Systemic inflammation, metabolic syndrome and progressive renal disease

Association of Self-Reported Nighttime Sleep Duration with Chronic Kidney Disease: China Health and Retirement Longitudinal Study

INTRODUCTION

The cohort study aimed to assess the association of nighttime sleep duration and the change in nighttime sleep duration with chronic kidney disease (CKD) and whether the association between nighttime sleep duration and CKD differed by daytime napping.

METHODS

This study included 11,677 individuals from the China Health and Retirement Longitudinal Study (CHARLS) and used data from the 2011 baseline survey and four follow-up waves. Nighttime sleep duration was divided into three groups: short (<7 h per night), optimal (7-9 h), and long nighttime sleep duration (>9 h). Daytime napping was divided into two groups: no nap and with a nap. We used Cox proportional hazards model to examine the effect of nighttime sleep duration at baseline and change in nighttime sleep duration on incident CKD and a joint effect of nighttime sleep duration and nap time on onset CKD.

RESULTS

With a follow-up of 7 years, the incidence of CKD among those with short, optimal, and long nighttime sleep duration was 9.89, 6.75, and 9.05 per 1,000 person-years, respectively. Compared to individuals with optimal nighttime sleep duration, short nighttime sleepers had a 44% higher risk of onset CKD (hazard ratio [HR]: 1.44, 95% confidence interval [CI]: 1.21-1.72). Compared to participants with persistent optimal nighttime sleep duration, those with persistent short or long nighttime sleep duration had an increased risk of incident CKD (HR: 1.44, 95% CI: 1.15-1.80). We found a lower incidence of CKD in participants with short nighttime sleep duration and a nap (HR: 0.74, 95% CI: 0.60-0.93), compared to those with short nighttime sleep duration and no nap.

CONCLUSION

Short nighttime sleep duration and persistent long or short nighttime sleep duration were associated with a higher risk of onset CKD. Keeping persistent optimal nighttime sleep duration may help reduce CKD risk later in life. Daytime napping may be protective against CKD incidence.

Association of Systemic Immune Inflammation Index with Estimated Pulse Wave Velocity, Atherogenic Index of Plasma, Triglyceride-Glucose Index, and Cardiovascular Disease: A Large Cross-Sectional Study

In the U.S. general population, there is a lack of understanding regarding the association between the systemic immune inflammation (SII) index and estimated pulse wave velocity (ePWV), atherogenic index of plasma (AIP), and triglyceride-glucose (TyG) index and cardiovascular disease (CVD). As a result, the objective of our research was to investigate the association between the SII index and ePWV, AIP, and TyG index and incident CVD. We used the National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2018 to conduct this study. The correlation between the SII index and ePWV, AIP, and TyG index was examined using generalized additive models with smooth functions. In addition, the association between SII index and triglyceride (TC), high-density lipoprotein cholesterol (HDL-C), and fast glucose (FBG) also were explored. Finally, we further performed multivariable logistic regression analysis, restricted cubic spline (RCS) plots, and subgroup analysis to study the connection between the SII index and CVD. Our analysis included 17389 subjects from the NHANES database. A substantial positive association existed between SII, WV, and the TyG index. In addition, with the increase of the SII index, AIP showed a trend of decreasing first, then rising, and then decreasing. The SII index was inversely and linearly associated with triglyceride (TG), while positively and linearly associated with fast glucose (FBG). However, high-density lipoprotein cholesterol (HDL-C) had a tendency of first declining, then climbing, and finally falling with the rise in the SII index. After adjusting for potential confounders, compared with the lowest quartiles, the odds ratios with 95% confidence intervals for CVD across the quartiles were 0.914 (0.777, 1.074), 0.935 (0.779, 1.096), and 1.112 (0.956, 1.293) for SII index. The RCS plot showed an inverse U-shaped curve relationship between the SII index and CVD. Overall, this study found a strong correlation between a higher SII index and ePWV and the TyG index. Additionally, these cross-sectional data also revealed a U-shaped connection between the SII index and CVD.

Clinical and biological risk factors associated with inflammation in patients with type 2 diabetes mellitus

BACKGROUND

Chronic inflammation has been associated with insulin resistance and related metabolic dysregulation, including type 2 diabetes mellitus (T2DM). Several non modifiable (i.e. genetic predisposition) and modifiable (i.e. sedentary lifestyle, energy-dense food) risk factors were suggested to explain the mechanisms involved in the development of inflammation, but are difficult to assess in clinical routine. The present study aimed to identify easy to asses clinical and biological risk factors associated with inflammation in patients with T2DM.

METHODS

One hundred nine patients (51 men, 58 women), 28-60 years old, from seven primary healthcare centers in Gaza City, Palestine, took part to the cross-sectional study (November 2013-May 2014). Study participants had T2DM with no history of inflammatory diseases, cardiovascular diseases, medication and/or any health condition that might affect the inflammatory markers, interleukin 6 (IL-6) and C-reactive protein (CRP). Inflammation was defined for IL-6 ≥ 2 pg/mL and CRP ≥ 6 mg/L. Multivariable logistic regressions were used to identify the relationship between inflammation and clinical and biological risk factors.

RESULTS

After adjustment for age and gender, inflammation seems to increase with increased body mass index (BMI) (OR: 1.427 [1.055-1.931]), increased fasting blood glucose (OR: 1.029 [1.007-1.052]) and decreased adiponectin values (OR: 0.571 [0.361-0.903]). There were also significant relationships between inflammation and BMI (OR: 1.432 [1.042-1.968]), fasting blood glucose (OR: 1.029 [1.006-1.052]) and adiponectin (OR: 0.569 [0.359-0.902]), after adjustment for smoking habits and physical activity.

CONCLUSION

Managing obesity and associated complications (i.e. hyperglycemia, high adiponectin levels) might help decreasing inflammation in individuals with T2DM.

Determination of risk factors associated with inflammation in hypertensive patients with type-2 diabetes mellitus in a Palestinian Diabetes Study

OBJECTIVE

To determine the risk factors associated with inflammation in hypertensive patients with type-2 diabetes mellitus.

