Body mass index is associated with increased creatinine clearance by a mechanism independent of body fat distribution

Comprehensive strategy for identifying extracellular vesicle surface proteins as biomarkers for chronic kidney disease

Chronic kidney disease (CKD) poses a significant health burden worldwide. Especially, obesity-induced chronic kidney disease (OCKD) is associated with a lack of accuracy in disease diagnostic methods. The identification of reliable biomarkers for the early diagnosis and monitoring of CKD and OCKD is crucial for improving patient outcomes. Extracellular vesicles (EVs) have emerged as potential biomarkers in the context of CKD. In this review, we focused on the role of EVs as potential biomarkers in CKD and OCKD and developed a comprehensive list of EV membrane proteins that could aid in the diagnosis and monitoring of the disease. To assemble our list, we employed a multi-step strategy. Initially, we conducted a thorough review of the literature on EV protein biomarkers in kidney diseases. Additionally, we explored papers investigating circulating proteins as biomarkers in kidney diseases. To further refine our list, we utilized the EV database Vesiclepedia.org to evaluate the qualifications of each identified protein. Furthermore, we consulted the Human Protein Atlas to assess the localization of these candidates, with a particular focus on membrane proteins. By integrating the information from the reviewed literature, Vesiclepedia.org, and the Human Protein Atlas, we compiled a comprehensive list of potential EV membrane protein biomarkers for CKD and OCKD. Overall, our review underscores the potential of EVs as biomarkers in the field of CKD research, providing a foundation for future studies aimed at improving CKD and OCKD diagnosis and treatment.

Effect of Filgotinib on Body Mass Index (BMI) and Effect of Baseline BMI on the Efficacy and Safety of Filgotinib in Rheumatoid Arthritis

INTRODUCTION

This post hoc analysis of the phase 3 rheumatoid arthritis (RA) filgotinib clinical trial program assessed the effect of filgotinib on body mass index (BMI) in patients with RA and the impact of BMI on the efficacy and safety of filgotinib.

METHODS

FINCH 1-3 were randomized, double-blind, active- or placebo-controlled phase 3 trials of filgotinib 100 and 200 mg in patients with RA (N = 3452). BMI assessments included the mean change from baseline in BMI and the proportion of patients whose BMI increased by incremental thresholds. Efficacy measures included American College of Rheumatology (ACR) 20/50/70 response and low disease activity/remission according to Disease Activity Score 28 using C-reactive protein. The exposure-adjusted incident rate (EAIR) of adverse events (AEs) was assessed by baseline BMI, using integrated data from the FINCH 1-4 and the phase 2 DARWIN 1-3 studies (total filgotinib exposure = 8085 patient-years).

RESULTS

Mean change from baseline in BMI over time was similar across treatment arms. In most patients, BMI increased by ≤ 1 or 2 kg/m2 at both weeks 12 and 24, regardless of treatment group or baseline BMI; few patients had increases of ≥ 4 kg/m2. For most efficacy measures, filgotinib 200 mg was more efficacious than filgotinib 100 mg or active comparators or placebo across BMI subgroups. For the higher filgotinib dose, the EAIR of serious treatment-emergent AEs, venous thrombotic and embolic events, and major adverse cardiovascular events increased with increasing BMI.

CONCLUSIONS

Filgotinib did not lead to substantial changes in BMI, and BMI did not appear to affect the efficacy of filgotinib.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT02889796, NCT02873936, NCT02886728, NCT03025308, NCT01888874, NCT01894516, NCT02065700.

Novel Multi-Ingredient Supplement Facilitates Weight Loss and Improves Body Composition in Overweight and Obese Individuals: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

BACKGROUND

Despite the growing recognition of the obesity crisis, its rates continue to rise. The current first-line therapies, such as dietary changes, energy restriction, and physical activity, are typically met with poor adherence. Novel nutritional interventions can address the root causes of obesity, including mitochondrial dysfunction, and facilitate weight loss.

OBJECTIVE

The objective of this study was to investigate the effects of a multi-ingredient nutritional supplement designed to facilitate mitochondrial function and metabolic health outcomes over a 12 wk period.

METHODS

Fifty-five overweight and/or obese participants (age (mean ± SEM): 26 ± 1; body mass index (BMI) (kg/m2): 30.5 ± 0.6) completed this double-blind, placebo-controlled clinical trial. Participants were randomized to 12 wks of daily consumption of multi-ingredient supplement (MIS; n = 28; containing 50 mg forskolin, 500 mg green coffee bean extract, 500 mg green tea extract, 500 mg beet root extract, 400 mg α-lipoic acid, 200 IU vitamin E, and 200 mg CoQ10) or control placebo (PLA, n = 27; containing microcrystalline cellulose) matched in appearance. The co-primary outcomes were bodyweight and fat mass (kg) changes. The secondary outcomes included other body composition measures, plasma markers of obesity, fatty liver disease biomarkers, resting energy metabolism, blood pressure, physical performance, and quality of life. The post-intervention differences between MIS and PLA were examined via ANCOVA which was adjusted for the respective pre-intervention variables.

RESULTS

After adjustment for pre-intervention data, there was a significant difference in weight (p < 0.001) and fat mass (p < 0.001) post-intervention between the PLA and MIS treatment arms. Post-intervention weight and fat mass were significantly lower in MIS. Significant post-intervention differences corrected for baseline were found in markers of clinical biochemistry (AST, p = 0.017; ALT, p = 0.008), molecular metabolism (GDF15, p = 0.028), and extracellular vesicle-associated miRNA species miR-122 and miR-34a in MIS (p < 0.05).

CONCLUSIONS

Following the 12 wks of MIS supplementation, weight and body composition significantly improved, concomitant with improvements in molecular markers of liver health and metabolism.

Association of obesity, diabetes, and hypertension with arsenic in drinking water in the Comarca Lagunera province (north-central Mexico)

Chronic endemic regional hydroarsenicism (CERHA) is a global issue that affects over 200 million people exposed to arsenic (As) in drinking water. This includes 1.75 million individuals residing in La Comarca Lagunera, a region in north-central Mexico. Arsenic levels in this region typically exceeds the WHO guideline of 10 µg L^-1. Biochemical alterations related to the human As metabolism may increase the risk of overweight and obesity (O&O), type 2 diabetes (T2D), and hypertension (AHT). In our study, we investigated the role of As in drinking water as a risk factor for these metabolic diseases. We focused on populations with historically moderate (San Pedro) and low (Lerdo) drinking water As levels and people with no historical evidence of As water contamination. The exposure assessment to As was based on measurements of the drinking water (medians 67.2, 21.0, 4.3 µg L^-1) and urinary As concentrations in women (9.4, 5.3, 0.8 µg L^-1) and men (18.1, 4.8, 1.0 µg L^-1). A significant correlation between As in drinking water and urine evidenced the As exposure in the population (R² = 0.72). Adjusted odds ratios with 95% confidence intervals evidenced higher chances of being diagnosed with T2D (1.7, 1.2-2.0) and AHT (1.8, 1.7-1.9) in individuals living in San Pedro than those in Lerdo. Still, there was no significant association with obesity. Individuals living in CERHA towns were found to have a higher risk of obesity (1.3-1.9), T2D (1.5 to 3.3), and AHT (1.4 to 2.4) compared to those residing in non-CERHA towns. Finally, obesity is more probable in women [inverse of OR and 95%CI 0.4 (0.2-0.7)] compared to men, while men is more likely to be diagnosed with T2D [OR = 2.0 (1.4-2.3)] and AHT [OR = 2.0 (1.5-2.3)] than women, independently of the municipality.

High-dose cephalexin for cellulitis: a pilot randomized controlled trial

BACKGROUND

Up to 3% of all Emergency Department (ED) visits are due to skin and soft tissue infections such as non-purulent cellulitis. The current treatment failure rate is approximately 20%. Evidence is lacking regarding the optimal outpatient management of cellulitis.

OBJECTIVES

To evaluate the feasibility of a randomized trial comparing high-dose (1000 mg) to standard-dose (500 mg) cephalexin to treat ED patients with cellulitis.

METHODS

A parallel arm double-blind randomized controlled pilot trial conducted at two EDs in Canada. Eligible participants were adults (age ≥ 18 years) presenting to the ED with non-purulent cellulitis and determined by the treating emergency physician to be eligible for outpatient management with oral antibiotics. Participants were randomized to high-dose or standard-dose cephalexin four times daily for 7 days. The primary feasibility outcome was participant recruitment rate (target ≥ 35%). The preliminary primary effectiveness outcome was oral antibiotic treatment failure.

RESULTS

Of 134 eligible participants approached for trial participation, 69 (51.5%, 95% CI 43.1 to 59.8%) were recruited and randomized. After excluding three randomized participants due to an alternate diagnosis, 33 participants were included in each arm. Nineteen eligible cases (14.2%) were missed. Loss to follow-up was 6.1%. Treatment failure occurred in four patients (12.9%) in the standard-dose arm versus one patient (3.2%) in the high-dose arm. A greater proportion had minor adverse events in the high-dose arm. No patients had an unplanned hospitalization within 14 days.

CONCLUSION

This pilot randomized controlled trial comparing high-dose to standard-dose cephalexin for ED patients with cellulitis demonstrated a high participant recruitment rate and that a full-scale trial is feasible. High-dose cephalexin had fewer treatment failures but with a higher proportion of minor adverse effects. The findings of this pilot will be used to inform the design of a future large trial.

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov (NCT04471246).

Prenatal and early childhood critical windows for the association of nephrotoxic metal and metalloid mixtures with kidney function

INTRODUCTION

As renal development and maturation processes begin in utero and continue through early childhood, sensitive developmental periods arise during which metal exposures can program subclinical nephrotoxicity that manifests later in life. We used novel dentine biomarkers of established nephrotoxicants including arsenic (As), cadmium (Cd), lead (Pb), chromium (Cr), and lithium (Li), and their mixtures, to identify critical windows of exposure-associated kidney function alterations in preadolescents.

