Association of non-alcoholic fatty liver disease with renal stone disease detected on computed tomography

Older age and low testosterone levels are independently associated with kidney stone prevalence in men: results from a large cross-sectional study

We aimed to evaluate the relationship between serum testosterone levels and kidney stone prevalence in men. We examined cross-sectional data from 3234 men who participated in a health examination (2010-2020). A full metabolic work-up, including serum testosterone levels, was performed. Combined ultrasonography with KUB radiography was used for stone detection. The participants' median age and testosterone concentration were 53.0 years and 4.7 ng/mL, respectively. A total of 178 men had kidney stones. A cutoff value for determining the presence of kidney stones was a testosterone concentration <3.33 ng/mL ng/mL. After adjusting for confounders, only age and a testosterone concentration <3.33 ng/mL were significantly related to the presence of kidney stones. However, body mass index, blood pressure, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, creatinine, blood urea nitrogen, HbA1c, uric acid, hs-CRP, calcium, aspartate transaminase, alanine aminotransferase, and albumin were not significantly and independently related to kidney stones. The odds ratios (95% confidence intervals) for kidney stones according to age and testosterone concentration <3.33 ng/mL were 1.029 (1.010-1.04) and 1.655 (1.071-2.556), respectively. Our study revealed that the prevalence of kidney stones significantly and independently increased when the serum testosterone was less than 3.33 ng/mL in men.

Using Incidental Radiologic Findings of Hepatic Steatosis to Improve the Diagnosis of Metabolic Dysfunction-Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a common cause of liver disease worldwide. In patients with MASLD, liver fibrosis stage is the most significant predictor of mortality; therefore, early identification of patients at the greatest risk of advanced fibrosis is essential. Noninvasive tests predict advanced fibrosis and are recommended for use in primary care settings to determine which patients would benefit most from specialty care. The adoption of these tools is not widespread, and several studies have reported underrecognition of cirrhosis in patients with MASLD and diabetes. The finding of hepatic steatosis on imaging performed for evaluation of nonliver conditions may present an avenue for opportunistic screening to identify more patients with MASLD. This article will review recommendations for when hepatic steatosis is found on imaging and noninvasive tests that can be used to help predict fibrosis staging. This is a significant area of research because a new treatment for MASLD has been approved, and other treatments may follow.

Metabolic dysfunction-associated fatty liver disease as a mediator of urolithiasis risk: evidence from cross-sectional and genetic studies

Introduction: The rising prevalence of urolithiasis and metabolic dysfunction-associated fatty liver disease (MAFLD) has become a significant concern within urology and hepatology, respectively. Emerging studies reveal a compelling association between these conditions, yet the underlying relationship remains poorly understood. This study aims to investigate the connection between urolithiasis and MAFLD within the Chinese population and leverages Mendelian Randomization (MR) analysis to explore potential causal links between the two diseases, shedding light on new avenues for both prevention and treatment. Methods: This cross-sectional study included 98,232 Chinese participants and employed logistic regression models and subgroup analyses to assess the association between MAFLD and urolithiasis. For the MR analysis, genetic instruments from genome-wide association studies served as instrumental variables. Bidirectional MR was conducted to investigate the potential causal relationship between genetically predicted MAFLD and urolithiasis. Additionally, multivariable MR and mediation analysis were used to assess both the direct effect of MAFLD on urolithiasis and any mediating pathways involved. Results: In a cohort of 98,232 Chinese participants, 10.1% (9,928) had urolithiasis, and 26.7% (26,217) had MAFLD. MAFLD was positively associated with urolithiasis, with an unadjusted odds ratio (OR) of 1.563 (95% CI, 1.495-1.633), an adjusted OR in model 1 of 1.204 (95% CI, 1.146-1.265), and an adjusted OR in model 2 of 1.137 (95% CI, 1.079-1.199). Subgroup analysis showed consistent associations across most subgroups, except for a significant interaction between MAFLD and triglyceride (TG) levels (p for interaction < 0.05). Bidirectional MR analysis suggested that genetically predicted MAFLD increased the risk of urinary stone disease, while no significant causal effect was observed from urolithiasis to MAFLD. Furthermore, multivariable MR and mediation analyses highlighted MAFLD as a key mediator in kidney stone formation driven by obesity and type 2 diabetes. Conclusions: This study demonstrates a causal link between MAFLD and an increased risk of urolithiasis, supported by both epidemiological and genetic evidence. Furthermore, MAFLD serves as a significant mediator in the pathway from obesity and type 2 diabetes to urolithiasis development.

