Underestimated incidence of kidney disease in nonrenal outpatient

Background and aims: Chronic kidney disease (CKD) has been regarded as a severe threaten to public health, a large percentage of CKD are secondary to other diseases. Serum creatinine is the most common marker of renal function, but it did not always reflect glomerular filtration rate (GFR) accurately. In order to investigate the prevalence of kidney disease in non-renal departments and to provide a basis for the prevention of kidney injury, the present study was conducted in several medical centers. Methods: A total of 17,462 outpatients were selected randomly from the departments of cardiology, endocrinology, and neurology in 16 hospitals and the incidence of kidney disease was screened. Estimated GFR (eGFR) was calculated by using MDRD-formula. Results: There are 5293 (30.1%) patients' eGFR above 90mL/min/1.73m(2) among all the subjects in non- renal departments, and 4055(23%) patients' eGFR lower than 60 mL/min/1.73m(2) including 80 patients whose eGFR were below 15 mL/min/1.73m(2). Furthermore, among 16616 subjects who have a normal SCr level, there are 3209 respondents' eGFR lower than 60 mL/min/1.73m(2). Moreover, individuals with hypertension or diabetes had a high prevalence of decreased renal function. Conclusions: This survey indicated kidney injury wildly existed in non- renal outpatients, and the incidence of CKD is underestimated.