The link between the renin-angiotensin-aldosterone system and renal injury in obesity and the metabolic syndrome

Fructooligosaccharides Ameliorate Renal Injury and Dysfunction Through the Modulation of Gut Dysbiosis, Inhibition of Renal Inflammation, Oxidative Stress, Fibrosis, and Improve Organic Anion Transporter 3 Function in an Obese Rat Model

SCOPE

High-fat diet (HFD) consumption causes obesity and gut dysbiosis which induces kidney injury. It has been reported that prebiotics improve gut dysbiosis and insulin sensitivity and decelerate the progression of kidney disease. This study investigates the impact of fructooligosaccharides (FOS) on renoprotection and the prevention of gut dysbiosis and intestinal barrier injury in obese rats.

METHODS AND RESULTS

Wistar rats are treated with HFD for 16 weeks. Then, the HFD fed rats (HF) are given FOS 1 g day-1 (HFFOS1), 2 g day-1 (HFFOS2), or metformin 30 mg kg-1 day-1 (HFMET), by intragastric feeding for 8 weeks. Blood, urine, feces, kidney, and intestine are collected to determine the metabolic changes, gut dysbiosis, and the expression of proteins involved in kidney and intestinal injury. FOS can attenuate insulin resistance and hypercholesterolemia concomitant with the inhibition of renal inflammation, oxidative stress, fibrosis, and apoptosis, which are related to the deceleration of the overexpression of renal Toll-like receptor 4 (TLR4) and NADPH oxidase (NOX4). Moreover, FOS shows a greater efficacy than metformin in the reduction of the intestinal injury and loss of tight junction proteins induced by HFD.

CONCLUSION

FOS may be used as a supplement for therapeutic purposes in an obese condition to improve intestinal integrity and prevent renal complications.

Malnutrition management in children with chronic kidney disease

Chronic kidney disease (CKD) encompasses diverse conditions such as congenital anomalies, glomerulonephritis, and hereditary nephropathies, necessitating individualized nutritional interventions. Early detection is pivotal due to the heightened risk of adverse outcomes, including compromised growth and increased healthcare costs. The nutritional assessment in pediatric CKD employs a comprehensive, multidisciplinary approach, considering disease-specific factors, growth metrics, and dietary habits. The prevalence of malnutrition, as identified through diverse tools and guidelines, underscores the necessity for regular and vigilant monitoring. Nutritional management strategies seek equilibrium in calorie intake, protein requirements, and electrolyte considerations. Maintaining a well-balanced nutritional intake is crucial for preventing systemic complications and preserving the remaining kidney function. The nuanced landscape of enteral nutrition, inclusive of gastrostomy placement, warrants consideration in scenarios requiring prolonged support, with an emphasis on minimizing risks for optimized outcomes. In conclusion, the ongoing challenge of managing nutrition in pediatric CKD necessitates continuous assessment and adaptation. This review underscores the significance of tailored dietary approaches, not only to foster growth and prevent complications but also to enhance the overall quality of life for children grappling with CKD.

Blood pressure responses to testosterone therapy are amplified by hematocrit levels in opioid-induced androgen deficiency: a double-blind, randomized, placebo-controlled trial

Our study aimed to examine the effect of testosterone replacement therapy (TRT) on blood pressure in opioid-treated men with relative hypogonadism, and whether the effect of TRT on blood pressure was modified by body composition, red blood cell levels, or carotid intima media thickness. Men (over 18 years old) receiving opioid treatment and total testosterone less than 12 nmol were randomly assigned to receive either TRT or placebo. Baseline and 6-month measurements included anthropometric measurements, office blood pressure (OBPM), 24-h ambulatory blood pressure, blood samples, and carotid ultrasound. The mean systolic OBPM increased by 6.2 mmHg (0.2-12.1) in the TRT group and decreased by 7.0 mmHg (1.0-15.1) in the placebo group, with a mean difference of 13.2 mmHg (3.4-23.1), P  = 0.01. In the TRT group, a 10 mmHg increase in systolic OBPM was associated with an increase in hematocrit of 0.3% points (0.1-0.5) ( P  = 0.01), whereas no association was observed in the placebo group ( P  = 0.266). Daytime SBP showed a nonsignificant increase of 5.2 mmHg (-1.7, 12.1) ( P  = 0.134) in the TRT group compared to that in the placebo group. However, the impact of TRT on the increase in daytime ambulatory blood pressure was significantly accentuated by baseline values of BMI, hematocrit, and hemoglobin. In conclusion, TRT was associated with higher OBPM compared to placebo, and the increase in blood pressure was linked to higher hematocrit during TRT. Our data suggest that men with opioid-induced androgen deficiency, particularly those with obesity or red blood cell levels in the upper normal range, are more susceptible to increased daytime SBP during TRT.

Identification, rapid screening, docking mechanism and in vitro digestion stability of novel DPP-4 inhibitory peptides from wheat gluten with ginger protease

To better understand the hypoglycemic potential of wheat gluten (WG), we screened dipeptidyl peptidase IV (DPP-4) inhibitory active peptides from WG hydrolysates. WG hydrolysates prepared by ginger protease were found to have the highest DPP-4 inhibitory activity among the five enzymatic hydrolysates, from which a 1-3 kDa fraction was isolated by ultrafiltration. Further characterization of the fraction with nano-HPLC-MS/MS revealed 1133 peptides. Among them, peptides with P'2 (the second position of the N-terminal) and P2 (the second position of the C-terminal) as proline residues (Pro) accounted for 12.44% and 43.69%, respectively. The peptides including Pro-Pro-Phe-Ser (PPFS), Ala-Pro-Phe-Gly-Leu (APFGL), and Pro-Pro-Phe-Trp (PPFW) exhibited the most potent DPP-4 inhibitory activity with IC50 values of 56.63, 79.45, and 199.82 μM, respectively. The high inhibitory activity of PPFS, APFGL, and PPFW could be mainly attributed to their interaction with the S2 pocket (Glu205 and Glu206) and the catalytic triad (Ser630 and His740) of DPP-4, which adopted competitive, mixed, and mixed inhibitory modes, respectively. After comparative analysis of PPFS, PPFW, and PPF, Ser was found to be more conducive to enhancing the DPP-4 inhibitory activity. Interestingly, peptides with P2 as Pro also exhibited good DPP-4 inhibitory activity. Meanwhile, DPP-4 inhibitory peptides from WG showed excellent stability, suggesting a potential application in type 2 diabetes (T2DM) therapy or in the food industry as functional components.

Obesity in Hypertensive Patients Is Characterized by a Dawn Phenomenon in Systolic Blood Pressure Values and Variability

One of the causes of hypertension is excess weight gain, which can also affect the course of this disease. Both the diagnosis and management of hypertension commonly use ambulatory blood pressure monitoring; the results of which correlate more strongly with cardiovascular diseases and cardiovascular death than office blood pressure monitoring. We evaluated blood pressure values and their variability from hour to hour to see if and when they differed between hypertensive patients with and without obesity. The study included 1345 patients who underwent 24 h ambulatory blood pressure monitoring and then were divided into groups according to body mass index and waist circumference. The obtained data were analyzed according to the subjects' wake-up time, and short-term blood pressure variability parameters were calculated as the mean of the absolute values of the differences between consecutive measurements. The systolic blood pressure in obese subjects was significantly higher between 1 and 5 h before waking than in normal-weighted individuals. In turn, the variability in systolic and diastolic blood pressure was higher with increasing body mass index. The difference in systolic blood pressure values and blood pressure variability was most prominent in the last 5 h of sleep in obese patients.

Protective effect of moringa seed extract on kidney damage in rats fed a high-fat and high-fructose diet

Objective

Moringa is a common plant that contains high levels of antioxidants. In this study, we aimed to analyze the protective effect of moringa seed extract on the kidneys of a rat model maintained on a high-fat and high-fructose (HFHF) diet.

Methods

An experiment with a pretest-posttest control group design was used to measure metabolic parameters and determine kidney function, while a posttest-only method was used for the control group to determine glomerular volume and superoxide dismutase (SOD) expression. Purposive sampling was used on 28 rats divided into four groups: a control (K1) group, and three groups fed a HFHF diet for 53 days (K2, K3, and K4). Subsequently, K3 and K4 were given 150 and 200 mg/kg BW per day moringa seed extract for 28 days. Data were analyzed using IBM® SPSS® Statistics version 22 software.

Results

Analysis showed that the diet increased the risk of metabolic syndrome, as evidenced by weight gain, glucose, and triglycerides. The optimal dose of moringa seed extract significantly improved glomerular volume (p = 0.001). The expression of SOD in kidney tubules and glomeruli was significantly different with each group (p = 0.002 and p = 0.001) respectively.

Conclusion

The administration of moringa seed extract provided a protective effect on the kidney by reducing serum creatinine levels, improving overall structure, and increasing the expression of SOD, a key antioxidant.

Exosomal microRNAs: potential nanotherapeutic targets for diabetic kidney disease

Diabetic kidney disease (DKD) is a primary cause for end-stage renal disease, but no specific therapeutic approaches exist. Exosomal miRNAs, a key functional cargo of nanovesicles, play crucial roles in the pathophysiological processes of DKD. Exosomal miRNAs are involved in cell-to-cell transfer of biological information, mediating nephritic inflammation, oxidative stress, apoptosis, autophagy, epithelial-mesenchymal transition and fibrosis. Circulating exosomal miRNAs derived from urine or serum might function as noninvasive prognostic biomarkers for DKD. Exosomal miRNAs from stem cells have been reported to exert beneficial effects on diabetic kidneys, which suggests that these exosomes might function as potential nanotherapy tools for treating DKD. In this review, we have summarized recent studies based on the association between exosomal miRNAs and DKD.