METHODS

A total of 164 hypertensive patients with type 2 diabetes patients aged 38-60 years were selected from 7 primary healthcare centers in Gaza city, Palestine. Interview questionnaire were employed to collect data related to age, gender, smoking habits, and physical activity pattern. Laboratory biochemical tests included fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), interleukin 6 (IL-6), high sensitive C reactive protein (hs-CRP), and adiponectin were estimated in all patients.

RESULTS

The study involved 118 (72%) women and 46 (28%) men; the mean of age was 53.7 ± 0.46 years. A tertile of inflammation feature with hs-CRP was developed. The highest tertile of hs-CRP was significantly associated with women, higher obesity indices, metabolic dysregulation involving lipid profile markers, FBG and blood pressure, IL-6, and lower adiponectin. After adjusting for age, gender, smoking habits, and physical activity; the risk factor of high level of hs-CRP were the increased body mass index [OR: 1.17, p = .018], IL-6 [OR: 2.22, p = .025] and FBG [OR: 1.01, p = .007], as well as reduced adiponectin [OR: 0.81, p = .002].

CONCLUSION

The inflammation state was affected by obesity and had been related to altered adipokines levels of IL-6 and adiponectin, as well as affected by the glycemic control, as evidenced by higher serum level of FBG.

The association of nighttime sleep duration and quality with chronic kidney disease in middle-aged and older Chinese: a cohort study

OBJECTIVE

This cohort study aimed to assess the associations between sleep duration and quality with the risk of incident chronic kidney disease (CKD) in middle-aged and older Chinese.

METHODS

We used the 2011 and 2015 surveys of the China Health and Retirement Longitudinal Study (CHARLS). Nighttime sleep duration was categorized into five groups: ≤4, (4-6], (6-8], (8-10], and >10 h/night. Sleep quality was assessed by restless days in the past week (<1, 1-2, 3-4, and 5-7 days/week). Multivariate logistic regression was used to assess the association between sleep duration and quality with incident CKD.

RESULTS

A total of 11,339 participants free of CKD at baseline were included in this study. After four years follow-up, the incidence of CKD was 7.8%. There was a "U-shaped" association between sleep duration and risk of CKD. Compared to 6-8 h of nighttime sleep duration, those who slept ≤4 h/night (RR: 1.639, 95% CI: 1.287-2.087) or >10 h/night (RR: 2.342, 95% CI: 1.007-5.451) had increased risk of developing CKD after adjustment for confounders. Participants with 5-7 restless days per week had significantly increased risk of CKD (adjusted RR: 1.686, 95% CI: 1.352-2.102), compared to those who rarely or never had a restless sleep.

CONCLUSIONS

Extreme nighttime sleep duration and poor sleep quality were associated with increased risk of CKD in middle-aged and older Chinese. Obtaining an optimal nighttime sleep duration and better sleep quality might reduce the risk of CKD.

InforMing the PAthway of COPD Treatment (IMPACT) trial: fibrinogen levels predict risk of moderate or severe exacerbations

BACKGROUND

Fibrinogen is the first qualified prognostic/predictive biomarker for exacerbations in patients with chronic obstructive pulmonary disease (COPD). The IMPACT trial investigated fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) triple therapy versus FF/VI and UMEC/VI in patients with symptomatic COPD at risk of exacerbations. This analysis used IMPACT trial data to examine the relationship between fibrinogen levels and exacerbation outcomes in patients with COPD.

METHODS

8094 patients with a fibrinogen assessment at Week 16 were included, baseline fibrinogen data were not measured. Post hoc analyses were performed by fibrinogen quartiles and by 3.5 g/L threshold. Endpoints included on-treatment exacerbations and adverse events of special interest (AESIs).

RESULTS

Rates of moderate, moderate/severe, and severe exacerbations were higher in the highest versus lowest fibrinogen quartile (0.75, 0.92 and 0.15 vs 0.67, 0.79 and 0.10, respectively). The rate ratios (95% confidence interval [CI]) for exacerbations in patients with fibrinogen levels ≥ 3.5 g/L versus those with fibrinogen levels < 3.5 g/L were 1.03 (0.95, 1.11) for moderate exacerbations, 1.08 (1.00, 1.15) for moderate/severe exacerbations, and 1.30 (1.10, 1.54) for severe exacerbations. There was an increased risk of moderate/severe exacerbation (hazard ratio [95% CI]: highest vs lowest quartile 1.16 [1.04, 1.228]; ≥ 3.5 g/L vs < 3.5 g/L: 1.09 [1.00, 1.16]) and severe exacerbation (1.35 [1.09, 1.69]; 1.27 [1.08, 1.47], respectively) with increasing fibrinogen level. Cardiovascular AESIs were highest in patients in the highest fibrinogen quartile.

CONCLUSIONS

Rate and risk of exacerbations was higher in patients with higher fibrinogen levels. This supports the validity of fibrinogen as a predictive biomarker for COPD exacerbations, and highlights the potential use of fibrinogen as an enrichment strategy in trials examining exacerbation outcomes.

TRIAL REGISTRATION

NCT02164513.

Fatty liver: The metabolic syndrome increases major hepatectomy mortality

BACKGROUND

As the obesity epidemic worsens, the prevalence of fatty liver disease has increased. However, minimal data exist on the impact of combined fatty liver and metabolic syndrome on hepatectomy outcomes. Therefore, the aim of this analysis is to measure the outcomes of patients who do and do not have a fatty liver undergoing hepatectomy in the presence and absence of the metabolic syndrome.

METHODS

Patients with fatty and normal livers undergoing major hepatectomy (≥3 segments) were identified in the 2014 to 2018 American College of Surgeon National Surgical Quality Improvement Program database. Patients undergoing partial hepatectomy and those with missing liver texture data were excluded. Propensity matching was used and adjusted for multiple variables. A subgroup analysis stratified by the metabolic syndrome (body mass index ≥30 kg/m², hypertension and diabetes) was performed. Demographics and outcomes were compared by χ² and Mann-Whitney tests.