METHODS

Participants included 353 children in the Programming Research in Obesity Growth, Environment and Social Stressors (PROGRESS) longitudinal birth cohort study based in Mexico City. Estimated glomerular filtration rate (eGFR) was assessed in 8-12 year old children using serum cystatin C measures. Pre- and postnatal metal(loid) concentrations were assessed in weekly increments by analyzing deciduous teeth with laser ablation-inductively coupled plasma-mass spectrometry. We used reverse distributed lag models (rDLMs) and lagged Weighted Quantile Sum (L-WQS) regression to examine time-varying associations between weekly perinatal metal(loid) exposure or metal(loid) mixtures and preadolescent eGFR while adjusting for age, sex, BMI z-score, SES and prenatal tobacco smoke exposure.

RESULTS

We identified a critical window of susceptibility to Pb exposure, in the late 3rd trimester (5 weeks prior to birth) during which higher Pb exposure was associated with children's increased eGFR. When all elements were assessed as a mixture, we identified late 2nd/early 3rd trimester (weeks 8-17 of gestation) as a window of vulnerability associated with decreased eGFR, with Li and Cr contributing the greatest weights to the association. When stratified by sex, we observed stronger effects among boys than girls.

CONCLUSIONS

Using tooth-matrix biomarkers, we identified discrete developmental exposure windows wherein Pb and metal(loid) mixtures were associated with altered preadolescent kidney function.

Glomerular hyperfiltration in morbid obesity: Role of the inflammasome signalling

AIM

Obesity is associated with glomerular hyperfiltration which may precede the development of overt renal damage. Few studies evaluated the link between inflammasome signalling and hyperfiltration. The aim is to evaluate the relationship between IL1-β/Caspase-1, insulin sensitivity and hyperfiltration in subjects with severe obesity, before and after weight loss.

METHODS

Forty-six patients with BMI > 35 kg/m² , without type-2-diabetes or hypertension, were evaluated at baseline and 6 months after bariatric surgery with oral glucose tollerance test, bioimpedance analysis and blood tests. The eGFR was calculated according to EPIcr-cys formula and insulin sensitivity by Oral Glucose Insulin Sensitivity. IL-1β/Caspase-1 were measured with the ELISA-kit. HF was defined as eGFR ≥ 140 ml/min (non-indexed for BSA).

RESULTS

Sixteen subjects at baseline had hyperfiltration, with a higher insulin resistance, BMI, lean mass and plasma levels of IL-1β/Caspase-1. After surgery, there was a reduction in BMI and improvement in insulin resistance in all patients. However, in 8 of 16 patients hyperfiltration persisted and IL-1β/Caspase-1 levels did not decrease (3.22 ± 0.79 vs. 3.13 ± 1.03 and 23.7 ± 12.1 vs. 20.6 ± 9.1, pre vs. post, pg/ml), while cytokines normalized in all the other patients in parallel with the eGFR. In a logistic regression model, correcting for the main covariates, lean mass and IL-1β before surgery (p = .01 and p = .03, respectively), were the only predictors of hyperfiltration.

CONCLUSION

Weight loss is effective in reducing hyperfiltration in most, but not all patients. Hyperfiltration remains unchanged in subjects who do not have a reduction in IL-1β/Caspase-1, suggesting a pathogenetic role of the inflammasome signalling in the early stages of nephropathy.

Critical windows of perinatal particulate matter (PM2.5) exposure and preadolescent kidney function

Air pollution exposure, especially particulate matter ≤2.5 μm in diameter (PM2.5), is associated with poorer kidney function in adults and children. Perinatal exposure may occur during susceptible periods of nephron development. We used distributed lag nonlinear models (DLNMs) to examine time-varying associations between early life daily PM2.5 exposure (periconceptional through age 8 years) and kidney parameters in preadolescent children aged 8-10 years. Participants included 427 mother-child dyads enrolled in the PROGRESS birth cohort study based in Mexico City. Daily PM2.5 exposure was estimated at each participant's residence using a validated satellite-based spatio-temporal model. Kidney function parameters included estimated glomerular filtration rate (eGFR), serum cystatin C, and blood urea nitrogen (BUN). Models were adjusted for child's age, sex and body mass index (BMI) z-score, as well as maternal education, indoor smoking report and seasonality (prenatal models were additionally adjusted for average first year of life PM2.5 exposure). We also tested for sex-specific effects. Average perinatal PM2.5 was 22.7 μg/m3 and ranged 16.4-29.3 μg/m3. Early pregnancy PM2.5 exposures were associated with higher eGFR in preadolescence. Specifically, we found that PM2.5 exposure between weeks 1-18 of gestation was associated with increased preadolescent eGFR, whereas exposure in the first 14 months of life after birth were associated with decreased eGFR. Specifically, a 5 μg/m3 increase in PM2.5 during the detected prenatal window was associated with a cumulative increase in eGFR of 4.44 mL/min/1.732 (95%CI: 1.37, 7.52), and during the postnatal window we report a cumulative eGFR decrease of -10.36 mL/min/1.732 (95%CI: -17.68, -3.04). We identified perinatal windows of susceptibility to PM2.5 exposure with preadolescent kidney function parameters. Follow-up investigating PM2.5 exposure with peripubertal kidney function trajectories and risk of kidney disease in adulthood will be critical.

Metabolic Syndrome Severity Score, Comparable to Serum Creatinine, Could Predict the Occurrence of End-Stage Kidney Disease in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

This study investigated whether the metabolic syndrome (MetS) severity (MSSS) at diagnosis could predict poor outcomes during follow-up in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients with MetS. The equation for the MSSS at diagnosis used in this study was developed and validated in Korean adults aged 20–59 years. The medical records of 261 patients with AAV were retrospectively reviewed, and finally, 36 AAV patients with MetS aged 20–59 years fulfilling the inclusion criteria were included in this study. All-cause mortality, relapse, end-stage kidney disease (ESKD), cerebrovascular accident, and cardiovascular disease were assessed as the poor outcomes of AAV. Their median age was 51.2 years and 36.1% were male. The MSSS was significantly correlated with age and serum albumin but not AAV-specific indices. Among the five poor outcomes, only ESKD showed a relatively significant area under the curve (area 0.696) in receiver operating characteristic curve analysis. In the multivariable Cox hazards model analysis, both serum creatinine (HR 3.033) and MSSS (HR = 2.221) were significantly associated with ESKD occurrence. When the cut-off of the MSSS for ESKD was set at 1.72, ESKD occurred more frequently in patients with MSSS ≥ 1.72 than in those with MSSS < 1.72 (75.0% versus 14.3%, p = 0.002). Furthermore, patients with MSSS ≥ 1.72 exhibited a significantly lower cumulative ESKD-free survival rate than those with MSSS < 1.72 (p = 0.001). MSSS at the time of AAV diagnosis independently predicted the occurrence of ESKD during follow-up in patients with AAV and MetS.

Obesity Related Glomerulopathy in Adolescent Women: The Effect of Body Surface Area

Background

Adolescent obesity, a risk factor for cardiorenal morbidity in adulthood, has reached epidemic proportions. Obesity-related glomerulopathy (ORG) has an early reversible stage of hyperfiltration. Age-appropriate formulae for eGFR, which are standardized to ideal body surface area (BSA) and provide assessment of kidney function in ml/min/1.73 m², may underestimate prevalence of early ORG. We investigated whether adjusting eGFR to actual BSA more readily identifies early ORG.

Methods

We studied a cohort of 22,417 young individuals, aged 12-21 years, from a New York metropolitan multi-institutional electronic health records clinical database. eGFR was calculated in two ways: BSA-standardized eGFR, and absolute eGFR. Hyperfiltration was defined above a threshold of 135 ml/min per 1.73 m² or 135 ml/min, respectively. The prevalence of hyperfiltration according to each formula was assessed in parallel to creatinine clearance.

Results

Serum creatinine values and hyperfiltration prevalence according to BSA-standardized eGFR were similar, 13%-15%, across body mass index (BMI) groups. The prevalence of hyperfiltration determined by absolute eGFR differed across BMI groups: underweight, 2%; normal weight, 6%; overweight, 17%; and obese, 31%. This trend paralleled the rise in creatinine clearance across BMI groups.

Conclusions

Absolute eGFR more readily identifies early ORG than the currently used formulae, which are adjusted to a standardized BSA and are not representative of current population BMI measures. Using absolute eGFR in clinical practice and research may improve the ability to identify, intervene, and reverse early ORG, which has great importance with increasing obesity rates.

Prenatal blood lead levels and reduced preadolescent glomerular filtration rate: Modification by body mass index

BACKGROUND

For the developing kidney, the prenatal period may represent a critical window of vulnerability to environmental insults resulting in permanent nephron loss. Given that the majority of nephron formation is complete in the 3rd trimester, we set out to test whether 1) prenatal lead exposure is associated with decreased preadolescent kidney function and 2) whether preadolescent obesity acts synergistically with early life lead exposure to reduce kidney function.

METHODS

Our study included 453 mother-child pairs participating in the PROGRESS birth cohort. We assessed prenatal blood lead levels (BLLs) in samples collected in the 2nd and 3rd trimesters and at delivery, as well as tibial and patellar bone lead measures assessed one-month postpartum. Preadolescent estimated glomerular filtration rate (eGFR) was derived from serum levels of creatinine and/or cystatin C measured at age 8-12 years. We applied linear regression to assess the relationship between prenatal bone and BLL with preadolescent eGFR, and adjusted for covariates including age, sex, BMI z-score, indoor tobacco smoke exposure, and socioeconomic status. We also examined sex-specific associations and tested for effect modification by BMI status.

RESULTS

We observed null associations between prenatal lead exposure and eGFR. However, in interaction analyses we found that among overweight children, there was an inverse association between BLL (assessed at 2nd and 3rd trimester and at delivery) and preadolescent eGFR. For example, among overweight participants, a one ln-unit increase in 2nd trimester BLL was associated with a 10.5 unit decrease in cystatin C-based eGFR (95% CI: -18.1, -2.8; p = 0.008). Regardless of lead exposure, we also observed null relationships between BMI z-score and eGFR overall, as well as among overweight participants. However, among participants with preadolescent obesity, we observed a significant 5.9-unit decrease in eGFR. We observed no evidence of sex-specific effects.

