Nutritional Assessment And Dietary Pattern Of Patients With Chronic Kidney Disease

The emergence of metabolic abnormalities with different severity during the progression of chronic kidney disease(CKD) coupled with different degrees of anorexia,and protein missing form the urine resulting from metabolic waste accumulation are quite likely to cause protein-energy(PEM) malnutrition, which is one of the independent risk factors for patients with CKD. At present, clinical physicians tend to take measures to correct malnutrition only when abnormal indexes such as decreased albumin and anemia occur in patients with CKD. And there are few researches on dietary pattern.Then, prognosis will be greatly affected. Correct malnutrition assessment is the basis of early diagnosis and treatment. Despite the availability of numerous indexes for assessing the nutritional status of patients with CKD at present, there still exist some shortcomings. Therefore, it is of great importance to seek convenient and effective methods to accurately assess, understand the nutritional status and dietary pattern and timely correct the malnutrition of patients with CKD.Objectives:This research aims at assessing the nutritional status and dietary patterns of the patients with CKD in each period and analyzing their dietary pattern characteristics by discovering the nutritional assessment tools suitable for them through a comprehensive analysis of several common clinical nutritional assessing methods in combination with the dietary weighing method intended for a dietary survey on the patients, thus providing a scientific basis for the nutritional monitoring and reasonable nutrient-supporting treatment for patients with CKD.Methods:1. Nutritional status assessment of hospitalized patients with CKDA total of 106 hospitalized patients with confirmed CKD in the Nephrology Department of the General Hospital of Armed Police were selected. They were divided into four periods according to the progression of the disease, with 32 cases in CKD2 period, 28 cases in CKD3, 24 cases in CKD4 period and 22 cases in CKD5 period. This study adopted the nutritional assessment methods commonly used in clinic, namely, the nutritional risk screening method in Europe(NRS2002), subjective global assessment of nutrition(SGA) and anthropometric parameters, including body mass index(BMI), triceps skinfold thickness(TSF) and arm muscle circumference(AMC), as well as laboratory indexes, mainly including total lymphocyte count(Lymph), plasma albumin(ALB) and hemoglobin(Hb), followed by the assessment and analysis of their nutritional status.2. Dietary pattern characteristics of patients with CKD and their relations with the disease in each periodDietary weighing method was used to investigate the 106 patients with CKD. Dieticians receiving professional training were responsible for the weighing and recording of all the food eaten by the patients within 3 days after admitted to hospital as well as the recycling and measuring of food residues. After this, they input the data obtained to the dietary services system for analysis so as to get the dietary pattern for patients and the average intake of nutrients in recommanded nutrient intakes(RNI) before conducting the assessment with statistical methods. During hospitalization, nutritious meals must be customized for patients, who could make a choice according to their daily dietary habits. The fruits and cakes in the extra meal for patients were also supplied by the nutrition canteen, accurate to 0.1g in weight.ResultsPart I1.1 Results of NRS2002 screening among patients with CKDFor the patients with CKD in each period, the difference between the groups with ages showed no statistical significance(P>0.05). Using NRS2002 method, we found that the incidence of malnutrition in patients with CKD was 45.28%. And the corresponding incidences of malnutrition from CKD2 to CKD5 were, 31.25%, 39.29%, 41.67% and 77.27% respectively. The incidence of malnutrition in patients with CKD exhibited an obvious increase as the disease proceeded. The difference between groups was statistically significant(P<0.05).1.2 Nutritional assessment of patients with CKD in each period using SGA methodWeight loss and dietary situation of patients with CKD in each period showed no statistically significant difference between the two groups(P>0.05). In terms of such indexes as digestive tract symptoms, motility, sebum changes, stress, edema, muscle wasting and overall assessment, the difference between groups was statistically significant(P<0.05). Using SGA method, the incidence of mild-to-moderate malnutrition in patients with CKD was found to be 33.96%, with 31.25%, 28.57%, 50.00% and 27.27% from CKD2 to CKD5, respectively. Severe malnutrition was 13.21%, with 0, 14.29%, 16.67% and 27.27% from CKD2 to CKD5, respectively.1.3 Comparison of anthropometric and laboratory indexes for patients with CKD in each periodTSF and TLC levels of patients with CKD in each period showed no statistically significant difference between the groups(P>0.05), while the four indexes AMC, BMI, Hb and ALB showed statistically significant difference between the groups(P<0.05).1.4 Comparison of anthropometric indexes for patients with CKD in each periodThe incidences of malnutrition concerning the TSF, AMC, BMI, Hb, ALB and TLC indexes for patients with CKD in each period were respectively, 43.40%, 47.17%, 20.75%, 47.17%, 28.30% and 32.08%. The difference between the groups was statistically significant(P<0.05).1.5 Comparison between anthropometric indexes and NRS2002 method:The 106 patients with CKD assessed