Association between the Fatty Liver Index, Metabolic Dysfunction-Associated Steatotic Liver Disease, and the Risk of Kidney Stones

INTRODUCTION

This study aimed to investigate the potential association between the fatty liver index (FLI), metabolic dysfunction-associated steatotic liver disease (MASLD), and the risk of kidney stones using large-scale population-based data.

METHODS

This study employed a cross-sectional design, utilizing data from the 2007 to 2018 National Health and Nutrition Examination Survey (NHANES) database. A total of 24,342 participants were enrolled in the study, and fatty liver status was assessed by calculating the FLI. MASLD was diagnosed by FLI in conjunction with cardiometabolic criteria. Data on the history of kidney stones were obtained by self-report. We employed logistic regression models to analyze the association between FLI, MASLD, and kidney stone risk and constructed multivariable adjustment models to control for potential confounders. Furthermore, we used restricted cubic spline curve models to investigate the dose-response relationship between FLI and kidney stone risk and conducted subgroup and interaction analyses.

RESULTS

The study's results indicate a strong correlation between increasing FLI quartiles and a notable rise in the prevalence of kidney stones. Specifically, the risk of developing kidney stones was 1.68 times higher among participants in the highest FLI quartile compared to those in the lowest. Furthermore, patients with MASLD exhibited a 1.35-fold increased risk of developing kidney stones compared to those with non-MASLD. Subgroup analyses demonstrated that the correlation between MASLD and kidney stone risk was consistent across multiple subgroups. However, a significant interaction was observed in the subgroups of smoking status, physical activity level, and hypertension (interaction p < 0.05). The restricted cubic spline analysis did not yield a statistically significant nonlinear association between FLI and kidney stone risk. However, the study did identify inflection point values for FLI.

CONCLUSION

This study demonstrated an association between FLI and MASLD and the risk of kidney stones. This suggests that these conditions may be pivotal risk factors for kidney stones. Further investigation is required to elucidate these associations' underlying mechanisms and develop efficacious interventions to reduce the risk of kidney stones. Also, formulating personalized prevention and treatment strategies for different population subgroups is paramount.

Advanced Glycation End-Product-Modified Heat Shock Protein 90 May Be Associated with Urinary Stones

BACKGROUND

Urinary stones (urolithiasis) have been categorized as kidney stones (renal calculus), ureteric stones (ureteral calculus and ureterolith), bladder stones (bladder calculus), and urethral stones (urethral calculus); however, the mechanisms underlying their promotion and related injuries in glomerular and tubular cells remain unclear. Although lifestyle-related diseases (LSRDs) such as hyperglycemia, type 2 diabetic mellitus, non-alcoholic fatty liver disease/non-alcoholic steatohepatitis, and cardiovascular disease are risk factors for urolithiasis, the underlying mechanisms remain unclear. Recently, heat shock protein 90 (HSP90) on the membrane of HK-2 human proximal tubular epithelium cells has been associated with the adhesion of urinary stones and cytotoxicity. Further, HSP90 in human pancreatic and breast cells can be modified by various advanced glycation end-products (AGEs), thus affecting their function. Hypothesis 1: We hypothesized that HSP90s on/in human proximal tubular epithelium cells can be modified by various types of AGEs, and that they may affect their functions and it may be a key to reveal that LSRDs are associated with urolithiasis. Hypothesis 2: We considered the possibility that Japanese traditional medicines for urolithiasis may inhibit AGE generation. Of Choreito and Urocalun (the extract of Quercus salicina Blume/Quercus stenophylla Makino) used in the clinic, Choreito is a Kampo medicine, while Urocalun is a characteristic Japanese traditional medicine. As Urocalun contains quercetin, hesperidin, and p-hydroxy cinnamic acid, which can inhibit AGE generation, we hypothesized that Urocalun may inhibit the generation of AGE-modified HSP90s in human proximal tubular epithelium cells.

