Which anthropometric measurements including visceral fat, subcutaneous fat, body mass index, and waist circumference could predict the urinary stone composition most?

Higher weight-adjusted waist index is associated with increased likelihood of kidney stones

Objectives

The objective of this study was to evaluate the association between weight-adjusted waist index (WWI) and the prevalence of kidney stones among adults in the United States.

Methods

The cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) spanning the years 2007-2018. A total of 31,344 participants were categorized into two groups: those with kidney stones and those without. WWI was determined by dividing waist circumference (cm) by the square root of body weight (kg). To examine the relationship between kidney stones and WWI, multivariate logistic regression models, smoothed curve fitting, and weighted generalized additive model (GAM) regression were employed. Subgroup analysis and interaction tests were conducted to explore the stability of this association across different groups.

Results

The final analysis comprised a total of 31,344 participants, including 2,928 individuals who had a history of kidney stones. In the fully adjusted model, an increase in WWI exhibited a positive correlation with the prevalence of kidney stones (OR=1.34, 95% CI: 1.18-1.51). When WWI was converted into quartiles (Q1-Q4), participants in the highest quartile (Q4) had a 69% greater risk of developing kidney stones compared to those in the lowest quartile (Q1) (OR=1.69, 95% CI: 1.28-2.25). This positive association was particularly notable among non-diabetic patients.

Conclusion

Our study demonstrates a significant positive association between weight-adjusted waist index levels and an elevated prevalence of kidney stones among US adults. Furthermore, this research highlights the potential utility of weight-adjusted waist index in the prevention of kidney stones in the overall population. This relationship is limited and further research is needed to test this hypothesis.

Relationship between anthropometric and body composition parameters and anti-SARS-CoV-2 specific IgG titers in females vaccinated against COVID-19 according to the heterologous vaccination course: A cohort study

INTRODUCTION

The aim of this cohort study was to evaluate the relationship between anthropometric and body composition parameters and anti-SARS-CoV-2 IgG titers in a group of females who were vaccinated against COVID-19 with two doses of ChAdOx1 vaccine and then boosted with the BNT162b2 vaccine.

MATERIALS AND METHODS

The study group consisted of 63 women. Basic demographic and clinical data were collected. To assess the anti-SARS-CoV-2 immunoglobulin G titers following the vaccination, five blood draws were performed: 1) before the first dose, 2) before the second dose, 3) 14-21 days after the primary vaccination, 4) before the booster, and 5) 21 days after the booster. Blood samples were analyzed using a two-step enzymatic chemiluminescent assay. Body mass index and body composition were evaluated using bioelectrical impedance analysis. To select the most distinguishing parameters and correlations between anthropometric and body composition parameters and anti-SARS-CoV-2 IgG titers, factor analysis using the Principal Component Analysis was conducted.

RESULTS

Sixty-three females (mean age: 46.52 years) who met the inclusion criteria were enrolled. 40 of them (63.50%) participated in the post-booster follow-up. After receiving two doses of the ChAdOx1 vaccine, the study group's anti-SARS-CoV-2 IgG titers were 67.19 ± 77.44 AU/mL (mean ± SD), whereas after receiving a heterologous mRNA booster, the level of anti-SARS-CoV-2 IgG titers was about three-times higher and amounted to 212.64 ± 146.40 AU/mL (mean ± SD). Our data shows that seropositivity, obesity, non-fat-related, and fat-related body composition parameters all had a significant effect on the level of IgG titer after a two-dose vaccination of ChAdOx1. However, only non-fat-related and fat-related body composition parameters had a significant effect on the IgG titer after booster vaccination.

CONCLUSION

COVID-19 infection before the first dose of vaccination is not related to IgG titer after booster administration. Body composition has a significant effect on the production of anti-SARS-CoV-2 IgG after booster vaccination in females.

The combination of mean and maximum Hounsfield Unit allows more accurate prediction of uric acid stones

