Decline in measured glomerular filtration rate is associated with simple renal cyst in Chinese patients with type 2 diabetes.

Aims/introduction: Simple renal cysts (SRC) are associated with age, hypertension and hyperuricemia, which are risk factors of renal impairment. This study aimed to investigate the prevalence of SRC and its association with measured glomerular filtration rate (mGFR) in patients with type 2 diabetes mellitus in China.

Methods: A total of 3,552 patients with type 2 diabetes mellitus admitted to Shanghai Sixth People's Hospital from January 2012 to December 2016 were investigated. All participants were diagnosed as SRC by color Doppler, and all participants were measured for GFR by using dynamic renal scintigraphy with technetium-99m-diethylene triamine peta-acetic acid.

Results: The prevalence of SRC was 17.4% (619 cases). Participants with SRC had significantly lower mGFR values than those without SRC (86.16 ± 26.20 vs 94.88 ± 23.98 mL/min/1.73 m , P < 0.001). In 478 participants with unilateral renal cyst, the mGFR of the kidney affected by SRC was significantly lower than that of the unaffected kidney (43.32 ± 13.74 vs 44.18 ± 13.34 mL/min/1.73 m , P = 0.014). The participants were divided into four groups according to the quartiles of mGFR level (≥109.50, 93.80-109.49, 76.90-93.79 and <76.90 mL/min/1.73 m ). The prevalence of SRC gradually increased with decreasing mGFR level (12.9, 13.9, 16.6 and 27.8%, respectively; P trend <0.01). After adjusting for age, sex, duration of diabetes, hypertension and other potential confounders, the logistic regression showed that SRC was an independent risk factor for impaired GFR (<60 mL/min/1.73 m ; odds ratio 1.656; 95% confidence interval 1.451-1.890, P < 0.001).

Conclusion: SRC is an independent risk factor for the decrease of mGFR in Chinese diabetes patients, and could affect the renal GFR measured by dynamic renal scintigraphy on the SRC side.