The Relationship between Renin-Angiotensin-Aldosterone System (RAAS) Activity, Osteoporosis and Estrogen Deficiency in Type 2 Diabetes

Type 2 diabetes (T2D) is associated with a plethora of comorbidities, including osteoporosis, which occurs due to an imbalance between bone resorption and formation. Numerous mechanisms have been explored to understand this association, including the renin-angiotensin-aldosterone system (RAAS). An upregulated RAAS has been positively correlated with T2D and estrogen deficiency in comorbidities such as osteoporosis in humans and experimental studies. Therefore, research has focused on these associations in order to find ways to improve glucose handling, osteoporosis and the downstream effects of estrogen deficiency. Upregulation of RAAS may alter the bone microenvironment by altering the bone marrow inflammatory status by shifting the osteoprotegerin (OPG)/nuclear factor kappa-Β ligand (RANKL) ratio. The angiotensin-converting-enzyme/angiotensin II/Angiotensin II type 1 receptor (ACE/Ang II/AT1R) has been evidenced to promote osteoclastogenesis and decrease osteoblast formation and differentiation. ACE/Ang II/AT1R inhibits the wingless-related integration site (Wnt)/β-catenin pathway, which is integral in bone formation. While a lot of literature exists on the effects of RAAS and osteoporosis on T2D, the work is yet to be consolidated. Therefore, this review looks at RAAS activity in relation to osteoporosis and T2D. This review also highlights the relationship between RAAS activity, osteoporosis and estrogen deficiency in T2D.

Effects of garlic supplementation on components of metabolic syndrome: a systematic review, meta-analysis, and meta-regression of randomized controlled trials

BACKGROUND

Garlic (Allium sativum), the underground bulb of the Allium genus, has been consumed on Earth for thousands of years. Many clinical trials of garlic supplementation on components of metabolic syndrome (MetS) have emerged in recent years, but there is no consensus on the effect. This meta-analysis aimed at systematically evaluating the effect of garlic supplementation on components of MetS.

METHODS

In this meta-analysis, we searched Pubmed, Embase, Cochrane, Medline, Web of Science databases, and clinical trials online sites from inception to November 1, 2022, with language restrictions to English. We engaged participants > 18 years and eligible for the clinical diagnosis of MetS or those with metabolic disorders and garlic was the only intervention. Outcomes included waist circumference, and body mass index, triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, blood pressure, and fasting blood glucose. Meta-regression and subgroup analyses were conducted based on six covariates (total sample size, the mean age, the mean dose, the duration of intervention, the oral form of garlic, and the dietary intervention).

RESULTS

Results from 19 RCTs were included engaging 999 participants. Compared to placebo, garlic significantly reduced TG [SMD (95%CI) = -0.66 (-1.23, -0.09)], TC [SMD (95%CI) = -0.43 (-0.86, -0.01)], LDL [SMD (95%CI) = -0.44(-0.88, -0.01)], DBP [SMD (95%CI) = -1.33 (-2.14, -0.53)], BMI [SMD (95%CI) = -1.10(-1.90, -0.20)], and WC [SMD (95%CI) = -0.78(-1.09, -0.47)]. Meta-regression showed age and sample size are potential effect modifiers.

CONCLUSION

According to the results of meta-analysis, the modulatory effect of garlic on some MetS components is evident. More high-quality, large-scale RCTs are needed to confirm iat based on the high heterogeneity and potential publication bias of the current data.

TRIAL REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=373228 , ID: CRD42022373228.

A metabolic blueprint of COVID-19 and long-term vaccine efficacy

Viruses are obligatory protein-coated units and often utilize the metabolic functions of the cells they infect. Viruses hijack cellular metabolic functions and cause consequences that can range from minor to devastating, as we have all witnessed during the COVID-19 pandemic. For understanding the virus-driven pathogenesis and its implications on the host, the cellular metabolism needs to be elucidated. How SARS-CoV-2 triggers metabolic functions and rewires the metabolism remains unidentified but the implications of the metabolic patterns are under investigation by several researchers. In this review, we have described the SARS-CoV-2-mediated metabolic alterations from in vitro studies to metabolic changes reported in victims of COVID-19. We have also discussed potential therapeutic targets to diminish the viral infection and suppress the inflammatory response, with respect to evidenced studies based on COVID-19 research. Finally, we aimed to explain how we could extend vaccine-induced immunity in people by targeting the immunometabolism.

Perindopril prevents development of obesity and hypertension in middle aged diet-induced obese rat models of metabolic syndrome

AIMS

The therapeutic properties of anti-hypertensive medications that extend beyond blood pressure lowering have started to become important clinical targets in recent years. This study aimed to assess the cardioprotective effects of perindopril in attenuating complications associated with metabolic syndrome in diet induced obese rats.

MAIN METHODS

Male Wistar-Kyoto (WKY) rats aged 16 weeks were fed either standard rat chow (SC) or given a high-fat-high-carbohydrate (HFHC) diet for 20 weeks. Perindopril treatment (1 mg/kg/day) was administered to a subset of WKY rats commencing at week 8 of the 20 week HFHC feeding period. Body weights, food, water and energy intakes, blood pressure, heart rate and glucose tolerance were measured throughout the treatment period. Oxidative stress and inflammatory markers, lipid levels, cardiac collagen deposition, vascular function, aortic and cardiac electrical function were examined after the treatment.

KEY FINDINGS

WKY rats developed metabolic syndrome after 20 weeks of HFHC feeding, evidenced by the presence of abdominal obesity, dyslipidaemia, glucose intolerance and hypertension. Perindopril treatment prevented the development of obesity and hypertension in WKY-HFHC. Perindopril improved blood lipid profiles in HFHC rats with decreases in LDL cholesterol, triglycerides and total cholesterol. Type I collagen levels were decreased in WKY-HFHC rats along with decreases in left ventricle mass. Perindopril treated rats also showed improved cardiac electrical function indicated by decreases in action potential at 90 % of repolarisation in WKY-HFHC rats.

SIGNIFICANCE

These results show that perindopril has a profound effect on preventing the development of metabolic syndrome in animals fed a HFHC diet.

The association between obesity and vitamin D deficiency modifies the progression of kidney disease after ischemia/reperfusion injury

Acute kidney injury (AKI) alters renal hemodynamics, leading to tubular injury, activating pathways of inflammation, proliferation, and cell death. The initial damage caused to renal tissue after an ischemia/reperfusion (I/R) injury exerts an important role in the pathogenesis of the course of AKI, as well as in the predisposition to chronic kidney disease. Vitamin D deficiency has been considered a risk factor for kidney disease and it is associated with tubulointerstitial damage, contributing to the progression of kidney disease. Obesity is directly related to diabetes mellitus and hypertension, the main metabolic disorders responsible for the progression of kidney disease. Furthermore, the expansion of adipose tissue is described as an important factor for increased secretion of pro-inflammatory cytokines and their respective influence on the progression of kidney disease. We aimed to investigate the influence of vitamin D deficiency and obesity on the progression of renal disease in a murine model of renal I/R. Male Wistar rats underwent renal I/R surgery on day 45 and followed until day 90 of the protocol. We allocated the animals to four groups according to each diet received: standard (SD), vitamin D-depleted (VDD), high fat (HFD), or high fat vitamin D-depleted (HFDV). At the end of 90 days, we observed almost undetectable levels of vitamin D in the VDD and HFDV groups. In addition, HFD and HFDV groups presented alterations in the anthropometric and metabolic profile. The combination of vitamin D deficiency and obesity contributed to alterations of functional and hemodynamic parameters observed in the HFDV group. Moreover, this combination favored the exacerbation of the inflammatory process and the renal expression of extracellular matrix proteins and phenotypic alteration markers, resulting in an enlargement of the tubulointerstitial compartment. All these changes were associated with an increased renal expression of transforming growth factor β and reduced expression of the vitamin D receptor. Our results show that the synergistic effect of obesity and vitamin D deficiency exacerbated the hemodynamic and morphological changes present in the evolution of renal disease induced by I/R.

