The relationship between simple renal cysts and glomerular filtration rate in the elderly

Multiple and large simple renal cysts are associated with glomerular filtration rate decline: a cross-sectional study of Chinese population

BACKGROUND

Although simple renal cyst (SRC) is a kind of structural alterations of kidney with age, the relationship between SRC and renal function is still obscure. We investigated the relationship between SRC and renal function in Chinese population.

METHODS

The medical records of 41,842 individuals who underwent physical examinations at the Health Check-up Center at our institution in 2018 were reviewed. According to whether with SRC, they were divided into no-SRC and SRC groups. SRCs were classified into subgroups based on number (< 2 vs. ≥ 2) and size (< 2 cm vs. ≥ 2 cm). Logistic regression was used to examine the relationship between SRC and estimated glomerular filtration rate (eGFR).

RESULTS

Multinomial logistic regression analysis showed that the adjusted odds ratio (OR) for eGFR slight decline in subjects with SRC was 1.26(95% confidence interval (95% CI):1.17-1.35, p < 0.001), and the OR for eGFR severe decline was 1.35(95% CI: 1.16-1.56, p < 0.001) compared with no-SRC. The adjusted OR of SRC number ≥ 2 and ≥ 2 cm on the risk of eGFR severe decline was the highest (OR:1.68, 95% CI:1.25-2.23, p < 0.01) of four SRC subgroups.

CONCLUSIONS

SRC is related to eGFR decline, especially when the person with one more SRCs and the size of SRC is more than 2 cm. SRC could be a warning sign for clinicians to judge the decline of renal function.

Parapelvic Cysts: An Imaging Marker of Kidney Disease Potentially Leading to the Diagnosis of Treatable Rare Genetic Disorders? A Narrative Review of the Literature

Simple renal cysts are a common finding during abdominal imaging assessment. The incidence increases with age and it is higher in male gender. Parapelvic cysts are a subset of simple cysts that arise within the renal parenchyma, adjacent to the renal sinus, characterized by being generally single, larger, and incompletely surrounded by renal parenchyma. Noteworthy, parapelvic cysts are a rare and understudied condition which, although considered clinically insignificant due to the absence of influence on renal function, still have a controversial aetiopathogenesis. On the other hand, urological management and differential diagnosis have been thoroughly investigated. The aim of our review is to provide an overall vision on this rare condition, usually misdiagnosed and underestimated, on the basis of more recent data. An accurate differential diagnosis of parapelvic cysts can lead to the identification of treatable conditions such as Fabry disease, autosomal dominant polycystic kidney disease, polycystic liver disease and tuberous sclerosis complex disease.

Relationship Between Sporadic Renal Cysts and Renal Function Detected by Isotope Renography in Type 2 Diabetes

PURPOSE

This study aimed to reveal the relationship between the volume of sporadic renal cysts and renal function in patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

One hundred and seventy-one patients that underwent renal imaging and other routine examinations at the Shanghai Pudong Hospital were included in this study. The Gates' method of glomerular filtration rate (GFR) was measured by ^99mTc-DTPA renal dynamic imaging in addition to the eGFR, calculated by the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI).

RESULTS

Our results showed that BMI, total iGFR, and eGFR showed significant differences between patients with T2D with or without SRC (p < 0.05). Spearman correlation analysis showed that cyst volume was positively correlated with Scr and gender but not iGFR (p > 0.05). The total iGFR positively correlated with eGFR (r = 0.83, p < 0.0001) and negatively with Scr (r = -0.78, p < 0.0001), age (r = -0.43, p < 0.0001), duration of T2D (r = -0.25, p = 0.001), and BMI (r = -0.21, p = 0.006) but not gender (r = -0.03, p = 0.668). The multilinear regression model revealed that gender (β = 0.346, p < 0.001), iGFR (β = -0.705, p < 0.001), and serum uric acid (β = 0.195, p = 0.032) were independent predictors of Scr. Moreover, we observed a significant increase in Scr in males (p < 0.05). Finally, we found that the split kidney function reflected by iGFR and related parameters such as time to peak (PTT) and half time of excretion (excrete t1/2) did not mutually distinguish from each other significantly whether they are measured in patients with renal cysts or in those without renal cysts (p > 0.05).

CONCLUSION

Our preliminary results suggest that in T2D, SRCs may be a renal complication of diabetic nephropathy. Although we found that the patients with renal cysts may display reduced iGFR, the volume of simple cysts seems not to exacerbate renal insufficiency. Isotope renography is a useful tool to evaluate the split kidney functions in diabetic patients who acquire single-side cysts.