Association between metabolic dysfunction-associated steatotic liver disease and risk of urolithiasis: an updated systematic review and meta-analysis

Epidemiological studies have reported an association between metabolic dysfunction-associated steatotic liver disease (MASLD) and the risk of urolithiasis. However, the magnitude of the risk and whether this risk varies with the severity of MASLD remains uncertain. We performed a meta-analysis of observational studies to quantify the magnitude of the association between MASLD and urolithiasis. We systematically searched PubMed, Scopus, and Web of Science from database inception to March 31, 2024, using predefined keywords to identify relevant observational studies in which imaging methods or survey questionnaires diagnosed MASLD and urolithiasis. Meta-analysis was performed using random-effects modelling. We identified seven cross-sectional studies and one prospective cohort study with aggregate data on 248,936 adults from different countries. MASLD was significantly associated with an increased risk of prevalent urolithiasis (pooled random-effects odds ratio 1.87, 95% CI 1.34-2.60; I2 = 91%). This association remained significant in those studies whose results were adjusted for age, sex, ethnicity, obesity, diabetes, and other potential confounders. There was a positive graded association between the ultrasonographic severity of MASLD and urolithiasis. Meta-analysis of the single prospective cohort study showed that MAFLD was not associated with risk of developing incident urolithiasis (pooled random-effects hazard ratio 1.08, 95% CI 0.90-1.30), although a significant association was reported in men. Sensitivity analyses did not modify these findings. The funnel plot did not reveal any significant publication bias. This updated meta-analysis provides evidence for a significant association between MASLD and the presence of urolithiasis. Whether MASLD is associated with a higher risk of developing incident urolithiasis remains to be established.

Association between chinese visceral adiposity index and risk of kidney stones in a health screening population: an ultrasonography based cross-sectional study

BACKGROUND

Obesity is an important risk factor for kidney stones(KS). Chinese Visceral Adiposity Index (CVAI), as a specific indicator for visceral obesity in the Chinese population, can more accurately assess the visceral fat content in Chinese individuals compared to Visceral Adiposity Index (VAI). However, the association between CVAI and risk for KS has not been studied.

METHODS

A total of 97,645 participants from a health screening cohort underwent ultrasound examinations for the diagnosis of kidney stones, along with measurements of their CVAI. Logistic regressions were utilized to determine the relationship between different quartiles of CVAI and the incidence of kidney stones. Simultaneously, subgroup analysis and the computation of dose-response curves were employed to pinpoint susceptible populations.

RESULTS

Among the participants, 2,888 individuals (3.0%) were diagnosed with kidney stones. The mean CVAI values ± standard deviation for the four groups were: Q1 (18.42 ± 19.64), Q2 (65.24 ± 10.39), Q3 (98.20 ± 9.11), and Q4 (140.40 ± 21.73). In the fully adjusted multivariable model, CVAI was positively correlated with urolithiasis (OR = 1.001; 95% CI = 1.000, 1.002). Compared with the first quartile of CVAI, the population in the fourth quartile of CVAI had a higher prevalence of kidney stones (OR = 1.231; 95% CI = 1.066, 1.415). Through subgroup analysis, a positive correlation between CVAI and the risk of kidney stones was found in non-smokers (OR = 1.001, 95%CI:1.000, 1.002), non-drinkers (OR = 1.001, 95%CI:1.000, 1.002), non-hypertensive subgroups (OR = 1.003, 95%CI:1.002, 1.003), and non-diabetes subgroups (OR = 1.001, 95%CI:1.000, 1.002).

CONCLUSION

The findings suggest that CVAI could be a reliable and effective biomarker for assessing the potential risk of kidney stone prevalence, with significant implications for the primary prevention of kidney stones and public health.

A two-sample mendelian randomization analysis excludes causal relationships between non-alcoholic fatty liver disease and kidney stones

Objectives

Non-alcoholic fatty liver disease (NAFLD) has been linked to an increased risk of kidney stones in prior observational studies, However, the results are inconsistent, and the causality remains to be established. We aimed to investigate the potential causal relationship between NAFLD and kidney stones using two-sample Mendelian randomization (MR).

Methods

Genetic instruments were used as proxies for NAFLD. Summary-level data for the associations of exposure-associated SNPs with kidney stones were obtained from the UK Biobank study (6536 cases and 388,508 controls) and the FinnGen consortium (9713 cases and 366,693 non-cases). MR methods were conducted, including inverse variance weighted method (IVW), MR-Egger, weighted median, and MR-PRESSO. MR-Egger Regression Intercept and Cochran's Q test were used to assess the directional pleiotropy and heterogeneity.

