Prevalence and clinical characteristics of simple renal cyst.
BACKGROUND
We investigated simple renal cysts to understand the prevalence in healthy individuals and evaluate their clinical characteristics to determine whether or not there are any risk factors associated with simple renal cysts.


METHODS
Abdominal sonography was performed in 577 individuals (317 men, 260 women; mean age, 48.84 years; age range, 20-94 years) who received health check-up in January to February 2005. Data including age, sex, renal sonographic findings (cyst number, site, diameter, renal stones), values of serum cholesterol, glucose and creatinine, urine analysis (proteinuria, hematuria, pyuria), and smoking habit were analyzed.


RESULTS
The overall prevalence of simple renal cysts was 10.7%, ranging from 2.38% in the 2nd to 35.29% in the 7th or later decade of life. The prevalence increased with age (p<0.001). The mean age of individuals with cysts was significantly older than those without cysts (57.65+/-13.35 vs. 47.78+/-12.40 years; p<0.001). Male-to-female ratio was 2.81 (15.14% vs. 5.38%; p<0.001). The majority of cysts were solitary (82.3%). Mean largest diameter of cysts was 20.89+/-12.62 mm. The mean size of cysts in every age group was not statistically different. Factors significantly associated with simple renal cysts were age (odds ratio [OR], 4.37; p<0.001), sex (OR, 0.32; p<0.001), serum creatinine (OR, 11.77; p=0.001), proteinuria (OR, 3.11; p=0.004), renal stone (OR, 2.47; p=0.006), and smoking (OR, 2.80; p<0.001). However, in multivariate analysis, except proteinuria, all of the above factors were significantly related to the occurrence of simple renal cysts.


CONCLUSIONS
The overall prevalence of simple renal cysts in healthy individuals was 10.7%. Age, sex, renal stone, serum creatinine, and smoking were found to be risk factors for the presence of simple renal cysts.
Division of Urology, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
Chang-Chi
CC
Chang
Junne-Yih
JY
Kuo
Wan-Leong
WL
Chan
Kuang-Kuo
KK
Chen
Luke S
LS
Chang
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging; D052177:Kidney Diseases, Cystic / Q000150:complications / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012907:Smoking / Q000009:adverse effects; D013624:Taiwan / Q000453:epidemiology; D014463:Ultrasonography