Prevalence, risk factors and clinical characteristics of renal dysfunction in Chinese outpatients with growth simple renal cysts

Background

Researchers have proved that simple renal cysts (SRCs) might be correlated with renal dysfunction, but it is still controversial. Thus, we conducted clinical research study with large sample size and long-term follow-up to clarify the relationship between SRCs and renal dysfunction.

Methods

A total of 571 SRCs patients in outpatients of nephrology department were included, we investigated the clinical characteristics of growth SRCs compared with non-growth SRCs, evaluated the incidence of renal dysfunction in SRCs and explored the risk factors of renal dysfunction in growth SRCs.

Results

The mean baseline age was 51.31 ± 14.37 years in the whole cohort, ranging from 19 to 79 years, and 57.6% of them were male. The median follow-up duration was 3 years, ranging from 1 to 10 years. In addition, the final maximum diameter increased 1 mm (2.74%) per year. Patients in growth SRCs group tented to have higher percentage of hypertension, hematuria, large cyst and multiple cysts compared with non-growth SRCs group. The prevalence of renal dysfunction was 15.6% after the follow-up, and the prevalence of renal dysfunction was about 10 times higher in growth SRCs group than non-growth SRCs group (23.3% vs. 2.4%). Renal dysfunction was significantly associated with age, female, total cholesterol, diastolic blood pressure, final maximum diameter and yearly change in maximum diameter in growth SRCs.

Conclusions

SRCs were closely related to the decline of renal function, we recommend close follow-up for growth SRCs.

The Relationship Between Simple Renal Cysts and Renal Function in Patients With Type 2 Diabetes

Introduction: Simple renal cysts (SRCs) are the most common acquired cystic kidney disease, but the relationship between SRCs and renal function has not been clarified in patients with type 2 diabetes mellitus (T2DM).

Methods: A retrospective study was conducted to analyze the clinical features of renal cysts and ultrasound data of the kidney in 4,304 patients with T2DM.

Results: The prevalence of SRCs in patients with T2DM was 21.1%. Compared to patients with no SRCs, patients with SRCs had worse renal function (estimated glomerular filtration rate: 108.65 ± 40.93 vs. 92.38 ± 42.1 ml/min/1.73 m², p < 0.05). After adjusting the confounders, SRC was related to estimated glomerular filtration rate in patients with T2DM [odds ratio = 1.49, 95% confidence interval (1.24, 1.79), p < 0.01]. Age, gout, proteinuria, cerebrovascular disease (CVD), and increased serum phosphorus levels were associated with SRCs in patients with T2DM.

Conclusion: SRCs are associated with worse renal function in patients with T2DM. More attention should be paid to gout, proteinuria, CVD, serum phosphorus levels, and renal function in T2DM patients with SRCs.

Long-term renal function in living kidney donors with simple renal cysts: A retrospective cohort study

Simple (Bosniak I) renal cysts are considered acceptable in living kidney donor selection in terms of cancer risk. However, they tend to increase in number and size over time and might compromise renal function in donors. To clarify their implications for long-term renal function, we characterized the prevalence of renal cysts in 454 individuals who donated at our center from 2000 to 2007. We estimated the association between the presence of cysts in the kidney remaining after nephrectomy (ie, retained cysts) and postdonation eGFR trajectory using mixed-effects linear regression. Donors with retained cysts (N = 86) were older (P < .001) and had slightly lower predonation eGFR (median 94 vs 98 mL/min/1.73 m2 , P < .01) than those without cysts. Over a median 7.8 years, donors with retained cysts had lower baseline eGFR (-8.7 -5.6 -2.3  mL/min/1.73 m2 , P < .01) but similar yearly change in eGFR (-0.4 0.02 0.4  mL/min/1.73 m2 , P = .2) compared to those without retained cysts. Adjusting for predonation characteristics, there was no difference in baseline eGFR (P = .6) or yearly change in eGFR (P > .9). There continued to be no evidence of an association when we considered retained cyst(s) ≥10 mm or multiple retained cysts (all P > .05). These findings reaffirm current practices of accepting candidates with simple renal cysts for donor nephrectomy.

Association between simple renal cyst and kidney damage in a Chinese cohort study

Background: The presence of simple renal cyst (SRC) has been associated to renal dysfunction, but the results were inconsistent. Accordingly, we conducted a longitudinal cohort study to explore the association between SRC and kidney damage.

