Increased prevalence of simple renal cysts in patients with gout

Association between serum uric acid levels and simple renal cyst risk in a nondiabetic population: A nested case-control study

BACKGROUND

Previous studies have found a relationship between hypertension or cardiovascular disease and simple renal cysts (SRCs) in health check-up population, but SRCs incidence is still controversially associated with serum uric acid (SUA) concentration in the nondiabetic participants. In this single-centre nest case-control study, serum uric acid levels were examined in relation to the incidence of SRCs in nondiabetic individuals.

METHOD

Participants who underwent at least two renal ultrasound examinations with an interval of more than 12 months were enrolled. The results of clinical examinations, laboratory tests and abdominal ultrasound tests were recorded for each participant and analysed in this retrospective observation study.

RESULT

A total of 144 control and 144 SRC patients were ultimately confirmed and included in further analysis. Hyperuricaemia (OR 2.846, 95% CI 1.519-5.332, p = 0.001) was significantly correlated with SRC formation according to multivariable analysis. In both the male and female groups, SRC patients had significantly higher serum uric acid levels compared with control subjects. In 54 SRC patients with cyst puncture, the serum uric acid concentration was positively correlated with the uric acid concentration in cyst fluid (r = 0.6144, p < 0.0001). The serum uric acid concentration was positively correlated with the maximum cyst diameter in the SRC patients (r = 0.4531, p < 0.0001).

CONCLUSION

In a nondiabetic population, hyperuricaemia was significantly independently associated with a higher SRCs incidence. In SRC participants with cyst puncture, the SUA level had a significantly positive correlation with the uric acid level in cyst fluid. In SRC patients, the SUA level had a significantly positive correlation with cyst maximum diameter.

Association of simple renal cysts with metabolic syndrome in adults

Background and aims

Metabolic syndrome is common nowadays and may increase risk of hypertension, type 2 diabetes mellitus, cardiovascular complications and even mortality. Renal cysts are also frequently found during routine examination. However, the relationship between simple renal cysts (SRCs) and metabolic syndrome remains unclear. This study aimed to investigate the association of SRCs with metabolic syndrome.

Methods

A total of 16,216 subjects aged ≥18 years were enrolled in this study. SRCs were diagnosed with ultrasonography by finding: sharp, thin posterior walls, a round/oval shape, absence of internal echoes, and posterior enhancement. SRCs were categorized by number (0, 1, and ≥2) and size (<2 and ≥2 cm). Metabolic syndrome was diagnosed according to the consensus statement from the International Diabetes Federation.

Results

In multivariate analysis, SRCs were positively related to metabolic syndrome (OR: 1.18, 95% CI: 1.06-1.34). The risk of metabolic syndrome was higher for SRCs with a number ≥2 (OR: 1.35, 95% CI: 1.08-1.68) and size ≥2 cm (OR: 1.33, 95% CI: 1.10-1.61). When considering the SRC number and size concomitantly, SRCs with a number ≥2/size ≥2 cm (OR: 1.42, 95% CI: 1.02-1.98) or <2/size ≥2 cm (OR: 1.30, 95% CI: 1.04-1.62) were positively related to metabolic syndrome.

Conclusions

Simple renal cysts were found to be related to a higher risk of metabolic syndrome, and the association is more significant in those with larger (sizes ≥2cm) or plural (numbers ≥2) SRCs.

Drugs in Clinical Development to Treat Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive cyst formation that ultimately leads to kidney failure in most patients. Approximately 10% of patients who receive kidney replacement therapy suffer from ADPKD. To date, a vasopressin V2 receptor antagonist (V2RA) is the only drug that has been proven to attenuate disease progression. However, aquaresis-related adverse events limit its widespread use. Data on the renoprotective effects of somatostatin analogues differ largely between studies and medications. This review discusses new drugs that are investigated in clinical trials to treat ADPKD, such as cystic fibrosis transmembrane conductance regulator (CFTR) modulators and micro RNA inhibitors, and drugs already marketed for other indications that are being investigated for off-label use in ADPKD, such as metformin. In addition, potential methods to improve the tolerability of V2RAs are discussed, as well as methods to select patients with (likely) rapid disease progression and issues regarding the translation of preclinical data into clinical practice. Since ADPKD is a complex disease with a high degree of interindividual heterogeneity, and the mechanisms involved in cyst growth also have important functions in various physiological processes, it may prove difficult to develop drugs that target cyst growth without causing major adverse events. This is especially important since long-standing treatment is necessary in this chronic disease. This review therefore also discusses approaches to targeted therapy to minimize systemic side effects. Hopefully, these developments will advance the treatment of ADPKD.