Proteinuria as a Nascent Predictor of Frailty Among People With Metabolic Syndrome: A Retrospective Observational Study

Frailty is a commonly occurring geriatric condition that increases the risk of adverse health outcomes. The factors and predictors behind frailty are not yet well understood. A better understanding of these factors can enable prevention of frailty in elderly patients. The objective of this study was to determine the association between proteinuria and frailty in US individuals with metabolic syndrome (MetS). Data from the National Health and Nutrition Examination Survey III (NHANES III, 1988–1994) conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention. This is a cross-sectional study, and proteinuria and frailty were measured only once at enrollment. The study included 2,272 participants with MetS aged 40–90 years from the NHANES III. The participants underwent assessments to evaluate frailty and frailty components (low body weight, weakness, exhaustion, low physical activity, and slow walking). Proteinuria was represented as albumin-to-creatinine ratio (ACR) (mg/g) and divided into tertiles: T1-normal range (ACR <30 mg/g), T2-microalbuminuria (ACR 30–299 mg/g), and T3-macroalbuminuria (ACR ≥ 300 mg/g). We applied multiple logistic regression to determine the odds ratios (ORs) of frailty for T2 vs. T1 and T3 vs. T1 in both sexes. In the adjusted analysis for male participants, the ORs of frailty for T2 and T3 vs. T1 were 3.106 (95% confidence interval [CI] = 1.078–8.948, P = 0.036) and 14.428 (95% CI = 4.231–49.193, P < 0.001), respectively. For female participants, the ORs of frailty for T2 and T3 vs. T1 were 1.811 (95% CI = 1.071–3.063, P = 0.027) and 2.926 (95% CI = 1.202–7.124, P = 0.018), respectively. The positive association between T2 and T3 vs. T1, and frailty were statistically significant. The trends of higher likelihood of every frailty component were also statistically significant across increasing tertiles of proteinuria after multiple levels of adjustment for covariates (P < 0.05). Increased proteinuria levels were positively associated with frailty and each frailty component. Proteinuria might be a useful maker for frailty in individuals with MetS.

A high triglyceride glucose index is associated with early renal impairment in the hypertensive patients

OBJECTIVE

Serum β2-microglobulin (β2-MG) and serum cystatin C (CysC) are sensitive and reliable indicators of early renal impairment. Triglyceride glucose index (TyG) is an emerging vital indicator of insulin resistance and is associated with increased risk of hypertension. We aimed to analyze the relationship between TyG and early renal impairment in hypertensive patients.

METHODS

A retrospective analysis was performed on 881 hypertensive patients treated in Qinghai Provincial People, s Hospital from March 2018 to March 2021, their clinical data and corresponding laboratory index values were recorded, and the TyG index was calculated. According to the TyG index, the patients were divided into a low TyG (L-TyG) group (TyG ≤ 8.50, n=306), medium TyG (M-TyG) group (8.51≤TyG ≤ 8.94, n=281), and high TyG (H-TyG) group (TyG>8.95, n=294) in sequence by using tertiles. Then, according to serum β2-MG and CysC levels, they were divided into a normal renal function group (β2-MG ≤ 2.4 mg/L, n=700 and CysC ≤ 1.25mg/L, n=721) and a renal function injury group (β2-MG>2.4 mg/L, n=181, and CysC>1.25 mg/L, n=160). Multivariate linear regression analysis was used to analyze the influencing factors of serum β2-microglobulin and cystatin C. Multivariate Logistic regression was used to analyze the relationship between the TyG index and early renal impairment in hypertensive patients. The receiver operating characteristic curve (ROC) was used to determine the value of the TyG index in predicting early renal impairment in patients with hypertension.

RESULT

As the TyG index level increased, serum β2-MG and CysC levels also gradually increased. Multivariate linear regression analysis showed that TyG index was the influencing factor of serum β2-MG (B=0.060, P=0.007) and serum CysC (B=0.096, P<0.001). For every 1 standard deviation increase in the TyG index, the serum β2-MG and CysC increased by 0.06mg/L and 0.096mg/L, respectively. When compared to the normal group, the TyG level (8.91 ± 0.65 vs 8.64 ± 0.60, P<0.001) was higher in the renal impairment group with β2-MG>2.4 mg/L. The results of multivariate logistic regression analysis revealed that for every 1 standard deviation increase in the TyG index, the risk of early renal impairment in hypertensive patients increased 1.53 times (OR=1.53, 95%CI 1.006-2.303).The ROC curves showed that the TyG index was not superior to TG in predicting early renal impairment in hypertensive patients. the AUC values were 0.623 and 0.617, respectively. Then, when CysC>1.25 mg/L was used as the renal damage group, the level of TyG was still higher than that in the normal group (8.94 ± 0.67 and 8.64 ± 0.60, P<0.001). Multivariate Logistic regression analysis showed that for every 1 standard deviation increase in the TyG index, the risk of early renal impairment in hypertensive patients increased 2.82 times (OR=2.82, 95%CI 1.863-4.262). The ROC curves showed that the TyG index was not superior to TG in predicting early renal impairment in hypertensive patients. the AUC values were 0.629 and 0.626, respectively.

CONCLUSION

TyG index is an influential factor in serum β2-MG and CysC levels. The elevated TyG index levels are closely associated with the occurrence and development of early renal impairment in hypertensive patients, but it should be used cautiously in the prediction of early renal impairment.

Female Gender Is Associated with Higher Susceptibility of Weight Induced Arterial Stiffening and Rise in Blood Pressure

Arterial stiffness is an important predictor of cardiovascular events, independent of traditional risk factors. Stiffening of arteries, though an adaptive process to hemodynamic load, results in substantial increase in the pulsatile hemodynamic forces that detrimentally affects the microcirculation perfusing the vital organs such as the brain, heart and kidneys. Studies have proposed that arterial stiffness precedes and may contribute to the development of hypertension in individuals with obesity. Our study sought to determine the gender-based effects on arterial stiffening in obesity which may predispose to the development of hypertension. We found female sex is associated with higher susceptibility of weight-related arterial stiffening and rise in blood pressure in obesity. Women had significantly higher carotid-femoral pulse wave velocity (CF-PWV) with higher body mass index (BMI) status (normal: 7.9 ± 2 m/s; overweight: 9.1 ± 2 m/s; obese: 9 ± 2 m/s, p < 0.001), whereas it was similar in males across all BMI categories. The linear association between arterial stiffness and BMI following adjustment for age and brachial systolic and diastolic blood pressure (BP), remained significant in females (β = 0.06; 95% CI 0.01 to 0.1; p < 0.05) but not in males (β = 0.04; 95% CI -0.01 to 0.1; p > 0.05). The mean CF-PWV values increased by 0.1 m/s for every 1 kg/m² increase in BMI in the female subjects in the age adjusted linear model, while such effect was not seen in the male subjects. In line with arterial stiffening, the overweight and obese females demonstrated significantly higher systolic brachial BP. (BP difference: ΔBP 9-11 mmHg, p < 0.01) and central systolic pressure (ΔBP 8-10 mmHg, p < 0.05) compared to their lean counterparts, unlike the male subjects. Our results suggest that female gender is associated with higher susceptibility of weight-related arterial stiffening and rise in blood pressure.

Lock, Stock and Barrel: Role of Renin-Angiotensin-Aldosterone System in Coronavirus Disease 2019

Since the end of 2019, the medical-scientific community has been facing a terrible pandemic caused by a new airborne viral agent known as SARS-CoV2. Already in the early stages of the pandemic, following the discovery that the virus uses the ACE2 cell receptor as a molecular target to infect the cells of our body, it was hypothesized that the renin-angiotensin-aldosterone system was involved in the pathogenesis of the disease. Since then, numerous studies have been published on the subject, but the exact role of the renin-angiotensin-aldosterone system in the pathogenesis of COVID-19 is still a matter of debate. RAAS represents an important protagonist in the pathogenesis of COVID-19, providing the virus with the receptor of entry into host cells and determining its organotropism. Furthermore, following infection, the virus is able to cause an increase in plasma ACE2 activity, compromising the normal function of the RAAS. This dysfunction could contribute to the establishment of the thrombo-inflammatory state characteristic of severe forms of COVID-19. Drugs targeting RAAS represent promising therapeutic options for COVID-19 sufferers.

New Pandemic: Obesity and Associated Nephropathy

Incidence of obesity related renal disorders have increased 10-folds in recent years. One of the consequences of obesity is an increased glomerular filtration rate (GFR) that leads to the enlargement of the renal glomerulus, i.e., glomerulomegaly. This heightened hyper-filtration in the setting of type 2 diabetes irreparably damages the kidney and leads to progression of end stage renal disease (ESRD). The patients suffering from type 2 diabetes have progressive proteinuria, and eventually one third of them develop chronic kidney disease (CKD) and ESRD. For ameliorating the progression of CKD, inhibitors of renin angiotensin aldosterone system (RAAS) seemed to be effective, but on a short-term basis only. Long term and stable treatment strategies like weight loss via restricted or hypo-caloric diet or bariatric surgery have yielded better promising results in terms of amelioration of proteinuria and maintenance of normal GFR. Body mass index (BMI) is considered as a traditional marker for the onset of obesity, but apparently, it is not a reliable indicator, and thus there is a need for more precise evaluation of regional fat distribution and amount of muscle mass. With respect to the pathogenesis, recent investigations have suggested perturbation in fatty acid and cholesterol metabolism as the critical mediators in ectopic renal lipid accumulation associated with inflammation, increased generation of ROS, RAAS activation and consequential tubulo-interstitial injury. This review summarizes the renewed approaches for the obesity assessment and evaluation of the pathogenesis of CKD, altered renal hemodynamics and potential therapeutic targets.