RESULTS

Of 2,927 hepatectomies, 30% of patients (N = 863) had a fatty liver. The median body mass index was 28.6, and the metabolic syndrome was present in 6.3% of patients (N = 184). After propensity matching, 863 patients with fatty and 863 with normal livers were compared. Multiple outcomes were significantly worse in patients with fatty livers (P <.05), including serious morbidity (32% vs 24%), postoperative invasive biliary procedures (15% vs 10%), organ space infections (11% vs 7.8%), and pulmonary complications. Patients with fatty livers and the metabolic syndrome had significantly increased postoperative cardiac arrests, pulmonary embolisms, and mortality (P < .05).

CONCLUSION

Fatty liver disease is associated with significantly worse outcomes after major hepatectomy. The metabolic syndrome confers an increased risk of postoperative mortality.

Periodic and Intermittent Fasting in Diabetes and Cardiovascular Disease

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is one of the leading causes of death globally. Nutrition plays a central role in CVD risk by affecting aging, adiposity, glycemia, blood pressure, cholesterol, inflammation, and other risk factors and can affect CVD risk not only based on calorie intake and dietary composition but also the timing and range of meals. This review evaluates the effects of fasting, fasting-mimicking diets, and time-restricted eating on the reduction of CVD risk factors and provides initial data on their potential to serve as CVD prevention and treatment therapies.

RECENT FINDINGS

Intermittent fasting (IF), time-restricted eating (TRE), prolonged fasting (PF), and fasting-mimicking diets (FMD) show promise in the reduction of CVD risk factors. Results on IF, TRE, PF, and FMD on CVD risk factors are significant and often independent of weight loss, yet long-term studies on their effect on CVD are still lacking. Coupling periodic and prolonged, or intermittent and more frequent cycles of fasting or fasting-mimicking diets, designed to maximize compliance and minimize side effects, has the potential to play a central role in the prevention and treatment of CVD and metabolic syndrome.

Dietary pattern and incidence of chronic kidney disease among adults: a population-based study

Background & Aims

Although dietary patterns have been linked to chronic diseases such as cardiovascular disease, sparse data are available for a relationship between dietary patterns and incident chronic kidney disease (CKD) in West Asian populations. The aim of this study was to evaluate the association of population-based dietary pattern with the risk of incident CKD after 6.1 years of follow-up.

Methods

At baseline, habitual dietary intakes of 1630 participants of the Tehran Lipid and Glucose Study (TLGS) who were free of CKD was assessed by a valid and reliable food-frequency questionnaire. The following three major dietary patterns were identified using a principal components analysis: Lacto-vegetarian dietary pattern, traditional Iranian dietary pattern, and high fat, high sugar dietary pattern. Estimated glomerular filtration rate (eGFR) was calculated, using the Modification of Diet in Renal Disease (MDRD) Study equation and CKD was defined as eGFR < 60 mL/min/1.73m². Odds ratio (OR) using multivariable logistic regression was calculated for the association of incident CKD with the extracted dietary patterns.

Results

After adjusting for age, sex, smoking, total energy intake, physical activity, body mass index, diabetes, and hypertension the OR for participants in the highest compared with those in the lowest tertile of the lacto-vegetarian dietary pattern was 0.57 (95% confidence interval [CI]: 0.41 to 0.80, P-trend = 0.002). In contrast, the high fat, high sugar dietary pattern was positively associated with the incidence of CKD (OR for the third tertile compared with first tertile: 1.46; 95% CI: 1.03-2.09; P-trend = 0.036). Traditional Iranian dietary pattern was not associated with incident CKD.

Conclusion

The high fat, high sugar dietary pattern was associated with significantly increased (46%) odds of incident CKD, whereas a lacto-vegetarian dietary pattern may be protective against the occurrence of CKD by 43%.

Association of sugar sweetened beverages consumption with non-alcoholic fatty liver disease: a systematic review and meta-analysis

PURPOSE

The relationship between consumption of sugar sweetened beverages (SSB) and NAFLD has been reported in several epidemiological studies, but the results are inconsistent. The present systematic review and meta-analysis of observational studies was carried out to assess the relationship between sugar sweetened beverages consumption and NAFLD.

METHODS

Online databases were searched systematically through December, 2016 for studies investigating association between SSB consumption and NAFLD but limited to observational studies in human. Pooled odds ratio (OR) and 95% confidence intervals were calculated using Der-Simonian and Laird method while random effects meta-analysis was used, taking into account conceptual heterogeneity. Heterogeneity was assessed with the Cochran Q statistic and quantified with the I² statistic.

RESULTS

Of the 1015 identified articles, 42 were reviewed in depth and six studies (four cross-sectional, one case-control, and one cohort) met the criteria for inclusion in our systematic review with 6326 participants and 1361 cases of NAFLD in both men and women. Finally, four cross-sectional studies were included in the meta-analysis. Higher intake of SSBs (highest compared to lowest categories) was significantly associated with NAFLD, with a 40% increased Odds of NAFLD after adjusting for important potential confounders (pooled odds ratio 1.40; 95% CI 1.07, 1.82). There was no evidence for significant heterogeneity across studies [P = 0.226 (Q statistics), I² = 31.0%]. A significant positive association between SSB consumption and NAFLD was observed consistently in a sensitivity analysis [range of summary ORs 1.39-1.49]. There was no evidence of publication bias for the association between SSB and NAFLD.

CONCLUSIONS

This meta-analysis supports a positive significant association between higher consumption of SSB and NAFLD in both men and women. These findings strengthen the evidence that intake of SSBs should be limited to reduce fatty liver disease.

Is there a J-shaped relationship between the fatty liver index and risk of microalbuminuria in the general population?

BACKGROUND

We investigated whether the fatty liver index (FLI), as a clinical indicator of hepatic fat accumulation based on body mass index, gamma-glutamyl-transferase, triglycerides, and waist circumference, has an association with microalbuminuria.

METHODS

We analyzed anthropometric and biochemical data from a nation-wide, population-based, cross-sectional study. A total of 1605 participants included were healthy native Korean 40years or older and divided into quintiles according to their log-FLI and sex. Microalbuminuria was defined as urine albumin/creatinine ratio (UACR) between 30 and 300mg/g.

