Inequalities in the management of diabetic kidney disease in UK primary care: A cross-sectional analysis of a large primary care database

AIMS

To determine differences in the management of diabetic kidney disease (DKD) relevant to patient sex, ethnicity and socio-economic group in UK primary care.

METHODS

A cross-sectional analysis as of January 1, 2019 was undertaken using the IQVIA Medical Research Data dataset, to determine the proportion of people with DKD managed in accordance with national guidelines, stratified by demographics. Robust Poisson regression models were used to calculate adjusted risk ratios (aRR) adjusting for age, sex, ethnicity and social deprivation.

RESULTS

Of the 2.3 million participants, 161,278 had type 1 or 2 diabetes, of which 32,905 had DKD. Of people with DKD, 60% had albumin creatinine ratio (ACR) measured, 64% achieved blood pressure (BP, <140/90 mmHg) target, 58% achieved glycosylated haemoglobin (HbA1c, <58 mmol/mol) target, 68% prescribed renin-angiotensin-aldosterone system (RAAS) inhibitor in the previous year. Compared to men, women were less likely to have creatinine: aRR 0.99 (95% CI 0.98-0.99), ACR: aRR 0.94 (0.92-0.96), BP: aRR 0.98 (0.97-0.99), HbA1c : aRR 0.99 (0.98-0.99) and serum cholesterol: aRR 0.97 (0.96-0.98) measured; achieve BP: aRR 0.95 (0.94-0.98) or total cholesterol (<5 mmol/L) targets: aRR 0.86 (0.84-0.87); or be prescribed RAAS inhibitors: aRR 0.92 (0.90-0.94) or statins: aRR 0.94 (0.92-0.95). Compared to the least deprived areas, people from the most deprived areas were less likely to have BP measurements: aRR 0.98 (0.96-0.99); achieve BP: aRR 0.91 (0.8-0.95) or HbA1c : aRR 0.88 (0.85-0.92) targets, or be prescribed RAAS inhibitors: aRR 0.91 (0.87-0.95). Compared to people of white ethnicity; those of black ethnicity were less likely to be prescribed statins aRR 0.91 (0.85-0.97).

CONCLUSIONS

There are unmet needs and inequalities in the management of DKD in the UK. Addressing these could reduce the increasing human and societal cost of managing DKD.

Regional Variation in Hemoglobin Distribution Among Individuals With CKD: the ISN International Network of CKD Cohorts

Introduction

Despite recognized geographic and sex-based differences in hemoglobin in the general population, these factors are typically ignored in patients with chronic kidney disease (CKD) in whom a single therapeutic range for hemoglobin is recommended. We sought to compare the distribution of hemoglobin across international nondialysis CKD populations and evaluate predictors of hemoglobin.

Methods

In this cross-sectional study, hemoglobin distribution was evaluated in each cohort overall and stratified by sex and estimated glomerular filtration rate (eGFR). Relationships between candidate predictors and hemoglobin were assessed from linear regression models in each cohort. Estimates were subsequently pooled in a random effects model.

Results

A total of 58,613 participants from 21 adult cohorts (median eGFR range of 17-49 ml/min) and 3 pediatric cohorts (median eGFR range of 26-45 ml/min) were included with broad geographic representation. Hemoglobin values varied substantially among the cohorts, overall and within eGFR categories, with particularly low mean hemoglobin observed in women from Asian and African cohorts. Across the eGFR range, women had a lower hemoglobin compared to men, even at an eGFR of 15 ml/min (mean difference 5.3 g/l, 95% confidence interval [CI] 3.7-6.9). Lower eGFR, female sex, older age, lower body mass index, and diabetic kidney disease were all independent predictors of a lower hemoglobin value; however, this only explained a minority of variance (R2 7%-44% across cohorts).

Conclusion

There are substantial regional differences in hemoglobin distribution among individuals with CKD, and the majority of variance is unexplained by demographics, eGFR, or comorbidities. These findings call for a renewed interest in improving our understanding of hemoglobin determinants in specific CKD populations.

Fat mass, weight and body shape changes at menopause - causes and consequences: a narrative review

In addition to age-related weight gain, menopause adds additional challenges for women with the occurrence of significant metabolic alterations and central and visceral fat redistribution. The changes in body composition then influence risks of cardiovascular disease, metabolic disruption, cancer, fracture, lung disease, sexual dysfunction, mental health disorders and dementia. They may also heighten the severity of vasomotor symptoms. Treatment of these changes requires a flexible long-term strategy. This narrative review explores the pathogenesis of the metabolic changes at menopause and effective management options.

