Among the many risk factors that affect the outcomes of ESRD patients, especially MHD patients, nutritional deficiency plays a major role. The prevalence of malnutrition among MHD patients varies from 30–75% [20, 21]. In this study, we evaluated the effects of oral fat based high-energy supplements (Fresubin) on nutritional and inflammatory status in MHD patients. These findings suggested that Fresubin nutritional support could continuously and effectively improve the nutritional status and inflammation in MHD patients after 80 days intervention.
Inadequate dietary protein and energy intake levels are important causes of PEW in ESRD patients and may be caused by anorexia. Furthermore, there is additional nutritional loss during dialysis, such as amino acids, albumin and some trace elements, in the dialysate and inflammatory stimuli associated with the dialysis procedure . The recommended daily protein and energy requirements for haemodialysis patients are 1.2 g/kg of ideal body weight per day and 30-35 kcal/kg of ideal body weight per day . In fact, in many dialysis patients, the levels of protein and energy intake do not reach the recommended proper goals. The protein and energy intake of these research participants are both insufficient.
The ISRNM proposed 4 main categories to diagnose PEW: biochemical criteria, low body mass, decreased muscle mass and low protein intake . Among biochemical indicators, serum albumin is a consistent indicator for PEW, and low serum albumin is one of the strongest predictors of mortality in MHD patients [9, 23]. More importantly, a change in the serum level of Alb over time is associated with alterations in the risk of mortality, in that only a small increase or decrease in serum Alb concentration over a period of time is associated with increased or decreased survival, respectively [24, 25]. In this study, we treated patients who had poor nutrition status with an oral high-energy nutrient solution, Fresubin 120 mL/day, for 80 days and found that the level of Alb increased quickly and that the increase continued until the end of the study. Another nutritional marker, PA, also increased in the treatment group, and the difference in the change in PA between the two groups was significantly different.
There is an important consideration when we ask patients to improve their dietary intake or provide nutrition support. The potential increase in the intake of several harmful elements, especially phosphorus, is a troublesome clinical problem. Hyperphosphatemia is an independent risk factor for cardiovascular disease and death in patients with CKD [26, 27]. Interestingly, the amount of dietary protein is usually correlated with phosphorus content and serum phosphorus concentration in ESRD patients. In adenine-induced CKD rats, a high-phosphorus diet was found to induce systemic inflammation and oxidative stress, resulting in the development of PEW, weight loss and hypoalbuminemia . We need to find a method of compromise that does not increase phosphorus intake but improves the nutritional status of patients. Some foods with a low P/protein ratio should be suggested. In our test, we used the ONS Fresubin to improve the nutritional status of patients while improving the serum Alb without a significant effect on phosphorus. Fresubin treatment also had no effect on other biochemical indexes that we should closely monitor, such as blood lipids, Glu, K and Ca.
Inflammation is a major driving force for many uraemic complications, including PEW. Persistent, low-grade inflammation has been recognized as a component of CKD . Animal studies have shown that infusions of TNF, IL-1, and IL-6 cause increased muscle protein breakdown, resulting in muscle atrophy . Clinical studies have shown that malnutrition, inflammation and atherosclerosis are closely related in patients with ESRD . Our study found that the level of the inflammatory biomarker Hs-CRP tended to decrease after nutritional intervention, and the difference in the change value between the two groups was statistically significant. This phenomenon has also been observed in other nutritional interventions [31-33].
Anthropometric and body composition parameters are also independent predictors of mortality in haemodialysis patients . Contrary to the general population, many studies in ESRD patients have reported a “reverse epidemiology”, where higher BMI is paradoxically associated with better survival, especially among those with a higher muscle mass[35, 36]. In our study, only the change value of AC was different between the two groups, with no significant differences in other parameters, which may be related to the short intervention time.
Throughout the study period, most patients in the treatment group were able to adhere to daily oral nutrient solution support, 2 patients developed nausea after taking Fresubin and withdrew, and 3 patients developed mild abdominal distension, but it resolved on its own. Fresubin therapy was well tolerated, and no other significant adverse reactions were observed.
This study has several limitations. First, the sample size was small. Second, the time interval between the two groups was short, and a longer follow-up period would yield more information.