Increased body mass index is a risk factor for end-stage renal disease in the Chinese Singapore population

Association of daytime napping with incidence of chronic kidney disease and end-stage kidney disease: A prospective observational study

BACKGROUND AND AIMS

Few studies have examined the relationship between daytime napping and risk of kidney diseases. We aimed to investigate the association of daytime napping with the incidence of chronic kidney disease (CKD) and end-stage kidney disease (ESKD). We also examined whether sleep duration modified the association of nap with CKD or ESKD.

METHODS

We recruited 460,571 European middle- to older-aged adults without prior CKD or ESKD between March 13, 2006, and October 1, 2010, in the UK Biobank. Sleep behavior data were obtained through questionnaires administered during recruitment. The analysis of the relationship between napping and the occurrence of CKD and ESKD utilized Cox proportional hazards regression models. The modification role of sleep duration on the effect of nap on CKD and ESKD was also examined.

RESULTS

After a mean follow-up of 11.1 (standard deviation 2.2) years, we observed 28,330 incident CKD cases and 927 ESKD cases. The daytime napping was associated with incident CKD (P for trend = .004). After fully adjusted, when compared with participants who did not take nap, those in sometimes and usually nap groups had higher risk of CKD. Nevertheless, the available evidence did not support a link between daytime napping and ESKD (P for trend = .06). Simultaneously, there was insufficient evidence suggesting that sleeping duration modified the association of daytime napping with incident CKD or ESKD.

CONCLUSION

Daytime napping was associated with an increased risk of CKD. However, the absence of conclusive evidence did not indicate a connection between daytime napping and ESKD.

Obesity-related glomerulopathy is associated with elevated WT1 expression in podocytes

BACKGROUND

The prevalence of obesity is increasing worldwide at an alarming rate. In addition to the increased incidence of cardiovascular and metabolic diseases, obesity is the most potent risk factor for developing chronic kidney disease (CKD). Although systemic events such as hemodynamic factors, metabolic effects, and lipotoxicity were implicated in the pathophysiology of obesity-related glomerulopathy (ORG) and kidney dysfunction, the precise mechanisms underlying the association between obesity and CKD remain unexplored.

METHODS

In this study, we employed spontaneous WNIN/Ob rats to investigate the molecular events that promote ORG. Further, we fed a high-fat diet to mice and analyzed the incidence of ORG. Kidney functional parameters, micro-anatomical manifestations, and podocyte morphology were investigated in both experimental animal models. Gene expression analysis in the rodents was compared with human subjects by data mining using Nephroseq and Kidney Precision Medicine Project database.

RESULTS

WNIN/Ob rats were presented with proteinuria and several glomerular deformities, such as adaptive glomerulosclerosis, decreased expression of podocyte-specific markers, and effacement of podocyte foot process. Similarly, high-fat-fed mice also showed glomerular injury and proteinuria. Both experimental animal models showed increased expression of podocyte-specific transcription factor WT1. The altered expression of putative targets of WT1 such as E-cadherin, podocin (reduced), and α-SMA (increased) suggests elevated expression of WT1 in podocytes elicits mesenchymal phenotype. Curated data from CKD patients revealed increased expression of WT1 in the podocytes and its precursors, parietal epithelial cells.

CONCLUSION

WT1 is crucial during nephron development and has minimal expression in adult podocytes. Our study discovered elevated expression of WT1 in podocytes in obesity settings. Our analysis suggests a novel function for WT1 in the pathogenesis of ORG; however, the precise mechanism of WT1 induction and its involvement in podocyte pathobiology needs further investigation.

Sleep traits and risk of end-stage renal disease: a mendelian randomization study

BACKGROUND

Epidemiological evidence relating sleep disorders to end-stage renal disease (ESRD) has been obscure. The present study is sought to examine the association between sleep traits and ESRD.

METHODS

For this analysis, we selected genetic instruments for sleep traits from published genome-wide association studies (GWAS). As instrumental variables, independent genetic variations linked with seven sleep-related features (sleep duration, getting up in the morning, daytime napping, chronotype of morning/evening person, sleeplessness/insomnia, non-snoring, and daytime dozing) were chosen. A two-sample Mendelian randomization (TSMR) study was conducted to assess the causal relationship between sleep traits and ESRD (N = 33,061). The reverse MR analysis subsequently determined the causal relationship between ESRD and sleep traits. The causal effects were estimated using inverse variance weighted, MR-Egger, weighted median. To conduct sensitivity studies, Cochran's Q test, MR-Egger intercept test, MR-PRESSO, leave-one-out analysis, and funnel plot were used. To study the potential mediators, multivariable mendelian randomization analyses were undertaken further.