RESULTS

Participants in higher quintiles of log-FLI were more obese and hypertensive and had greater glycemic exposure, poorer lipid profiles, and greater increases in log-UACR compared with lower quintiles. Linear regression analysis demonstrated that log-FLI was associated with systolic and diastolic blood pressure, body mass index, waist circumference, fasting plasma glucose, glycated hemoglobin, and log-UACR. In logistic regression adjusted for age, sex, body mass index, waist circumference, and fasting plasma glucose, the OR of microalbuminuria was elevated in quintile 1 (adjusted OR=2.161, 95% CI=0.453-10.31) and quintile 5 (adjusted OR=6.387, 95% CI=1.317-51.58), when compared to quintile 2.

CONCLUSIONS

There appears to be a J-shaped association between FLI and UACR in healthy general population.

Vasopressin Mediates the Renal Damage Induced by Limited Fructose Rehydration in Recurrently Dehydrated Rats

Recurrent dehydration and heat stress cause chronic kidney damage in experimental animals. The injury is exacerbated by rehydration with fructose-containing beverages. Fructose may amplify dehydration-induced injury by directly stimulating vasopressin release and also by acting as a substrate for the aldose reductase-fructokinase pathway, as both of these systems are active during dehydration. The role of vasopressin in heat stress associated injury has not to date been explored. Here we show that the amplification of renal damage mediated by fructose in thermal dehydration is mediated by vasopressin. Fructose rehydration markedly enhanced vasopressin (copeptin) levels and activation of the aldose reductase-fructokinase pathway in the kidney. Moreover, the amplification of the renal functional changes (decreased creatinine clearance and tubular injury with systemic inflammation, renal oxidative stress, and mitochondrial dysfunction) were prevented by the blockade of V1a and V2 vasopressin receptors with conivaptan. On the other hand, there are also other operative mechanisms when water is used as rehydration fluid that produce milder renal damage that is not fully corrected by vasopressin blockade. Therefore, we clearly showed evidence of the cross-talk between fructose, even at small doses, and vasopressin that interact to amplify the renal damage induced by dehydration. These data may be relevant for heat stress nephropathy as well as for other renal pathologies due to the current generalized consumption of fructose and deficient hydration habits.

Obesity and inflammation: the linking mechanism and the complications

Obesity is the accumulation of abnormal or excessive fat that may interfere with the maintenance of an optimal state of health. The excess of macronutrients in the adipose tissues stimulates them to release inflammatory mediators such as tumor necrosis factor α and interleukin 6, and reduces production of adiponectin, predisposing to a pro-inflammatory state and oxidative stress. The increased level of interleukin 6 stimulates the liver to synthesize and secrete C-reactive protein. As a risk factor, inflammation is an imbedded mechanism of developed cardiovascular diseases including coagulation, atherosclerosis, metabolic syndrome, insulin resistance, and diabetes mellitus. It is also associated with development of non-cardiovascular diseases such as psoriasis, depression, cancer, and renal diseases. On the other hand, a reduced level of adiponectin, a significant predictor of cardiovascular mortality, is associated with impaired fasting glucose, leading to type-2 diabetes development, metabolic abnormalities, coronary artery calcification, and stroke. Finally, managing obesity can help reduce the risks of cardiovascular diseases and poor outcome via inhibiting inflammatory mechanisms.

Associations of sugar- and artificially sweetened soda with nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND/OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is the major concern of public health worldwide. The risk of NAFLD in subjects who regularly drink soda is controversial. The aim of this study was to assess the association between consumption of sugar-sweetened soda and NAFLD.

METHODS

A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from inception through June 2015. Studies that reported relative risks, odd ratios, or hazard ratios comparing the risk of NAFLD in patients consuming a significant amount of either sugar or artificially sweetened soda vs. those who did not consume soda were included. Pooled risk ratios (RRs) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

RESULTS

Seven observational studies were included in our analysis to assess the association between consumption of sugar-sweetened soda and NAFLD. The pooled RR of NAFLD in patients consuming sugar-sweetened soda was 1.53 (95% CI: 1.34-1.75, I(2) = 0). When meta-analysis was limited only to studies with adjusted analysis, the pooled RR of NAFLD was 1.55 (95% CI: 1.36-1.78, I(2) = 0). The data on association between consumption of artificially sweetened soda and NAFLD were limited; one observational study reported no significant increased risk of NAFLD in artificially sweetened soda consumption.

CONCLUSIONS

Our study demonstrates statistically significant association between sugar-sweetened soda consumption and NAFLD. This finding may impact clinical management and primary prevention of NAFLD.

The fructose tolerance test in patients with chronic kidney disease and metabolic syndrome in comparison to healthy controls

Background

Fructose acutely raises serum uric acid in normal subjects, but the effect in subjects with metabolic syndrome or subjects with chronic kidney disease is unknown. The aim of the study was to evaluate changes in serum uric acid during the fructose tolerance test in patients with chronic kidney disease, metabolic syndrome with comparison to healthy controls.

Methods

Studies were performed in 36 subjects with obesity (body mass index >30) and metabolic syndrome, 14 patients with stage 3 chronic kidney disease, and 25 healthy volunteers. The fructose tolerance test was performed in each patient. The change in serum uric acid during the fructose challenge was correlated with baseline ambulatory blood pressure, serum uric acid, metabolic, and inflammatory markers, and target organ injury including carotid intima media thickness and renal resistive index (determined by Doppler).

Results

Absolute serum uric acid values were highest in the chronic kidney disease group, followed by the metabolic syndrome and then healthy controls. Similar increases in serum uric acid in response to the fructose tolerance test was observed in all three groups, but the greatest percent rise was observed in healthy controls compared to the other two groups. No significant association was shown between the relative rise in uric acid and clinical or inflammatory parameters associated with kidney disease (albuminuria, eGFR) or metabolic syndrome.

Conclusions

Subjects with chronic kidney disease and metabolic syndrome have higher absolute uric acid values following a fructose tolerance test, but show a relatively smaller percent increase in serum uric acid. Changes in serum uric acid during the fructose tolerance test did not correlate with changes in metabolic parameters, inflammatory mediators or with target organ injury. These studies suggest that acute changes in serum uric acid in response to fructose do not predict the metabolic phenotype or presence of inflammatory mediators in subjects with obesity, metabolic syndrome or chronic kidney disease.

