Is There a Difference in Metabolic Outcome Between Different Enteral Formulas?From the Hebrew University and Hadassah Medical School, Jerusalem, Israel Correspondence: Ephraim Rimon, The Hebrew University and Hadassah Medical School, Jerusalem, Israel, Geriatric Department E, F, POB 48, Gedera, Israel 70750. Electronic mail may be sent to efraim_r{at}clalit.org.il. Background: Despite appropriate enteral nutrition, many elderly patients do not reach a good metabolic outcome. Two nutrition formulas are commonly used in Israel with no evidence-based medicine to indicate preference of one over the other. Methods: We describe a 2-month observational study of patients fed by 1 of the 2 formulas. The first (Osmolite, Abbott Company, Abbott Park, IL) is without fiber, and the second (Easy Fiber, Easyline Company Givataim, Israel) in addition to containing fiber is also richer in protein, vitamins, and minerals. The formula was selected by the primary care physician before enrollment in the study and was not influenced by the investigators. Routine blood tests as well as body weight were monitored at the start of enteral feeding and during the 2 months following as part of the regular follow-up. Results: Fifty-seven patients were fed with the regular formula and 77 with the enriched one. No statistically significant differences were noted between the groups during the follow-up period, in body weight, cholesterol levels, total lymphocyte count, renal function tests, or electrolyte balance. However, in the enriched formula group there was a significant decrease in glucose (p < .05), and increase in albumin (p < .05) and hemoglobin (p = .01) levels. Conclusions: Enteral feeding with enriched formula appears to improve albumin and hemoglobin levels as well as diabetic control, thus it may be more appropriate than the nonfiber diet for use in long-term care patients. Enteral nutrition is the treatment of choice for patients who cannot maintain sufficient oral intake but have a functional gastrointestinal tract. This makes it particularly common in the elderly (over 65), which comprised about 13% of the U.S. population in 2000 and is expected to reach 20% by 2030.1 During the last decade, the number of enterally fed patients has doubled in the United States, and this trend is expected to continue in the next decade.2,3 Elderly patients are more vulnerable to nutrition deprivation and undernutrition, reaching 65% in long-term care homes and 58% in general hospitals,4 increasing their morbidity and mortality.5 In a search of the English literature, we found few studies about the metabolic outcome of patients fed by enteral tube feeding. Metabolic outcome was defined as clinical and laboratory variables that are considered as predicting the nutrition status of the patient (eg, weight changes, improvement in blood albumin levels). After a survey of the literature revealed a dearth of studies on the subject, we set out to observe and compare the metabolic outcome of 2 enterally applied nutrition formulas for a period of 2 months. Two nutrition formulas are used in Israel, with no evidence-based medicine to prefer one over the other.
One hundred seventy residents of 6 long-term care facilities in Israel who met the study entry criteria were enrolled in the study. Inclusion criteria were age over 65 years, total tube feeding (percutaneous endoscopic gastrostomy and nasogastric tubes; Table I) for the first time in their lives by 1 of the 2 nutrition formulas described below, at least 8 weeks of continuous tube feeding after enrollment, and availability of blood tests before entering the study and again 8 weeks later. The first formula, Osmolite HN from Ross (Abbott Laboratories, Abbott Park, IL), is fiber free, and the second, Easy Fiber (EasyLine Company Ltd, Givataim, Israel), in addition to being enriched with fiber of soy origin, is also rich in protein, vitamins, and minerals (Table II). Osmolite meets 100% of the dietary reference intakes (DRI) for vitamins and minerals in 2000 kcal (1887 mL), and Easy Fiber, in 1210 kcal (1100 mL).
The formula was selected by the primary care physician from the line of products provided by the institute before enrollment in the study and was not influenced by the investigators. The volume, the amount of calories, and protein were calculated by the clinical dietitian of the facility according to the DRIs (28 kcal/kg for women and 27 kcal/kg for men, 0.8 g/kg of protein for both sexes). Blood levels of glucose, urea, electrolytes, albumin, cholesterol, hemoglobin, white blood cell count (WBC), and thyroid-stimulating hormone (TSH) were measured before beginning the enteral nutrition and 8 weeks later. The patients were also weighed before and again once a month during the study. These measurements are all performed regularly on patients with new-onset enteral tube feeding in Israel as part of good medical practice. These parameters are also considered as clinical indicators of malnutrition. The data were all collected by the institutes' dietitians. The protocol of the study was approved by the local ethical committee of Kaplan-Harzfeld Medical Center. Blood counts were measured by an automated analyzer (Technicon H*2; Technicon Instruments Corp, Terrytown, NY). Glucose, urea, electrolytes, albumin, and cholesterol were measured using a closed Hitachi system (Roche Diagnostics Systems, Basel, Switzerland) according to a guanidine hydrochloride/ferrozine reaction.