RESULTS

Genetically predicted sleeplessness/ insomnia (OR = 6.11, 95%CI 1.00-37.3, P = 0.049, FDR = 0.105), getting up in the morning easily(OR = 0.23, 95%CI 0.063-0.85; P = 0.0278, FDR = 0.105), non-snoring (OR = 4.76E-02, 95%CI 2.29E-03-0.985, P = 0.0488, FDR = 0.105) was suggestively associated with the risk of ESRD. However, we found no evidence favoring a causal association between other sleep traits and ESRD through the IVW method.

CONCLUSION

The present TSMR found no strong evidence of a bidirectional causal association between genetically predicted sleep traits and ESRD.

Renal UTX-PHGDH-serine axis regulates metabolic disorders in the kidney and liver

Global obesity epidemics impacts human health and causes obesity-related illnesses, including the obesity-related kidney and liver diseases. UTX, a histone H3K27 demethylase, plays important roles in development and differentiation. Here we show that kidney-specific knockout Utx inhibits high-fat diet induced lipid accumulation in the kidney and liver via upregulating circulating serine levels. Mechanistically, UTX recruits E3 ligase RNF114 to ubiquitinate phosphoglycerate dehydrogenase, the rate limiting enzyme for de novo serine synthesis, at Lys³¹⁰ and Lys³³⁰, which leads to its degradation, and thus suppresses renal and circulating serine levels. Consistently, phosphoglycerate dehydrogenase and serine levels are markedly downregulated in human subjects with diabetic kidney disease or obesity-related renal dysfunction. Notably, oral administration of serine ameliorates high-fat diet induced fatty liver and renal dysfunction, suggesting a potential approach against obesity related metabolic disorders. Together, our results reveal a metabolic homeostasis regulation mediated by a renal UTX-PHGDH-serine axis.

Obesity as a predictive factor for chronic kidney disease in adults: systematic review and meta-analysis

Chronic kidney disease (CKD) is one of the main chronic diseases affecting the world population due to its high prevalence and increasing morbidity. Similarly, obesity gained the interest of the scientific community as it directly or indirectly increases mortality from cardiovascular causes, and its prevalence characterizes a pandemic. The objective of this study was to investigate obesity measured by body mass index as a predictor for end-stage renal disease in the general adult population. A systematic review and meta-analysis was carried out by searching 10 databases for prospective or retrospective cohort studies, with no restrictions on the language of publication, including adults with obesity without previous renal disease and who evolved to CKD (diagnosed by estimated glomerular filtration rate below 60 mL&mac_middot;min^-1&mac_middot;(1.73 m²)^-1 over the follow-up period. The R software and Meta package were used for data analysis. After removing duplicates, 5431 studies were submitted to the steps of the systematic review, and 21 articles were included in the data analysis. In total, 3,504,303 patients, 521,216 with obesity, and an average follow-up time of 9.86 years were included. The relative risk of obese people for developing CKD in the random effects model was 1.81 (95%CI: 1.52-2.16). The evidence found in this meta-analysis confirmed that obese people are at higher risk of developing CKD that the non-obese population (1.81 times higher), with obesity being a priority risk factor in preventive actions.

Healthful dietary patterns and risk of end-stage kidney disease: the Singapore Chinese Health Study

BACKGROUND

Although adherence to healthful dietary patterns has been associated with a lower risk of kidney function decline in Western populations, evidence in Asian populations remains scanty.

OBJECTIVES

We examined predefined dietary patterns, namely, the Alternate Healthy Eating Index-2010 (AHEI-2010), the Dietary Approaches to Stop Hypertension (DASH), and the alternate Mediterranean diet (aMED), in relation to risk of end-stage kidney disease (ESKD).

METHODS

We included 56,985 Chinese adults (aged 45-74 y) in the Singapore Chinese Health Study who were free of cancer, stroke, coronary artery disease, and ESKD at recruitment (1993-1998). Dietary pattern scores were calculated based on a validated 165-item FFQ. AHEI-2010 and aMED scores were modified by excluding the alcohol intake component because daily drinking has been associated with a higher risk of ESKD in our study population. We identified 1026 ESKD cases over a median follow-up of 17.5 y via linkage with the nationwide Singapore Renal Registry. Multivariable Cox regression models were used to compute HRs and their 95% CIs.