Trial registration

The study was registered in ClinicalTrials.gov. Identifier : NCT01332526. www.register.clinicaltrials.gov/01332526

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0048-y) contains supplementary material, which is available to authorized users.

Effects of acute exercise on markers of inflammation in pediatric chronic kidney disease: a pilot study

BACKGROUND

Children and adolescents with chronic kidney disease (CKD) are chronically exposed to high levels of inflammation, placing them at an increased risk of secondary health complications. Regular exercise may represent an effective therapy to reduce inflammation. The aims of this pilot study were to determine the effects of acute exercise on inflammation and immune cell counts in CKD.

METHODS

Nine children and adolescents (4 males) with CKD stages III-V performed a graded exercise test to determine peak oxygen uptake (VO2peak). Following a 10-min break, participants cycled for 20 min at 50 % of VO2peak. Blood samples were collected before and after the exercise period for the determination of complete blood counts, natural killer cells (NK(bright), NK(dim)) and circulating progenitor cell (CPC) counts, as well as interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) concentrations.

RESULTS

Complete blood counts and NK(dim) cell and CPC counts were unchanged with exercise. Following exercise, NK(bright) cell counts increased (7.4 ± 4.3 vs. 12.2 ± 8.3 × 10(6) cells/L; p = 0.02), while trends were observed for an increase in IL-6 (2.1 ± 2.2 vs. 2.7 ± 2.6 pg/mL; p = 0.08), decrease in TNF-α (4.5 ± 1.2 vs. 4.2 ± 1.0 pg/mL; p = 0.08) and an increase in the IL-6:TNF-α ratio (0.6 ± 0.7 vs. 0.8 ± 0.8; p = 0.07).

CONCLUSIONS

Our findings suggest that acute exercise may create an anti-inflammatory environment in children and adolescents with CKD stages III-V.

The therapeutic effect of monocyte chemoattractant protein-1 delivered by an electrospun scaffold for hyperglycemia and nephrotic disorders

Here, we investigated in diabetic mice the therapeutic effect of monocyte chemoattractant protein-1 (MCP-1), locally delivered by an electrospun scaffold, on transplanted islets. This therapeutic scheme is expected to exert a synergistic effect to ameliorate hyperglycemia and its associated nephrotic disorders. The cumulative amount of MCP-1 released from the scaffold in vitro within a 3-week window was 267.77±32.18 ng, without a compromise in bioactivity. After 8 weeks following the transplantation, the islet population stimulated by MCP-1 was 35.14%±7.23% larger than the non-stimulated islet population. Moreover, MCP-1 increased concentrations of blood insulin and C-peptide 2 by 49.83%±5.29% and 43.49%±9.21%, respectively. Consequently, the blood glucose concentration in the MCP-1 group was significantly lower than that in the control group at week 2 post-surgery. MCP-1 also enhanced the tolerance of sudden oral glucose challenge. The rapid decrease of blood creatinine, urine creatinine, and blood urea nitrogen suggested that the recovery of renal functions compromised by hyperglycemia could also be attributed to MCP-1. Our study shed new light on a synergistic strategy to alleviate hyperglycemia and nephrotic disorders in diabetic patients.

Multifunctional compounds: smart molecules for multifactorial diseases

Multifunctional compounds (MFCs) are designed broadly as hybrid or conjugated drugs or as chimeric drugs from two or more pharmacophores/drugs having specific pharmacological activities. These are capable of eliciting multiple pharmacological actions and have emerged as magic bullets in treatment of multifactorial diseases. Many research articles disclosing the development of such compounds for treatment of multifactorial diseases are published during last 7 years. Some successful MFC candidates for multifactorial CNS disorders include ziprasidone, duloxetine, ladostigil and M-30 whereas sunitinib, lapatinib and synthetic oleandane triterpinoids are the successful MFC candidates for various cancers. Many more compounds derived from berberine, tacrine, artemisnin, quinine, NSAIDs, pralidoxine, donepezil, rivastigmine, curcumin and various antioxidants are under investigations for exploration of their multifunctional potential. In general, MFCs possess the advantages of reduced molecularity, no drug-drug interactions and improved pharmacokinetics and pharmacodynamics. A MFC derived from two or more different pharmacophores exerts its activities by interacting with respective receptors of its constituent pharmacophores. It may also exhibit additional binding interactions with the receptor sites that may be responsible for significantly improved or additional activities. The present review discusses various MFCs developed for specific class of disorders with an aim to provide an insight into the strategies in medicinal chemistry for development of such compounds.

The inflammation-lipocalin 2 axis may contribute to the development of chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is an important risk factor for coronary heart disease, and previous studies indicated the involvement of low-grade inflammation in the pathogenesis of CKD.

METHODS

The study was designed to (i) identify and confirm genes and their products upregulated in mesangial cells cocultured with endotoxin-stimulated macrophages and (ii) determine the clinical relevance of genes and proteins upregulated in mesangial cells under inflammatory conditions by an epidemiological approach.

RESULTS

DNA microarray analysis revealed upregulated expression of many genes and their products including several cytokines and chemokines, as well as the inflammatory marker, lipocalin 2 gene. The gene expression and protein upregulation of lipocalin 2 were synergistically affected by endotoxin and tumor necrosis factor (TNF)-α stimulation. In human studies, lipocalin 2 level was significantly associated with creatinine (r = 0.419, P < 0.001) and negatively associated with eGFR (r = -0.365, P < 0.001). Multiple logistic regression analysis revealed a significant association between lipocalin 2 and soluble tumor necrosis factor receptor 2 (sTNF-R2), eGFR and uric acid in general subjects attending regular annual medical check-up (n = 420). When subjects with diabetes were excluded from the analysis, lipocalin 2 remained associated with sTNF-R2, eGFR and uric acid.