CONCLUSIONS

Our findings, if confirmed in other studies, suggest a complex interplay between the combined adverse effects of adiposity and perinatal lead exposure as they relate to adolescent kidney function. Future studies will assess kidney function and adiposity trajectories through adolescence to better understand environmental risk factors for kidney function decline.

Dietary fiber intake and urinary creatinine: methodological implications for epidemiological studies

Creatinine values are used to estimate renal function and to correct for urinary dilution in exposure assessment studies. Interindividual variability in urinary creatinine (UCR) is determined positively by protein intake and negatively by age and diabetes. These factors, among others, need to be accounted for, to increase comparability throughout epidemiological studies. Recently, dietary fiber has been shown to improve renal function. This study aims to evaluate dietary fiber intake relationship with UCR and its methodological implications for studies using UCR-corrected measurements. In a cross-sectional study, we analyzed information regarding UCR, dietary fiber, age, and other UCR-related factors in 801 women residing in Northern Mexico during 2007-2009. The median fiber intake in this population was 33.14 g/day, above the adequate intake level for women > 18 years. We estimated an age-adjusted increase of 10.04 mg/dL UCR for a 10 g/day increase in dietary fiber intake. The main dietary sources of fiber in this population were corn tortillas, raw onions, flour tortillas, and beans. Our results suggest that epidemiological studies adjusting analytes by UCR should also consider controlling dietary fiber intake to improve the comparability of creatinine-corrected values and associations across different populations, such as those in Mexico and Latin America, where protein and fiber intake vary significantly.

Anthropometric Development in Children: Possible Changes in Body Mass, Basal Metabolic Rate and Inflammatory Status

(1) Background: Worldwide, public health policies focus on studying dietary patterns and the related anthropometric changes in children. Their aim is to improve the measures meant to reduce global malnutrition rates. Our goal was to study the main changes in the inflammatory status related to anthropometric changes and total daily energy intake. (2) Methods: We tested the study hypothesis by analyzing serum IL-6 and IL-8 levels, cholesterol and triglycerides values, as well as total proteins and creatinine levels, RMR, and food journals in a sample of 160 healthy subjects aged between 6 and 12 years old. (3) Results: IL-6 was correlated with the skinfold values. Changes in the skinfolds were significantly correlated with total proteins and triglycerides. Both weight for age and height for age were related to the skinfold values. Through the BMR measurements, peak carbohydrate metabolism changed significantly based upon IL-6 values, which were significantly correlated with the respiratory coefficient values. Based on the basal metabolic rate, an increased IL-8 ratio was related to the RQ value. (4) Conclusions: Skinfolds have been significantly correlated with IL-6 and IL-8 levels. With changes in body weight, we encountered differences in both serum cholesterol and serum triglycerides values, unlike total proteins and creatinine, which failed to change.

Speed and Blood Parameters Differ between Arabian and Žemaitukai Horses during Endurance Racing

Fédération Equestre Internationale (FEI) has described equine endurance racing as the second largest discipline in the world, above which is only show jumping. The Žemaitukai is an ancient indigenous Lithuanian horse breed known since the 6th or 7th century. The Arabian horse breed is one of the oldest human-developed horse breeds in the world. Compared with other race horse breeds, the muscle tissue of Arabian horses is characterized by significant differences in structure-a predominance of oxidative fiber type I is observed in Arabians, making them the prevailing breed in endurance racing. The Arabian horses are recognized as the leading breed in endurance competitions. Speed, pace, and total time in the race strategy have been extensively studied in human sports, and in contrast, this strategy appears to have been virtually ignored in equestrian sport, despite the potential for contributing to performance optimization. In relation to speed and total time in the race, there are limited data on postrace physical, biochemical, and blood gas parameters of endurance horses. Thus, this study was carried out to investigate the effects of speed on the blood parameters of the Arabian and Žemaitukai horses during an endurance race. Blood samples were taken before and immediately after the exercise. Biochemical and blood gas indicators were analyzed. The study showed significant increases in mean blood gasometrical indicators, such as partial carbon dioxide pressure (8.09-15.18%, p < 0.001); base excess in the extracellular fluid (14.01%, p < 0.001 in the Arabian horses and 172.01% in the Žemaitukai breed, p = 0.006); decreases of the blood electrolyte ionized calcium (4.38-8.72%, p < 0.001) and the hematocrit and hemoglobin values (20.05-20.12%, p < 0.001 in the Arabian horses and 6.22-6.23% in the Žemaitukai breed, p = 0.003-0.004); and decreases in the base excess in the blood values (29.24-39.38%, p < 0.001) and lactate (13.45-31.97%, p < 0.001) in the blood of both breeds in the post-competition horses. Significant increases after competition were determined for the values of creatinine (21.34-30.82%, p = 0.001-0.004), total bilirubin (50.84-56.24%, PH < 0.001), and albumin (2.63-4.48%, p = 0.048-0.001) for both breeds. For the faster Arabian horse breed, recovering after racing took half the time that the local Žemaitukai breed did.

Renal functional impairment in the elderly, the importance of fasting plasma glucose: the Northern Shanghai Study

BACKGROUND

Chronic kidney disease is a global health problem that is closely related to the aging population. Although plasma glucose levels have been shown to be related to renal dysfunction, risk factors for renal functional impairment in the geriatric population are unknown. The authors therefore aimed to investigate the determinants of renal functional impairment in an elderly population.

METHODS

From June 2014 to August 2015, 912 participants (aged > 65 years) were recruited. Renal function was assessed at baseline; follow-up was conducted in 2016. Within the framework of comprehensive cardiovascular examinations, all conventional cardiovascular risk factors, fasting plasma glucose (FPG), and renal function were assessed. Renal function was evaluated by the estimated glomerular filtration rate (e-GFR) using a modified Modification of Diet in Renal Disease formula. Rapid decline in e-GFR was defined as an e-GFR slope > 5 mL/min per 1.73 m² per year.

RESULTS

We observed that FPG levels were significantly higher in participants with (6.15 ± 2.76 mmol/L) than in those without (5.56 ± 1.61 mmol/L) a rapid decline in e-GFR (p = 0.02). The average decline in e-GFR was 0.149 mL/min/1.73m² per year in this elderly population, and the increasing risk of having rapid decline in e-GFR was 0.44-fold each year. In the full adjustment model, decline in e-GFR (p = 0.02) and rapid decline in e-GFR (OR1.33, 95% CI 1.03-1.72) were significantly associated with FPG, independent of other conventional cardiovascular risk factors. Using the same models, decline in e-GFR (p = 0.04) and rapid decline in e-GFR (OR 1.57, 95% CI 1.05-2.35) were also significantly associated with FPG in diabetic population, but they were not in non-diabetic population.

CONCLUSIONS

In community-dwelling elderly Chinese, the average decline in e-GFR was 0.149 mL/min/1.73m² per year. FPG control is important for delaying renal functional impairment in elderly population. Trial registration NSS, NCT02368938.

Urinary bisphenol A concentrations and the risk of obesity in Korean adults

This study was aimed to evaluate the association between urinary bisphenol A (BPA) levels and risk of obesity in Korean adults. We analyzed data from the Korean National Environmental Health Survey (KoNEHS) Cycle 2 (2012–2014) and Cycle 3 (2015–2017). A total of 10,021 participants aged ≥ 19 years were included. Urine dilution was corrected by the covariate-adjusted standardization (CAS) method. We performed meta-analysis, logistic regression analysis by matching all covariates with a 1:1 propensity score, and a 4-knot restricted cubic spline plot model to calculate the odds ratios (ORs) for obesity according to natural log-transformed BPA levels. Mean urinary BPA concentration was 1.12 µg/L in KoNEHS Cycle 2 and 1.32 µg/L in Cycle 3. BPA levels were significantly higher among obese adults than among non-obese adults in both KoNEHS Cycles 2 and 3. In pooled data of KoNEHS Cycles 2 and 3, BPA showed significant positive associations with ORs for obesity in both sexes, which were more prominent in females (linear) than in males (non-linear). These associations were confirmed in spline analyses. CAS-applied BPA concentrations were positively associated with obesity in nationwide representative samples of Korean adults. Further studies are warranted to confirm and elucidate the underlying mechanism.

Relationship between butyrylcholinesterase activity and lipid parameters in workers occupationally exposed to pesticides

Exposure to organophosphate pesticides (OP) has been associated with the inhibition of cholinesterase enzymatic activity, such as butyrylcholinesterase (BuChE). Changes in BuChE activity have been associated with obesity, diabetes, hyperthyroidism, and metabolic syndrome. However, few studies have evaluated the effects of pesticides on both BuChE and lipid parameters. The aim of this study was to evaluate lipid parameters in urban sprayers and their association with BuChE activity. An analytical cross-sectional study was conducted in workers exposed to pesticides. The pesticide exposures were evaluated by the measurement of urinary dialkylphosphates. BuChE activity was determined spectrophotometrically in serum, and biochemical parameters were determined at a certified laboratory. Information regarding general characteristics, lifestyle, and other aspects was obtained from a structured questionnaire. The results showed variations in glucose, cholesterol, albumin, atherogenic index, creatinine, LDL, VLDL, triglycerides, and total lipids according to the level of exposure to pesticides in individuals with overweight and obesity. Furthermore, positive correlations between BuChE activity and lipid parameters were observed; these effects were associated with the body mass index. More studies are needed in human population to better elucidate the role of BuChE in lipid metabolism.

Association of obesity and muscle mass with risk of albuminuria in renal transplant recipients

BACKGROUND

Increased albuminuria is a predictor of graft loss in kidney graft recipients. It is unknown whether obesity is an independent risk factor for the development of increased albuminuria in this population. The aim of this study was to elucidate the association between obesity and albuminuria in renal transplant recipients.