RESULTS

Higher scores of all 3 dietary patterns were associated with lower ESKD risk in a dose-dependent manner. Compared with the lowest quintiles, the multivariable-adjusted HRs (95% CIs) of ESKD were 0.75 (0.61, 0.92) for the highest quintile of AHEI-2010, 0.67 (0.54, 0.84) for DASH, and 0.73 (0.59, 0.91) for aMED (all P-trend ≤ 0.004). These inverse associations were stronger with increasing BMI (in kg/m2), and the HRs for the diet-ESKD association were lowest in the obese (BMI ≥ 27.5), followed by the overweight (BMI = 25 to <27.5) participants, compared with those in lower BMI categories; the P-interaction values between BMI and diet scores were 0.03 for AHEI-2010, 0.004 for aMED, and 0.06 for DASH.

CONCLUSIONS

Adherence to healthful dietary patterns was associated with a lower ESKD risk in an Asian population, especially in overweight or obese individuals.

The impact of diabetes on the association between alcohol intake and the risk of end-stage kidney disease in the Singapore Chinese Health Study

BACKGROUND

The relationship between alcohol intake and end-stage kidney disease (ESKD) risk is controversial. Moreover, while evidence has shown that the relationship between alcohol and atherosclerosis may be modified by diabetes, whether this applies to ESKD is unknown.

METHODS

We examined these associations in the Singapore Chinese Health Study, a prospective cohort of 63 257 adults aged 45 to 74 years. Information on alcohol intake, diet, lifestyle factors, and medical history was collected at recruitment. We identified 1217 ESKD cases via linkage with the Singapore Renal Registry after a mean follow-up of 17.5 years. Cox regression models were used to estimate hazard ratios (HRs) and 95% CI of ESKD.

RESULTS

Among the participants without diabetes at baseline, monthly to weekly drinking was associated with a decreased risk of ESKD (HR 0.69; 95% CI, 0.54-0.87) compared to nondrinkers. In contrast, this association was attenuated and not significant among those with diabetes (HR 0.82; 95% CI, 0.58-1.16; P_interaction = .19). Comparatively, alcohol intake of ≥2 drinks per day was significantly associated with an increased risk of ESKD compared to nondrinkers among those with diabetes (HR 2.00; 95% CI, 1.14-3.53) but not among those without diabetes (HR 0.91; 95% CI, 0.53-1.56; P_interaction = .01). The risk of ESKD among those with diabetes and who also consumed ≥2 drinks per day was increased by nearly 12-fold compared to nondrinkers without diabetes (HR 11.6; 95% CI, 6.73-19.9).

CONCLUSION

Low-dose drinking is associated with a reduced risk of ESKD among individuals without diabetes. However, joint exposure to heavy drinking and diabetes is associated with a substantially higher risk of ESKD.

Pulse Pressure and the Risk of End-Stage Renal Disease Among Chinese Adults in Singapore: The Singapore Chinese Health Study

Background Although hypertension is an established risk factor for chronic kidney disease, less is known about the relationship of pulse pressure (PP), a measure of arterial stiffness, with chronic kidney disease. We investigated the association of systolic blood pressure (BP), diastolic BP, PP, and mean arterial pressure with the risk of end-stage renal disease (ESRD) in the prospective population-based Singapore Chinese Health Study. Methods and Results We used data from 30 636 participants who had BP measured at ages 46 to 85 years during follow-up I interviews between 1999 and 2004. Information on lifestyle factors was collected at recruitment from 1993 to 1998, and selected factors were updated at follow-up I. We identified 463 ESRD cases over an average 11.3 years of follow-up I by linkage with the nationwide Singapore Renal Registry. Cox proportional hazards regression models were used to assess the relations between different BP indexes and ESRD risk. Each BP index was positively associated with ESRD when studied individually. However, when PP was included as a covariate, systolic and diastolic BP and mean arterial pressure were no longer associated with ESRD. Conversely, PP remained significantly associated with ESRD risk in a dose-dependent manner (Ptrend<0.001) after adjusting for systolic or diastolic BP. Compared with the lowest group (<45 mm Hg) of PP, the hazard ratio was 5.25 (95% CI, 3.52-7.84) for the highest group (≥85 mm Hg). The association between hypertension and ESRD risk was attenuated and no longer significant after adjusting for PP. Conclusions Our findings provide a basis for targeting reduction of arterial stiffness to decrease ESRD risk.

