Obesity and kidney disease: hidden consequences of the epidemic

The evaluation of kidney function estimation during lifestyle intervention in children with overweight and obesity

BACKGROUND

Children with overweight and obesity are at risk for developing chronic kidney disease (CKD). During lifestyle adjustment, the first step in the treatment of childhood obesity, body proportions are likely to change. The aim of this study was to examine how lifestyle intervention affects creatinine-based kidney function estimation in children with overweight and obesity.

METHODS

This longitudinal lifestyle intervention study included 614 children with overweight and obesity (mean age 12.17 ± 3.28 years, 53.6% female, mean BMI z-score 3.32 ± 0.75). Loss to follow-up was present: 305, 146, 70, 26, and 10 children were included after 1, 2, 3, 4, and 5 (about yearly) follow-up visits, respectively. Serum creatinine (SCr) was rescaled using Q-age and Q-height polynomials.

RESULTS

At baseline, 95-97% of the children had a SCr/Q-height and SCr/Q-age in the normal reference range [0.67-1.33]. SCr/Q significantly increased each (about yearly) follow-up visit, and linear mixed regression analyses demonstrated slopes between 0.01 and 0.04 (corresponding with eGFR FAS reduction of 1.1-4.1 mL/min/1.73 m2) per visit. BMI z-score reduced in both sexes and this reduction was significantly higher in males. No correlation between change in rescaled SCr and BMI z-score reduction could be demonstrated.

CONCLUSIONS

Rescaled serum creatinine (SCr/Q) slightly increases during multidiscipline lifestyle intervention in this cohort of children with overweight and obesity. This effect seems to be independent from change in BMI z-score. Whether this minor decrease in estimated kidney function has clinical consequences in the long term remains to be seen in trials with a longer follow-up period.

CLINICAL TRIAL REGISTRATION

ClinicalTrial.gov; Registration Number: NCT02091544.

Mediterranean diet in the management and prevention of obesity

The current pandemic of obesity represents a major global public health problem, mainly due to its association with chronic non-communicable disabling conditions and with increased mortality. Population aging increases the chances of non-communicable chronic diseases allowing a longer exposure to risk factors for these disabling conditions. Obesity is a major risk factor contributing to pathological aging. Numerous epidemiological studies have shown that the risk of death due to cardiovascular disease and cancer increases progressively as overweight and obesity rise. Nutrition research is now focused on the effects of combinations of foods in dietary patterns instead of those of single nutrients or foods. The dietary model with the largest body of evidence of health benefit is that traditionally followed by inhabitants of some Mediterranean countries. There is evidence confirming the inverse association of adhering to Mediterranean diet with overweight and obesity. Four meta-analyses of randomized controlled trials, including up to 16 trials, have shown a greater reduction of body weight and BMI with MedDiet compared to other diets, while a meta-analysis of 7 prospective cohort studies, found a reduced risk of becoming obese and gaining weight over time associated with a higher adherence to MedDiet. This narrative review examines studies reporting inverse associations of a higher adherence to the MedDiet with overweight/obesity and with age-associated chronic diseases related to obesity.

Determinants of hypertension in Nepal using odds ratios and prevalence ratios: an analysis of the Demographic and Health Survey 2016

This cross-sectional study investigated the factors associated with hypertension among Nepalese adults aged 18 years or above using data from the Nepal Demographic and Health Survey 2016. Prevalence ratios (PRs) and odds ratios (ORs) were obtained using log-binomial regression and logistic regression, respectively. Initially, unadjusted PRs and ORs were obtained. The variables that yielded a significance level below 0.2 in unadjusted analyses were included in the multivariable analysis. The overall prevalence of hypertension among the 13,393 participants (58% male and 61.2% urban) was 21.1% (n = 2827). In the adjusted analysis, those aged 30-49 years (adjusted PR [APR]: 3.1, 95% Confidence Interval (CI): 2.6, 3.7; adjusted OR [AOR]: 3.6, 95% CI: 2.9, 4.5), 50-69 years (APR: 5.3, 95% CI: 4.4, 6.6; AOR: 8.2, 95% CI: 6.4, 10.4) and ≥70 years (APR: 7.3, 95% CI: 5.8, 9.2; AOR: 13.6, 95% CI: 10.1, 18.3) were more likely to be hypertensive than younger participants aged 18-29 years. Males (APR: 1.3, 95% CI: 1.2, 1.4; AOR: 1.5, 95% CI: 1.3, 1.7), overweight/obese participants (APR: 1.8, 95% CI: 1.7, 2.0; AOR: 2.4, 95% CI: 2.2, 2.8) and those in the richest wealth quintile (APR: 1.3, 95% CI: 1.1, 1.5; AOR: 1.5, 95% CI: 1.1, 1.9) had higher prevalences and odds of hypertension than their female, normal weight/underweight and poorest wealth quintile counterparts, respectively. Those residing in Province 4 (APR: 1.2, 95% CI: 1.0, 1.5; AOR: 1.4, 95% CI: 1.1, 1.8) and Province 5 (APR: 1.2, 95% CI: 1.0, 1.4; AOR: 1.3, 95% CI: 1.1, 1.7) were more likely to be hypertensive than those residing in Province 1. The point estimate was inflated more in magnitude by ORs than by PRs, but the direction of association remained the same. Public health programmes in Nepal aimed at preventing hypertension should raise awareness among the elderly, males, individuals in the richest wealth quintile and the residents of Provinces 4 and 5.