METHODS

We enrolled 330 renal transplant recipients and prospectively collected demographic, anthropomorphic, clinical and laboratory variables susceptible to influence albumin excretion. The outcome was albuminuria, measured using accurately timed urine collections. Data from 201 patients were analyzed after exclusion of participants with missing data and patients enrolled less than 6 months since renal transplantation. Analysis was carried out for an early and a late period, defined according to the 2.4-year median follow-up time.

RESULTS

Body mass index (BMI), waist circumference and urinary creatinine excretion rate were independent predictors of albuminuria in the late post-transplant period, indicating that the predictive value of body mass index for albuminuria is related to both increased abdominal fat mass and increased muscle mass. BMI was an independent predictor of microalbuminuria. Waist circumference and urinary creatinine were independent predictors of microalbuminuria for values above certain cutoffs: 110% of the accepted thresholds defining abdominal obesity and 1500 mg/day, respectively.

CONCLUSIONS

These associations, which have not previously been reported, suggest, but do not prove, that an imbalance between metabolic demand and nephron mass may be responsible for increased albuminuria in the renal transplant population.

Renal changes and estimation of glomerular filtration rate using different equations in morbidly obese Egyptian patients

BACKGROUND AND AIMS

Obesity is a worldwide pandemic with multiple consequences including kidney affection. This study aimed to assess the effects of obesity on renal functions and to detect the most reliable formula of estimated glomerular filtration rate (eGFR) in morbidly obese patients.

METHODS

A cross-sectional, observational study was conducted on 82 morbidly obese patients. Anthropometric measurements were done for all patients and body adiposity (BAI) and visceral adiposity (VAI) indices were calculated after assessment of abdominal fat tissue analysis by computerized tomography (CT). Serum creatinine was incorporated into six different formulae of eGFR, then eGFR was compared with the 24-h measured creatinine clearance (CL_cr) values.

RESULTS

The mean body mass index was 55.8 ± 9.5 kg/m². Proteinuria and glomerular hyperfiltration (CL_cr > 130 ml/min/1.73 m²) were detected in 68.3% and 91.5% of the patients, respectively. Cockcroft-Gault formula using total (CCG-TBW-eGFR) and adjusted body water (CCG-AjBW-eGFR) had the nearest values to measured CL_Cr. These two formulae had a moderate reliability and the lowest percentage of error (30% and 23%, respectively). Visceral and total abdominal fat tissue surface area and volume assessed by CT were directly correlated to the 24-h urinary protein excretion (r = 0.32, 0.24, 0.37 and 0.34, respectively; p = 0.02, 0.03, 0.004 and 0.002, respectively).

CONCLUSIONS

Glomerular hyperfiltration and proteinuria are highly prevalent in morbidly obese patients. There is no ideal formula for GFR estimation in morbidly obese patients, however, TBW and AjBW incorporated into the Cockcroft-Gault can be helpful in those patients.

The effect of body mass index and creatinine clearance on serum trough concentration of vancomycin in adult patients

Background

The aim of this study was to evaluate the influence of patient body mass index (BMI) and estimated creatinine clearance (CrCl) on serum vancomycin concentrations to define a possible optimal dosage regimen in overweight patients based on data obtained during therapeutic drug monitoring.

Methods

This retrospective study used data collected from January 2017 to January 2019. Adult patients (n = 204) received vancomycin treatment at a dose of 1000 mg every 12 h and underwent serum monitoring. Data collected included patient disease category, sex, age, height, weight, vancomycin concentrations, and serum creatinine. The CrCl values were estimated using the Cockcroft-Gault formula. In this study, statistical comparisons were performed on the results of patients according to serum vancomycin concentration.

Results

Serum vancomycin concentration was significantly related to BMI (P <  0.001) and CrCl (P <  0.05) in adult patients. Furthermore, the trough serum vancomycin concentration showed a logarithmic correlation with BMI (R = − 0.5108, 95% CI: − 0.6082 to − 0.3982, P <  0.001) and CrCl (R = − 0.5739, 95% CI: − 0.6616 to − 0.4707, P <  0.001). The multivariate analysis showed that BMI and CrCl are independent contributors to the trough vancomycin concentration. Moreover, some of the patients with higher BMI (≥ 24 kg/m²) met the goal trough concentration after an adjustment from 1000 mg every 12 h to 1000 mg every 8 h.

Conclusions

Serum vancomycin concentration decreases progressively with increasing BMI and the augmentation in CrCl in adult patients. The trough concentration of vancomycin should be continuously monitored for patients with a BMI ≥ 24 kg/m², and the dosage regimen should be adjusted to reach the target trough concentration in these patients to reduce the impact of BMI.

High Dietary Protein Does Not Alter Renal Prostanoids and Other Oxylipins in Normal Mice or in Those with Inherited Kidney Disease

BACKGROUND

Ex vivo studies suggest that increased renal prostanoids can mediate effects of high-protein (HP) compared with low-protein (LP) diets on normal and diseased kidneys. However, a short-term HP feeding study in normal male rats failed to demonstrate higher renal prostanoids in vivo.

OBJECTIVES

The aim of the present study was to investigate whether long-term HP feeding alters renal prostanoids in male and female mice, with and without kidney disease.

METHODS

Weanling normal mice (CD1) and mice with kidney disease (CD1-pcy/pcy mice) were fed standard diets with normal protein [NP, 20% of energy (%E)] or HP (35%E) for 13 wk. Renal disease was assessed by histomorphometric analysis of cysts and fibrosis, and measurement of serum urea nitrogen (SUN) and creatinine concentrations. Targeted analysis of renal oxylipins was performed by HPLC-MS/MS.

RESULTS

The HP diet increased kidney size and water content of normal kidneys, and worsened disease in CD1-pcy/pcy mice as indicated by higher (P < 0.05) kidney weights (8-31%), water content (8-10%), cyst volume (36-60%), fibrous volume (44-53%), and SUN (47-55%). Diseased compared with normal kidneys had higher (P < 0.05) concentrations of 6 of 11 prostanoids and lower (P < 0.05) concentrations of 33 of 54 other oxylipins. This is consistent with previously known effects of dietary HP and disease effects on the kidney. However, the HP diet did not alter renal prostanoids and other renal oxylipins in either normal or diseased kidneys (P < 0.05), despite having the expected physiological effects on normal and diseased kidneys. This study also showed that females have higher concentrations of renal prostanoids [9 of 11 prostanoids higher (P < 0.05) in females], but lower concentrations of other oxylipins [28 of 54 other oxylipins lower (P < 0.05) in females].

CONCLUSIONS

The effects of HP diets on normal and diseased kidneys in CD1 and CD1-pcy/pcy mice are independent of renal oxylipin alterations.

Association of urine mitochondrial DNA with clinical measures of COPD in the SPIROMICS cohort

BACKGROUNDMitochondrial dysfunction, a proposed mechanism of chronic obstructive pulmonary disease (COPD) pathogenesis, is associated with the leakage of mitochondrial DNA (mtDNA), which may be detected extracellularly in various bodily fluids. Despite evidence for the increased prevalence of chronic kidney disease in COPD subjects and for mitochondrial dysfunction in the kidneys of murine COPD models, whether urine mtDNA (u-mtDNA) associates with measures of disease severity in COPD is unknown.METHODSCell-free u-mtDNA, defined as copy number of mitochondrially encoded NADH dehydrogenase-1 (MTND1) gene, was measured by quantitative PCR and normalized to urine creatinine in cell-free urine samples from participants in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) cohort. Urine albumin/creatinine ratios (UACR) were measured in the same samples. Associations between u-mtDNA, UACR, and clinical disease parameters - including FEV1 % predicted, clinical measures of exercise tolerance, respiratory symptom burden, and chest CT measures of lung structure - were examined.RESULTSU-mtDNA and UACR levels were measured in never smokers (n = 64), smokers without airflow obstruction (n = 109), participants with mild/moderate COPD (n = 142), and participants with severe COPD (n = 168). U-mtDNA was associated with increased respiratory symptom burden, especially among smokers without COPD. Significant sex differences in u-mtDNA levels were observed, with females having higher u-mtDNA levels across all study subgroups. U-mtDNA associated with worse spirometry and CT emphysema in males only and with worse respiratory symptoms in females only. Similar associations were not found with UACR.CONCLUSIONU-mtDNA levels may help to identify distinct clinical phenotypes and underlying pathobiological differences in males versus females with COPD.TRIAL REGISTRATIONThis study has been registered at ClinicalTrials.gov ( NCT01969344).FUNDINGUS NIH, National Heart, Lung and Blood Institute, supplemented by contributions made through the Foundation for the NIH and the COPD Foundation from AstraZeneca/MedImmune, Bayer, Bellerophon Therapeutics, Boehringer-Ingelheim Pharmaceuticals Inc., Chiesi Farmaceutici S.p.A., Forest Research Institute Inc., GlaxoSmithKline, Grifols Therapeutics Inc., Ikaria Inc., Novartis Pharmaceuticals Corporation, Nycomed GmbH, ProterixBio, Regeneron Pharmaceuticals Inc., Sanofi, Sunovion, Takeda Pharmaceutical Company, and Theravance Biopharma and Mylan.

Similarities and differences of dietary and other determinants of iodine status in pregnant women from three European birth cohorts

PURPOSE

As a component of thyroid hormones, adequate iodine intake is essential during pregnancy for fetal neurodevelopment. Across Europe, iodine deficiency is common in pregnancy, but data are lacking on the predictors of iodine status at this life stage. We, therefore, aimed to explore determinants of iodine status during pregnancy in three European populations of differing iodine status.

METHODS

Data were from 6566 pregnant women from three prospective population-based birth cohorts from the United Kingdom (ALSPAC, n = 2852), Spain (INMA, n = 1460), and The Netherlands (Generation R, n = 2254). Urinary iodine-to-creatinine ratio (UI/Creat, µg/g) was measured in spot-urine samples in pregnancy (≤ 18-weeks gestation). Maternal dietary intake, categorised by food groups (g/day), was estimated from food-frequency questionnaires (FFQs). Multivariable regression models used dietary variables (energy-adjusted) and maternal characteristics as predictors of iodine status.