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.

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.

Nephrolithiasis in gout: prevalence and characteristics of Brazilian patients

BACKGROUND

The aims of this article were to assess the prevalence of nephrolithiasis and the factors associated with nephrolithiasis in Brazilian patients with primary gout.

METHODS

One hundred twenty-three patients with primary gout were recruited from a tertiary referral hospital in São Paulo, Brazil. All patients underwent ultrasonography and had their clinical and laboratory characteristics assessed.

RESULTS

One hundred fifteen (93.5%) patients were male, with a mean age of 62.9 ± 9.4 years. Twenty-three (18.7%) patients had asymptomatic nephrolithiasis (detected only by ultrasonography), 7 (6.0%) had symptomatic nephrolithiasis (detected by ultrasonography and a positive clinical history), and 13 (10.0%) had a history of kidney stones, but ultrasonography at evaluation did not show nephrolithiasis. Therefore, 35.0% of the patients had nephrolithiasis (detected either by ultrasonography and/or a positive clinical history). Nephrolithiasis was associated with male gender (43 [100%] vs 72 [90%], p = 0.049), the use of potassium citrate (13 [30.2%] vs 0, p <  0.001) and the use of medications for diabetes (10 [23.3%] vs 8 [10%], p = 0.047) and dyslipidemia (15 [34.9%] vs 10 [12.5%], p = 0.003); benzbromarone had an inverse association with nephrolithiasis (21 [48.8%] vs 55 [68.8%], p = 0.030). In patients with and without nephrolithiasis, no differences were found in the laboratory and ultrasonography characteristics, including serum uric acid levels, urinary uric acid excretion and urine pH.

CONCLUSIONS

The prevalence of nephrolithiasis in primary gout was 35.0%, and 18.7% of the patients were asymptomatic. Nephrolithiasis was associated with male gender, diabetes and dyslipidemia. A positive history of nephrolithiasis probably biased the prescription of potassium citrate and benzbromarone.

Hyperuricemia and overexcretion of uric acid increase the risk of simple renal cysts in type 2 diabetes

Previous studies have discussed the relationship between simple renal cysts (SRC) and serum uric acid level in healthy individuals. We performed a cross-sectional study to evaluate the association between serum uric acid level and fractional excretion of uric acid (FEUA) and simple renal cysts in males and postmenopausal females with type 2 diabetes. The overall prevalence of SRC was 18.1% in our population. SRC prevalence was significantly higher in hyperuricemic than normouricemic subjects (27.3% vs. 16.8%, P < 0.001). Subjects who overexcreted uric acid had a higher prevalence of SRC than underexcretors (total population: 21.6% vs. 16.3%; normouricemic subjects: 19.8% vs. 13.7%; hyperuricemic subjects: 50.0% vs. 22.7%, all P-values < 0.05). Hyperuricemia (odds ratio [OR] 1.824, 95% confidence interval [CI] 1.332-2.498, P < 0.001); FEUA (OR 1.046, 95% CI 1.002-1.091, P < 0.05); male gender (OR 1.922, 95% CI 1.489-2.480, P < 0.001); age (OR 1.049, 95% CI 1.035-1.064, P < 0.001); and albuminuria (OR 1.492, 95% CI 1.176-1.892, P < 0.01) were independent risk factors for SRC development. These findings suggested that hyperuricemia and high level of FEUA were both independent risk factors for SRC development in males and postmenopausal females with type 2 diabetes. Half of overproduction hyperuricemic patients had SRC.