Systematic Investigation of the Effects of Long-Term Administration of a High-Fat Diet on Drug Transporters in the Mouse Liver, Kidney and Intestine

BACKGROUND

Long-term intake of a high-fat diet is a crucial factor contributing to obesity, which has become a global public health problem. Progressive obesity subsequently leads to hepatic injury, renal damage and intestinal atrophy. Transporters expressed in the liver, kidney and intestine play important roles in the deposition of nutrients and drugs, but researchers have not clearly determined whether/how the expression of transporters changes after long-term administration of a High-Fat Diet (HFD). This study aims to explore the effects of the long-term administration of a HFD on the expression of drug transporters in the liver, kidney and intestine in mice and to provide useful information for medical applications in the clinic.

METHODS

Male C57BL/6J mice were fed either a basal diet or HFD for 24 weeks, and oral glucose tolerance tests were performed after 3, 11 and 23 weeks. Serum was obtained to measure lipid metabolism, inflammatory mediators, renal function and hepatic function. Adipose tissues, kidney, pancreas and liver were collected for hematoxylin and eosin (H&E) staining after 4, 12 and 24 weeks. The mRNA and proteins expression of drug transporters in the liver, kidney and intestine were detected using real-time PCR and western blot, respectively.

RESULTS

Compared with the control group, long-term HFD administration significantly increased the adipose index. The serum lipid levels, including Total Cholesterol (TC), Triglyceride (TG), and Low-Density Lipoprotein Cholesterol (LDL-C), as well as the levels of the inflammatory cytokines Interleukin-10 (IL-10) and tumor necrosis factor-α (TNF-α) were significantly elevated in HFD-induced obese mice. H&E staining revealed pathological changes in the adipose cells, liver, kidney and pancreas from the obese group following the long-term administration of the HFD. The liver of the obese group presented increased mRNA expression of the efflux transporter Mrp2 and uptake transporter Oat2 at 24 weeks. The relative expression of Oat2 increased 4.08-fold and the protein expression of Oat2 was upregulated at 24 weeks in HFD-fed mice, while the mRNA expression of the uptake transporters Oct1, Oatp1b2 and Oatp1a4 decreased by 79%, 61% and 19%, respectively. The protein expression of Oct1 was significantly downregulated in obese mice at 12 weeks. The mRNA expression of the efflux transporter Mdr1a was significantly reduced in HFD-fed mice compared with the control group at 24 weeks. Western blot showed that the trend of protein level of Mdr1 was consistent with the mRNA expression. In the kidney, the level of the Oct2 mRNA increased 1.92- and 2.46-fold at 4 and 12 weeks in HFD-fed mice, respectively. The expression of the Oat1 and Oat3 mRNAs was markedly downregulated in the kidneys of mice with HFD-induced obesity at 4 weeks. The decrease of 72% and 21% in Mdr1a mRNA expression was observed in the obese model at 4 weeks and 12 weeks, respectively. Western blot showed that the protein levels of Mdr1 and Oat1 were consistent with the mRNA expression. The qPCR experiments showed a 2.87-fold increase in Bcrp mRNA expression at 24 weeks, and the expression of the Pept1 mRNA increased 2.84-fold in intestines of obese mice subjected to long-term administration of the HFD compared with control mice at 12 weeks. Western blot showed that the trend of protein levels of Mdr1 and Mrp2 were consistent with the mRNA expression.

CONCLUSION

The expression of uptake and efflux transporters mRNAs and protein levels were altered in obese mice compared with control mice, providing scientific evidence for future medical applications in the clinic.

Augmented renal clearance in pediatric intensive care: are we undertreating our sickest patients?

Many critically ill patients display a supraphysiological renal function with enhanced renal perfusion and glomerular hyperfiltration. This phenomenon described as augmented renal clearance (ARC) may result in enhanced drug elimination through renal excretion mechanisms. Augmented renal clearance seems to be triggered by systemic inflammation and therapeutic interventions in intensive care. There is growing evidence that ARC is not restricted to the adult intensive care population, but is also prevalent in critically ill children. Augmented renal clearance is often overlooked due to the lack of reliable methods to assess renal function in critically ill children. Standard equations to calculate glomerular filtration rate (GFR) are developed for patients who have a steady-state creatinine production and a stable renal function. Those formulas are not reliable in critically ill patients with acutely changing GFR and tend to underestimate true GFR in patients with ARC. Tools for real-time, continuous, and non-invasive measurement of fluctuating GFR are most needed to identify changes in kidney function during critical illness and therapeutic interventions. Such devices are currently being validated and hold a strong potential to become the standard of practice. In the meantime, urinary creatinine clearance is considered the most reliable method to detect ARC in critically ill patients. Augmented renal clearance is clearly associated with subtherapeutic antimicrobial concentrations and subsequent therapeutic failure. This warrants the need for adjusted dosing regimens to optimize pharmacokinetic and pharmacodynamic target attainment. This review aims to summarize current knowledge on ARC in critically ill children, to give insight into its possible pathophysiological mechanism, to evaluate screening methods for ARC in the pediatric intensive care population, and to illustrate the effect of ARC on drug exposure, therapeutic efficacy, and clinical outcome.