Kidney Biopsy In Elderly Chinese Patients

Background:Aging population and high incidence of various chronic diseases such as hypertension and diabetes are associated with an increasing prevalence of kidney disease.The elderly patients are affected by physiological aging and chronic diseases,so they are susceptible to kidney disease.Because advanced age was considered a relative contraindication for kidney biopsy,epidemiological data on biopsies among elderly patients are lacking.Most studies are single-center and small in scale.So far,china still lacks large samples and high-quality studies to explore the spectrum of biopsy-proven kidney diseases among elderly patients.Objective:The present study was designed to examine the spectrum of kidney diseases and their clinical presentations in elderly patients undergoing kidney biopsy in China.In addition,this study assessed differences in disease composition between genders,age groups,and among regions.Methods:This retrospective,multicenter study constitutes the largest study of kidney biopsies obtained from elderly(age,≥65 years)patients in China.A total of 7917 kidney biopsies were obtained from 668 local hospitals spanning 222 cities across China from January 2014 to April 2018.General information of study population including age,sex,city of residence,date,hospital performing the biopsy,indications for biopsy,and clinical diagnosis.For statistical analysis,categorical variables are summarized using frequency and proportion and compared by chi-square.The odds ratios(ORs)of a specific type of glomerulopathy among all patients as well as in different subgroups were estimated by generalized logistic models with adjustment for age,sex,region,the level of the hospital that performed the biopsy,the time of kidney biopsy,and indications of biopsy.Results:The most common indication for kidney biopsy in elderly patients was nephrotic syndrome(NS,63.1%),followed by proteinuria(without NS)(23.9%),progressive chronic kidney disease(7.8%)and acute kidney injury(2.8%).Membranous nephropathy was the most frequent histological type(53.2%),followed by minimal change disease(9.8%),IgA nephropathy(8.1%)and focal segmental glomerulosclerosis(4.3%).Women tended to be less frequently diagnosed with diabetic glomerulosclerosis(OR,0.69;95%confidence interval[95%CI],0.54-0.88),and amyloidosis(OR,0.76;95%CI,0.59-0.97)than men.By contrast,IgA nephropathy(OR,1.26;95%CI,1.07-1.50),and lupus nephritis(OR,2.19;95%CI,1.27-3.79)were more frequently diagnosed in women,even after adjusting for age,region,indications for biopsy,the level of hospital that performed the biopsy,and the time of kidney biopsy.Patients aged≥80 years were significantly less likely to be diagnosed with membranous nephropathy(OR,0.70;95%CI,0.52-0.96)and diabetic glomerulosclerosis(OR,0.12;95%CI,0.02-0.85)than patients aged 65-69 years,but focal segmental glomerulosclerosis(OR,2.09;95%CI,1.22-3.59)and membranoproliferative glomerulonephritis(OR,4.25;95%CI,2.19-8.24)were significantly more prevalent in patients aged≥80 years than in the aged 65-69 years group,even after adjusting for covariates.The histopathologic data of the 7713 elderly patients were compared with those of the 87383 patients aged 18-64 years undergoing kidney biopsy within the same time period.Membranous nephropathy(OR,1.99;95%CI,1.88-2.10),diabetic glomerulosclerosis(OR,1.23;95%CI,1.08-1.39),amyloidosis(OR,3.79;95%CI,3.29-4.36),ANCA-associated vasculitis(OR,5.40;95%CI,4.55-6.43)and membranoproliferative glomerulonephritis(OR,1.94;95%CI,1.61-2.34)were significantly more prevalent in the elderly patients,but minimal change disease(OR,0.60;95%CI,0.55-0.65),IgA nephropathy(OR,0.30;95%CI,0.28-0.33)and lupus nephritis(OR,0.14;95%CI,0.11-0.19)were significantly less prevalent in elderly patients than in the control group.There were significant differences in the diagnosis of glomerulopathies among different geographic regions after adjusting for covariates.204 elderly patients had two coincident glomerular diseases,the most frequent combinations were diabetic glomerulosclerosis with hypertensive nephrosclerosis and diabetic glomerulosclerosis with membranous nephropathy.Our study showed that the proportion of non-diabetic nephropathy was up to 61.2%in elderly patients with diabetes and kidney damage,and the most common type of non-diabetic nephropathy was membranous nephropathy,while only 34.6%had pure diabetic nephropathy.Conclusion:Kidney biopsy in elderly patients is increasing in China.NS was the leading indication for kidney biopsy in the elderly.MN was the most common kidney disease in elderly patients.The spectrum of kidney diseases in elderly patients varied across genders,age groups and regions.Non-diabetic nephropathy was common among elderly patients with diabetes and kidney damage,and the most common pathological type was membranous nephropathy.Kidney biopsy should be encouraged to provide a more accurate diagnosis and enable specific treatment for potentially reversible kidney diseases in elderly patients.