Kidney Adaptations Prevent Loss of Trace Elements in Wistar Rats with Early Metabolic Syndrome

Metabolic syndrome (MetS) represents a cluster of related metabolic abnormalities, including central obesity, hypertension, dyslipidemia, hyperglycemia, and insulin resistance. These metabolic derangements present significant risk factors for chronic kidney disease that carries to loss of essential micronutrients, which accelerates comorbidity apparition. The work aimed was to evaluate the trace element homeostasis regarding morphological adaptations and renal function in MetS early-onset. Fifty male Wistar rats were divided into two groups: (a) control group and (b) hypercaloric diet group that developed MetS early-onset after 3 months. Classical zoometric parameters do not show changes; however, biochemical modifications were observed such as hyperglycemia, protein glycation, insulin resistance, dyslipidemia, hyperinsulinemia, and hypoadiponectinemia. MetS early-onset group observed renal structural modifications, but no functional changes. The structural modifications observed were minimal glomerular injury, glomerular basement membrane thickening, as well as mesangial and tubular cells that showed growth and proliferation. In serum and kidney (cortex and medulla), the concentrations of Zn, Fe, Cr, Mg, Mn, Cu, Co, and Ni were no differences between the experimental groups, but excretory fractions of these were lower in the hypercaloric diet group. In conclusion, MetS early-onset coexist renal structural modification and a hyperreabsorptive activity of essential trace elements that avoid its loss; thus, the excretory fraction of oligo-elements could be used a biomarker of early renal injury caused by metabolic diseases in the clinical practice.

Gut Dysbiosis and Western Diet in the Pathogenesis of Essential Arterial Hypertension: A Narrative Review

Metabolic syndrome is a cluster of the most dangerous cardiovascular (CV) risk factors including visceral obesity, insulin resistance, hyperglycemia, alterations in lipid metabolism and arterial hypertension (AH). In particular, AH plays a key role in the complications associated with metabolic syndrome. High salt intake is a well-known risk factor for AH and CV diseases. Vasoconstriction, impaired vasodilation, extracellular volume expansion, inflammation, and an increased sympathetic nervous system (SNS) activity are the mechanisms involved in the pathogenesis of AH, induced by Western diet. Gut dysbiosis in AH is associated with reduction of short chain fatty acid-producing bacteria: acetate, butyrate and propionate, which activate different pathways, causing vasoconstriction, impaired vasodilation, salt and water retention and a consequent high blood pressure. Moreover, increased trimethylamine N-oxide and lipopolysaccharides trigger chronic inflammation, which contributes to endothelial dysfunction and target organs damage. Additionally, a high salt-intake diet impacts negatively on gut microbiota composition. A bidirectional neuronal pathway determines the “brain–gut” axis, which, in turn, influences blood pressure levels. Then, we discuss the possible adjuvant novel treatments related to gut microbiota modulation for AH control.

Association between obesity and urinary albumin-creatinine ratio in the middle-aged and elderly population of Southern and Northern China: a cross-sectional study

OBJECTIVE

The relationship between obesity and albuminuria has not been clarified. This study aimed to investigate the correlation between obesity and the urinary albumin-creatinine ratio (UACR) in Southern and Northern China.

DESIGN

A descriptive, cross-sectional study.

SETTING

Eight regional centres in REACTION (China's Risk Evaluation of cAncers in Chinese diabeTic Individuals, a lONgitudinal study), including Dalian, Lanzhou, Zhengzhou, Guangzhou, Guangxi, Luzhou, Shanghai and Wuhan.

PARTICIPANTS

A total of 41 085 patients who were not diagnosed with chronic kidney disease (CKD) and had good compliance were selected according to the inclusion criteria. Patients who were diagnosed with CKD, who had other kidney diseases that could lead to increased urinary protein excretion, who were using angiotensin-converting-enzyme inhibitors or angiotensin II receptor blockers and whose important data were missing were excluded.

RESULTS

Participants with both, central and peripheral obesity, had a higher risk of elevated UACR, even after adjusting for multiple factors (OR: 1.14, 95% CI: 1.07 to 1.12, p<0.001), and the risk of high UACR in the South was more prominent than that in the North (OR _South: 1.22, 95% CI: 1.11 to 1.34; OR _North: 1.13, 95% CI: 1.04 to 1.22, p<0.001). The risk was also elevated in the male population, hypertensive individuals, glycosylated haemoglobin (HbA1c)≥6.5% and age ≥60 years in the South. Besides the above groups, diabetes was also a risk factor for the Northern population.

CONCLUSIONS

In China, people with both central and peripheral obesity are prone to a high UACR, and the southern population has a higher risk than northern population. Factors such as male sex, hypertension, HbA1c≥6.5% and an age ≥60 years are also risk factors for CKD.

Obesity is a predictor of increased morbidity after tracheostomy

OBJECTIVE

The purpose of this study was to analyze the relationship between body mass index (BMI) and 30-day morbidity and mortality risk in patients undergoing tracheostomy using the American College of Surgeons National Quality Improvement Program (ACS-NSQIP).

STUDY DESIGN

This is a retrospective, cross-sectional, cohort study.

SETTING

Patients were identified with Current Procedural Terminology codes in the ACS-NSQIP database.

SUBJECTS AND METHODS

Patients who underwent tracheostomy from 2005 to 2018 were queried. They were stratified into four BMI classes and matched to normal BMI cohorts. Multivariate logistic regression was used to identify independent predictors for complications, readmissions, and unplanned reoperations within 30 days.

RESULTS

Among 3784 patients meeting inclusion and exclusion criteria, obesity was shown to be a significant independent risk factor for overall complications (OR 1.439, 95% CI 1.226-1.689, p < 0.001), postoperative acute renal failure (OR 10.715, 95% CI 1.213-94.646, p = 0.033), and unplanned readmissions (OR 1.702, 95% CI 1.095-2.647, p = 0.018). A significantly lower rate of postoperative transfusions was observed for obese patients (OR 0.581, 95% CI 0.432-0.781, p < 0.001).

CONCLUSIONS

Obesity was found to be independently associated with an increased risk of overall complication, developing acute renal failure, and having an unplanned 30-day readmission following tracheostomy. The risk of postoperative transfusion appears to be lower in obese patients.

LEVEL OF EVIDENCE

4.

Augmented transcripts of kidney injury markers and renin angiotensin system in urine samples of overweight young adults

Obesity has been firmly established as a major risk factor for common disease states including hypertension, type 2 diabetes mellitus, and chronic kidney disease. Increased body mass index (BMI) contributes to the activation of both the systemic and intra-tubular renin angiotensin systems (RAS), which are in turn associated with increased blood pressure (BP) and kidney damage. In this cross-sectional study, 43 subjects of normal or increased body weight were examined in order to determine the correlation of BMI or body fat mass (BFM) with blood pressure, fasting blood glucose (FBG), and urinary kidney injury markers such as interleukin-18 (IL-18), connective tissue growth factor (CTGF), neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 (KIM-1). Our results showed that: (1) subjects with increased body weight showed significantly higher BP, BFM, total body water and metabolic age; (2) BMI was positively correlated to both systolic (R² = 0.1384, P = 0.01) and diastolic BP (R² = 0.2437, P = 0.0008); (3) BFM was positively correlated to DBP (R² = 0.1232, P = 0.02) and partially correlated to urine protein (R² = 0.047, P = 0.12) and FBG (R² = 0.07, P = 0.06); (4) overweight young adults had higher urinary mRNA levels of renin, angiotensinogen, IL-18 and CTGF. These suggest that BMI directly affects BP, kidney injury markers, and the activation of the intra-tubular RAS even in normotensive young adults. Given that BMI measurements and urine analyses are non-invasive, our findings may pave the way to developing a new and simple method of screening for the risk of chronic kidney disease in adults.

Kidney size in relation to ageing, gender, renal function, birthweight and chronic kidney disease risk factors in a general population

BACKGROUND

The relationship of kidney size to ageing, kidney function and kidney disease risk factors is not fully understood.

METHODS

Ultrasound length and parenchymal kidney volume were determined from a population-based sample of 3972 Sardinians (age range 18-100 years). We then identified the subset of 2256 'healthy' subjects to define age- and sex-specific reference ranges (2.5-97.5 percentile) of kidney volume. Logistic regression (accounting for family clustering) was used to identify the clinical characteristics associated with abnormally large kidneys or abnormally small kidneys.

RESULTS

In the healthy subset, kidney volume and length increased up to the fourth to fifth decade of life followed by a progressive decrease in men, whereas there was a gradual kidney volume decrease throughout the lifespan of women. In the whole sample, independent predictors of lower kidney volume (<2.5 percentile for age and sex) were male sex, low body mass index, short height, low waist:hip ratio and high serum creatinine (SCr); the independent predictors of larger kidney volume (>97.5 percentile for age and sex) were younger age, female sex, diabetes, obesity, high height, high waist:hip ratio and lower SCr. Estimated heritability for kidney volume was 15%, and for length 27%; kidney volume correlated strongly with birthweight.

CONCLUSIONS

Overall, in a general healthy population, kidney measures declined with age differently in men and women. The determinants of kidney parenchymal volume include genetic factors and modifiable clinical factors.

The renin-angiotensin-aldosterone system as a link between obesity and coronavirus disease 2019 severity

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory distress coronavirus 2 (SARS-CoV2), is a rapidly evolving pandemic challenging the world and posing unprecedented public health issues. Current data show that COVID-19 is associated with increased disease severity in individuals with obesity. Obesity is usually associated with dysregulated renin-angiotensin-aldosterone (RAAS) axis. RAAS has also been implicated in acute lung injury as well as myocardial injury and has thus attracted interest as a potential regulator of COVID-19 severity. Whilst research all over the world is still struggling to provide a detailed characterization of the biology of SARS-CoV2 and its associated disease profile, it has become evident that SARS-CoV2 uses the membrane-bound form of angiotensin-converting enzyme 2 (ACE2) as a receptor for cell internalization. ACE2 is a protective component of the RAAS axis and is downregulated after SARS-CoV2 infection. The RAAS axis could thus be a link between obesity and COVID-19 severity; therefore, more accurate understanding of the underlying mechanisms would be needed with the hope of proposing efficient therapeutic interventions.