Results

cALT-associated NAFLD did not exhibit an association with kidney stones in the Inverse variance weighted (IVW) methods, in both the FinnGen consortium (OR: 1.02, 95%CI: 0.94-1.11, p = 0.632) and the UKBB study (OR: 1.000, 95%CI: 0.998-1.002, p = 0.852). The results were consistent in European ancestry (FinnGen OR: 1.05, 95%CI: 0.98-1.14, p = 0.144, UKBB OR: 1.000, 95%CI: 0.998-1.002, p = 0.859). IVW MR analysis also did not reveal a significant causal relationship between NAFLD and the risk of kidney stone for the other three NAFLD-related traits, including imaging-based, biopsy-confirmed NAFLD, and more stringent biopsy-confirmed NAFLD. The results remained consistent and robust in the sensitivity analysis.

Conclusions

The MR study did not provide sufficient evidence to support the causal associations of NAFLD with kidney stones.

What is the prevalence of hepatic steatosis on ultrasonography in patients followed for nephrolithiasis?

INTRODUCTION

Patients with non-alcoholic fatty liver disease (NAFLD) have higher prevalence of nephrolithiasis. The aim of the present study was to determine prevalence of hepatic steatosis on ultrasonography in nephrolithiasis patients.

METHODS

Charts of 318 consecutive nephrolithiasis patients seen in stone clinic between January and February 2018 were retrospectively reviewed. Ultrasound reports were reviewed for hepatic steatosis. Subsequent liver investigations were noted. Patients' demographic predictors of hepatic steatosis were identified using univariable logistic regression models.

RESULTS

A total of 162 patients was included, of which 76 (46.9%) were found to have hepatic steatosis and 22 (13.6%) were found to have moderate-to-severe hepatic steatosis. Median followup was 2.03 years. Predictors of hepatic steatosis included higher body mass index and smoking (both p<0.05). Progression of fatty liver on ultrasound was noted for 13 (17.1%) and regression was noted for two (2.6%). Of the 16 patients with a Fibrosis-4 (FIB-4) score, four (25.0%) patients required further investigation and 12 (75.0%) were unlikely to have advanced fibrosis. Of 12 patients who underwent fibroscan, one (8.3%) had both fibrosis and cirrhosis, two (16.7%) fibrosis only, and two (16.7%) moderate-to-severe steatosis.

CONCLUSIONS

Hepatic steatosis on ultrasound followup of nephrolithiasis patients is common, especially in smokers and overweight patients. Current recommendations suggest that primary care physicians calculate a FIB-4 score upon the detection of hepatic steatosis on ultrasound. The decision to refer to hepatology for a corroborative fibroscan is then based on the FIB-4 score.

Epigenomic and transcriptional profiling identifies impaired glyoxylate detoxification in NAFLD as a risk factor for hyperoxaluria

Epigenetic modifications (e.g. DNA methylation) in NAFLD and their contribution to disease progression and extrahepatic complications are poorly explored. Here, we use an integrated epigenome and transcriptome analysis of mouse NAFLD hepatocytes and identify alterations in glyoxylate metabolism, a pathway relevant in kidney damage via oxalate release-a harmful waste product and kidney stone-promoting factor. Downregulation and hypermethylation of alanine-glyoxylate aminotransferase (Agxt), which detoxifies glyoxylate, preventing excessive oxalate accumulation, is accompanied by increased oxalate formation after metabolism of the precursor hydroxyproline. Viral-mediated Agxt transfer or inhibiting hydroxyproline catabolism rescues excessive oxalate release. In human steatotic hepatocytes, AGXT is also downregulated and hypermethylated, and in NAFLD adolescents, steatosis severity correlates with urinary oxalate excretion. Thus, this work identifies a reduced capacity of the steatotic liver to detoxify glyoxylate, triggering elevated oxalate, and provides a mechanistic explanation for the increased risk of kidney stones and chronic kidney disease in NAFLD patients.

The new patterns of nephrolithiasis: What has been changing in the last millennium?

Nephrolithiasis has been increasing over the last millennium. Although early epidemiologic studies have shown that kidney stones were two to three times more frequent in males than in females, recent reports have suggested that this rate is decreasing. In parallel a dramatic increase of nephrolithiasis has also been observed among children and adolescents. Furthermore, epidemiologic studies have shown a strong association between metabolic syndrome (Mets) traits and kidney stone disease. Patients with hypertension have a higher risk of stone formation and stone formers are predisposed to develop hypertension compared to the general population. An incidence of nephrolithiasis greater than 75% has been shown in overweight and obese patients compared to those of normal weight. It has also been reported that a previous diagnosis of diabetes mellitus increases the risk of future nephrolithiasis. Additionally, an association between metabolic syndrome and uric acid stone formation has been clearly recognized. Furthermore, 24-h urinary metabolic abnormalities have been decreasing among patients with nephrolithiasis over the last decades. Finally, nephrolithiasis could cause chronic kidney disease (CKD) and end stage renal disease (ESRD), especially in women and overweight patients. According to these observations, a better understanding of these new features among stone former patients may be required. Hence, the recognition and the correction of metabolic disorders could help not only to reduce the primary disease, but also stone recurrence.