Based on mean Hounsfield Unit (HuMean), we aimed to evaluate the additional use of standard deviation of Hounsfield Unit (HuStd), minimum Hounsfield Unit (HuMin), and maximum Hounsfield Unit (HuMax) in noncontrast computed tomography (NCCT) to evaluate uric acid (UA) stones more accurately. The data of patients who underwent the NCCT examination and infrared spectroscopy in our hospital from August 2017 to December 2021 were analyzed retrospectively. Based on CT scans, the HuMean, HuStd, HuMin, and HuMax of all patients were measured. The patients were divided into groups according to the stone composition. The attenuation value of mixed stones was in the middle of their pure stones. Except for Str, statistically significant differences between UA stones and other pure stones were observed for HuMean, HuStd, HuMin, and HuMax. A moderate correlation was found between HuMean, HuStd, HuMin, and HuMax and UA stones (r_s showed -0.585, -0.409, -0.492, and -0.577, respectively). Receiver operator characteristic (ROC) curve showed that the area under the curve (AUC) of HuMean and HuMax were higher than those of HuStd and HuMin (AUC = 0.896, AUC = 0.891 vs. AUC = 0.777, AUC = 0.833). Higher AUC (0.904), specificity (0.899) and positive predictive value (PPV) (0.712) can be obtained by combining HuMean and HuMax in the diagnosis of UA stones. In conclusion, HuMean and HuMax can better predict UA stones than HuStd and HuMin. The combined use of HuMean and HuMax can lead to higher accuracy.

Association Between Body Fat Mass and Kidney Stones in US Adults: Analysis of the National Health and Nutrition Examination Survey 2011-2018

BACKGROUND

The association between total and truncal body fat and kidney stone (KS) remains unclear.

OBJECTIVE

To evaluate the association between total and truncal body fat and KS in the US adult population.

DESIGN, SETTING, AND PARTICIPANTS

The National Health and Nutrition Examination Survey (NHANES) comprises a series of nationally representative cross-sectional surveys. Data from females and males aged 20-59 yr who participated in four 2-yr NHANES cycles between 2011 and 2018 were obtained.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariable-adjusted logistic regression models were used to investigate the association between dual-energy x-ray absorptiometry (DXA) scan-measured total and truncal body fat percentage and mass with KS.

RESULTS AND LIMITATIONS

A total of 10 271 participants (50.3% females) were included. Weighted KS prevalence was 8.11% in femalesand 7.55% in males. In males, higher fat percentage was associated with higher odds of KS (per 5% total fat: odds ratio [OR] = 1.19, 95% confidence interval [CI] 1.08-1.32; per 5% truncal fat: OR = 1.22, 95% CI 1.10-1.35), particularly in those aged 40-59 yr (per 5% total fat: OR = 1.36, 95% CI 1.16-1.59; per 5% truncal fat: OR = 1.41, 95% CI 1.20-1.65, p-interaction < 0.05). In females, higher fat percentage was associated with higher odds of KS overall (per 5% total fat: OR = 1.23, 95% CI 1.10-1.37; per 5% truncal fat: OR = 1.20, 95% CI 1.08-1.33) and in both age groups (20-39 and 40-59 yr, p-interaction > 0.05). The observed associations were stronger in "other" ethnicities and non-Hispanic white. Similar patterns were observed for per 5 kg body fat mass.

CONCLUSIONS

Total and truncal fat parameters are associated with a higher prevalence of KS in adult females and males who are ≥40 yr old. Truncal fat mass may be at least equal or superior to total fat mass in assessing the association of body fat with KS. Further studies are warranted to elaborate on the pathophysiologic mechanism of this association to decrease the prevalence of KS.

PATIENT SUMMARY

Total and truncal body fat are associated with a higher prevalence of kidney stone (KS) in adult females and males aged ≥40 yr. Truncal fat mass may be similar or superior to total fat mass in assessing the association between body fat and KS.

Quantification of abdominal fat from computed tomography using deep learning and its association with electronic health records in an academic biobank

OBJECTIVE

The objective was to develop a fully automated algorithm for abdominal fat segmentation and to deploy this method at scale in an academic biobank.

MATERIALS AND METHODS

We built a fully automated image curation and labeling technique using deep learning and distributive computing to identify subcutaneous and visceral abdominal fat compartments from 52,844 computed tomography scans in 13,502 patients in the Penn Medicine Biobank (PMBB). A classification network identified the inferior and superior borders of the abdomen, and a segmentation network differentiated visceral and subcutaneous fat. Following technical evaluation of our method, we conducted studies to validate known relationships with visceral and subcutaneous fat.

RESULTS

When compared with 100 manually annotated cases, the classification network was on average within one 5-mm slice for both the superior (0.4 ± 1.1 slice) and inferior (0.4 ± 0.6 slice) borders. The segmentation network also demonstrated excellent performance with intraclass correlation coefficients of 1.00 (P < 2 × 10-16) for subcutaneous and 1.00 (P < 2 × 10-16) for visceral fat on 100 testing cases. We performed integrative analyses of abdominal fat with the phenome extracted from the electronic health record and found highly significant associations with diabetes mellitus, hypertension, and renal failure, among other phenotypes.

CONCLUSIONS

This work presents a fully automated and highly accurate method for the quantification of abdominal fat that can be applied to routine clinical imaging studies to fuel translational scientific discovery.