Amelioration of risk factors associated with diabetic nephropathy in diet-induced pre-diabetic rats by an uracil-derived diimine ruthenium(II) compound

Diabetic renal injury advances through different stages of structural and functional changes in the glomerulus, therefore treatment during the pre-diabetic state could be used as therapeutic target in the management and prevention of diabetic nephropathy (DN). Once diagnosed, dietary interventions and pharmacological therapy have been recommended to manage DN and pre-diabetic related complications. However, poor patient compliance still results, therefore newer alternative drugs are required. High fat high carbohydrates (HFHC) diet was used to induce pre-diabetes for 20 weeks. After the induction, pre-diabetic rats were randomly allocated to respective treatment groups. Subcutaneous ruthenium(II) Schiff base complex injection (15 mg/kg) was administered to pre-diabetic rats in both the presence and absence of dietary intervention once a day every third day for 12 weeks. The administration of ruthenium(II) complex resulted in reduced blood glucose, aldosterone, fluid intake and urinary output which correlated with a restoration in plasma and urinary electrolytes along with plasma antioxidants concentration. Furthermore, there was a decrease in kidney injury molecule-1 (KIM-1) concentration, albumin excretion rate (AER) albumin creatinine ratio (ACR) and mRNA expression of podocin in urine in ruthenium-treated pre-diabetic rats. Ruthenium(II) Schiff base complex ameliorated renal function while preventing the progression of DN in prediabetic-treated rats.

Associations Between Changes in Plasma Renin Activity and Aldosterone Concentrations and Changes in Kidney Function After Treatment for Primary Aldosteronism

Introduction

Greater reduction in estimated glomerular filtration rate (eGFR) after specific treatment for primary aldosteronism (PA) reflects improvement in glomerular hyperfiltration associated with PA and leads to better patient outcomes. However, little is known regarding the mechanisms underlying eGFR reduction after treatment for PA.

Methods

We analyzed data from the nationwide PA registry in Japan. Patients were assigned to adrenalectomy (n = 438) and mineralocorticoid receptor (MR) antagonist (n = 746) groups. We assessed associations between changes in blood pressure (BP), plasma renin activity (PRA) and plasma aldosterone concentrations (PAC), and eGFR before and 6 months after treatment for both groups.

Results

In a multivariable linear regression, the adjusted β values (95% confidence interval [CI]) for change in eGFR after treatment were −2.76 (−4.29, −1.22) ml/min per 1.73 m² for PRA (per 3.2 ng/ml per hour), and 1.97 (1.08, 2.85) ml/min per 1.73 m² for PAC (per 236.1 pg/ml) in the adrenalectomy group; and −0.45 (−0.89, −0.01) ml/min per 1.73 m² for PRA and −0.72 (−1.62, 0.18) ml/min per 1.73 m² for PAC in the MR antagonist group. Change in mean arterial pressure after treatment was not significantly associated with change in eGFR in either group. Changes in PRA and PAC but not BP before and 6 months after treatment for PA were associated with greater reductions in eGFR.

Conclusion

Post-treatment improvements in glomerular hyperfiltration may be attributable to decreased MR activity in the kidneys, but not to reductions in systemic BP.

Renin-Angiotensin System in Lung Tumor and Microenvironment Interactions

The mechanistic involvement of the renin-angiotensin system (RAS) reaches beyond cardiovascular physiopathology. Recent knowledge pinpoints a pleiotropic role for this system, particularly in the lung, and mainly through locally regulated alternative molecules and secondary pathways. Angiotensin peptides play a role in cell proliferation, immunoinflammatory response, hypoxia and angiogenesis, which are critical biological processes in lung cancer. This manuscript reviews the literature supporting a role for the renin-angiotensin system in the lung tumor microenvironment and discusses whether blockade of this pathway in clinical settings may serve as an adjuvant therapy in lung cancer.

Waist height ratio predicts chronic kidney disease: a systematic review and meta-analysis, 1998-2019

BACKGROUND

The incidence of chronic kidney disease (CKD) increases each year, and obesity is an important risk factor for CKD. The main anthropometric indicators currently reflecting obesity are body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR), but the rationality and merits of various indicators vary. This article aims to find whether the WHtR is a more suitable physical measurement that can predict CKD.

METHODS

Pubmed, embase, the cochrane library, and web of science were systematically searched for articles published between 1998 and 2019 screening CKD through physical indicators. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted the data, and evaluated the quality of the methodology included in the study. Meta-analysis used the Stata 12.0 software.

RESULTS

Nine studies were included, with a total of 202,283 subjects. Meta-analysis showed that according to the analysis of different genders in 6 studies, regardless of sex, WHtR was the area with the largest area under the curve (AUC). Except WHtR and visceral fat index (VFI) in women which showed no statistical difference, WHtR and other indicators were statistically different. In three studies without gender-based stratification, the area under the curve AUC for WHtR remained the largest, but only the difference between WHtR and BMI was statistically significant. When the Chinese population was considered as a subgroup, the area under the curve AUC for WHtR was the largest. Except for WHtR and VFI which showed no statistical difference in women, there was a statistically significant difference between WHtR and other indicators in men and women.

CONCLUSION

WHtR could be better prediction for CKD relative to other physical measurements. It also requires higher-quality prospective studies to verify the clinical application of WHtR.

Female Mice Exposed to Postnatal Neglect Display Angiotensin II-Dependent Obesity-Induced Hypertension

Background We have previously reported that female mice exposed to maternal separation and early weaning (MSEW), a model of early life stress, show exacerbated diet-induced obesity associated with hypertension. The goal of this study was to test whether MSEW promotes angiotensin II-dependent hypertension via activation of the renin-angiotensin system in adipose tissue. Methods and Results MSEW was achieved by daily separations from the dam and weaning at postnatal day 17, while normally reared controls were weaned at postnatal day 21. Female controls and MSEW weanlings were placed on a low-fat diet (LF, 10% kcal from fat) or high-fat diet (HF, 60% kcal from fat) for 20 weeks. MSEW did not change mean arterial pressure in LF-fed mice but increased it in HF-fed mice compared with controls (P<0.05). In MSEW mice fed a HF, angiotensin II concentration in plasma and adipose tissue was elevated compared with controls (P<0.05). In addition, angiotensinogen concentration was increased solely in adipose tissue from MSEW mice (P<0.05), while angiotensin-converting enzyme protein expression and activity were similar between groups. Chronic enalapril treatment (2.5 mg/kg per day, drinking water, 7 days) reduced mean arterial pressure in both groups of mice fed a HF (P<0.05) and abolished the differences due to MSEW. Acute angiotensin II-induced increases in mean arterial pressure (10 μg/kg SC) were attenuated in untreated MSEW HF-fed mice compared to controls (P<0.05); however, this response was similar between groups in enalapril-treated mice. Conclusions The upregulation of angiotensinogen and angiotensin II in adipose tissue could be an important mechanism by which female MSEW mice fed a HF develop hypertension.

The effect of a multidisciplinary weight loss program on renal circadian rhythm in obese adolescents

Adolescent obesity is a serious health problem associated with many comorbidities. Obesity-related alterations in circadian rhythm have been described for nocturnal blood pressure and for metabolic functions. We believe renal circadian rhythm is also disrupted in obesity, though this has not yet been investigated. This study aimed to examine renal circadian rhythm in obese adolescents before and after weight loss.In 34 obese adolescents (median age 15.7 years) participating in a residential weight loss program, renal function profiles and blood samples were collected at baseline, after 7 months, and again after 12 months of therapy. The program consisted of dietary restriction, increased physical activity, and psychological support. The program led to a median weight loss of 24 kg and a reduction in blood pressure. Initially, lower diurnal free water clearance (- 1.08 (- 1.40-- 0.79) mL/min) was noticed compared with nocturnal values (0.75 (- 0.89-- 0.64) mL/min). After weight loss, normalization of this inverse rhythm was observed (day - 1.24 (- 1.44-1.05) mL/min and night - 0.98 (- 1.09-- 0.83) mL/min). A clear circadian rhythm in diuresis rate and in renal clearance of creatinine, solutes, sodium, and potassium was seen at all time points. Furthermore, we observed a significant increase in sodium clearance. Before weight loss, daytime sodium clearance was 0.72 mL/min (0.59-0.77) and nighttime clearance was 0.46 mL/min (0.41-0.51). After weight loss, daytime clearance increased to 0.99 mL/min (0.85-1.17) and nighttime clearance increased to 0.78 mL/min (0.64-0.93).Conclusion: In obese adolescents, lower diurnal free water clearance was observed compared with nocturnal values. Weight loss led to a normalization of this inverse rhythm, suggesting a recovery of the anti-diuretic hormone activity. Both before and after weight loss, clear circadian rhythm of diuresis rate and renal clearance of creatinine, solutes, sodium, and potassium was observed.What is Known:• Obesity-related alterations in circadian rhythm have been described for nocturnal blood pressure and for metabolic functions. We believe renal circadian rhythm is disrupted in obesity, though this has not been investigated yet.What is New:• In obese adolescents, an inverse circadian rhythm of free water clearance was observed, with higher nighttime free water clearance compared with daytime values. Weight loss led to a normalization of this inverse rhythm, suggesting a recovery of the anti-diuretic hormone activity.• Circadian rhythm in diuresis rate and in the renal clearance of creatinine, solutes, sodium, and potassium was preserved in obese adolescents and did not change after weight loss.