Nonalcoholic Fatty Liver Disease Is an Independent Risk Factor for Nephrolithiasis in Women: Findings from NHANES III

Objective: To determine if radiologically diagnosed nonalcoholic fatty liver disease (NAFLD) is an independent risk factor for nephrolithiasis using data from National Health and Nutrition Examination Survey III (NHANES III). Patients and Methods: NHANES III participants aged 20-74 years who underwent hepatobiliary ultrasound were classified as with NAFLD (moderate or severe hepatic steatosis in absence of other known causes of liver disease; n = 2498) or without NAFLD (controls; n = 9361). Risk of nephrolithiasis caused by NAFLD was estimated using logistic regression with propensity score adjustment. Secondary outcomes included medical stone management, lithotripsy, and surgical stone removal. Results: Participants with NAFLD were older (48.7 ± 0.4 vs 43.3 ± 0.3 years, p < 0.001) and exhibited greater prevalence of all components of metabolic syndrome: obesity (48% vs 21%), impaired glucose tolerance (17% vs 11%), diabetes mellitus (15% vs 6%), hypertension (36% vs 24%), and gout (4% vs 2%) (all p < 0.001). After adjusting for demographic, lifestyle, and metabolic factors, NAFLD was associated with increased risk nephrolithiasis (odds ratio [OR] = 1.29, 95% confidence interval [CI] [1.02-1.61], p = 0.03). The association persisted in women (OR = 1.65, 95% CI [1.17-2.32], p = 0.004) but not in men (OR = 1.04, 95% CI [0.77-1.40], p = 0.80). NAFLD was not associated with increased occurrence of medical management (OR = 1.31, 95% CI [0.84-2.05], p = 0.24), lithotripsy (OR = 1.61, 95% CI [0.83-3.33], p = 0.20), or surgical stone removal (OR = 0.83, 95% CI [0.48-1.44], p = 0.52). Conclusions: In a large U.S. population-based cross-sectional analysis, NAFLD was found to be associated with increased risk of nephrolithiasis in women after adjusting for demographic, clinical, and metabolic factors.

Relationship Between Urolithiasis and Fatty Liver Disease: Findings in Computed Tomography

There are no studies that allow a joint diagnostic or therapeutic intervention for the treatment of fatty liver and urolithiasis, perhaps because it is not known if there is an association between these 2 diseases. We aimed to identify a relationship between renal lithiasis and fatty liver disease by examining for common factors that could be used to reduce their incidence and complications. Our study supports the association of fatty liver and urolithiasis. Given the increase in frequency of these 2 diseases, we believe there is a common pathway within the malabsorptive and metabolic syndromes, thus leading for a new field of research to find a mechanism that allows timely interventions.

Obesity and Its Impact on Kidney Stone Formation

The prevalence of obesity is rising and places this cohort at risk for developing kidney stones. Some of the pathophysiologic responses that link obesity and kidney stone formation have been identified. Herein, we review the involved mechanisms driving this relationship and the impact of various weight loss strategies on kidney stone risk.

NAFLD and Extra-Hepatic Comorbidities: Current Evidence on a Multi-Organ Metabolic Syndrome

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide and its incidence is definitely increasing. NAFLD is a metabolic disease with extensive multi-organ involvement, whose extra-hepatic manifestations include type 2 diabetes mellitus, cardiovascular disease, obstructive sleep apnea, chronic kidney disease, osteoporosis, and polycystic ovarian syndrome. Recently, further evidence has given attention to pathological correlations not strictly related to metabolic disease, also incorporating in this broad spectrum of systemic involvement hypothyroidism, psoriasis, male sexual dysfunction, periodontitis, and urolithiasis. The most common cause of mortality in NAFLD is represented by cardiovascular disease, followed by liver-related complications. Therefore, clinicians should learn to screen and initiate treatment for these extra-hepatic manifestations, in order to provide appropriate multidisciplinary assessments and rigorous surveillance. This review evaluates the current evidence regarding extra-hepatic associations of NAFLD, focusing on the pathogenic hypothesis and the clinical implications.