Covid-19: Fat, Obesity, Inflammation, Ethnicity, and Sex Differences

Although obesity is known to be a risk factor for COVID-19 severity, there is an urgent need to distinguish between different kinds of fat—visceral and subcutaneous fat—and their inflammation status in COVID-19. These different fat types have partially diverging biochemical roles in the human body, and they are differentially associated with SARS-CoV-2, which targets the angiotensin-converting enzyme 2 (ACE2) for cell entry. ACE2 is highly expressed in adipose tissue, especially in visceral fat, suggesting an important role for this tissue in determining COVID-19 disease severity. In this perspective article, we discuss group differences in the amount of visceral fat levels and the extent of inflammation in adipocytes of visceral fat tissue, which may, in part, drive population, cross-national, ethnic, and sex differences in COVID-19 disease. It is vital to steer the scientific community’s attention to the effects of visceral fat in creating individual and population differences in COVID-19 severity. This can help researchers unravel the reasons for the reported population, ethnic, and sex differences in COVID-19 severity and mortality.

The Urological Association of Asia clinical guideline for urinary stone disease

The Urological Association of Asia, consisting of 25 member associations and one affiliated member since its foundation in 1990, has planned to develop Asian guidelines for all urological fields. The field of stone diseases is the third of its guideline projects. Because of the different climates, and social, economic and ethnic environments, the clinical practice for urinary stone diseases widely varies among the Asian countries. The committee members of the Urological Association of Asia on the clinical guidelines for urinary stone disease carried out a surveillance study to better understand the diversity of the treatment strategy among different regions and subsequent systematic literature review through PubMed and MEDLINE database between 1966 and 2017. Levels of evidence and grades of recommendation for each management were decided according to the relevant strategy. Each clinical question and answer were thoroughly reviewed and discussed by all committee members and their colleagues, with suggestions from expert representatives of the American Urological Association and European Association of Urology. However, we focused on the pragmatic care of patients and our own evidence throughout Asia, which included recent surgical trends, such as miniaturized percutaneous nephrolithotomy and endoscopic combined intrarenal surgery. This guideline covers all fields of stone diseases, from etiology to recurrence prevention. Here, we present a short summary of the first version of the guideline - consisting 43 clinical questions - and overview its key practical issues.

Pre-operative CT scan measurements for predicting complications in patients undergoing complex ventral hernia repair using the component separation technique

Background

The component separation technique (CST) is considered an excellent technique for complex ventral hernia repair. However, postoperative infectious complications and reherniation rates are significant. Risk factor analysis for postoperative complication and reherniation has focused mostly on patient history and co-morbidity and shows equivocal results. The use of abdominal morphometrics derived from CT scans to assist in risk assessment seems promising. The aim of this study is to determine the predictability of reherniation and surgical site infections (SSI) using pre-operative CT measurements.

Methods

Electronic patient records were searched for patients who underwent CST between 2000 and 2013 and had a pre-operative CT scan available. Visceral fat volume (VFV), subcutaneous fat volume (SFV), loss of domain (LOD), rectus thickness and width (RT, RW), abdominal volume, hernia sac volume, total fat volume (TFV), sagittal distance (SD) and waist circumference (WC) were measured or calculated. Relevant variables were entered in multivariate regression analysis to determine their effect on reherniation and SSI as separate outcomes.

Results

Sixty-five patients were included. VFV (p = 0.025, OR = 1.65) was a significant predictor regarding reherniation. Hernia sac volume (p = 0.020, OR = 2.10) and SFV per 1000 cm³ (p = 0.034, OR = 0.26) were significant predictors of SSI.

Conclusion

Visceral fat volume, subcutaneous fat volume and hernia sac volume derived from CT scan measurements may be used to predict reherniation and SSI in patients undergoing complex ventral hernia repair using CST. These findings may aid in optimizing patient-tailored preoperative risk assessment.