with NRS2002 method were divided into two groups: eutrophy group(58 cases) and malnutrition group(48 cases). According to the observation of the anthropometric and laboratory indexes for two groups of patients, TLC-evaluated malnutrition showed no statistically significant difference between the groups(P>0.05), while the five indexes TSF, AMC, BMI, Hb and ALB showed statistically significant difference between the groups(P<0.05).1.6 Comparison between anthropometric indexes and SGA method:The 106 patients with CKD assessed with SGA method were divided into three groups: eutrophy group(56 cases), mild-to-moderate malnutrition group(36 cases) and severe malnutrition group(14 cases). These three groups of patients and their nutrition indexes were measured. As indicated by the assessment results, TLC-evaluated malnutrition showed no statistically significant difference between the groups(P>0.05), while the five indexes TSF, AMC, BMI, Hb and ALB showed statistically significant difference between the groups(P<0.05).1.7 Correlation analysis of NRS2002, SGA with anthropometric indexesThe Spearman correlation analysis results suggested that TSF, AMC, BMI, Hb and ALB were positively correlated with NRS2002 and SGA methods, showing statistical significance(P<0.05).1.8 Consistency analysis of NRS2002, SGA methods and anthropometric indexesMcnemar consistency analysis demonstrated that indexes TSF, AMC and Hb were consistent with the assessment of NRS2002 and SGA aggregate scores, showing statistical significance(P>0.05), but BMI, ALB and TLC assessment were inconsistent with the assessment of NRS2002 and SGA aggregate scores, with P<0.05. There existed consistency between NRS2002 method and SGA method.Part II2.1 Comparison of dietary nutrients in each periodThe 106 patients with CKD were divided into four groups according to the periods of this disease. Specifically, there were 32 cases in CKD2, 28 cases in CKD3, 24 cases in CKD4 and 22 cases in CKD5. The intake of energy, protein, fat and carbohydrates were the objects of this research. The items in each period, except for energy, showed no significant difference between the groups(P>0.05). Energy intake in CKD3 began to decrease when compared to CKD2(P<0.05) and its intake in CKD4 reduced significantly in comparison with CKD3(P<0.05). No significant difference existed between CKD4 and CKD5(P>0.05). Follow the condition changes, energy intake showed a trend of decline.2.2 Comparison of key nutrients intake between groupsAccording to the results of the comparison of CKD2 with CKD3-CKD5 and of CKD3 with CKD4-CKD5, the difference between the three indexes carbohydrates, fats and protein was statistically significant(P<0.05). Difference in dietary calcium intake between period CKD2, CKD3 and CKD5 was significant(P<0.05) and difference in dietary phosphorus intake between CKD2-CKD4 and CKD5 was significant(P<0.05).2.3 Correlation analysis of nutrients intake with the division of disease periodsThe research showed that there was linear correlation between the division of disease periods and the indexes excluding sodium ion and vitamin C, exhibiting a positive correlation with phosphorus and a negative correlation with the rest.2.4 Main sources of dietary protein in each periodAccording to the single factor analysis of variance, the protein in patients with CKD mainly derive from cereals, potatoes, beans, and animal-based food, with the plant protein provided by beans and other plants accounting for a larger proportion and animal protein making up less than 50% of the total protein intake. It is necessary to increase the intake of animal protein and supply of high quality protein. The proportion of protein supply showed no significant difference between groups(P>0.05).2.5 Source of dietary calciumThe result of ANOVA shows that the dietary calcium of patients with CKD mainly comes from plant-based foods. There are no statistically significant differences in source of calcium between different groups(P>0.05).2.6 Comparison of sources of dietary ferrum between different groupsThe analysis indicates that most of dietary iron in different disease progressions derives from plant-based foods. The sources of dietary at different stages show no significant differences(P>0.05).Conclusions1. SGA method has the largest malnutrition rate(47.17%), followed by NRS2002 method(45.28%). And the malnutrition rate increases with the development and progression of disease. The results of the two assessment methods are quite consistent and reliable, and the both methods may be complementary to each other.2. The assessment result using a single anthropometric parameter causes large error and can not be used as a separate index for malnutrition assessment. Therefore, we should combine it with the above two methods.3. Although the constituent ratio of the three major heat production nutrients among patients with CKD is reasonable, their intakes begin to decline since CKD3 period and further decrease with the progression of disease, which is consistent with the result of NRS2000 assessment. Therefor, insufficient intake is the important cause of protein-energy malnutrition.4. The sources of dietary protein, calcium and iron are unreasonable, in which the plant-based source is disproportionately high, while the proportion of the animal origin is low.5. All dietary vitamins and trace elements are insufficient at the early stage(CKD2 period) except iron and decrease as the disease progresses. The amount of the dietary phosphorus exceeds the recommended amount, which is contrary to the principle of high calcium and low phosphorus.