The Relationship Between Visceral Fat Area And Uric Acid Stone Formation Based On Abdominal Computed Tomography

BackgroundUrinary calculus is one of the most common diseases in urology.During the past few decades,the diagnosis and treatment of urinary calculi have made great progress.However,with the change in life style and dietary habits,the incidence and recurrence rate of urinary calculi,especially uric acid stones,have been increasing year by year,which has brought a heavy burden on both individuals and society.The causes of urinary calculi are complex and diverse,including age,gender,race,heredity,environment,diet and occupation.Recent studies have suggested that urinary calculi were actually a kind of metabolic disease,which was closely related to metabolic syndrome.Metabolic syndrome is a series of metabolic disorders characterized by abdominal obesity,hypertension,diabetes mellitus and dyslipidemia.Many previous studies have reported that the incidence of urinary calculi increased significantly in obese population.Body mass index(BMI)is usually used to assess the degree of body fatness,but it is hard to effectively distinguish the abdominal obesity.Therefore,it is necessary for us to take a newly measurement method that can comprehensively evaluate the body fatness to better reflect the degree of abdominal obesity.ObjectiveTo investigate the relationship between uric acid stone formation and visceral fat area based on abdominal computed tomography and to provide a prejudging basis for clinical prevention and treatment of urinary calculi.MethodsWe retrospectively reviewed the records of 247 patients admitted to the first affiliated hospital of Soochow University from January 2017 to January 2018.There were 161 males(65.2%)and 86 females(34.8%).The average age was 51(from 20-88 years).There were 72 patients(29.1%)with hypertension,26 patients(10.5%)with diabetes mellitus and 57 patients(23.1%)with hyperlipidemia.According to the results of stone analysis after surgery,the patients were divided into two groups:uric acid stone group and non-uric acid stone group.According to the abdominal CT scan,Image J software was used to measure the anthropometric measurements like waist circumference,total fat area(TFA),visceral fat area(VFA),subcutaneous fat area(SFA).The clinical characteristics of two groups were compared.A univariate and multivariate logistic regression analysis was used to identify the independent factors associated with uric acid stone formation.Different anthropometric measurements were compared by using the area under receiver operating characteristic curve.ResultsOf the 247 patients,35 patients were uric acid stones and 212 were non-uric acid stones.The uric acid stones in high VFA group(28/110;25.5%)were obviously more frequent than that in the low VFA group(7/137;5.1%)(P<0.05).The results of the univariate logistic regression analysis showed that age,diabetes,hyperlipidemia,TFA,waist circumference,body mass index(BMI),VFA,uric acid,urine pH were statistically significant(P<0.05).Multivariate logistic regression analysis revealed that diabetes(0R=3.408,95%CI1.123?10.340,P=0.030),VFA(OR=6.740,95%CI1.951?23.279,P=0.003),uric acid(OR=3.182,95%CI 1.120?9.040,P=0.030)and urine pH(OR=4.052,95%CI 1.095?14.989,P=0.036)were independent factors associated with uric acid stone formation.Correlation analysis showed that:VFA was significantly positively correlated with age,hypertension,hyperlipidemia,hemoglobin,albumin,hs-CRP,uric acid and significantly negatively correlated with gender,urine pH.The area under the curve of TFA,waist circumference,BMI,VFA,SFA were 0.659,0.665,0.632,0.723 and 0.544,respectively.Conclusions1?Diabetes,VFA,uric acid and urine pH are independent factors influencing the formation of uric acid stones.2?Compared with other anthropometric measurements like TFA,waist circumference,BMI,SFA,VFA can better assess abdominal obesity and predict the formation of uric acid stones.