Predictors of Uric Acid Stones: Mean Stone Density, Stone Heterogeneity Index, and Variation Coefficient of Stone Density by Single-Energy Non-Contrast Computed Tomography and Urinary pH

We analyzed the capacities of pertinent parameters (determined by single-energy non-contrast computed tomography [NCCT]) and urinary pH to predict uric acid stones. We reviewed the medical records of 501 patients whose stones were removed surgically or passed spontaneously between December 2014 and April 2016. Qualifying participants (n = 420) were stratified by the nature of the stone (calcium oxalate, uric acid, or infectious). Based on NCCT, we determined maximal stone length (MSL), mean stone density (MSD), and stone heterogeneity index (SHI) using Hounsfield units (HU) and calculated the variant coefficient of stone density (VCSD = SHI/MSD × 100). Urinary pH was also ascertained. Mean patient age was 55.55 ± 15.46 years. MSD (448.59 ± 173.21 HU), SHI (100.81 ± 77.37 HU), and VCSD (22.58 ± 10.55) proved to be significantly lower in uric acid versus other types of stones, as did urinary pH (5.33 ± 0.56; all p < 0.001). Receiver operating characteristic (ROC) curves depicting predictability of uric acid stones yielded area under ROC curve (AUC) values for MSD, SHI, VCSD, and urinary pH of 0.806 (95% CI: 0.761⁻0.850), 0.893 (95% CI: 0.855⁻0.931), 0.782 (95% CI: 0.726⁻0.839), and 0.797 (95% CI: 0.749⁻0.846), respectively, with corresponding cutpoints of 572.3 HU, 140.4 HU, 25.79, and 6.0. Among these four parameters, SHI was verifiably (DeLong's test) the most effective predictor of uric acid stones (all p < 0.001). Compared with MSD, VCSD, and urinary pH, SHI may better predict uric acid stones, using a cutpoint of 140.4 HU.

Residual Effect of Sodium Glucose Cotransporter 2 Inhibitor, Tofogliflozin, on Body Weight After Washout in Japanese Men With Type 2 Diabetes

Background

We investigated the potential mechanism underlying body weight reduction by the sodium glucose cotransporter 2 (SGLT2) inhibitor, tofogliflozin, during treatment and after subsequent washout.

Methods

Ten Japanese men with type 2 diabetes (average age: 66.3 years) were orally administered tofogliflozin (20 mg/day) for 8 weeks followed by a subsequent 8-week washout period (16 weeks).

Results

Significant reductions were observed in blood glucose, hemoglobin A1c (HbA1c), uric acid, body weight and waist circumference with an increase in high-molecular weight (HMW) adiponectin at 8 weeks. We also evaluated these markers at 16 weeks and found that unlike HbA1c and uric acid, body weight and HMW adiponectin did not return to baseline levels. To clarify the potential mechanism underlying the body weight reduction during treatment with tofogliflozin (8 weeks) and after washout (at 16 weeks), we investigated the correlations between changes from baseline (0 week) in body weight and those in waist circumference (or HMW adiponectin). The changes in body weight between 0 weeks versus 8 weeks were not significantly correlated with those in waist circumference or HMW adiponectin. In contrast, changes in body weight between 0 and 16 weeks did show a significant correlation to those in waist circumference and HMW adiponectin.

Conclusion

The body weight reduction caused by tofogliflozin may be due to several factors as well as fat reduction at 8 weeks, but is most likely due to fat reduction alone after a subsequent 8 weeks of washout of this agent.

Obesity and kidney stone disease: a systematic review

INTRODUCTION

Currently, abdominal obesity has reached an epidemic stage and obesity represents an important challenge for worldwide health authorities. Epidemiologic studies have demonstrated that the stone risk incidence increases with Body Mass Index, through multiple pathways. Metabolic syndrome and diabetes are associated with an increased renal stones disease incidence. The aim of this systematic review was to investigate the prevalence, morbidity, risk factors involved in the association between obesity and urolithiasis.

EVIDENCE ACQUISITION

The search involved finding relevant studies from MEDLINE, EMBASE, Ovid, the Cochrane Central Register of Controlled Trials, CINAHL, Google Scholar, and individual urological journals between January 2001 and May 2017. The inclusion criteria were for studies written in the English language, reporting on the association between obesity and urinary stones.

EVIDENCE SYNTHESIS

The underlying pathophysiology of stone formation in obese patients is thought to be related to insulin resistance, dietary factors, and a lithogenic urinary profile. Uric acid stones and calcium oxalate stones are observed frequently in these patients. Insulin resistance is thought to alter the renal acid-base metabolism, resulting in a lower urine pH, and increasing the risk of uric acid stone disease. Obesity is also associated with excess nutritional intake of lithogenic substances and with an increase in urinary tract infection incidence. Recent studies highlighted that renal stone disease increases the risk of myocardial infarction, progression of chronic kidney disease, and diabetes. Contemporary, bariatric surgery has been shown to be associated with hyperoxaluria and oxalate nephropathy. Certainly, the many health risks of obesity, including nephrolithiasis, will add more burden on urologists and nephrologists.