Obesity and risk of end-stage renal disease in patients with chronic kidney disease: a cohort study

Background

Obesity is a risk factor for de novo chronic kidney disease (CKD) in the general population. Obesity has been increasingly prevalent in patients with CKD and may lead to further progression of pre-existing CKD. However, whether obesity is associated with the development of end-stage renal disease (ESRD) in patients with CKD is not well understood.

Objective

We investigated the impact of obesity on ESRD (needing chronic dialysis treatment or pre-emptive renal transplantation) or all-cause mortality in patients with moderate to advanced CKD.

Design

A total of 322 patients with stages 3-5 CKD who were not yet on dialysis were prospectively followed for a median of 4.9 y. Obesity was defined by body mass index (BMI, in kg/m2) ≥30 or body fat percentage (BF%) >25% in men and >35% in women. BF% was assessed with the use of the Body Composition Monitor, a multifrequency bioimpedance spectroscopy device.

Results

In total, 100 participants progressed to ESRD and 39 participants died. Obesity, whether defined by BMI or BF%, was not associated with a significantly increased risk of ESRD in Cox proportional hazards models that adjusted for age, sex, diabetes mellitus, cardiovascular disease, estimated glomerular filtration rate, urine protein:creatinine ratio, high-sensitivity C-reactive protein, and use of renin-angiotensin-aldosterone system inhibitors or statins, accounting for the competing risk for mortality (subdistribution HR: 1.15; 95% CI: 0.62, 2.14 for BMI-defined obesity and subdistribution HR: 0.84, 95% CI: 0.54, 1.29 for BF%-defined obesity, respectively). Results were similar when BMI and BF% were analyzed as continuous or time-dependent variables. Whereas higher BMI was protective, higher BF% appeared to be associated with increased all-cause mortality.

Conclusions

Obesity did not confer an increased risk of ESRD in patients with moderate to advanced CKD. This trial was registered at http://www.clinicaltrials.gov as NCT03285074.

Sleep duration and risk of end-stage renal disease: the Singapore Chinese Health Study

OBJECTIVES

Although epidemiological evidence suggests that short sleep duration may affect renal function, the influence of long sleep and risk of end-stage renal disease (ESRD) is unclear. We examined the association between sleep duration and risk of ESRD.

METHODS

We investigated sleep duration and ESRD risk in the Singapore Chinese Health Study, a prospective population-based cohort of 63,257 Chinese in Singapore, who were aged 45-74 years at recruitment (1993-1998). Information on daily sleep duration (including naps), diet, medical history and other lifestyle factors was collected at recruitment from in-person interviews. ESRD cases were identified via linkage with the nationwide Singapore Renal Registry through year 2014. We used the Cox proportional hazards regression method to estimate hazard ratio (HR) and 95% confidence interval (CI) of ESRD in relation to sleep duration.

RESULTS

After an average 16.8 years of follow-up, 1143 (1.81%) ESRD cases were documented. Sleep duration had a U-shaped association with risk of ESRD (P for quadratic trend < 0.001). Compared with participants with 7 h/day of sleep, the multivariable adjusted HR (95% CI) of ESRD was 1.43 (1.18-1.74) for short sleep (≤5 h/day) and 1.28 (1.03-1.60) for long sleep duration (≥9 h/day). The increased risk was stronger in participants with more than 10 years of follow-up compared to those with shorter follow-up time, especially for long sleep (P for interaction = 0.003).

CONCLUSIONS

Our findings demonstrated that both short and long sleep durations were associated with a higher risk of ESRD in this Asian population.

Activation of mineralocorticoid receptor by ecdysone, an adaptogenic and anabolic ecdysteroid, promotes glomerular injury and proteinuria involving overactive GSK3β pathway signaling

Ecdysone is an arthropod molting hormone and has been marketed as a non-androgenic natural anabolic and adaptogen. However, the safety profile of ecdysone is largely undetermined. After ecdysone treatment for 2 weeks, mice developed albuminuria with histologic signs of glomerular injury, including hypertrophy, mesangial expansion, mild glomerulosclerosis and podocyte injury. A direct glomerulopathic activity of ecdysone seems to contribute, since addition of ecdysone to cultured glomerular cells induced cytopathic changes, including apoptosis, activation of mesangial cells, podocyte shape changes and a decreased expression of podocyte markers. To explore the molecular target responsible for the pathogenic actions, we employed an in silico modeling system of compound-protein interaction and identified mineralocorticoid receptor (MR) as one of the top-ranking proteins with putative interactions with ecdysone. The molecular structure of ecdysone was highly homologous to mineralocorticoids, like aldosterone. Moreover, ecdysone was capable of both inducing and activating MR, as evidenced by MR nuclear accumulation in glomerular cells both in vitro and in vivo following ecdysone treatment. Mechanistically, glycogen synthase kinase (GSK) 3β, which has been recently implicated in pathogenesis of glomerular injury and proteinuria, was hyperactivated in glomeruli in ecdysone-treated mice, concomitant with diverse glomerulopathic changes. In contrast, spironolactone, a selective blockade of MR, largely abolished the cytopathic effect of ecdysone in vitro and attenuated albuminuria and glomerular lesions in ecdysone treated mice, associated with a mitigated GSK3β overactivity in glomeruli. Altogether, ecdysone seems able to activate MR and thereby promote glomerular injury and proteinuria involving overactive GSK3β pathway signaling.