The association between a non-invasive hepatic fibrosis score and urolithiasis among non-alcoholic fatty liver disease (NAFLD) patients in China: a cross-sectional study

OBJECTIVE

Mounting data now support a strong link between the presence of non-alcoholic fatty liver disease (NAFLD) and an increased risk of urolithiasis. However, little is known on the association between hepatic fibrosis and the risk of urolithiasis among NAFLD patients. Therefore, this study aimed to investigate the prevalence of urolithiasis among NAFLD patients and determine whether the Fibrosis-4 (FIB-4) score, a surrogate marker of hepatic fibrosis, is associated with urolithiasis among NAFLD patients.

DESIGN

Cross-sectional studies.

SETTING

China.

METHODS

A total of 2058 adult patients with NAFLD were included in this study. Logistic regression analysis was used to detect the association between FIB-4 score and urolithiasis. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic value of FIB-4 score for the detection of urolithiasis among NAFLD patients.

RESULTS

200 (9.7%) individuals had ultrasonography-diagnosed urolithiasis among 2058 NAFLD patients. FIB-4 score (OR=1.58; 95% CI 1.06 to 2.31), age (OR=1.11; 95% CI 1.08 to 1.13), obesity (OR=3.16; 95% CI 2.29 to 4.39) and hyperuricemia (OR=3.79; 95% CI 2.67 to 5.36) were independent factors associated with urolithiasis among NAFLD patients. Moreover, a novel algorithm including multiple variables (FIB-4 score, age, obesity and hyperuricemia) showed an area under a ROC curve of 0.813 (95% CI 0.795 to 0.829) for identifying urolithiasis among NAFLD patients. The optimal cut-off value of > -2.23 for the multivariate model provides a sensitivity of 76% and a specificity of 74% for predicting urolithiasis among NAFLD patients.

CONCLUSION

Urolithiasis among NAFLD patients is associated with FIB-4 score. Further, a novel algorithm based on FIB-4 score could serve as a useful tool for identifying individuals with a higher risk of urolithiasis among NAFLD patients, although prospective cohort studies are still needed in the future.

Incidental hepatic steatosis on unenhanced computed tomography performed for suspected renal colic: Gaps in reporting and documentation

INTRODUCTION

Hepatic steatosis is a common incidental finding on computed tomography (CT) in patients presenting to the emergency department (ED). The aims of our study were to assess the prevalence of hepatic steatosis in ED patients with suspected renal colic and to assess documentation in radiology reports and medical charts correlated with alanine transaminase (ALT) levels.

METHODS

Over 18 months from January 2016 to June 2017, all unenhanced CTs performed for suspected renal colic were reviewed. Quantitative assessment measuring hepatic and splenic attenuation in Hounsfield Units was performed. Hepatic steatosis was defined using multiple CT criteria including liver/spleen (L/S) ratio. Radiology reports, medical charts and ALT levels, if collected within 24 h of CT, were reviewed.

RESULTS

A total of 1290 patients were included with a median age 52.5 years (range 16-98) and male predominance (835 [64.7%]). A total of 336 (26%) patients had hepatic steatosis measured by L/S ratio of ≤ 1.0. Ninety-four patients (28%) had radiology reports noting steatosis. Documentation in medical charts was noted in 18 of the 94 patients (19.1%) for whom steatosis was reported. Liver enzymes were available for 704 (54.6%) patients. There was a significantly higher mean ALT level in patients with hepatic steatosis (42.2 U/L; 95% CI 38.4-46.0) compared to patients without (28.8 U/L; 95% CI 25.7-31.9) (P < 0.0001).

CONCLUSION

Our findings highlight multiple gaps in the reporting and evaluation of hepatic steatosis among radiologists and emergency clinicians alike. Recognising and reporting this incidental finding may impact health outcomes.

