns: growth, body composition, energy and protein requirements, constipation, swallowing difficulties, bone health, and complementary medicine. This review article addresses the nutrition aspects of DMD.

Bariatric surgery, an effective treatment for morbid obesity, may result in complications that require nutrition support. Common goals for nutrition support in post–bariatric surgery patients include nutrition repletion, avoiding overfeeding, preserving lean body mass, and promoting wound healing. It is often questioned if continued weight loss can be part of the nutrition goals and if weight loss is safe for patients who become critically ill following bariatric surgery. Recent clinical practice guidelines from both the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) and Society of Critical Care Medicine (SCCM) have recommended the use of hypocaloric, high-protein nutrition support in both critically and non–critically ill obese patients. Hypocaloric feedings of 50%–70% of estimated energy requirements based on predictive equations or <14 kcal/kg actual body weight, as well as high-protein feedings of 1.2 g/kg actual weight or 2–2.5 g/kg ideal body weight, are suggested by A.S.P.E.N. in the 2013 clinical guidelines for nutrition support of hospitalized adult patients with obesity. Two small studies in complicated post–bariatric surgery patients requiring nutrition support have shown that the strategy of hypocaloric, high-protein feedings can result in positive outcomes, including positive nitrogen balance, wound healing, weight loss, and successful transition to oral diets. Additional research, including large, randomized studies, is still needed to validate these findings. However, based on a review of available clinical practice guidelines, predictive equations, indirect calorimetry, case studies, and systematic reviews, hypocaloric, high-protein nutrition support appears to at least be equal to eucaloric feedings and may be a useful tool for clinicians to achieve continued weight loss in complicated bariatric surgery patients requiring nutrition support.

Background: For patients awaiting liver transplantation, we aimed to determine the prevalence and predictors of insufficient protein intake as well as to determine whether very low protein intake was an independent predictor of malnutrition and mortality. Materials and Methods: Adults with cirrhosis who were activated on our local liver transplant waiting list between January 2000 and October 2009 were included. Estimated protein intake was derived from dietary records. Patients with incomplete dietary records were excluded. Multivariable logistic regression and competing risk analysis were used. Results: Of 742 potential patients, 112 were excluded due to insufficient data, leaving 630 patients for evaluation. Mean protein intake was 1.0 ± 0.36 g/kg/d and only 24% of patients met the expert consensus recommended threshold of > 1.2 g/kg of protein per day. Very low protein intake (< 0.8 g/kg/d) was associated with worse liver disease severity (as measured by Child-Pugh or MELD). Protein intake below 0.8 g/kg/d was an independent predictor both of malnutrition as measured by the subjective global assessment (adjusted odds ratio [95% confidence interval (CI)]: 2.0 [1.3–3.0]) and of transplant waiting list mortality (adjusted hazard ratio [95% CI]: 1.8 [1.2–2.7]). Conclusion: In this large cohort of liver transplant waitlisted patients, very low protein intake was prevalent and independently associated with malnutrition and mortality. Unlike many other prognostic factors, protein intake is potentially modifiable. Prospective studies are warranted to evaluate the effect of targeted protein repletion on clinically relevant outcomes such as muscle mass, muscle function, immune function, and mortality.