RESULTS

Median UI/Creat in pregnant women of ALSPAC, INMA, and Generation R was 121, 151, and 210 µg/g, respectively. Maternal age was positively associated with UI/Creat in all cohorts (P < 0.001), while UI/Creat varied by ethnicity only in Generation R (P < 0.05). Of the dietary predictors, intake of milk and dairy products (per 100 g/day) was positively associated with UI/Creat in all cohorts [ALSPAC (B = 3.73, P < 0.0001); INMA (B = 6.92, P = 0.002); Generation R (B = 2.34, P = 0.001)]. Cohort-specific dietary determinants positively associated with UI/Creat included fish and shellfish in ALSPAC and INMA, and eggs and cereal/cereal products in Generation R.

CONCLUSIONS

The cohort-specific dietary determinants probably reflect not only dietary habits but iodine-fortification policies; hence, public-health interventions to improve iodine intake in pregnancy need to be country-specific.

Treating Patients With Locally Advanced Squamous Cell Carcinoma of the Head and Neck Unsuitable to Receive Cisplatin-Based Therapy

Concurrent chemoradiotherapy with high-dose cisplatin (100 mg/m² every 3 weeks) is the preferred regimen with curative intent for patients with unresected locally advanced squamous cell carcinoma of the head and neck (LA SCCHN). This treatment is associated with acute and late toxicities, including myelosuppression, severe nausea/vomiting, irreversible renal failure, hearing loss, and neurotoxicity. Because of cisplatin's safety profile, treatment adherence to high-dose cisplatin can be suboptimal. Patients commonly receive less than the total cumulative target dose of 300 mg/m² or the minimum recommended dose of 200 mg/m², which can have a negative impact on locoregional control and survival. Alternatively, cetuximab plus radiotherapy may be most suitable for patients at high risk of non-adherence to high-dose cisplatin. We discuss the baseline characteristics dictating the unsuitability/borderline unsuitability of cisplatin and the available alternative evidence-based treatment regimens for patients with LA SCCHN. We non-systematically reviewed published phase II and III trials and retrospective analyses of high-dose cisplatin-based chemoradiation in LA SCCHN conducted between 1987 and 2018, focusing on recent key phase III studies. We defined the baseline characteristics and associated prescreening tests to determine unsuitability and borderline unsuitability for high-dose cisplatin in combination with radiotherapy in patients with LA SCCHN. Patients with any pre-existing comorbidities that may be exacerbated by high-dose cisplatin treatment can be redirected to a non-cisplatin-based option to minimize the risk of treatment non-adherence. High-dose cisplatin plus radiotherapy remains the preferred treatment for fit patients with unresected LA SCCHN; patients who are unsuitable or borderline unsuitable for high-dose cisplatin could be identified using available tests for potential comorbidities and should be offered alternative treatments, such as cetuximab plus radiotherapy.

Urinary metabolites of organophosphate esters (OPEs) are associated with chronic kidney disease in the general US population, NHANES 2013-2014

Organophosphate esters (OPEs) have been widely used in building materials and consumer products as flame retardants and plasticizers. In vitro studies have suggested adverse effects of OPEs on the kidney. Despite accumulating evidence indicating widespread exposure to OPEs, their association with renal function in humans has not been evaluated. This study aims to investigate the association between OPEs exposure and chronic kidney disease (CKD) among the general US adult population by employing data from the US National Health and Nutrition Examination Survey (NHANES) 2013-2014. Among 1578 adults who were not currently pregnant, the associations of the urinary OPE metabolites with two CKD-related parameters, i.e., estimated glomerular filtration rate (eGFR) and albumin-to-creatinine ratio (ACR), and CKD were assessed. To account for urine dilution, in addition to conventional creatinine-adjustment, covariate-adjusted creatinine standardization, which controls for potential confounding by kidney function, was employed. Multi-pollutant models were also constructed to verify the associations observed in the models on individual OPE metabolites. The urinary bis(2-chloroethyl) phosphate (BCEP) level was negatively associated with eGFR only with the covariate-adjusted standardization method, but not with the conventional creatinine adjustment. In addition, both bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and di-n-butyl phosphate (DNBP) were positively associated with the ACR, regardless of methods of urine dilution adjustment. These three compounds were also associated with CKD. Following adjusting urine dilution with the covariate-adjusted standardization method, the association became more evident. Moreover, similar results were observed in the secondary analysis with the multi-pollutant models. Among the US general population, several OPEs were identified as potential chemical determinants of CKD. Experimental studies are warranted to understand the potential mechanisms underlying this observation.

Metabolic syndrome and extensive adipose tissue inflammation in morbidly obese Göttingen minipigs

OBJECTIVE

The worldwide prevalence of obesity has increased to 10% in men and 15% in women and is associated with severe comorbidities such as diabetes, cancer, and cardiovascular disease. Animal models of obesity are central to experimental studies of disease mechanisms and therapeutic strategies. Diet-induced obesity (DIO) models in rodents have provided important insights into the pathophysiology of obesity and, in most instances, are the first in line for exploratory pharmacology studies. To deepen the relevance towards translation to human patients, we established a corresponding DIO model in Göttingen minipigs (GM).

METHODS

Young adult female ovariectomized GM were fed a high-fat/high-energy diet for a period of 70 weeks. The ration was calculated to meet the requirements and maintain body weight (BW) of lean adult minipigs (L-GM group) or increased stepwise to achieve an obese state (DIO-GM group). Body composition, blood parameters and intravenous glucose tolerance were determined at regular intervals. A pilot chronic treatment trial with a GLP1 receptor agonist was conducted in DIO-GM. At the end of the study, the animals were necropsied and a biobank of selected tissues was established.

RESULTS

DIO-GM developed severe subcutaneous and visceral adiposity (body fat >50% of body mass vs. 22% in L-GM), increased plasma cholesterol, triglyceride, and free fatty acid levels, insulin resistance (HOMA-IR >5 vs. 2 in L-GM), impaired glucose tolerance and increased heart rate when resting and active. However, fasting glucose concentrations stayed within normal range throughout the study. Treatment with a long-acting GLP1 receptor agonist revealed substantial reduction of food intake and body weight within four weeks, with increased drug sensitivity relative to observations in other DIO animal models. Extensive adipose tissue inflammation and adipocyte necrosis was observed in visceral, but not subcutaneous, adipose tissue of DIO-GM.

CONCLUSIONS

The Munich DIO-GM model resembles hallmarks of the human metabolic syndrome with extensive adipose tissue inflammation and adipocyte necrosis reported for the first time. DIO-GM may be used for evaluating novel treatments of obesity and associated comorbidities. They may help to identify triggers and mechanisms of fat tissue inflammation and mechanisms preventing complete metabolic decompensation despite morbid obesity.

Community Water Fluoridation and Urinary Fluoride Concentrations in a National Sample of Pregnant Women in Canada

BACKGROUND

Fluoride exposures have not been established for pregnant women who live in regions with and without community water fluoridation.

OBJECTIVE

Our aim was to measure urinary fluoride levels during pregnancy. We also assessed the contribution of drinking-water and tea consumption habits to maternal urinary fluoride (MUF) concentrations and evaluated the impact of various dilution correction standards, including adjustment for urinary creatinine and specific gravity (SG).

METHODS

We measured MUF concentrations in spot samples collected in each trimester of pregnancy from 1,566 pregnant women in the Maternal-Infant Research on Environmental Chemicals cohort. We calculated intraclass correlation coefficients (ICCs) to assess variability in MUF concentrations across pregnancy. We used regression analyses to estimate associations between MUF levels, tea consumption, and water fluoride concentrations as measured by water treatment plants.

RESULTS

Creatinine-adjusted MUF values ([Formula: see text]; milligrams per liter) were almost two times higher for pregnant women living in fluoridated regions ([Formula: see text]) compared with nonfluoridated regions ([Formula: see text]; [Formula: see text]). MUF values tended to increase over the course of pregnancy using both unadjusted values and adjusted values. Reproducibility of the unadjusted and adjusted MUF values was modest ([Formula: see text]). The municipal water fluoride level was positively associated with creatinine-adjusted MUF ([Formula: see text], 95% CI: 0.46, 0.57), accounting for 24% of the variance after controlling for covariates. Higher MUF concentrations correlated with numbers of cups of black ([Formula: see text] but not green tea ([Formula: see text]). Urinary creatinine and SG correction methods were highly correlated ([Formula: see text]) and were interchangeable in models examining predictors of MUF.

CONCLUSION

Community water fluoridation is a major source of fluoride exposure for pregnant women living in Canada. Urinary dilution correction with creatinine and SG were shown to be interchangeable for our sample of pregnant women. https://doi.org/10.1289/EHP3546.

Effects of Weight Reduction After Sleeve Gastrectomy on Metabolic Variables in Saudi Obese Subjects in Aseer Province of Kingdom of Saudi Arabia

OBJECTIVES

The objectives of this study were to investigate the occurrence of oxidative stress, status of protective antioxidants enzymes, inflammatory biomarkers, and some metabolic health variables in the blood and to compare the results between those of the normal controls and obese patients submitted to sleeve gastrectomy-induced weight loss over a 1-year follow-up period.

MATERIALS AND METHODS

A prospective study was conducted in Aseer Central Hospital and Abha Private Hospital in the Kingdom of Saudi Arabia from January 2012 to January 2013 on 50 normal (BMI = 22-25 kg/m²) control subjects and 50 obese (BMI = 45-50 kg/m²) patients. A subset of 20 men and 80 women patients, aged 20-45 years, was included. The systemic blood cell counts were determined by Beckman Coulter UniCel analyzer. The occurrence of oxidative stress, the status of antioxidant enzyme system in the blood, levels of serum hepatic enzymes, cardiovascular risk factors, and serum sodium, potassium, copper, and zinc levels were determined by spectrophotometric procedures. The concentration of TSH and T₄ were analyzed by Siemens Immunoassay System.