Histone deacetylase inhibitor CG200745 ameliorates high-fat diet-induced hypertension via inhibition of angiotensin II production

Obesity is growing rapidly worldwide due to consumption of westernized diet and lack of exercise. Obesity is one of the major risk factors of hypertension. The novel histone deacetylase (HDAC) inhibitor CG200745 was originally developed to treat various cancers. Previous studies showed that CG200745 attenuated hypertension through inhibition of cardiac hypertrophy and fibrosis in deoxycorticosterone acetate-induced hypertensive rat. The purpose of this study is to investigate the role and underlying mechanism of CG200745 in high-fat diet (HFD)-induced hypertension. Nine-week old C57BL/6 mice were fed a normal diet (ND) or HFD for 17 weeks. Each group of mice was treated with vehicle or CG200745 by intraperitoneal injection for 9 days. HFD group showed higher body weight, blood pressure (BP), HDAC activities, angiotensinogen and renin expressions in kidney, angiotensin-converting enzyme (ACE) expression in the lung, serum angiotensin II (Ang II) concentration, and myosin light chain₂₀ (MLC₂₀) phosphorylation in mesenteric artery compared with ND group. CG200745 lowered BP, HDAC activity, renin and angiotensinogen in the kidney, ACE in the lung, serum Ang II level, and phosphorylation of MLC₂₀ in HFD group. In conclusion, CG200745 ameliorated HFD-induced hypertension through inhibition of HDAC/Ang II/vascular contraction axis. Our results offer CG200745 as a novel therapeutic option for HFD-induced hypertension.

Different anthropometric indicators of central obesity can predict hypertension in older adults

Objective: to investigate the association between hypertension and anthropometric indicators of central obesity, obtained from two anatomical sites in older adults.Methodology: cross-sectional study that involved 145 older adults, from whom socioeconomic and demographic data and anthropometric indicators of central obesity (waist circumference [CC] and abdominal circumference [CA]) were obtained, which were considered independent variables. A logistic regression model was used to analyze associations and for the discriminatory power of the cut-off points of the hypertension anthropometric indicators, receiver operating characteristic (ROC) curve was performed. Comparisons were made between ROC curves, with the aim of identifying significant differences in the discriminatory power of the anthropometric indicators studied.Results: out of the 145 individuals, 79 were females (54%) and 66 males (46%). Results showed a high prevalence of arterial hypertension in men (69,7%) and women (73,4%). Both CC and CA were significantly associated with hypertension in both genders. Parameters of the ROC curve revealed that both anthropometric indicators of central obesity exhibit good discriminatory power for hypertension in the studied population. The cut-off point for CC was > 83,2 cm for men and > 82,6 cm for women; while for CA it was > 85,1 cm and > 85,4 cm for men and women, respectively.Conclusion: CA and CC are significantly associated with hypertension in both genders, and there is no superiority between them to predict hypertension in the elderly population.

Polymorphisms of the renin-angiotensin system are not associated with overweight and obesity in a general adult population

OBJECTIVE

The increased prevalence of obesity and associated comorbidities, such as cardiovascular and metabolic diseases, has gained attention worldwide, and the renin-angiotensin system (RAS) has been pointed out as a possible link. Thus, the present study aimed to verify the possible association between angiotensinogen (AGT) or angiotensin-converting enzyme (ACE) polymorphisms with overweight and obesity in adults.

SUBJECTS AND METHODS

The present investigation was a population-based cross-sectional study including 1,567 individuals from an urban area in Brazil. Anthropometric, clinical and biochemical parameters were evaluated, and all individuals were genotyped for the ACE I/D and AGT M/T polymorphisms.

RESULTS

The prevalence of overweight was higher among men, whereas obesity was more prevalent among women. However, the frequency of ACE or AGT polymorphisms was similar among body mass index (BMI) categories. In addition, the mean age-adjusted BMI averages did not change significantly for ACE or AGT polymorphisms, regardless of sex or BMI category. The age-adjusted BMI average for the combination of ACE and AGT genotypes evidenced no significant differences regardless of sex or BMI categories. Results were similar when BMI was replaced by waist circumference (WC).

CONCLUSIONS

We were not able to find any associations between BMI and WC (overweight/obesity) and ACE and AGT polymorphisms, indicating that the RAS system might not be involved in overweight and obesity, at least based on genetic backgrounds. However, further studies must measure RAS components to elucidate this question.

Metabolic phenotypes of obese, overweight, and normal weight individuals and risk of chronic kidney disease: a systematic review and meta-analysis

OBJECTIVE

Chronic kidney disease (CKD) risk is inconsistent in the normal-weight, overweight, and obese individuals due to the heterogeneity of metabolic status. This meta-analysis aimed to examine the combined effects of body mass index (BMI) and metabolic status on CKD risk.

MATERIALS AND METHODS

The MEDLINE, EMBASE, and Web of Knowledge databases were systematically searched up to March 2019 to identify all eligible studies investigating the CKD risk (defined as GFR < 60 mL/min per 1.73 m2 and/or microalbuminuria or proteinuria) associated with the body size phenotypes which are known as metabolically unhealthy normal-weight (MUNW), metabolically healthy overweight (MHOW), metabolically unhealthy overweight, metabolically healthy obese (MHO) and metabolically unhealthy obese (MUHO). The classification of subjects in included studies as metabolically unhealthy was based on the presence of three components of metabolic syndrome. BMI categorization was based on the criteria of included studies. The risk estimates and 95% confidence intervals (CIs) were extracted and pooled using random effects analysis.

RESULTS

A total of 9 prospective cohort studies with 128773 participants and 4797 incident cases were included in the meta-analysis. Compared with healthy normal-weight individuals as reference, MUNW and MHO subjects showed an increased risk for CKD events with a pooled RR of 1.58 (95% CI = 1.28-1.96) in MUNW and 1.55 (95% CI = 1.34-1.79) in MHO persons. Also, MHOW was at increased risk for CKD (RR = 1.34, 95% CI = 1.20-1.51). MUHO individuals were at the highest risk for the development of CKD (RR = 2.13, 95% CI = 1.66-2.72).

CONCLUSIONS

Individuals with metabolic abnormality, although at normal-weight, have an increased risk for CKD. Healthy overweight and obese individuals had higher risk; refuting the notion that metabolically healthy overweight and obese phenotypes are benign conditions.

Bisdemethoxycurcumin protects against renal fibrosis via activation of fibroblast apoptosis

Renal fibrosis is the common final outcome of nearly all progressive chronic kidney diseases (CKD) that eventually develop into end-stage renal failure, which threatens the lives of patients. Currently, there are no effective drugs for the treatment of renal fibrosis. However, studies have shown that certain plant natural products have a fibrosis-alleviating effect. Thus, we have screened a large number of natural products for their ability to protect against renal fibrosis and found that bisdemethoxycurcumin has a good therapeutic effect in renal fibrosis according to the data obtained in a mouse model of unilateral ureteral obstruction (UUO). The results indicate that bisdemethoxycurcumin can efficiently attenuate renal fibrosis induced by UUO. Additional studies of the bisdemethoxycurcumin mechanism of action in the treatment of renal fibrosis demonstrated that the therapeutic effect of bisdemethoxycurcumin is mediated by the specific induction of fibroblast apoptosis at a concentration of 20 μM. bisdemethoxycurcumin can efficiently protect against renal fibrosis both in vitro and in vivo. This discovery will provide new ideas for renal fibrosis treatment in clinics and a new direction for the development of effective drug therapy of renal fibrosis.

Salt Induces Adipogenesis/Lipogenesis and Inflammatory Adipocytokines Secretion in Adipocytes

It is well known that high salt intake is associated with cardiovascular diseases including hypertension. However, the research on the mechanism of obesity due to high salt intake is rare. To evaluate the roles of salt on obesity prevalence, the gene expression of adipogenesis/lipogenesis and adipocytokines secretion according to adipocyte dysfunction were investigated in salt-loading adipocytes. High salt dose-dependently increased the expression of adipogenic/lipogenic genes, such as PPAR-γ, C/EBPα, SREBP1c, ACC, FAS, and aP2, but decreased the gene of lipolysis like AMPK, ultimately resulting in fat accumulation. With SIK-2 and Na⁺/K⁺-ATPase activation, salt increased the metabolites involved in the renin-angiotensin-aldosterone system (RAAS) such as ADD1, CYP11β2, and MCR. Increasing insulin dependent insulin receptor substrate (IRS)-signaling, resulting in the insulin resistance, mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) and Akt-mTOR were activated but AMPK(Thr¹⁷²) was depressed in salt-loading adipocytes. The expression of pro-inflammatory adipocytokines, TNFα, MCP-1, COX-2, IL-17A, IL-6, leptin, and leptin to adiponectin ratio (LAR) were dose-dependently increased by salt treatment. Using the inhibitors of MAPK/ERK, U0126, we found that the crosstalk among the signaling pathways of MAPK/ERK, Akt-mTOR, and the inflammatory adipogenesis can be the possible mechanism of salt-linked obesity. The possibilities of whether the defense mechanisms against high dose of intracellular salts provoke signaling for adipocytes differentiation or interact with surrounding tissues through other pathways will be explored in future research.

