Effect of Oral Nutritional Supplementation Combined With Impedance Vectors

The objective of this study was to assess the effect of oral nutritional supplementation (ONS) combined with bioelectrical vector analysis (BIVA) on the nutritional and hydration status and the quality of life (QoL) in hemodialysis (HD) patients. Design and Methods: Thirty-two chronic HD patients were included in a 6-month randomized pilot study. Patients in SUPL group received a simultaneous intervention consisting of a personalized diet, 245 mL/d ONS and dry weight adjustment through BIVA. Patients in CON group received a personalized diet and dry weight adjustment by BIVA. Anthropometrical, biochemical, dietary, QoL, handgrip strength (HGS) and bioimpedance measurements were performed. Malnutrition Inflammation Score (MIS) was applied.

This was a randomized, controlled, pilot study. Due to the type of study, no sample size was calculated because the aim was to include all patients available . Patients were randomly assigned to one of two treatments: 1) simultaneous intervention of dry weight adjustment through BIVA, a personalized diet, and 245 mL/d of ONS (SUPL), or 2) dry weight adjustment by BIVA and a personalized diet (CON). Both treatments were given for six months All measurements were made in accordance with good clinical practice and the recommendations of the Helsinki Declaration on human studies. The protocol was registered and approved by the Ethics Committee of the Faculty of Natural Science of the Autonomous University of Queretaro (No. 252FCN2016) and by the Ethics Committee of the ISSSTE in Queretaro. All patients provided written informed consent to participate in this study.

The supplement was provided five days per week. Three days a week, the supplement was given at the beginning of the HD session and the patients were instructed to consume it slowly during the next 3 hours. The remaining two days, the supplement was consumed at home and instructed to be consumed between meals.

The ONS consisted of one can of polymeric formula (Enterex DBT, Victus Laboratories) and 5.6 g of a protein powder supplement (Proteinex, Victus Laboratories). The final mixture provided 240 kcal, 17 g protein, 8.1 g lipids, 25 g carbohydrates, 4 g dietary fiber, 201 mg sodium, 490 mg calcium, 356 mg phosphorus and 371 mg potassium. When the ONS was provided at the HD unit, the mixture was prepared at the hospital´s enteral mixing center and delivered to the patient in a plastic cup with lid and a straw. For the two remaining days, the patients were instructed about the mixture preparation and they were given two cans of supplement and two sealed plastic bags with 5.6 grams of protein powder each one. Adherence to supplement intake was determined by recording the number of servings consumed weekly. For this purpose, at the end of each HD session, the plastic cups were collected to ensure the total consumption of the supplement and for the ONS consumed at home, the patients were asked to return empty cans and plastic bags to the research staff.

Both groups received the intervention to adjust dry weight in order to reach normohydration. Those participants with post-dialysis vectors located within the 50 or 75% ellipses, were considered to be in dry weight, so they did not require any fluid removal adjustment. However, participants with vectors outside the 75% ellipse were considered overhydrated or dehydrated and dry weight was adjusted. In these patients, if the vectors fell outside the 75% ellipse but within the 95%, above or below the major axis, the established dry weight was adjusted by 0.5 Kg. If the vectors fell outside the 95% ellipse, the weight was adjusted by 1.0 Kg.

Patients in both groups also received a personalized diet according to the recommendations of the KDOQI guidelines and the European best practice guidelines on nutrition: 35 Kcal /ideal body weight/day, 1.2 g protein/ideal body weight/day, Na \<2000 mg/day, potassium \<2000 mg/day, and P \<1000 mg/day. Diets were planned and designed by trained renal dietitians and were given to the patients at the beginning of the study. To specify the adequate portion size, food models and photographs of utensils were used. Evaluation of food intake was performed monthly by a three-day food record in order to assess adherence.

Eligibility Criteria:
Inclusion Criteria:

* Patients on chronic HD undergoing thrice weekly hemodialysis (at least three hours per treatment) for more than three months were included.

Exclusion Criteria:

* Patients with amputations of any limb, metal implants, diagnosis of dementia, or current consumption of nutritional supplements were excluded.