Association Of Malnutrition And Serum Uric Acid In Elderly Inpatients

Objective: To observe the prevalence of malnutrition in elderly inpatients,and to explore the association of malnutrition and serum uric acid.To investigate the ability of serum uric acid to recognize malnutrition,with the purpose of improving the probability of detecting malnutrition in elderly inpatients,and in the meanwhile,to carry out a new method for clinicians.Methods: Patients were enrolled from a top-level hospital from January 1st to December 31 st in 2019.Age,gender,height,body weight,educational level,medical history,nutritional risk screening 2002(NRS2002),level of prealbumin,total protein,platelets,albumin,alanine aminotransferase,urea nitrogen,serum uric acid,blood creatinine,lymphocyte count,triglycerides,total cholesterol,leukocyte count and hemoglobin were collected.The research subjects were divided into malnutrition group and non-malnutrition group,and the general information and laboratory test levels of the two groups were compared.Receiver operating characteristic curve was used to get the cut-offs of recognizing malnutrition and non-malnutrition,the level of serum uric acid was divided into new normal uric acid group and new abnormal uric acid group by using the cut-offs.SPSS version 24.0 software was applied for statistical analysis.Quantitative variable based on normal distribution,quantitative variable based on non-normal distribution,binomial classification variable and polynomial classification variable was represented by mean± standard deviation,inter-quartile range and frequency,respectively.T-test,Mann-Whitney U and chi-square were used when comparing.Rank correlation was used for analyzing the association of malnutrition and serum uric acid.Cohen's kappa coefficient was used to measure inter-rater reliability of malnutrition and each indicator.Receiver operating characteristic curve was used to analyze the ability of each related markers to recognize malnutrition.The two-tailed significant level was set at 0.05.Results: 1.Totally 577 patients are collected,311 are males,and the proportion is 53.9%.266 are females,and the proportion is 46.1%.Among these subjects,age is between 65 years to 96 years,and middle age is 72 years.The proportion of education level is 13.52% for elementary school and below,44.54% for junior high school,18.02% for high school or technical secondary school,and 23.92% for tertiary school and above.Among all included patients,86.7% have hypertension,36.6% have type 2 diabetes,90.3% have coronary heart disease,27.7% have chronic renal failure,15.9% have carcinoma,and 36.9% have stroke.2.The distribution of age group,medical history of neoplasms and history of stroke in malnutrition and non-malnutrition group is significantly different(?2=57.633,P<0.01;?2=5.408,P=0.02;?2=11.516,P=0.001).3.The proportion of malnutrition in patients with hypertension is 36.80%,the proportion of malnutrition in patients with type 2 diabetes is 40.76%,the proportion of malnutrition in patients with coronary heart disease is 37.04%,the proportion of malnutrition in patients with chronic renal failure is 38.75%,the proportion of malnutrition in patients with carcinoma is 47.83%,and the proportion of malnutrition in patients with stroke is 46.01%.4.Average level of body mass index,prealbumin and total protein in patients without malnutrition is significantly higher than those with malnutrition(|| =11.01,P <0.01;||=13.681,P<0.01;||=9.535,P<0.01).5.Average level of albumin,blood creatinine,serum uric acid,triglycerides,total cholesterol,leukocyte count,lymphocyte count and hemoglobin in malnutrition and nonmalnutrition group is significantly different,respectively(|| =13.161,P <0.01;|| =3.05,P=0.002;|| =2.359,P=0.019;|| =3.358,P=0.001;|| =5.094,P <0.01;||=2.114,P=0.035;||=6.178,P<0.01;||=13.138,P<0.01).6.The association is statistically significant between malnutrition and serum uric acid(r=-0.096,P=0.021).There is a higher probability that the double-cut value is more likely to be associated with malnutrition than the single-cut value(?2=25.134>?2=19.596).7.Serum uric acid is divided into normal and abnormal group by the level of 255.5?mol/L to 433?mol/L.Inter-rater reliability of abnormal uric acid and gold standard of malnutrition is significant.The inter-rater reliability is not good enough,but higher than underweight(Kappa=0.208,P<0.01;Kappa=0.159,P<0.01).8.The sensitivity and specificity of abnormal uric acid to recognize malnutrition is 52.8% and 68.3%,respectively.And the ability is higher than underweight(AUC=0.606,95%CI:0.557~0.654,P<0.01;AUC=0.565,95%CI:0.516~0.615,P<0.01).9.The combined indicators of low prealbumin,low albumin,new abnormal uric acid,and low hemoglobin can better recognize malnutrition(AUC=0.771,95%CI:0.733~0.808,P<0.01).Conclusion: 1.It should be noticed that when level of serum uric acid is below 255.5?mol/L or above 433?mol/L,malnutrition probably has been occurred in elderly inpatients.2.The combined indicators of prealbumin,albumin,serum uric acid,and hemoglobin can better recognize malnutrition.