Statistical Analysis The similarity of baseline characteristics of the groups was tested using unpaired t-test or  2 tests. The groups were compared
with respect to change over time in body weight and blood tests, using ANOVA
for repeated measures. Paired t-tests were also performed on the mean
of changes over the 8-week period. The statistical analyses were performed
with SPSS (version 12; SPSS Inc, Chicago, IL), and significance level was set
at p > .05.
Two hundred patients were suitable for the study. Sixty-one patients were withdrawn: 22 died during the study, 6 were admitted to a general hospital due to acute illness, and 33 were missing significant data. Of the 139 patients enrolled in the study, 59 received the regular formula and 80 the enriched one. Twenty-two percent were men and 78% women, with an average age of 79 years. Forty-seven patients (34%) were fed enterally due to dysphagia, 70 patients (50%) because of feeding difficulty, 11 patients (8%) due to recurrent aspiration, 12 (9%) due to coma, and 13 (9%) because of weight loss. The baseline characteristics of both groups were similar (Table I), as was the baseline laboratory workup (Table III).
After 8 weeks' follow-up, there was a significant increase in hemoglobin (p < .01) and albumin (p < .01) levels in the enriched formula group (Table IV). In the regular formula, there was no statistically significant change in hemoglobin, but there was a decrease in albumin levels (p < .05) at the end of the 2-month follow-up. Similarly, glucose levels were significantly closer to the normal values in diabetic patients receiving the enriched formula (p = .01) but not in the regular one (Figure 1). No statistically significant differences were noted between the 2 groups in weight change, cholesterol levels, WBC and total lymphocyte count, renal function tests, or electrolyte balance (Table IV). Triglyceride levels showed a trend to become lower after 2-month follow-up in the enriched formula, with no statistically significant changes in the regular-formula patients.
There is abundant and conflicting evidence that different formula contents can influence metabolic outcome in enterally fed patients.6–10 Patients who need enteral tube feeding are usually in advanced malnutrition, but there is a serious delay in initiation of enteral nutrition in these patients. This may be due to diagnostic delay in some patients but, more important, due to the ethical debate in the western world. The ethical debate especially concerns demented patients and involves 2 questions: whether enteral nutrition prolongs survival in demented patients or whether it adds to their quality of life. Therefore, those patients are in poor nutrition status and need an enriched formula. Improvement in nutrition support like increased protein concentration or micro- and macronutrients can positively influence the metabolic outcome, as was demonstrated in the present study. The increase in hemoglobin concentration can be explained not only by the higher concentrations of iron, vitamin B12, and folic acid in the enriched formula but probably also by improvement in nutrition status of those patients.1 The improved glucose control probably reflects the high fiber content in the enriched formula, though no previous study was performed in tube-fed patients.11 The trend for better control of triglyceride levels probably has the same mechanism as the glucose control. Though albumin is not considered the best marker for malnutrition, the rise in its concentration is encouraging and could reflect the higher protein concentration in the enriched formula. The problem of volume overload is common in elderly patients due to multiorgan failure, especially heart and kidney failure. Osmolite meets the DRI with 1887 mL, whereas Easy Fiber meets the DRI with 1100 mL. Considering the additional water needed for rinsing the tube after each meal or medication delivered via the tube, the lower volume needed of daily Easy Fiber seems an advantage for the elderly. Malnutrition is associated with severe complications such as cognitive impairment, depression and apathy, recurrent infections, anemia, pressure wounds, increased morbidity, increased hospital admission rate, prolongation of hospital stay, delay in wound healing, weight loss, recurrent fall, and fractures.12 If improved nutrition status could have even a minor influence on those parameters, it could significantly improve quality of life and reduce costs.
This pilot study showed that an 8-week course of enriched enteral tube feeding can improve metabolic outcome in elderly residents and improve the control of glucose levels in diabetic patients. This could prevent complications of malnutrition and improve quality of life in those patients. Received for publication October 3, 2006.
Journal of Parenteral and Enteral Nutrition, Vol. 31, No. 4,
320-323 (2007) This article has been cited by other articles:
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
|
|
 |
|
Top
MATERIALS AND METHODS
RESULTS