Methods: A total of 4274 adults (aged 45.4 ± 13.6 years) without chronic kidney disease at baseline were enrolled in 2008. SRC was assessed by ultrasonography. Logistic regression analysis were applied to explore the relationships between SRC and indicators of kidney damage (proteinuria and renal insufficiency), and also with relatively rapid decline in renal function (defined as the lowest quartile of △eGFR).

Results: During 5 years of follow-up, participants in the SRC group had higher incidence of proteinuria (5.2% versus 2.4%, p = 0.004) and renal insufficiency (3.8% versus 0.97%, p < 0.001) compared with control group. SRC was correlated with proteinuria (OR 2.24; 95% CI 1.34–3.75) and renal insufficiency (OR 4.0; 95% CI 2.11–7.58) in univariable analysis, despite that the correlation was not significant after adjusted for traditional kidney disease risk factors. Furthermore, after adjusted for potential confounders, maximum diameter of the cyst (≥2.2 cm) was significantly associated with rapid decline in renal function (OR 2.19; 95% CI 1.24–3.87).

Conclusions: Participants with SRC may be associated with higher incidence of proteinuria and renal insufficiency. This relationship may be obscured by age and other traditional risk factors. Higher diameter of the cysts contributed to more rapid decline in renal function of SRC participants.

Prevalence of renal cysts and association with risk factors in a general population: an MRI-based study

PURPOSE

To assess the prevalence and size of renal cysts and to analyze associated risk factors in a general population using magnetic resonance imaging (MRI).

METHODS

Data of 2063 participants (1052 women) of the Study of Health in Pomerania who underwent whole-body MRI were included. Renal cyst prevalence was calculated separately for men and women and for 10-year age groups. The association between risk factors and occurrence of renal cysts was estimated.

RESULTS

The prevalence of renal cysts was 27% and higher in men (34%) than in women (21%; p < 0.001). Renal cyst prevalence increased from 14% in the youngest age group (20-29 years) to 55% in the oldest age group (≥ 70 years) for men and from 7% to 43% for women (both p < 0.001). In the subset of participants with renal cysts, the total mean number was higher in men (1.9) compared to women (1.6, p = 0.012) and was significantly associated with age. Mean renal cyst size was higher in men (1.50 cm) compared to women (1.18 cm, p < 0.001). Male sex (OR 1.83, 95% CI 1.47; 2.26), older age (OR 1.05, 95% CI 1.04; 1.06, per 1-year increment), and hypertension (OR 1.27, 95% CI 1.00; 1.61) were associated with higher renal cyst prevalence. In additional analyses, current smoking and ex-smoking showed a significantly higher risk for renal cysts (OR 1.47, 95% CI 1.05; 2.05 and OR 1.38, 95% CI 1.04; 1.82, respectively).

CONCLUSIONS

The prevalence, number, and mean size of renal cysts are higher in men compared to women and are associated with age. In addition, renal cyst prevalence is higher in hypertensive and smoking subjects.

Increased risk of kidney damage among Chinese adults with simple renal cyst

BACKGROUND

The presence of simple renal cyst (SRC) has been related to hypertension, the early and long-term allograft function, and aortic disease, but the relationship with kidney damage was still controversial. Accordingly, we conducted a large sample cross-sectional study to explore the association of SRC with indicators of kidney damage among Chinese adults.

METHODS

A total of 42,369 adults (aged 45.8 ± 13.67 years, 70.6% males) who visited the Health Checkup Clinic were consecutively enrolled. SRC was assessed by ultrasonography according to Bosniak category. Multiple regression models were applied to explore the relationships between SRC and indicators of kidney damage [proteinuria (dipstick urine protein ≥ 1+) and decreased estimated glomerular filtration rate (DeGFR) < 60 ml/min/1.73 m²].

RESULTS

Among all participants in the study, the prevalence of SRC was 10.5%. As a categorical outcome, participants with more 1 cyst and with 1 cyst had higher percentage of proteinuria [53 (5.3%) and 93 (2.7%) vs. 596 (1.6%), p < 0.001] and DeGFR [57 (5.7%) and 85 (2.5%) vs. 278 (0.7%), p < 0.001] compared with participants with no cyst. SRC significantly correlated with proteinuria [OR 1.59 (95% CI 1.30-1.95)] and DeGFR [OR 1.97 (95% CI 1.56-2.47)] after adjusting for potential confounders. Furthermore, the results also demonstrated that maximum diameter (per 1 cm increase), bilateral location, and multiple cysts significantly correlated with DeGFR in the multiple logistic regression analysis.

CONCLUSIONS

The study revealed that SRC significantly correlated with kidney damage and special attention should be paid among Chinese adults with SRC.