Suplementação nutricional para idosos com doença renal crônica em hemodiafiltração: impacto na sobrevida e estado nutricional

Abstract

Introduction: Individuals with chronic kidney disease (CKD) undergoing renal replacement therapy are at increased risk of malnutrition. Several factors contribute to its development, among them the accumulation of urea in the body, which triggers mechanisms of hypercatabolism and muscle proteolysis and generates inappetence, conditions that in elderly individuals can be aggravated due to the functional and organic decline of aging. Thus, nutritional status is a potentially modifiable risk factor in the mortality of this population. Oral nutritional supplementation (ONS) is shown to be an alternative for the treatment and prevention of malnutrition, given that it is capable of promoting increased caloric and protein intake, providing nutrients such as leucine, which acts directly on muscle protein synthesis. However, to date, there is no study on the effect of ONS in individuals with CKD undergoing hemodiafiltration (HDF) and there is no specific study in the elderly. Our hypothesis is that ONS for elderly people on HDF will be able to improve nutritional status and reduce the mortality rate. Methods: Elderly people aged 65 years or older, on HDF for at least three months, from September 2018 to June 2020 were included. The analysis of the medical records provided clinical, demographic and laboratory data. To assess nutritional status, anthropometric data such as body weight, height, body mass index and calf circumference were used, all measured post-HDF. The Subjective Global Assessment (SGA) and Malnutrition Inflammation Score (MIS) tools were also used. Muscle strength was assessed using manual dynamometry during HDF in the arm opposite the fistula and in the right arm in case of catheter. Octopolar multifrequency electrical bioimpedance was used to assess body composition, the assessment was performed 30 minutes after the HDF session. Sarcopenia was diagnosed when the participant had a skeletal muscle mass index (skeletal muscle mass/height²) below the cutoff points established by the European Working Group on Sarcopenia in Older People (EWGSOP), in which men < 8.87 kg/m2 and women < 6.42 kg/m2 in association with low muscle strength, when men had handgrip strength (HGS) <27 kgf and women <16 kgf. 3 types of SNO were used: a normocaloric and hyperprotein complete nutritional supplement (98kcal and 8.0g of protein per 100ml), a normocaloric and normoprotein complete nutritional supplement (112 kcal and 4.9g of protein per 100ml) and a nutritional supplement of protein isolated from powdered cow's milk whey (52 kcal and 13g of protein per 15g). Supplementation was initiated when the participant presented: severe weight loss (≥ 5% in 1 month), muscle depletion, nutritional status classified as moderately malnourished (ASG B) or severely malnourished (ASG C), food consumption with change in consistency as liquid or pasty. The choice of the type of supplement and the dose used was according to the nutritionist's assessment based on caloric and protein needs and better acceptance by the participant. Supplementation was daily throughout the follow-up period. The effect of nutritional supplementation on nutritional status, body composition, sarcopenia, muscle strength, albumen and C-reactive protein was evaluated after 6 months and on the mortality rate after 1 year. Results: We included 132 patients with a median age of 74 years (70 - 82), 77 (58.3%) male, 70 (53%) with diabetes. Participants who received ONS (N=85, 64.4%) were older, 78 years old (70 - 83) p=0.007, and had a higher concentration of vitamin D 24.2 ± 9.2 ng/dL (p= 0.042) than those without supplementation (N=47, 35.6%). Nutritional supplementation did not change weight, BMI, WC, HGS and the prevalence of sarcopenia over the 6 months. The prevalence of participants with MIS scores ≥ 7 decreased from 81.9% to 66.3% in the supplementation group (p=0.015). The ASG classification did not change during follow-up in either group. Fat mass increased in the group without supplementation and decreased in the group with supplementation (from 26.4 ± 10.3 kg to 27.0 ± 9.8 kg, vs. from 19.9 ± 8.4 kg to 19.6 ± 7.8 kg, respectively p=0.042). Nutritional supplementation stabilized the loss of skeletal muscle mass (from 17.4 ± 5.4 kg to 17.2 ± 4.8 kg, p = 0.039), while non-supplemented participants showed greater loss (from 19.8 ± 5.7 kg to 18.6 ± 6.6 kg), p=0.039. In the evaluation of the mortality outcome, 20 deaths were observed, 7 (14.9%) were not supplemented and 13 (15.3%) received supplementation (p=0.582). Non-survivors were older 79 7 years (p=0.012), with a higher concentration of C-reactive protein 25.7 (8.2 – 43.9) mg/L (p=0.046) and less skeletal muscle mass 15, 5 ± 5.4 kg (p=0.017). COX survival analysis showed that skeletal muscle mass (relative risk 0.90, 95% confidence interval 0.82-0.99, p=0.030) and age (relative risk 1.07, confidence interval 95% 1.01-1.14, p=0.046) were independent risk factors for mortality. Participants with and without supplementation did not differ in mortality rate (p=0.824) Conclusion: Nutritional supplementation in the elderly on HDF stabilized the loss of skeletal muscle mass and benefits survival, since the mortality rate of supplemented participants was similar to that of individuals who did not receive supplementation, even though they had more risk factors for mortality.