Impact of Demographic Factors and Systemic Disease on Urinary Stone Risk Parameters Amongst Stone Formers

This article examines via multivariate analysis the associations between demographic factors and systemic diseases on stone risk parameters in a stone-forming population. A retrospective chart review of adult stone formers who completed 24-hour urine collections from April 2004 through August 2015 was performed. Data was collected on age, sex, race, body mass index (BMI), and diagnoses of diabetes and hypertension. CT imaging and renal/abdominal ultrasonography (within ± 66 mo) were reviewed for diagnosis of fatty liver disease. Statistical analysis included Pearson and Spearman correlation analysis, and linear and logistic regression analyses, both univariate and multivariate. Five hundred eighty-nine patients were included. Numerous urinary parameters were significant in association with demographic factors or systemic diseases in a multivariate analysis. Older age was associated with decreased calcium (Ca) excretion (P = 0.0214), supersaturation of calcium oxalate (SSCaOx; P = 0.0262), supersaturation of calcium phosphate (SSCaP; P < 0.0001), and urinary pH (P = 0.0201). Men excreted more Ca (P = 0.0015) and oxalate (Ox; P = 0.0010), had lower urine pH (P = 0.0269), and higher supersaturation of uric acid (SSUA; P < 0.0001) than women. Blacks had lower urine volume (P = 0.0023), less Ca excretion (P = 0.0142), less Ox excretion (P = 0.0074), and higher SSUA (P = 0.0049). Diabetes was associated with more Ox excretion (P < 0.0001), lower SSCaP (P = 0.0068), and lower urinary pH (P = 0.0153). There were positive correlations between BMI and Ca excretion (P = 0.0386), BMI and Ox excretion (P = 0.0177), and BMI and SSUA (P = 0.0045). These results demonstrate that demographic factors and systemic disease are independently associated with numerous risk factors for kidney stones. The mechanisms responsible for these associations and disparities (racial differences) need to be further elucidated.

Prevalence of Nephrolithiasis in Patients with Chronic Liver Disease: A Case-Control Study

BACKGROUND AND AIMS

Nephrolithiasis is known to be associated with several systemic diseases including chronic kidney disease and renal failure, which can also occur as a complication of chronic liver disease (CLD). This study aimed to assess the prevalence of nephrolithiasis in patients with CLD.

METHODS

A short survey was completed by 198 patients with CLD and 322 controls matched by age, sex, and state of residence. A primary diagnosis of liver disease was confirmed with health record review.

RESULTS

The median age of the liver disease group was 63 years and 128 (65%) were male; the median age of the control group was 63 and 199 (63%) were male. Body mass index was higher in the liver disease group (27.8 vs 26.7, P < .01). The most common liver disease diagnosis was hepatitis C (60 [30%]) followed by alcoholic cirrhosis (42 [21.2%]). The self-reported prevalence of nephrolithiasis in the liver disease group was 26%, compared to 14% in the control group (P < .01). This association remained significant after adjusting for age, sex, body mass index, and family history of kidney stones or liver disease.

CONCLUSIONS

In this case-control, survey-based study, the prevalence of nephrolithiasis was 2 times higher in patients with CLD.

Clinical factors predicting drug-induced liver injury due to flucloxacillin

Objectives

Drug-induced liver injury (DILI) is a serious adverse reaction due to flucloxacillin. The pathogenesis is not fully understood. Female sex, age over 60 years, and a longer treatment duration have been suggested to be predisposing factors. Carriers of HLA-B*57:01 have an 80-fold increased risk, but due to the rarity of the reaction, testing of all patients is not cost-effective. We aimed to validate and detect clinical risk factors for flucloxacillin DILI.

Methods

Clinical characteristics of flucloxacillin-treated patients with (n=50) and without DILI (n=2,330) were compared in a retrospective case control study. Cases were recruited from the Swedish database of spontaneously reported adverse drug reactions. Treated controls were selected from the Swedish Twin Registry. Statistical comparisons were made using chi-squared test and logistic regression. The significance threshold was set to P<0.00357 to correct for multiple comparisons. Reliable variables were tested in a multiple regression model.

Results

DILI was associated with female sex, OR 2.79, 95% CI 1.50-5.17, P=0.0011, and with a history of kidney stones, OR 5.51, 95% CI 2.21-13.72, P=0.0003. Cases were younger than controls, OR per increase in years 0.91, 95% CI 0.88-0.94, P<0.0001, probably due to selection bias. No difference in treatment duration was detected, OR 1.03, 95% CI 0.98-1.08, P=0.1790.

Conclusion

We established female sex as a risk factor for flucloxacillin-induced DILI, and a history of kidney stones was identified as a potential risk factor. Clinical risk factors for flucloxacillin-induced DILI could be used to indicate whom to test for HLA-B*57:01 before treatment.