CONCLUSIONS

Obesity related nephrolithiasis seems to necessitate weight loss as primary treatment, but the recognition of the associated complications is necessary to prevent induction of new and equally severe medical problems. The optimal approach to obesity control that minimizes stone risk needs to be determined in order to manage obesity-induced renal stones disease.

Stone heterogeneity index on single-energy noncontrast computed tomography can be a positive predictor of urinary stone composition

The aim of this study was to investigate the correlation between stone composition and single-energy noncontrast computed tomography (NCCT) parameters, including stone heterogeneity index (SHI) and mean stone density (MSD), in patients with urinary calculi. We retrospectively reviewed medical records of 255 patients who underwent operations or procedures for urinary stones or had spontaneous stone passage between December 2014 and October 2015. Among these, 214 patients with urinary calculi who underwent NCCT and stone composition analyses were included in the study. Maximal stone length (MSL), mean stone density (MSD), and stone heterogeneity index (SHI) were determined on pretreatment NCCT. The mean MSD (454.68±177.80 HU) and SHI (115.82±96.31 HU) of uric acid stones were lower than those of all other types. Based on post hoc tests, MSD was lower for uric acid stones than for the other types (vs. CaOx: P<0.001; vs. infection stones: P<0.001). SHI was lower for uric acid stones than for the other types (vs. CaOx: P<0.001; vs. infection stones: P<0.001) Receiver operating characteristic curves of uric acid stones for MSD and SHI demonstrated that SHI (cut-off value: 140.4 HU) was superior to MSD (cut-off value: 572.3 HU) in predicting uric acid stones (P<0.001).

The Relationship Between Nephrolithiasis Risk with Body Fat Measured by Body Composition Analyzer in Obese People

BACKGROUND

Nephrolithiasis (kidney stones) continues to be a major cause of morbidity and healthcare spending that visceral and subcutaneous adipose tissue may associate with kidney stone formation. This study aimed to investigate the relationship between nephrolithiasis with visceral fat scale in obese people in Western Iran for the first time.

MATERIALS AND METHODS

In 2017, 103 participants with BMI≥30 kg/m² were selected for the present study. The participants were divided into two groups, 52 as case group (having the kidney stone) and 58 as healthy control group (no kidney stone or history of the kidney stone or any other disease). The levels of body composition were checked by body composition analyzer (BoCA x1) based on Bio Impedance mechanism.

RESULTS

Two groups were matched in terms of sex and BMI. There was a significant difference between two groups for the visceral fat to subcutaneous fat ratio (VSR) that accordingly, the mean VSR in the case group was higher than the control group. The difference for other variables between two groups was not significant.

CONCLUSIONS

The results showed that visceral and subcutaneous fat and VSR were important risk factors for kidney stone formation (nephrolithiasis). Evaluating these fats in stone formers may facilitate a tailored metabolic evaluation and treatment plan.

Vascular Disease and Kidney Stones: Abdominal Aortic Calcifications Are Associated with Low Urine pH and Hypocitraturia

OBJECTIVE

Vascular calcifications are associated with nephrolithiasis. Although studies have demonstrated correlations with vascular disease and calcium stones in kidney stone formers (KSF), an etiologic link has remained elusive. As a noncontrast CT (NCCT) scan is typically part of a stone evaluation, our objective was to evaluate the association of NCCT-based assessment of abdominal aortic calcifications (AACs) with 24-hour urine parameters and stone composition.

MATERIALS AND METHODS

Ninety-seven KSF were included with CT imaging and 24-hour urine studies. For each patient, semi-automated CT software was utilized to provide an AAC Agatston score from the celiac axis to the aortic bifurcation. Univariate analysis was performed to compare patients with or without AAC. Multivariate logistic regression was performed to assess for variables associated with 24-hour urine parameters and stone composition.

RESULTS

The presence of AAC was associated with hypertension, diabetes, peripheral vascular disease, and coronary artery disease. Patients with any AAC showed lower 24-hour urine citrate (399 vs 593 mg/day, p < 0.001) and lower 24-hour urine pH (5.862 vs 6.328, p = 0.003). When controlling for age, system comorbidities, the presence of AAC was associated with low urine pH <6 (odds ratio [OR] 2.86, p = 0.032) and hypocitraturia <320 mg/day (OR 4.37, p = 0.005). The receiver operating characteristic curve showed that increasing AAC was associated with low urine pH (area under the curve [AUC] 0.683, p = 0.002) and uric acid stone formation (AUC 0.698, p = 0.045).

CONCLUSIONS

NCCT-based diagnosis of AAC is associated with low urine pH, hypocitraturia, and uric acid stone formation. The presence of AAC could be considered an additional prognosticator for the utility of alkalinization therapy.