RESULTS

Group 1 (Obese: preoperative) This group compared with the normal controls exhibited significant (p < 0.05) increase in inflammatory biomarkers, a significant (p < 0.05) rise in hepatic enzymes, a significant (p < 0.05) decrease in serum total bilirubin. Concentration of serum total cholesterol (TC), triacylglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and fasting blood glucose(FBG) were significantly (p < 0.05) increased, but HDL cholesterol (HDL-C) was significantly depleted (p < 0.05). Serum urea and creatinine contents were significantly (p < 0.05) decreased. Serum copper and zinc levels were significantly (p < 0.05) increased. Group 2: Sleeve Gastrectomy Surgery (Obese: postoperative) This group compared with the obese group, preoperatively, demonstrated a profound reduction in body weight (-32%) as well as in BMI (-29%). Serum malondialdehyde, a stress index, was significantly (p < 0.001) inhibited and conversely, activities of antioxidant enzymes: superoxide dismutase(Cu-Zn SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), glucose-6-phosphate dehydrogenase (G6PDH), and vitamin C, were remarkably (p < 0.001) increased. Furthermore, remarkable improvements in deranged metabolic variables approaching normality were discernible. Inflammatory biomarkers in the blood and hepatic enzymes in serum were significantly (p < 0.001) decreased. Levels of TC, TG, LDL-C, FBG, and HDL-C in serum exhibited significant (p < 0.05) reductions, a reversal toward normality. Serum albumin and total bilirubin concentrations were significantly increased (p < 0.001). Serum sodium, potassium, copper, zinc, and TSH levels were significantly (p < 0.001) decreased.

CONCLUSIONS

Obesity is a chronic disease of multifactorial origin and resulted in perturbations of whole body metabolism in this study. It is thus likely that this imbalance was associated with an inhibition in protective antioxidants and occurrence of oxidative stress. The staging concept of sleeve gastrectomy is a safe and effective approach with remarkable efficacy in sustaining weight loss and bringing back normal metabolism of variables in tissues over a 1-year follow-up period.

Arsenic and Obesity: A Comparison of Urine Dilution Adjustment Methods

INTRODUCTION

A commonly used approach to adjust for urine dilution in analyses of biomarkers is to adjust for urinary creatinine. However, creatinine is a product of muscle mass and is therefore associated with body mass. In studies of urinary analytes and obesity or obesity-related outcomes, controlling for creatinine could induce collider stratification bias. We illustrate this phenomenon with an analysis of urinary arsenic.

OBJECTIVE

We aimed to evaluate various approaches of adjustment for urinary dilution on the associations between urinary arsenic concentration and measures of obesity.

METHODS

Using data from the National Health and Nutrition Examination Survey, we regressed body mass index (BMI) and waist-to-height ratios on urinary arsenic concentrations. We compared eight approaches to account for urine dilution, including standardization by urinary creatinine, osmolality, and flow rates, and inclusion of these metrics as independent covariates. We also used a recently proposed method known as covariate-adjusted standardization.

RESULTS

Inverse associations between urinary arsenic concentration with BMI and waist-to-height ratio were observed when either creatinine or osmolality were used to standardize or as covariates. Not adjusting for dilution, standardizing or adjusting for urinary flow rate, and using covariate-adjusted standardization resulted in null associations observed between arsenic concentration in relation to BMI and waist-to-height ratio.

CONCLUSIONS

Our findings suggest that arsenic exposure is not associated with obesity, and that urinary creatinine and osmolality may be colliders on the causal pathway from arsenic exposure to obesity, as common descendants of hydration and body composition. In studies of urinary biomarkers and obesity or obesity-related outcomes, alternative metrics such as urinary flow rate or analytic strategies such as covariate-adjusted standardization should be considered. https://doi.org/10.1289/EHP1202.

The predictive value of ABCB1, ABCG2, CYP3A4/5 and CYP2D6 polymorphisms for risperidone and aripiprazole plasma concentrations and the occurrence of adverse drug reactions

We investigated in ninety Caucasian pediatric patients the impact of the main polymorphisms occurring in CYP3A, CYP2D6, ABCB1 and ABCG2 genes on second-generation antipsychotics plasma concentrations, and their association with the occurrence of adverse drug reactions. Patients with the CA/AA ABCG2 genotype had a statistically significant lower risperidone plasma concentration/dose ratio (Ct/ds) (P-value: 0.007) and an higher estimated marginal probability of developing metabolism and nutrition disorders as compared to the ABCG2 c.421 non-CA/AA genotypes (P-value: 0.008). Multivariate analysis revealed that the ABCG2 c.421 CA/AA genotype was found associated to a higher hazard (P-value: 0.004) of developing adverse drug reactions classified as metabolism and nutrition disorders. The ABCB1 2677TT/3435TT genotype had a statistically significant lower aripiprazole Ct/ds if compared with patients with others ABCB1 genotypes (P-value: 0.026). Information obtained on ABCB1 and ABCG2 gene variants may result useful to tailor treatments with these drugs in Caucasian pediatric patients.

Visceral Adiposity Index and Lipid Accumulation Product Index: Two Alternate Body Indices to Identify Chronic Kidney Disease among the Rural Population in Northeast China

We aimed to compare the relative strength of the association between anthropometric obesity indices and chronic kidney disease (CKD). Another objective was to examine whether the visceral adiposity index (VAI) and lipid accumulation product index (LAPI) can identify CKD in the rural population of China. There were 5168 males and 6024 females involved in this cross-sectional study, and 237 participants (2.12%) suffered from CKD. Obesity indices included body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), VAI and LAPI. VAI and LAPI were calculated with triglyceride (TG), high-density lipoprotein (HDL), BMI and WC. VAI = [WC/39.68 + (1.88 × BMI)] × (TG /1.03) × (1.31/ HDL) for males; VAI = [WC/36.58 + (1.89 × BMI)] × (TG/0.81) × (1.52/HDL) for females. LAPI = (WC-65) × TG for males, LAPI = (WC-58) × TG for females. CKD was defined as an estimated glomerular filtration rate (eGFR) of less than 60 mL/min per 1.73 m². The prevalence of CKD increased across quartiles for WHtR, VAI and LAPI. A multivariate logistic regression analysis of the presence of CKD for the highest quartile vs. the lowest quartile of each anthropometric measure showed that the VAI was the best predictor of CKD in females (OR: 4.21, 95% CI: 2.09–8.47, p < 0.001). VAI showed the highest AUC for CKD (AUC: 0.68, 95% CI: 0.65–0.72) and LAPI came second (AUC: 0.66, 95% CI: 0.61–0.70) in females compared with BMI (both p-values < 0.001). However, compared with the traditional index of the BMI, the anthropometric measures VAI, LAPI, WC, and WHtR had no statistically significant capacity to predict CKD in males. Our results showed that both VAI and LAPI were significantly associated with CKD in the rural population of northeast China. Furthermore, VAI and LAPI were superior to BMI, WC and WHtR for predicting CKD only in females.

S100A12 is up-regulated in pulmonary tuberculosis and predicts the extent of alveolar infiltration on chest radiography: an observational study

Pulmonary tuberculosis (PTB) results in lung functional impairment and there are no surrogate markers to monitor the extent of lung involvement. We investigated the clinical significance of S100A12 and soluble receptor for advanced glycation end-products (sRAGE) for predicting the extent of lung involvement. We performed an observational study in India with 119 newly diagnosed, treatment naïve, sputum smear positive, HIV-negative PTB patients and 163 healthy controls. All patients were followed-up for six months. Sociodemographic variables and the serum levels of S100A12, sRAGE, esRAGE, HMGB-1, TNF-α, IFN-γ and CRP were measured. Lung involvement in PTB patients was assessed by chest radiography. Compared with healthy controls, PTB patients had increased serum concentrations of S100A12 while sRAGE was decreased. S100A12 was an independent predictor of disease occurrence (OR 1.873, 95%CI 1.212-2.891, p = 0.004). Under DOTS therapy, S100A12 decreased significantly after 4 months whereas CRP significantly decreased after 2 months (p < 0.0001). Importantly, although CRP was also an independent predictor of disease occurrence, only S100A12 was a significant predictor of lung alveolar infiltration (OR 2.60, 95%CI 1.35-5.00, p = 0.004). These results suggest that S100A12 has the potential to assess the extent of alveolar infiltration in PTB.

Sarcopenia associated with renal function in the patients with type 2 diabetes

AIMS

Studies have suggested that low muscle mass is associated with declining renal function in healthy populations, whether the association is relevant to patients with type 2 diabetes is not well understood. This study investigates the association between sarcopenia and estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratios (UACR) in the patients with type 2 diabetes.

METHODS

Two recruited groups consisted of 793 persons without diabetes (males/females=550/243) and 762 persons with type 2 diabetes (males/females=501/261).

RESULTS

The non-sarcopenia population demonstrated higher ASM/HT(2), GFR (P<0.001) and lower UACR (P＜0.05) than the sarcopenia population. In studied men, the association between ASM/HT(2) and eGFR was statistically significant in the group without diabetes (OR=0.580, P=0.020), a trend which persisted in women (OR=0.491, P=0.014). The association between ASM/HT(2) and UACR persisted in studied women of two groups (OR=0.269, P=0.005; OR=0.405, P=0.008, respectively). The highest quartile of ASM/HT(2) in the non-sarcopenia population exhibited a 3.753-fold risk of abnormal eGFR within the diabetes group (OR=3.753, P=0.020). The cutoff point of ASM/HT(2) to indicate abnormal renal function for population with non-sarcopenia was 6.32kg/m(2) in the group without diabetes and 6.31kg/m(2) in diabetes group.

CONCLUSIONS

Sarcopenia is associated with declining renal function, which induces lower eGFR and higher UACR. In the non-sarcopenia population, ASM/HT(2) presents as renal function risk factor, which perhaps associated with higher muscle mass to induce a greater underestimation for creatinine and urinary albumin.