The severity of NAFLD is associated with the risk of urolithiasis

BACKGROUND AND AIMS

Population-based studies suggest a strong association between the presence of nonalcoholic fatty liver disease (NAFLD) and an increased risk of urolithiasis. However, the available information on the association of the severity of NAFLD with urolithiasis is limited. We hypothesised a link between the severity of NAFLD and the risk of urolithiasis.

METHODS

We recruited 1527 adult patients with NAFLD who completed a comprehensive health checkup. The severity of NAFLD was measured with AST to platelet ratio (APRI score). Logistic regression analysis was used to detect the association of APRI score with the risk of urolithiasis among NAFLD patients. ROC analysis was used to assess the diagnostic value of APRI score for identifying urolithiasis among NAFLD patients.

RESULTS

Multivariate analysis showed three independent risk factors for urolithiasis: obesity (OR 2.06 95%CI 1.35-3.13), APRI score (OR 1.29 95%CI 1.05-1.59), and serum uric acid (OR 1.07 95%CI 1.05-1.09), suggesting an independent association between the noninvasive staging of liver fibrosis and the risk of urolithiasis in NAFLD patients. A three-variable model (obesity, APRI score, and serum uric acid) with an AUROC of 0.73 (95% CI 0.70-0.75) was significant in identifying urolithiasis.

CONCLUSIONS

The severity of NAFLD is associated with the risk of urolithiasis among NAFLD patients. Moreover, a three-variable model (obesity, APRI score, serum uric acid) could serve as a useful tool for identifying individuals at high risk for urolithiasis in these patients.

Non-alcoholic fatty liver disease and the risk of urolithiasis: A systematic review and meta-analysis

There is growing evidence that nonalcoholic fatty liver disease (NAFLD) is associated with a higher risk of urolithiasis, but it has not yet been determined that this association is reproducible and consistent across different studies. We performed a systematic review and meta-analysis of these studies to examine the association between NAFLD and the risk of urolithiasis.We searched PubMed, EMBASE, and Google scholar using terms "fatty liver" (OR "non-alcoholic fatty liver disease" OR "non-alcoholic steatohepatitis" OR "NAFLD" OR "NASH") AND "urolithiasis" (OR "nephrolithiasis" OR "kidney stone" OR "urinary calculi" OR "renal colic" OR "urologic disease"). Observational studies in which NAFLD and urolithiasis were diagnosed by either ultrasonography or computerized tomography were included.A total of 7 observational studies with 226,541 individuals (24.7% with NAFLD) and 19,184 urolithiasis (8.5%). NAFLD was significantly associated with an increased risk of urolithiasis (random effect odds ratio, OR 1.73, 95% confidence interval, CI 1.24-2.40, I=94.5%). Sensitivity analyses revealed the robustness of the results. Egger test and Begg test suggested no publication bias (P > .05).NAFLD is associated with an increased risk of urolithiasis. Therefore, patients with NAFLD should be carefully monitored for the development of urolithiasis.

The influence of metabolic syndrome and its components on the development of nephrolithiasis

The prevalence of kidney stone disease is increasing, afflicting 7%–11% of the United States population. Multiple systemic conditions, including obesity and diabetes, are also on the rise. Further, the literature has demonstrated a strong association between metabolic syndrome, its components, and kidney stone disease. In this article, we aim to review the associations of metabolic syndrome and nephrolithiasis, discussing the pathophysiology, urinary parameters, and clinical presentations. With this knowledge, urologists will have a more comprehensive understanding of this complex population of metabolic stone formers enabling improved patient management and treatment of stone disease.

Association between nephrolithiasis and fatty liver detected on non-enhanced CT for clinically suspected renal colic

PURPOSE

To estimate a direct association between nephrolithiasis and hepatosteatosis in patients referred to CT due to clinical suspicion of renal colic.

METHODS

A 508 non-contrast CT scans were examined for calculi in the kidneys or urinary tract, including measurements of liver attenuation, spleen attenuation, thickness of visceral and subcutaneous fat. Logistic regression examined the association of nephrolithiasis and hepatosteatosis findings.

RESULTS

Nephrolithiasis was found in 421 (83.9%) and hepatosteatosis in 80 (15.7%) cases. Univariate analysis showed a statistically significant association between nephrolithiasis and hepatosteatosis OR=3.24 (95% CI 1.36-7.68), p=0.008.

CONCLUSIONS

A significant association was determined between nephrolithiasis and hepatosteatosis.