Background: Central fat accumulation is important in nonalcoholic fatty liver disease (NAFLD) etiology. It is unknown whether any commonly used waist circumference measurement protocol (WCmp), as a whole and central fat accumulation marker, is preferable for patients with NAFLD. The present study sought to find a preferable WCmp to be used in patients with NAFLD, based on 3-fold criteria. Methods: Body fat (BF) was assessed through dual-energy x-ray absorptiometry in 28 patients with NAFLD (19 men, 51 ± 13 years; 9 women, 47 ± 13 years). WC was measured with 4 types of WCmp: WC1, narrowest torso; WC2, just above iliac crest; WC3, middistance between iliac crest and last rib; WC4, at the umbilicus. Results: All WC measurements were highly correlated with central BF depots, including trunk BF (r = 0.78, r = 0.82, r = 0.82, r = 0.84 for WC1, WC2, WC3, and WC4, respectively), abdominal BF (r = 0.78, r = 0.78, r = 0.80, r = 0.72 for WC1, WC2, WC3, and WC4, respectively), and central abdominal BF (r = 0.76, r = 0.77, r = 0.78, r = 0.68 for WC1, WC2, WC3, and WC4, respectively), controlling for age, sex, and body mass index. There were no differences between the correlation coefficients obtained between all studied waist circumference measurements and each whole and central analyzed BF variable. Conclusions: All studied WCmps seem suitable for use in patients with NAFLD, particularly as a central BF clinical assessment tool, though not interchangeably. Hence, biological and precision criteria alone did not sanction the superiority of any WCmp. Practical criteria may endorse WC measured at the iliac crest.

Background:We hypothesized that enteral protein supplementation in infants with brain injury would be safe and well tolerated and improve growth. Materials and Methods: Twenty-five infants with perinatal brain injury were randomized to a high-protein (4 g/kg/d) or standard-protein diet and followed for 12 months. Results: The whey protein powder was well tolerated by 9 of the 13 infants in the high-protein group, and no adverse events related to the supplement were seen. The protein group had higher serum urea nitrogen at 10 and 30 days after study initiation but no difference in bicarbonate levels at either time point. Infants in the protein group maintained their weight z score from birth to 3 months of age, while infants in the standard group had a significant decrease in their weight z score over the same time period. Conclusion: These results suggest that enteral protein supplementation may reduce growth failure in infants with brain injury.

The American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) started an intensive review of commercially available parenteral vitamin and trace element (TE) products in 2009. The chief findings were that adult multi-TE products currently available in the United States (U.S.) provide potentially toxic amounts of manganese, copper, and chromium, and neonatal/pediatric multi-TE products provide potentially toxic amounts of manganese and chromium. The multivitamin products appeared safe and effective; however, a separate parenteral vitamin D product is needed for those patients on standard therapy who continue to be vitamin D depleted and are unresponsive to oral supplements. The review process also extended to parenteral choline and carnitine. Although choline and carnitine are not technically vitamins or trace elements, choline is an essential nutrient in all age groups, and carnitine is an essential nutrient in infants, according to the Food and Nutrition Board of the Institute of Medicine. A parenteral choline product needs to be developed and available. Efforts are currently under way to engage the U.S. Food and Drug Administration (FDA) and the parenteral nutrient industry so A.S.P.E.N.’s recommendations can become a commercial reality.

Parenteral nutrition (PN) provision is complex, as it is a high-alert medication and prone to a variety of potential errors. With changes in clinical practice models and recent federal rulings, the number of PN prescribers may be increasing. Safe prescribing of this therapy requires that competency for prescribers from all disciplines be demonstrated using a standardized process. A standardized model for PN prescribing competency is proposed based on a competency framework, the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.)–published interdisciplinary core competencies, safe practice recommendations, and clinical guidelines. This framework will guide institutions and agencies in developing and maintaining competency for safe PN prescription by their staff.

Mulasi U, Kuchnia AJ, Cole AJ, Earthman CP. Bioimpedance at the bedside: current applications, limitations, and opportunities. Nutr Clin Pract. 2015;30:180-193. (Original DOI: 10.1177/0884533614568155)

In this article in the April 2015 issue of Nutrition in Clinical Practice, the phrase “ie, the styloid process of the radius” was incorrectly placed in paragraph 2 under “Principles of Bioimpedance” on p. 181. The corrected sentence is as follows: “The most common approach for generating whole-body composition estimates is the standard tetrapolar arrangement (also termed wrist-ankle), which involves the placement of 2 electrodes on the hand (one on the wrist between the styloid processes of the ulna and radius and the other just behind the metacarpals) and 2 electrodes on the foot (one on the ankle between the medial and lateral malleoli and the other just behind the metatarsals).”