Changes in obese metabolic phenotypes over time and risk of incident chronic kidney disease

AIM

To examine the association between metabolically healthy obese (MHO) phenotype and incident chronic kidney disease (CKD) and study whether changes in metabolic phenotypes over time could affect CKD risk.

METHODS

A total of 8589 subjects from the Korean Genome and Epidemiology Study were categorized into four groups based on the presence of obesity and metabolic abnormalities (MA). The primary endpoint was an onset of incident CKD defined as an estimated glomerular filtration rate of ≤ 60 mL/min/1.73 m² . Multivariable Cox analysis and time-varying Cox analysis were performed to delineate the relationship between obese metabolic phenotypes and incident CKD after adjustment for sociodemographic factors and clinical and laboratory parameters.

RESULTS

During a mean follow-up duration of 9.3 years, CKD occurred in 782 (9.1%) participants. In the multivariable Cox model, the hazard ratio (HR) for incident CKD in the MHO, metabolically abnormal non-obese (MANO), and metabolically abnormal obese (MAO) groups was 1.42 (P = 0.002), 1.45 (P < 0.001), and 1.77 (P < 0.001), respectively, compared with the metabolically healthy non-obese (MHNO) group. Time-varying analysis with these four phenotypes as time-varying exposures showed the same results. Furthermore, subjects with persistent MHO through follow-up were at a 2.0-fold increased risk of CKD (P < 0.001). 41.0% of subjects experienced phenotype changes during follow-up. Over the long term, the MHO group had a higher proportion of transition to the MA phenotype and unfavourable metabolic profiles than the MHNO group. Among MHO subjects, those who transitioned to MAO were at a 4.1-fold increased risk of incident CKD than those who regressed to MHNO. In addition, transition to MHO from other groups carried a higher risk of CKD than persistent MHNO.

CONCLUSION

MHO subjects are at increased risk for incident CKD.

Adipose Tissue and Modulation of Hypertension

PURPOSE OF REVIEW

Obesity is a major risk factor for the development of hypertension (HTN), a leading cause of cardiovascular morbidity and mortality. Growing body of research suggests that adipose tissue function is directly associated with the pathogenesis of obesity-related HTN. In this review, we will discuss recent research on the role of adipose tissue in blood pressure (BP) regulation and activation of brown adipose tissue (BAT) as a potentially new therapeutic means for obesity-related HTN.

RECENT FINDINGS

Adipose tissue provides mechanical protection of the blood vessels and plays a role in regulation of vascular tone. Exercise and fasting activate BAT and induce browning of white adipose tissue (WAT). BAT-secreted FGF21 lowers BP and protects against HTN. Browning of perivascular WAT improves HTN. New insights on WAT browning and BAT activation can open new avenues of potential therapeutic interventions to treat obesity-related HTN.

Impact of bariatric surgery on cardiovascular and renal complications of diabetes: a focus on clinical outcomes and putative mechanisms

INTRODUCTION

Cardiovascular and renal disease accounts for a substantial proportion of the morbidity and mortality associated with obesity and type 2 diabetes mellitus (T2DM). Bariatric surgery is associated with improved long-term cardiovascular and renal outcomes.

AREAS COVERED

All major case-control, cohort, and randomized controlled trial studies of bariatric surgery in adults with T2DM were screened and data on prespecified cardiovascular and renal outcomes collated. Bariatric surgery reduces all-cause mortality and risk of cardiovascular disease, albuminuria and progressive chronic kidney disease. Patients with poorer glycemic control and established microvascular disease preoperatively may stand to benefit the most from the surgical approach. Reduced sympathetic drive, remission of glomerular hypertension, enhanced natriuresis, gut microbiota shifts, reduced systemic and renal inflammation, improved lipoprotein profiles, and reductions in chronic cardiac remodeling may all be implicated.

EXPERT COMMENTARY

Ongoing RCTs of bariatric surgery selectively recruiting patients with class 1 obesity and established microvascular complications of diabetes will help to better characterize which subgroups of patients benefit most from this effective therapy.

GLP-1 receptor agonist ameliorates obesity-induced chronic kidney injury via restoring renal metabolism homeostasis

Increasing evidence indicates that obesity is highly associated with chronic kidney disease (CKD). GLP-1 receptor (GLP-1R) agonist has shown benefits on kidney diseases, but its direct role on kidney metabolism in obesity is still not clear. This study aims to investigate the protection and metabolic modulation role of liraglutide (Lira) on kidney of obesity. Rats were induced obese by high-fat diet (HFD), and renal function and metabolism changes were evaluated by metabolomic, biological and histological methods. HFD rats exhibited systemic metabolic disorders such as obesity, hyperlipidemia and impaired glucose tolerance, as well as renal histological and function damages, while Lira significantly ameliorated these adverse effects in HFD rats. Metabolomic data showed that Lira directly reduced renal lipids including fatty acid residues, cholesterol, phospholipids and triglycerides, and improved mitochondria metabolites such as succinate, citrate, taurine, fumarate and nicotinamide adenine dinucleotide (NAD+) in the kidney of HFD rats. Furthermore, we revealed that Lira inhibited renal lipid accumulation by coordinating lipogenic and lipolytic signals, and partly rescued renal mitochondria function via Sirt1/AMPK/PGC1α pathways in HFD rats. This study suggested that Lira alleviated HFD-induced kidney injury at least partly via directly restoring renal metabolism, thus GLP-1R agonist is a promising therapy for obesity-associated CKD.

The effect of treatment for sleep apnoea on determinants of blood pressure control

Our aim was to assess the effect of continuous positive airway pressure (CPAP) on the nocturnal evolution of peripheral chemosensitivity, renin–angiotensin–aldosterone system activity, sympathetic tone and endothelial biomarkers in obstructive sleep apnoea (OSA) patients with isolated nocturnal hypertension (INH) or day–night sustained hypertension (D-NSH).

In a crossover randomised trial, 32 OSA patients newly diagnosed with hypertension and without antihypertensive treatment were randomly assigned to 12 weeks of CPAP or sham CPAP. Peripheral chemosensitivity was evaluated before and after sleep using the hypoxic withdrawal test (%ΔVI).

At baseline, D-NSH patients showed higher %ΔVI before sleep and higher levels of aldosterone and diurnal catecholamines. CPAP only reduced the nocturnal increase of %ΔVI in INH patients (6.9%, 95% CI 1.0–12.8%; p=0.026). CPAP-induced change from baseline in %ΔVI after sleep was 7.5% (95% CI 2.6–12.2%, p=0.005) in the INH group and 5.7% (95% CI 2.2–9.3%, p=0.004) in the D-NSH group. In contrast, %ΔVI before sleep only decreased with CPAP in the D-NSH patients (3.0%, 95% CI 0.5–5.6%; p=0.023).

In conclusion, CPAP reduces the nocturnal increase of peripheral chemosensitivity experienced by INH patients and corrects the high daytime sensitivity of patients with D-NSH. Differences in response to CPAP between these patients can help better understand the mechanisms of perpetuation of hypertension in sleep apnoea.

The effects of body weight loss and gain on arterial hypertension control: an observational prospective study

BACKGROUND

Body weight changes are associated with significant variations in blood pressure (BP). Body mass modifications may, therefore, influence hypertension control in primary care.

METHODS

Patients with a history of essential arterial hypertension were observed for 12 months. Anthropometric data and clinical BP were evaluated at the time of the recruitment and after 12 months of follow-up. The association between (body mass index) BMI change and BP control was analyzed by logistic regression.

RESULTS

Sixteen thousand five hundred and sixty-four patients were recruited, while 13,631 patients (6336 men; 7295 women) finished the 1-year follow-up. In obese patients, a BMI decrease by at least 1 kg/m² was negatively associated with uncontrolled hypertension at the end of the follow-up (men p < 0.0001, OR = 0.586, 0.481-0.713, women p < 0.001, OR = 0.732, 0.611-0.876). A similar association was observed in overweight patients (men p < 0.05, OR = 0. 804, 95% CI: 0.636-0.997, women p < 0.05, OR = 0.730, 95% CI: 0.568-0.937). A BMI increase of at least 1 kg/m² was associated with a significantly higher odd of uncontrolled hypertension in obese (men p < 0.001, OR = 1.471, 1.087-1.991, women p < 0.001, OR = 1.422, 1.104-1.833) and overweight patients (men p < 0.0001, OR = 1.901, 95% CI: 1.463-2.470, women p < 0.0001, OR = 1.647, 95% CI: 1.304-2.080).

CONCLUSIONS

Weight loss is inversely associated and weight increase is positively associated with the probability of uncontrolled hypertension in obese and overweight hypertensives.