CONCLUSIONS

Since an activated TNF system, as demonstrated by elevated sTNF-R2, and elevated uric acid were recently implicated in an elevated CKD risk, we conclude that inflammation could play an important role in the pathogenesis of CKD, and that lipocalin 2 is a potential universal marker for impaired kidney function. Furthermore, the results obtained by the current microarray analysis could improve the understanding of gene profiles associated with the pathophysiology of CKD under inflammatory conditions.

Dietary fats and health: dietary recommendations in the context of scientific evidence

Although early studies showed that saturated fat diets with very low levels of PUFAs increase serum cholesterol, whereas other studies showed high serum cholesterol increased the risk of coronary artery disease (CAD), the evidence of dietary saturated fats increasing CAD or causing premature death was weak. Over the years, data revealed that dietary saturated fatty acids (SFAs) are not associated with CAD and other adverse health effects or at worst are weakly associated in some analyses when other contributing factors may be overlooked. Several recent analyses indicate that SFAs, particularly in dairy products and coconut oil, can improve health. The evidence of ω6 polyunsaturated fatty acids (PUFAs) promoting inflammation and augmenting many diseases continues to grow, whereas ω3 PUFAs seem to counter these adverse effects. The replacement of saturated fats in the diet with carbohydrates, especially sugars, has resulted in increased obesity and its associated health complications. Well-established mechanisms have been proposed for the adverse health effects of some alternative or replacement nutrients, such as simple carbohydrates and PUFAs. The focus on dietary manipulation of serum cholesterol may be moot in view of numerous other factors that increase the risk of heart disease. The adverse health effects that have been associated with saturated fats in the past are most likely due to factors other than SFAs, which are discussed here. This review calls for a rational reevaluation of existing dietary recommendations that focus on minimizing dietary SFAs, for which mechanisms for adverse health effects are lacking.

Post-ischemic azotemia as a partial 'brake', slowing progressive kidney disease

BACKGROUND

Recent experimental work suggests a paradox: although uremia evokes systemic toxicities, in the setting of AKI, it can induce intrarenal cytoprotective and anti-inflammatory effects. Whether these influences can attenuate post-ischemic kidney disease progression remains unknown.

METHODS

To explore this possibility, male CD-1 mice were subjected to a 30-min unilateral (left) kidney ischemia model, previously shown to reduce renal mass by ∼50% over 2-3 weeks. Stepwise azotemia/acute uremia was superimposed by inducing different lengths of contralateral (right) kidney ischemia (0, 15, 18, 20 min). Subsequent loss of left renal mass (kidney weight) was assessed 2 weeks later and contrasted with the degree of initial azotemia 24-h BUN.

RESULTS

A striking correlation between 24-h BUNs and 2-week left renal mass was observed (r, 0.77; P < 0.001). With 20 min of right kidney ischemia, left kidney size was completely preserved. This preservation did not result from increased tubular cell proliferation or decreased microvascular loss, as gauged by KI-67 and CD-34 immunohistochemistry, respectively. Rather, an early reduction in proximal tubule cell dropout (as judged by renal cortical N-acetyl-glucosaminidase content), with a subsequent preservation of tubule mass, was observed.

CONCLUSIONS

In summary, these findings advance a novel concept: acute uremia can confer early post-ischemic cytoprotection resulting in a slowed progression of post-ischemic kidney disease.

Role of the immune system in hypertension: modulation by dietary antioxidants

Hypertension is a major health problem worldwide. Individuals with hypertension are at an increased risk for stroke, heart disease, and kidney failure. Although the etiology of essential hypertension has a genetic component, lifestyle factors such as diet play an important role. Insulin resistance is a common feature of hypertension in both humans and animal models affecting glucose and lipid metabolism producing excess aldehydes including methylglyoxal. These aldehydes react with proteins to form conjugates called advanced glycation end products (AGEs). This alters protein structure and function and can affect vascular and immune cells leading to their activation and secretion of inflammatory cytokines. AGEs also act via receptors for advanced glycation end products on these cells altering the function of antioxidant and metabolic enzymes, and ion channels. This results in an increase in cytosolic free calcium, decrease in nitric oxide, endothelial dysfunction, oxidative stress, peripheral vascular resistance, and infiltration of vascular and kidney tissue with inflammatory cells leading to hypertension. Supplementation with dietary antioxidants including vitamins C, E, or B(6), thiols such as cysteine and lipoic acid, have been shown to lower blood pressure and plasma inflammatory cytokines in animal models and humans with essential hypertension. A well-balanced diet rich in antioxidants that includes vegetables, fruits, low fat dairy products, low salt, and includes whole grains, poultry, fish and nuts, lowers blood pressure and vascular inflammation. These antioxidants may achieve their antihypertensive and anti-inflammatory/immunomodulatory effects by reducing AGEs and improving insulin resistance and associated alterations. Dietary supplementation with antioxidants may be a beneficial, inexpensive, front-line alterative treatment modality for hypertension.

Effect of metabolic syndrome on perioperative outcomes after liver surgery: A National Surgical Quality Improvement Program (NSQIP) analysis

BACKGROUND

The problem of obesity has risen to epidemic levels in the United States. A subset of patients with obesity will have metabolic syndrome. We sought to examine the impact of metabolic syndrome on the risk of morbidity and mortality among a large cohort of patients who underwent hepatic resection.

METHODS

Patients included in the National Surgical Quality Improvement Program (NSQIP) dataset who underwent hepatic resection between January 2005 and December 2008 were identified. Data on clinical characteristics, comorbidities, operative details, as well as postoperative complications and mortality were collected and analyzed. Patients with BMI >30 kg/m(2) who also had hypertension and diabetes were defined as having metabolic syndrome.

RESULTS

A total of 3,973 patients who underwent a liver resection were identified. Overall mean body mass index was 28 kg/m(2); 31.7% patients were obese (>30 kg/m(2)). Of the patients who were obese, 256 (20%) had metabolic syndrome. Patients with metabolic syndrome were less likely to have had a major hepatectomy (≥hemi-hepatectomy, 36% vs 43%; P = .01) but had a greater mean number of red blood cell transfusions (1.6 vs 1; P = .02). The incidence of postoperative complications after hepatectomy was 23%. Patients with metabolic syndrome had a greater risk for reintubation (odds ratio [OR] 1.9; P = .02), >48 hours ventilator dependence (OR 2.0; P = .003), myocardial infarction (OR 5.5; P = .01) and superficial surgical-site infections (OR 1.7; P = .02) compared with nonmetabolic patients. Overall postoperative mortality was 3%. Metabolic syndrome was associated with an increased risk of postoperative death (OR 2.7; P = .001).

