Analysis of incidence and risk factors of renal insufficiency in solitary kidney patients

Objective To investigate the incidence of renal insufficiency in solitary kidney patients and analyze the risk factors. Methods Patients with solitary kidney who were admitted to the Second Hospital of Lanzhou University from January 2012 to January 2019 were retrospectively selected as subjects. According to estimated glomerular filtration rate (eGFR) level, the patients were divided into two groups: eGFR＜60 ml?min-1?(1.73 m2)-1 group and eGFR≥60 ml?min-1?(1.73 m2)-1 group. The data of the general information, laboratory examinations and kidney size were collected, and the differences of the above indicators between the two groups were compared. Logistic regression model was used to analyze the related factors of renal function decline. Results (1) A total of 323 solitary kidney patients with age of (53.8±15.8) years and median duration of 10.0 years were enrolled in the study, including 203 males (62.8%). There were 150 cases (46.4%) with hypertension, 136 cases (42.1%) with proteinuria, and 134 cases (41.5%) with renal insufficiency, even 29 cases(9.0%) had developed into end-stage renal disease. (2) Compared with those in eGFR≥60 ml?min-1?(1.73 m2)-1group, patients in eGFR＜60 ml?min-1?(1.73 m2)-1 group had higher age, mean arterial pressure, serum creatinine, serum uric acid, fasting blood glucose, and higher proportion of hypertension and proteinuria, but had lower proportion of congenital solitary kidney, hemoglobin, plasma albumin and residual kidney diameter. The differences of above indicators were statistically significant ( all P＜0.05). (3) Logistic regression analysis showed that increasing age (every ten years, OR=1.752, 95%CI 1.455-2.109, P＜0.001), anemia (OR=2.327, 95%CI 1.356-3.994, P=0.002), hyperuricemia (OR=5.097, 95%CI 2.873-9.042, P＜0.001) and high urine protein level (every 1+, OR=1.515, 95%CI 1.197-1.919, P=0.001) were independent risk factors for renal dysfunction in solitary kidney patients. Conclusions The incidence of renal insufficiency in solitary kidney patients is 41.5%. Patients with solitary kidney may perform varying degrees of kidney damage, such as hypertension, proteinuria and eGFR decline. Increasing age, anemia, hyperuricemia and high urine protein level are independent risk factors for renal insufficiency in solitary kidney patients.