Renal Metabolic Programming Is Linked to the Dynamic Regulation of a Leptin-Klf15 Axis and Akt/AMPKα Signaling in Male Offspring of Obese Dams

Childhood obesity is associated with renal diseases. Maternal obesity is a risk factor linked to increased adipocytokines and metabolic disorders in the offspring. Therefore, we studied the impact of maternal obesity on renal-intrinsic insulin and adipocytokine signaling and on renal function and structure. To induce maternal obesity, female mice were fed a high-fat diet (HFD) or a standard diet (SD; control group) prior to mating, during gestation, and throughout lactation. A third group of dams was fed HFD only during lactation (HFD-Lac). After weaning at postnatal day (P)21, offspring of all groups received SD. Clinically, HFD offspring were overweight and insulin resistant at P21. Although no metabolic changes were detected at P70, renal sodium excretion was reduced by 40%, and renal matrix deposition increased in the HFD group. Mechanistically, two stages were differentiated. In the early stage (P21), compared with the control group, HFD showed threefold increased white adipose tissue, impaired glucose tolerance, hyperleptinemia, and hyperinsulinemia. Renal leptin/Stat3-signaling was activated. In contrast, the Akt/ AMPKα cascade and Krüppel-like factor 15 expression were decreased. In the late stage (P70), although no metabolic differences were detected in HFD when compared with the control group, leptin/Stat3-signaling was reduced, and Akt/AMPKα was activated in the kidneys. This effect was linked to an increase of proliferative (cyclinD1/D2) and profibrotic (ctgf/collagen IIIα1) markers, similar to leptin-deficient mice. HFD-Lac mice exhibited metabolic changes at P21 similar to HFD, but no other persistent changes. This study shows a link between maternal obesity and metabolic programming of renal structure and function and intrinsic-renal Stat3/Akt/AMPKα signaling in the offspring.

Longer duration of obesity is associated with a reduction in urinary angiotensinogen in prepubertal children

BACKGROUND

We aimed to study the impact of obesity on urinary excretion of angiotensinogen (U-AGT) in prepubertal children, focusing on the duration of obesity and gender. Also, we aimed to evaluate whether plasma angiotensinogen (P-AGT) and hydrogen peroxide (H₂O₂) play a role in the putative association.

METHODS

Cross-sectional evaluation of 305 children aged 8-9 years (160 normal weight, 86 overweight, and 59 obese). Anthropometric measurements and 24-h ambulatory blood pressure monitoring were performed. Angiotensinogen (AGT) was determined by a commercial enzyme-linked immunosorbent assay (ELISA) kit and H₂O₂ by a microplate fluorometric assay.

RESULTS

U-AGT and P-AGT levels were similar across body mass index (BMI) groups and between sexes. However, boys who were overweight/obese since the age of 4 years presented lower levels of U-AGT compared with those of normal weight at the same age. In children who were overweight/obese since the age of 4, urinary H₂O₂ decreased with P-AGT.

CONCLUSIONS

A higher duration of obesity was associated with decreased U-AGT in boys, thus reflecting decreased intrarenal activity of the renin-angiotensin system. Also, children with a longer duration of obesity showed an inverse association between urinary H₂O₂ and P-AGT. Future studies should address whether these results reflect an early compensatory mechanism to limit obesity-triggered renal dysfunction.

Renin-angiotensin-aldosterone (RAAS): The ubiquitous system for homeostasis and pathologies

Renin-angiotensin-aldosterone system (RAAS) is a vital system of human body, as it maintains plasma sodium concentration, arterial blood pressure and extracellular volume. Kidney-secreted renin enzyme acts on its substrate to form angiotensin II, a versatile effector peptide hormone. Every organ is affected by RAAS activation and the resultant hypertension, cell proliferation, inflammation, and fibrosis. The imbalance of renin and angiotensin II can result in an overwhelming number of chronic and acute diseases. RAAS is influenced by other enzymes, hormones, pumps and signaling pathways, hence, this review discusses important facets of this system, its crosstalk with other crucial factors like estrogen, thyroid, cortisol, kallikrein-kinin system, Wnt/β-catenin signaling, and sodium-potassium pump. The nexus of RAAS with the above-discussed systems was scantily explored before. So, this review furnishes a new perspective in comprehension of inflammation diseases. It is followed by the formulation of hypotheses, which can contribute to better management of an array of pathologies plaguing mankind. Manipulation of RAAS, by bending it towards ACE2 expression can regulate endocrine functions, which can be critical for a number of pathological management. Dietary intervention can restore RAAS to normalcy.

Disruption of aromatase homeostasis as the cause of a multiplicity of ailments: A comprehensive review

Human health is beset with a legion of ailments, which is exacerbated by lifestyle errors. Out of the numerous enzymes in human body, aromatase, a cytochrome P450 enzyme is particularly very critical. Occurring at the crossroads of multiple signalling pathways, its homeostasis is vital for optimal health. Unfortunately, medications, hormone therapy, chemical additives in food, and endocrine-disrupting personal care products are oscillating the aromatase concentration beyond the permissible level. As this enzyme converts androgens (C19) into estrogens (C18), its agitation has different outcomes in different genders and age groups. Some common pathologies associated with aromatase disruption include breast cancer, prostate cancer, polycystic ovary syndrome (PCOS), endometriosis, osteoporosis, ovarian cancer, gastric cancer, pituitary cancer, Alzheimer's disease, schizophrenia, male hypogonadism, and transgender issues. Several drugs, cosmetics and pesticides act as the activators and suppressors of this enzyme. This carefully-compiled critical review is expected to increase public awareness regarding the threats resultant of the perturbations of this enzyme and to motivate researchers for further investigation of this field.

Association of Body Mass Index and Postoperative Acute Kidney Injury in Patients Undergoing Laparoscopic Surgery

BACKGROUND

Whether the deleterious effects of carbon dioxide pneumoperitoneum on the kidneys are exacerbated in the obese population remains unknown. We hypothesized that increased body mass index (BMI) is associated with an increased incidence of postoperative acute kidney injury (AKI) in patients undergoing noncardiac laparoscopic surgery.

METHODS

Following institutional review board approval, we analyzed data on 8,543 adult patients with American Society of Anesthesiologists physical status scores of I-IV who had inpatient noncardiac laparoscopic surgery from 2005-2014. Because the exposure (current BMI) is a chronic condition, we a priori assumed that diabetes mellitus, hypertension, coronary artery disease, and chronic obstructive pulmonary disease might mediate the effect of obesity on outcome. Our primary analysis was a proportional odds logistic regression model with current BMI as a predictor and AKI as an ordinal outcome.

RESULTS

After controlling for potential confounding variables, the odds of developing a more serious level of AKI was 7% (95% CI 0%, 15%) greater with a 5-unit increase in BMI (P=0.05). When the analysis was adjusted for the a priori mediators in an attempt to estimate the pure effect of BMI on AKI, the result was no longer significant (Wald test P=0.35), with the residual effect of BMI of 3% (95% CI -4%, 11%).

CONCLUSION

We found a marginal association between BMI and an increased risk of developing AKI in adult patients after having noncardiac laparoscopic surgery. The BMI effect became insignificant when potential mediator variables were considered. The association of BMI and AKI after noncardiac laparoscopic surgery is likely mediated through components of the metabolic syndrome.

Lower urinary tract symptoms and metabolic disorders: ICI-RS 2014

AIMS

To investigate the link between lower urinary tract symptoms (LUTS) and metabolic disorders.

MATERIALS AND METHODS

This report results from presentations and subsequent discussions about LUTS and metabolic disorders at the International Consultation on Incontinence Research Society (ICI-RS) in Bristol, 2014.

RESULTS

There are common pathophysiological determinants for the onset of LUTS and the metabolic syndrome (MetS). Both conditions are multifactorial, related to disorders in circadian rhythms and share common risk factors. As in men with erectile dysfunction, these potentially modifiable lifestyle factors may be novel targets to prevent and treat LUTS. The link between LUTS and metabolic disorders is discussed by using sleep, urine production and bladder function as underlying mechanisms that need to be further explored during future research.

CONCLUSION

Recent findings indicate a bidirectional relationship between LUTS and the MetS. Future research has to explore underlying mechanisms to explain this relationship, in order to develop new preventive and therapeutic recommendations, such as weight loss and increasing physical activity. The second stage is to determine the effect of these new treatment approaches on the severity of LUTS and each of the components of the MetS.

Contribution of Maladaptive Adipose Tissue Expansion to Development of Cardiovascular Disease

The overweight and obesity epidemic has led to an increase in the metabolic syndrome and associated cardiovascular disease (CVD). These abnormalities include insulin resistance, type 2 diabetes mellitus, vascular stiffness, hypertension, stroke, and coronary heart disease. Visceral white adipocyte tissue (WAT) expansion and associated fibrosis/stiffness of WAT promote insulin resistance and CVD through increases in proinflammatory adipokines, oxidative stress, activation of renin-angiotensin-aldosterone system, dysregulation of adipocyte apoptosis and autophagy, dysfunctional immune modulation, and adverse changes in the gut microbiome. The expansion of WAT is partly determined by activation of peroxisome proliferator-activated receptor gamma and mammalian target of rapamycin/ribosomal S6 kinase signaling pathways. Further, the chronic activation of these signaling pathways may not only induce adipocyte hypertrophy and fibrosis, but also contribute to systemic inflammation, and impairment of insulin metabolic signaling in fat, liver, and skeletal muscle tissue. Therefore, the interplay of adipocyte dysfunction, maladaptive immune and inflammatory responses, and associated metabolic disorders often coexist leading to systemic low-grade inflammation and insulin resistance that are associated with increased CVD in obese individuals. © 2017 American Physiological Society. Compr Physiol 7:253-262, 2017.