Arylsulphatase A Pseudodeficiency (ARSA-PD), hypertension and chronic renal disease in Aboriginal Australians

Chronic renal disease (CRD) associated with cardiovascular disease (CVD) and/or type 2 diabetes (T2D) is a significant problem in Aboriginal Australians. Whole exome sequencing data (N = 72) showed enrichment for ClinVar pathogenic variants in gene sets/pathways linking lipoprotein, lipid and glucose metabolism. The top Ingenuity Pathway Analysis canonical pathways were Farsenoid X Receptor and Retinoid Receptor (FXR/RXR; (P = 1.86 × 10⁻⁷), Liver X Receptor and Retinoid Receptor (LXR/RXR; P = 2.88 × 10⁻⁶), and atherosclerosis signalling (P = 3.80 × 10⁻⁶). Top pathways/processes identified using Enrichr included: Reactome 2016 chylomicron-mediated lipid transport (P = 3.55 × 10⁻⁷); Wiki 2016 statin (P = 8.29 × 10⁻⁸); GO Biological Processes 2017 chylomicron remodelling (P = 1.92 × 10⁻⁸). ClinVar arylsulfatase A pseudodeficiency (ARSA-PD) pathogenic variants were common, including the missense variant c.511 G > A (p.Asp171Asn; rs74315466; frequency 0.44) only reported in Polynesians. This variant is in cis with known ARSA-PD 3′ regulatory c.*96 A > G (rs6151429; frequency 0.47) and missense c.1055 A > G (p.Asn352Ser; rs2071421; frequency 0.47) variants. These latter two variants are associated with T2D (risk haplotype GG; odds ratio 2.67; 95% CI 2.32–3.08; P = 2.43 × 10⁻⁴) in genome-wide association data (N = 402), but are more strongly associated with quantitative traits (DBP, SBP, ACR, eGFR) for hypertension and renal function in non-diabetic than diabetic subgroups. Traits associated with CVD, CRD and T2D in Aboriginal Australians provide novel insight into function of ARSA-PD variants.

Comparison of visceral, body fat indices and anthropometric measures in relation to chronic kidney disease among Chinese adults from a large scale cross-sectional study

Background

The aim of the study was to assess the association between chronic kidney disease (CKD) and obesity in predicting CKD among Chinese adults, distinguishing between 5 different adiposity indices: visceral fat index (VFI), percentage body fat (PBF), body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR).

Methods

A total of 29,516 participants aged 35 years or above were selected using a stratified multistage random sampling method across China during 2012–2015. CKD was defined as an estimated glomerular filtration (eGFR) < 60 ml/min/1.72m².

Results

The overall weighted prevalence of CKD was 3.94% (3.62% in males and 4.25% in females). All five adiposity indices had significant negative correlations to eGFR (P < 0.05). The area under the ROC (receiver operating characteristic) curves (AUC) for PBF was almost significantly larger than the other adiposity indices (P < 0.001). In addition, PBF yielded the highest Youden index in identifying CKD (male: 0.15; female: 0.20). In the logistic analysis, PBF had the highest crude odds ratios (ORs) in both males (OR: 1.819, 95% CI 1.559–2.123) and females (OR: 2.268, 95% CI 1.980–2.597). After adjusted for age, smoking status, alcohol use, education level, marital status, rural vs. urban area, geographic regions, and diagnosis of hypertension, diabetes mellitus, myocardial infarction and stroke, the ORs on PBF remained significant for both genders (P < 0.05).

Conclusions

Obesity is associated with an increased risk of CKD. Furthermore, PBF was a better predictor for identifying CKD than other adiposity indices (BMI, WC, WHtR, and VFI).

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0837-1) contains supplementary material, which is available to authorized users.