CONCLUSION

The presence of metabolic syndrome was associated with a greater risk of perioperative complications. In addition, patients with metabolic syndrome had greater than a 2-fold increased risk of death after hepatic resection.

Consumption of fructose- but not glucose-sweetened beverages for 10 weeks increases circulating concentrations of uric acid, retinol binding protein-4, and gamma-glutamyl transferase activity in overweight/obese humans

Background

Prospective studies in humans examining the effects of fructose consumption on biological markers associated with the development of metabolic syndrome are lacking. Therefore we investigated the relative effects of 10 wks of fructose or glucose consumption on plasma uric acid and RBP-4 concentrations, as well as liver enzyme (AST, ALT, and GGT) activities in men and women.

Methods

As part of a parallel arm study, older (age 40–72), overweight and obese male and female subjects (BMI 25–35 kg/m²) consumed glucose- or fructose-sweetened beverages providing 25% of energy requirements for 10 wks. Fasting and 24-h blood collections were performed at baseline and following 10 wks of intervention and plasma concentrations of uric acid, RBP-4 and liver enzyme activities were measured.

Results

Consumption of fructose, but not glucose, led to significant increases of 24-h uric acid profiles (P < 0.0001) and RBP-4 concentrations (P = 0.012), as well as plasma GGT activity (P = 0.04). Fasting plasma uric acid concentrations increased in both groups; however, the response was significantly greater in subjects consuming fructose (P = 0.002 for effect of sugar). Within the fructose group male subjects exhibited larger increases of RBP-4 levels than women (P = 0.024).

Conclusions

These findings suggest that consumption of fructose at 25% of energy requirements for 10 wks, compared with isocaloric consumption of glucose, may contribute to the development of components of the metabolic syndrome by increasing circulating uric acid, GGT activity, suggesting alteration of hepatic function, and the production of RBP-4.

Xanthine oxidoreductase: a journey from purine metabolism to cardiovascular excitation-contraction coupling

Xanthine oxidoreductase (XOR) is a ubiquitous complex cytosolic molybdoflavoprotein which controls the rate limiting step of purine catabolism by converting xanthine to uric acid. It is known that optimum concentrations of uric acid (UA) and reactive oxygen species (ROS) are necessary for normal functioning of the body. The ability of XOR to perform detoxification reactions, and to synthesize UA and reactive oxygen species (ROS) makes it a versatile intra- and extra-cellular protective "housekeeping enzyme". It is also an important component of the innate immune system. The enzyme is a target of drugs against gout and hyperuricemia and the protein is of major interest as it is associated with ischemia reperfusion (I/R) injury, vascular disorders in diabetes, cardiovascular disorders, adipogenesis, metabolic syndrome, cancer, and many other disease conditions. Xanthine oxidoreductase in conjugation with antibodies has been shown to have an anti-tumor effect due to its ability to produce ROS, which in turn reduces the growth of cancer tissues. Apart from this, XOR in association with nitric oxide synthase also participates in myocardial excitation-contraction coupling. Although XOR was discovered over 100 years ago, its physiological and pathophysiological roles are still not clearly elucidated. In this review, various physiological and pathophysiological functional aspects of XOR and its association with various forms of cancer are discussed in detail.

Metabolic syndrome, chronic kidney disease, and cardiovascular disease: a dynamic and life-threatening triad

The metabolic syndrome (MS) and chronic kidney disease (CKD) have both become global public health problems, with increasing social and economic impact due to their high prevalence and remarkable impact on morbidity and mortality. The causality between MS and CKD, and its clinical implications, still does remain not completely understood. Moreover, prophylactic and therapeutic interventions do need to be properly investigated in this field. Herein, we critically review the existing clinical evidence that associates MS with renal disease and cardiovascular disease, as well as the associated pathophysiologic mechanisms and actual treatment options.

Persistent proteinuria and dyslipidemia increase the risk of progressive chronic kidney disease in lupus erythematosus

Advances in immunotherapy have improved survival of patients with systemic lupus erythematosus who now face an increasing burden of chronic diseases including that of the kidney. As systemic inflammation is also thought to contribute directly to the progression of chronic kidney disease (CKD), we assessed this risk in patients with lupus, with and without a diagnosis of nephritis, and also identified modifiable risk factors. Accordingly, we enrolled 631 patients (predominantly Caucasian), of whom 504 were diagnosed with lupus within the first year and followed them an average of 11 years. Despite the presence of a chronic inflammatory disease, the rate of decline in renal function of 238 patients without nephritis was similar to that described for non-lupus patient cohorts. Progressive loss of kidney function developed exclusively in patients with lupus nephritis who had persistent proteinuria and dyslipidemia, although only six required dialysis or transplantation. The mortality rate was 16% with half of the deaths attributable to sepsis or cancer. Thus, despite the presence of a systemic inflammatory disease, the risk of progressive CKD in this lupus cohort was relatively low in the absence of nephritis. Hence, as in idiopathic glomerular disease, persistent proteinuria and dyslipidemia (modifiable risks) are the major factors for CKD progression in lupus patients with renal involvement.

Allopurinol to Febuxostat: How far have we come?

For decades allopurinol has been used as a xanthine oxidase inhibitor for treatment of hyperuricemia and gout. Although effective in many patients, some experience sensitivity to the drug. In some cases, this sensitivity may lead to allopurinol hypersensitivity disorder, which if untreated can be fatal. Recently the Food and Drug Administration has approved the use of febuxostat as an alternative therapy for hyperuricemia and gout. Febuxostat is a new xanthine oxidase inhibitor, but is not purine based and therefore decreases adverse reactions due to patient sensitivity. This review is a comprehensive look at the background of hyperuricemia and gout treatment with allopurinol compared to recent clinical studies with febuxostat. Each clinical study is evaluated and summarized, identifying the advances in treatment that have been made as well as the concerns that still exist with either treatment.