Anthropometric measurements and markers of renal function in adults and older adults

Objective: To determine whether anthropometric indicators are associated with markers of renal function in adults and older adults. Methods: This cross-sectional study included 279 adults and older adults attending eight primary healthcare units in eastern Goiânia, Góias. Sociodemographic, lifestyle, and clinical data were collected using a standard questionnaire. Body mass index was categorized as overweight (≥25 kg/m²) or non-overweight. Waist circumference was classified as normal or high; chronic kidney disease was defined as a glomerular filtration rate below 60 mL/minutes/1.73 m²; micro/macroalbuminuria was defined as an albumin/creatinine ratio above 30 mg/g. The association between anthropometric indicators and renal function markers was assessed by multiple linear regression analysis. Results: Chronic kidney disease was present in 8.9% and micro/macroalbuminuria in 34.8% of the sample. The prevalence of overweight was 57.0%. Waist circumference and body mass index were positively associated with glomerular filtration rate, characterized as glomerular hyperfiltration. Microalbuminuria was positively associated with body mass index in women. Conclusion: The prevalences of chronic kidney disease and overweight were high in the study population. Overweight was positively associated with glomerular filtration rate.

Lean mass modulates glomerular filtration rate in males of normal and extreme body composition

BACKGROUND

Understanding determinants of glomerular filtration rate (GFR) is important in aiding prediction and interpretation of kidney function. Body composition is known to affect GFR but is not included in current screening of kidney disease. We investigated the association between GFR and body composition in healthy young men with differing body mass but without known diabetes or kidney injury.

METHODS

Three groups were recruited: normal BMI (n = 22) with a body mass index (BMI) <25 kg/m(2) , muscular (n = 23) with BMI ≥30 kg/m(2) and bioelectrical impedance body fat ≤20% and obese (n = 22) with BMI ≥30 kg/m(2) and bioelectrical impedance body fat ≥30%. Dietary analyses, GFR clearance by (99m) Tc-DTPA, urine protein and body composition by dual-energy X-ray absorptiometry were measured in all participants. Linear and nonlinear associations of constituents of body composition with GFR were assessed.

RESULTS

Muscular men had a higher GFR (mean 186.4 mL/min; 95% CI 171.7-201.1) than normal BMI and obese groups (P = 0.0007). Urine protein and albumin excretion were not elevated in any participants. On multiple regression analysis (r(2) = 0.60), the variables with strong associations with GFR were age (P = 0.0009) and lean mass (P = 0.0001). Fat mass, protein intake and smoking status were not associated. Skeletal muscle mass correlated significantly with GFR in all subgroups.

CONCLUSION

Age and lean mass were strong determinants of GFR. Estimates of GFR should therefore be indexed to an estimate of lean mass.

Influence of body mass index status on urinary creatinine and specific gravity for epidemiological study of children

In epidemiological studies, urinary biomonitoring is a valid approach to assess the association between environmental chemical exposure and children's health. Many clinical biomarkers (e.g., endogenous metabolites) are also based on analysis of urine. Considering the variability in urinary output, urinary concentrations of chemicals are commonly adjusted by creatinine and specific gravity (SG). However, there is a lack of systematic evaluation of their appropriateness for children. Furthermore, urinary SG and creatinine excretion could be influenced by body mass index (BMI), but the effect of BMI status on the two correction factors is unknown. We measured SG and creatinine concentrations of repeated first morning urine samples collected from 243 primary school children (8-11 years) over 5 consecutive weekdays. Urinary SG presented a higher temporal consistency compared with creatinine. Urinary SG was associated with sex (p < 0.001), whereas sex (p =0.034) and BMI (p = 00.008) were associated with urinary creatinine levels. Inter-day collection time was not associated with SG or creatinine after excluding the effect of Monday as a confounder. When stratified by BMI status, none of the factors were associated with creatinine among the overweight and obese children.

CONCLUSION

Generally, SG is preferable for correcting the variability in urinary output for children although creatinine correction may also perform well in overweight and obese children. SG correction is recommended for epidemiological exposure analysis in children based on urinary levels of exogenous or endogenous metabolites.

Clinical Decision Making in a Patient with Stage 5 CKD--Is eGFR Good Enough?

The development and widespread use of serum creatinine concentration-based prediction equations to calculate eGFR have been major advances for detection of patients with CKD and the epidemiologic study of CKD and its outcomes. However, these equations as well as those that also incorporate serum cystatin C concentration provide GFR estimates that, although reasonably precise on average, can differ markedly and in clinically important ways from actual GFR. Thus, it is important that clinicians who use these equations for clinical decision-making be familiar with their strengths and weaknesses and have an appreciation of their potential for error. More precise knowledge of actual GFR is important in certain clinical circumstances, including, as presented in this Attending Rounds, patients with stage 5 CKD, in whom decisions regarding dialysis initiation are necessary. Nephrologists should have the ability to accurately determine GFR when needed if clinical circumstances suggest inaccuracy of the calculated eGFR reported by the clinical laboratory.

Therapeutic effect of continuous exercise training program on serum creatinine concentration in men with hypertension: a randomized controlled trial

BACKGROUND

Creatinine (Cr) has been implicated as an independent predictor of hypertension and exercise has been reported as adjunct therapy for hypertension. The purpose of the present study was to investigate the effect of continuous training programme on blood pressure and serum creatinine concentration in black African subjects with hypertension.

METHODS

Three hundred and fifty seven male patients with mild to moderate (systolic blood pressure [SBP] between 140-180 & diastolic blood pressure [DBP] between 90-109 mmHg) essential hypertension were age matched and randomly grouped into continuous & control groups. The continuous group involved in an 8 weeks continuous training (60-79% HR reserve) of between 45 minutes to 60 minutes, 3 times per week, while the control group remain sedentary. SBP, DBP, VO2max, serum Cr, body mass index (BMI), waist hip ratio (WHR) and percent (%) body fat. Analysis of covariance (ANCOVA) and Pearson correlation tests were used in data analysis.

RESULTS

Findings of the study revealed significant decreased effects of continuous training programme on SBP, DBP, Cr, BMI, WHR, % body fat and significant increase in VO2max at p< 0.05. Serum Cr is significantly and negatively correlated with SBP (-.335), DBP (.194), BMI (.268), WHR (-.258) and % body fat (-.190) at p<0.05.

CONCLUSION

The present study demonstrated a rationale bases for the adjunct therapeutic role of moderate intensity continuous exercise training as a multi-therapy in the down regulation of blood pressure, serum Cr, body size and body fat in hypertension.

Obesity indices and adipokines in non-diabetic obese patients with early stages of chronic kidney disease

Background

The aim of this study was to estimate obesity parameters: waist circumference (WC), waist-to-hip ratio (WHR), weight-to-height ratio (WHtR), visceral adiposity index (VAI), body adiposity index (BAI), and serum adipokines (leptin, adiponectin, resistin) and their associations with estimated glomerular filtration rate (eGFR), serum creatinine, and microalbuminuria (MA) in patients with early stages of CKD and in non-CKD obese patients.

Material/Methods

67 non-diabetic obese (BMI ≥30 mg/kg²) out-clinic patients (25 males, 42 females), aged from 36.5 to 64 years were divided into 2 groups: Group A (n=15) – patients with early stages of CKD (eGFR between 30 and 60 ml/min/1.73 m² or with MA >20 mg/l in morning urine sample independently from GFR) and Group B – patients without chronic CKD (n=52).

Results

In Group A compared to Group B, BAI and leptin were higher (42.2±7.1 vs. 37.5±7.0; p<0.05 and 51.8±26.7 ng/mL vs. 35.3±24.9 ng/mL; p<0.05; respectively) and negative correlations occurred between eGFR and BAI (r=−0.709; p=0.003), leptin (r=−0.68; p=0.005), and resistin (r=−0.528; p<0.05). In Group B, negative correlations occurred between creatinine and VAI (r=−0.332; p<0.05), BAI (r=−0.619; p<0.0001), leptin (r=−0.676; p<0.0001), and adiponectin (r=−0.423; p=0.002), and between eGFR and resistin (r=−0.276; p<0.05).

Conclusions

BAI may be a valuable obesity parameter as a predictor of early stages of CKD in patients with obesity. Leptin may be an important pathogenic factor in obese patients with early stages of CKD. Resistin is associated with eGFR in obese patients, independently of CKD.

Prevalence, risk factors, and consequences of overweight in children and adolescents who underwent renal transplantation--short- and medium-term analysis

To determine the prevalence and risk factors for (i) overweight/obesity and (ii) weight gain six months after transplantation and to study the effect of weight excess on graft function and survival. We performed a retrospective study of kidney transplanted children.

ENDPOINTS

(i) prevalence of overweight/obesity at sixth month, (ii) gaining 1.0 BMI SDS from one to six months. To study the effects of weight excess, graft function and survival at 36 months were the endpoints. The study included 197 individuals. At sixth month, 57/197 (29%) presented overweight/obesity, and the factors associated to this outcome were: (i) age at transplantation (OR = 3.04) and (ii) overweight/obesity in the first month (OR = 22.16). Groups presented no difference on graft function and survival at 36 months. From one to six months, 90/197 (46%) patients gained >1.0 BMI SDS. This outcome was associated with (i) female sex (OR = 2.50), (ii) steroids' pulses (OR = 2.98), (iii) steroids exposure (OR = 1.04), and (iv) living donor (OR = 2.69). The group that gained BMI presented a lower 36 months graft survival (86% vs. 98%, p < 0.001). Weight excess and gain after transplantation are frequent, particularly in younger female recipients and in those receiving high steroids exposure. The lower graft survival in patients with rapid weight gain deserves investigation.

Iodine deficiency among Belgian pregnant women not fully corrected by iodine-containing multivitamins: a national cross-sectional survey

Low iodine intake during pregnancy may cause thyroid dysfunction in pregnant women and their newborn. In the present study, iodine status among a nation-wide representative sample of Belgian pregnant women in the first and third trimester of pregnancy was determined, and determinants of iodine status were assessed 1 year after the introduction of bread fortified with iodised salt. The women were selected according to a multistage proportionate-to-size sampling design. Urine samples were collected and a general questionnaire was completed face to face with the study nurse. The median urinary iodine concentration (UIC) among pregnant women (n1311) was 124·1 μg/l and 122·6 μg/g creatinine when corrected for urinary creatinine. The median UIC in the first trimester (118·3 μg/l) was significantly lower than that in the third trimester (131·0 μg/l) but significantly higher than among non-pregnant women (84·8 μg/l). Iodine-containing supplement intake was reported by 60·8 % of the women and 57·4 % of the women took this supplement daily. The risk of iodine deficiency was significantly higher in younger women, in women not taking iodine-containing supplements, with low consumption of milk and dairy drinks and during autumn. Women with a higher BMI had a higher risk of iodine deficiency but the risk was lower in women who reported alcohol consumption. The median UIC during pregnancy indicates iodine deficiency in Belgium and some women are at a higher risk of deficiency. The current low iodine intake in women of childbearing age precludes the correction of iodine deficiency in pregnant women supplemented with multivitamins containing 150 μg iodine as recommended.

Effects of a food supplement rich in arginine in patients with smear positive pulmonary tuberculosis--a randomised trial

In tuberculosis (TB), the production of nitric oxide (NO) is confirmed but its importance in host defense is debated. Our aim was to investigate whether a food supplement rich in arginine could enhance clinical improvement in TB patients by increased NO production. Smear positive TB patients from Gondar, Ethiopia (n = 180) were randomized to a food supplementation rich in arginine (peanuts, equivalent to 1 g of arginine/day) or with a low arginine content (wheat crackers, locally called daboqolo) during four weeks. The primary outcome was cure rate according to the WHO classification and secondary outcomes were sputum smear conversion, weight gain, sedimentation rate, reduction of cough and chest X-ray improvement as well as levels of NO in urine (uNO) or exhaled air (eNO) at two months. There was no effect of the intervention on the primary outcome (OR 1.44, 95% CI: 0.69-3.0, p = 0.39) or secondary outcomes. In the subgroup analysis according to HIV status, peanut supplemented HIV+/TB patients showed increased cure rate (83.8% (31/37) vs 53.1% (17/32), p < 0.01). A low baseline eNO (<10 ppb) in HIV+/TB patients was associated with a decreased cure rate. We conclude that nutritional supplementation with a food supplement rich in arginine did not have any overall clinical effect. In the subgroup of HIV positive TB patients, it significantly increased the cure rate and as an additional finding in this subgroup, low initial levels of NO in exhaled air were associated with a poor clinical outcome but this needs to be confirmed in further studies.

Decreased serum creatinine concentration is associated with short telomeres of adipose tissue cells

Decreased serum creatinine concentration has been recently described to constitute a new risk factor of type 2 diabetes. Increased free radicals have been consistently associated with decreased serum creatinine and with cellular senescence. Telomere length is considered as a biological marker for senescence. We aimed to study the association of telomere length with serum creatinine. Telomere length of subcutaneous adipose tissue cells was measured in a sample of obese and nonobese subjects (n = 49). Telomere length of subcutaneous adipose tissue cells was positively associated with serum creatinine (r = 0.40, P = 0.004), i.e., the lower the telomere length, the lower the serum creatinine, but not with glomerular filtration rate (GFR). In addition, telomere length was negatively associated with BMI (r = -0.45, P = 0.001) and systolic blood pressure (r = -0.41, P = 0.003). In a multiple linear regression analysis, BMI (P = 0.005), systolic blood pressure (P = 0.01) and telomere length (P = 0.03) independently contributed to 37% of serum creatinine variance after controlling for sex and age. In conclusion, the association of serum creatinine with a marker of cellular senescence suggests an underlying mechanism influencing both decreased serum creatinine and increased risk of type 2 diabetes.

Impaired fasting glucose is associated with renal hyperfiltration in the general population

OBJECTIVE

Increased glomerular filtration rate (GFR), also called hyperfiltration, is a proposed mechanism for renal injury in diabetes. The causes of hyperfiltration in individuals without diabetes are largely unknown, including the possible role of borderline hyperglycemia. We assessed whether impaired fasting glucose (IFG; 5.6-6.9 mmol/L), elevated HbA1c, or hyperinsulinemia are associated with hyperfiltration in the general middle-aged population.

RESEARCH DESIGN AND METHODS

A total of 1,560 individuals, aged 50-62 years without diabetes, were included in the Renal Iohexol Clearance Survey in Tromsø 6 (RENIS-T6). GFR was measured as single-sample plasma iohexol clearance. Hyperfiltration was defined as GFR>90th percentile, adjusted for sex, age, weight, height, and use of renin-angiotensin system inhibitors.

RESULTS

Participants with IFG had a multivariable-adjusted odds ratio of 1.56 (95% CI 1.07-2.25) for hyperfiltration compared with individuals with normal fasting glucose. Odds ratios (95% CI) of hyperfiltration calculated for a 1-unit increase in fasting plasma glucose (FPG) and HbA1c, after multivariable-adjustment, were 1.97 (1.36-2.85) and 2.23 (1.30-3.86). There was no association between fasting insulin levels and hyperfiltration. A nonlinear association between FPG and GFR was observed (df=3, P<0.0001). GFR increased with higher glucose levels, with a steeper slope beginning at FPG≥5.4 mmol/L.

CONCLUSIONS

Borderline hyperglycemia was associated with hyperfiltration, whereas hyperinsulinemia was not. Longitudinal studies are needed to investigate whether the hyperfiltration associated with IFG is a risk factor for renal injury in the general population.

Role of lean body mass in estimating glomerular filtration rate in Alzheimer disease

BACKGROUND

The association between estimated glomerular filtration rate (eGFR) and progression of Alzheimer disease (AD), as measured by cognitive decline and brain atrophy, has been infrequently studied. Since AD is characterized by sarcopenia and other changes in body composition, which are known to influence GFR, a determination of how lean mass (LM) affects estimation of GFR in AD patients is important.

METHODS

Participants were drawn from a prospective longitudinal study of brain ageing and AD in community-dwelling individuals. Control (n = 60) and AD (n = 61) participants were enrolled. Estimated GFR was calculated using the four-variable Modification of Diet in Renal Disease (MDRD), Cockroft-Gault, Macdonald appendicular LM and Taylor LM equations. Association of eGFR with 2-year change in cognitive function and brain volume was assessed.

RESULTS

Individuals with AD demonstrated a paradoxical finding in which lower baseline MDRD eGFR was associated with less cognitive decline (P = 0.04) and brain atrophy (P = 0.02), a phenomenon not observed in non-AD controls. This finding was abolished in the AD patients when either the Macdonald appendicular LM or Taylor LM equations were used. While significant group-by-eGFR interactions were present for cognitive decline (P = 0.006) and brain atrophy (P = 0.001) when the MDRD equation was used, no group-by-eGFR interactions were present when either the Macdonald LM (P = 0.58 and P = 0.10 for cognitive decline and brain atrophy, respectively) or Taylor LM (P = 0.97 and P = 0.55) equations were used.

CONCLUSIONS

Accounting for measures of LM in GFR estimation appears to significantly mitigate counterintuitive relationships between measures of AD progression and eGFR as calculated by more traditional measures of renal function. This suggests that consideration of LM in eGFR calculations may be important in patients with sarcopenia, such as the AD population.

Bardet-Biedl syndrome highlights the major role of the primary cilium in efficient water reabsorption

Studies of the primary cilium, now known to be present in all cells, have undergone a revolution, in part, because mutation of many of its proteins causes a large number of diseases, including cystic kidney disease. Bardet-Biedl syndrome (BBS) is an inherited ciliopathy characterized, among other dysfunctions, by renal defects for which the precise role of the cilia in kidney function remains unclear. We studied a cohort of patients with BBS where we found that these patients had a urinary concentration defect even when kidney function was near normal and in the absence of major cyst formation. Subsequent in vitro analysis showed that renal cells in which a BBS gene was knocked down were unciliated, but did not exhibit cell cycle defects. As the vasopressin receptor 2 is located in the primary cilium, we studied BBS-derived unciliated renal epithelial cells and found that they were unable to respond to luminal arginine vasopressin treatment and activate their luminal aquaporin 2. The ability to reabsorb water was restored by treating these unciliated renal epithelial cells with forskolin, a receptor-independent adenylate cyclase activator, showing that the intracellular machinery for water absorption was present but not activated. These findings suggest that the luminal receptor located on the primary cilium may be important for efficient transepithelial water absorption.

Association of endocrine disruptors and obesity: perspectives from epidemiological studies

Although changes in diet and physical activity are undoubtedly key causal factors related to the increase in obesity, there is growing interest in the possibility that endocrine disrupting chemicals (EDCs) may affect obesity-related pathways by altering cell signalling involved in weight and lipid homeostasis. Proposed mechanisms that could underlie associations between EDCs and obesity include effects on thyroid and steroid hormones, and activation of peroxisome proliferator-activated receptors, which play a major role in adipocyte differentiation and energy storage. Most evidence supporting the hypothesis that EDCs affect obesity comes from laboratory studies. We summarize the limited epidemiological literature on the topic, including prospective studies of human prenatal exposure to EDCs. We also present findings from a cross-sectional study of levels of six phthalate metabolites and body mass index (BMI) and waist circumference (WC), using data from the U.S. National Health and Nutrition Examination Survey. We found positive associations between BMI and WC among adult males for most phthalate metabolites. For example, in males aged 20-59, the adjusted mean BMI across quartiles of mono-benzyl phthalate was 26.7, 27.2, 28.4, 29.0 (p-trend = 0.0002). In females, BMI and WC increased with quartiles of mono-ethyl phthalate in 12-19 year olds (adjusted mean BMI = 22.9, 23.8, 24.1, 24.7, p-trend = 0.03), and a similar but less strong pattern was seen in 20-59 year olds. By contrast, higher levels of mono-2-ethylhexyl phthalate were associated with lower BMI in adolescent girls and females aged 20-59. This exploratory analysis found several associations between phthalate metabolites and obesity, including notable differences by gender. However, the cross-sectional data are a limitation. Additional prospective studies of the association between exposures to EDCs, especially during development, and obesity are warranted. As this field of research advances, there are challenging methodological questions that must be considered by both epidemiologists and toxicologists.