Soft drinks consumption and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a common clinical condition which is associated with metabolic syndrome in 70% of cases. Inappropriate dietary fat intake, excessive intake of soft drinks, insulin resistance and increased oxidative stress combine to increase free fatty acid delivery to the liver, and increased hepatic triglyceride accumulation contributes to fatty liver. Regular soft drinks have high fructose corn syrup which contains basic sugar building blocks, fructose 55% and glucose 45%. Soft drinks are the leading source of added sugar worldwide, and have been linked to obesity, diabetes, and metabolic syndrome. The consumption of soft drinks can increase the prevalence of NAFLD independently of metabolic syndrome. During regular soft drinks consumption, fat accumulates in the liver by the primary effect of fructose which increases lipogenesis, and in the case of diet soft drinks, by the additional contribution of aspartame sweetener and caramel colorant which are rich in advanced glycation end products that potentially increase insulin resistance and inflammation. This review emphasizes some hard facts about soft drinks, reviews fructose metabolism, and explains how fructose contributes to the development of obesity, diabetes, metabolic syndrome, and NAFLD.

Increased fructose consumption is associated with fibrosis severity in patients with nonalcoholic fatty liver disease

The rising incidence of obesity and diabetes coincides with a marked increase in fructose consumption. Fructose consumption is higher in individuals with nonalcoholic fatty liver disease (NAFLD) than in age-matched and body mass index (BMI)-matched controls. Because fructose elicits metabolic perturbations that may be hepatotoxic, we investigated the relationship between fructose consumption and disease severity in NAFLD. We studied 427 adults enrolled in the NASH Clinical Research Network for whom Block food questionnaire data were collected within 3 months of a liver biopsy. Fructose consumption was estimated based on reporting (frequency x amount) of Kool-aid, fruit juices, and nondietary soda intake, expressed as servings per week, and classified into none, minimum to moderate (<7 servings/week), and daily (> or =7 servings/week). The association of fructose intake with metabolic and histological features of NAFLD was analyzed using multiple linear and ordinal logistic regression analyses with and without controlling for other confounding factors. Increased fructose consumption was univariately associated with decreased age (P < 0.0001), male sex (P < 0.0001), hypertriglyceridemia (P < 0.04), low high-density lipoprotein (HDL) cholesterol (<0.0001), decreased serum glucose (P < 0.001), increased calorie intake (P < 0.0001), and hyperuricemia (P < 0.0001). After controlling for age, sex, BMI, and total calorie intake, daily fructose consumption was associated with lower steatosis grade and higher fibrosis stage (P < 0.05 for each). In older adults (age > or = 48 years), daily fructose consumption was associated with increased hepatic inflammation (P < 0.05) and hepatocyte ballooning (P = 0.05).

CONCLUSION

In patients with NAFLD, daily fructose ingestion is associated with reduced hepatic steatosis but increased fibrosis. These results identify a readily modifiable environmental risk factor that may ameliorate disease progression in patients with NAFLD.

Uremia impacts renal inflammatory cytokine gene expression in the setting of experimental acute kidney injury

Inflammatory cytokines are evoked by acute kidney injury (AKI) and may contribute to evolving renal disease. However, the impact of AKI-induced uremia on proinflammatory (e.g., TNF-alpha, MCP-1, TGF-beta1) and anti-inflammatory (e.g., IL-10) cytokine gene expression remains unknown. This study was undertaken to gain some initial insights into this issue. CD-1 mice were subjected to left renal ischemia-reperfusion (I/R) in the absence or presence of uremia (+/- right ureteral transection). TNF-alpha, MCP-1, TGF-beta1, and IL-10 mRNAs, cytokine protein levels, and RNA polymerase II (Pol II) recruitment to these genes were assessed. Renal cytokine mRNA levels were also contrasted with unilateral vs. bilateral renal parenchymal damage (I/R or ureteral obstruction). Potential effects of uremia on cytokine mRNAs in the absence of parenchymal renal damage [bilateral ureteral transection (BUTx)] were sought. Finally, the impact of simulated in vitro uremia (HK-2 tubular cells exposed to peritoneal dialysate from uremic vs. normal mice) on cytokine mRNA and microRNA profiles was assessed. Uremia blunted TNF-alpha, MCP-1, and TGF-beta1 mRNA increases in all three in vivo parenchymal acute renal failure models. These results were paralleled by reductions in cytokine protein levels and Pol II recruitment to their respective genes. Conversely, uremia increased IL-10 mRNA, both in the presence and absence (BUTx) of parenchymal renal damage. The uremic milieu also suppressed HK-2 cell proinflammatory cytokine mRNA levels and altered the expression of least 69 microRNAs (P < 0.0001). We conclude that both pro- and anti-inflammatory cytokine gene expressions are influenced by uremia, with a potential predilection toward an anti-inflammatory state. Changes in gene transcription (as reflected by Pol II recruitment), and possible posttranscriptional modifications (known to be induced by microRNAs), are likely involved.

Immune dysfunction in uremia

Kidney dysfunction leads to disturbed renal metabolic activities and to impaired glomerular filtration, resulting in the retention of toxic solutes affecting all organs of the body. Cardiovascular disease (CVD) and infections are the main causes for the increased occurrence of morbidity and mortality among patients with chronic kidney disease (CKD). Both complications are directly or indirectly linked to a compromised immune defense. The specific coordinated roles of polymorphonuclear leukocytes (PMNLs), monocytes/macrophages, lymphocytes and antigen-presenting cells (APCs) in maintaining an efficient immune response are affected. Their normal response can be impaired, giving rise to infectious diseases or pre-activated/primed, leading to inflammation and consequently to CVD. Whereas the coordinated removal via apoptosis of activated immune cells is crucial for the resolution of inflammation, inappropriately high apoptotic rates lead to a diminished immune response. In uremia, the balance between pro- and anti-inflammatory and between pro- and anti-apoptotic factors is disturbed. This review summarizes the interrelated parameters interfering with the immune response in uremia, with a special focus on the non-specific immune response and the role of uremic toxins.