Decreased renal function is associated with incident dementia: An IMRD-THIN retrospective cohort study in the UK

INTRODUCTION

Decreased renal function is a potential risk factor for dementia.

METHODS

This retrospective cohort study of 2.8 million adults aged ≥50 years used the IMRD-THIN database, representative of UK primary care, from January 1, 1995 to February 24, 2020. The associations between estimated glomerular filtration rate (eGFR) and urine albumin creatinine ratio (ACR) with incident all-cause dementia were analyzed using Cox regression.

RESULTS

In the eGFR cohort (n = 2,797,384), worsening renal dysfunction was associated with increased hazard of all-cause dementia, with greatest hazard at eGFR 15-30 ml/min/1.73min² (hazard ratio [HR] 1.26, 95% confidence interval [CI] 1.19-1.33). In the ACR cohort (n = 641,912), the hazard of dementia increased from ACR 3-30 mg/mmol (HR 1.13, 95% CI 1.10-1.15) to ACR > 30 mg/mmol (HR 1.25, 95% CI 1.18-1.33).

DISCUSSION

Worsening eGFR and albuminuria have graded associations with the risk of dementia, which may have significant implications for the care of patients with kidney disease.

Use of the kidney failure risk equation to inform clinical care of patients with chronic kidney disease: a mixed-methods systematic review

RATIONALE AND OBJECTIVE

The Kidney Failure Risk Equation (KFRE) predicts the risk of end-stage kidney disease in patients with chronic kidney disease (CKD). This study aimed to evaluate the impact of the utility of KFRE in clinical practice.

STUDY DESIGN

Systematic review.

SETTING AND STUDY POPULATIONS

Adult patients with CKD but not receiving renal replacement therapy enrolled in studies where KFRE was used in clinical care pathways.

SELECTION CRITERIA FOR STUDIES

All studies published from April 2011 to October 2021 identified from Medline, Cumulative Index to Nursing and Allied Health Literature, Embase and reference and citation searches of included studies.

DATA EXTRACTION

Relevant data were extracted, and two reviewers independently assessed study quality using appropriate appraisal tools.

ANALYTICAL APPROACH

Findings reported as a narrative synthesis due to heterogeneity of the included studies.

RESULTS

Of 1635 studies identified, 440 duplicates were removed. The remaining 1195 titles and abstracts were screened. All five studies for full-text review were included in the analysis. Three uses of KFRE were assessed: (1) primary to specialty care interface; (2) general nephrology to multidisciplinary care transition; and (3) treatment planning. Evidence of impact on number of patient referrals into nephrology care was conflicting. However, wait times improved in one study. Although KFRE identified high-risk patients for increased multidisciplinary support, there was concern patients stepped down, no longer meeting eligibility criteria, may lack access to services.

CONCLUSIONS

This is the first systematic review of studies that have assessed the actual impact of KFRE in clinical practice with five studies of varying quality reported to date. Trials are in progress assessing the impact on clinical outcomes of using KFRE in clinical practice, and KFRE is being incorporated into guidelines for CKD management. Further studies are needed to assess the impact of KFRE on clinical care.

TRIAL REGISTRATION NUMBER

Protocol registered on PROSPERO before initiation of the study (Ref: CRD42020219926).

Menopause status and climacteric symptoms in a birth cohort of mid-life New Zealand women

BACKGROUND

There is little current research on the transition to natural menopause among contemporary groups of mid-life women at age 40 years.

OBJECTIVE

This study reports on female members of the Christchurch Health and Development Study cohort. This research aimed to: document the menopause status, reproductive outcomes and climacteric symptoms of the women at age 40 years; examine the associations between menopause status and concurrent measures of psychosocial and economic well-being; and document the associations between menopause status and potential predictors of menopause reflecting childhood, family and individual factors prior to age 40 years.

METHODS

The Christchurch Health and Development Study is a longitudinal, representative, prospective cohort of 1265 babies (630 females) born in New Zealand in 1977. At age 40 years, 470 women (who had not experienced surgical menopause) were interviewed on their menopause status, climacteric symptoms and associated factors.

RESULTS

The majority of women were premenopausal, around 20% were perimenopausal and 2% were postmenopausal. Statistically significant associations were found reflecting higher rates of diagnosed reproductive disorder, climacteric symptoms, low occupational status, non-heterosexual sexuality and exposure to childhood sexual abuse amongst both perimenopausal and postmenopausal women at age 40 years.

CONCLUSION

These data will inform directions for future data collection and analyses.

Broadening the ecology of fear: non-lethal effects arise from diverse responses to predation and parasitism

Research on the 'ecology of fear' posits that defensive prey responses to avoid predation can cause non-lethal effects across ecological scales. Parasites also elicit defensive responses in hosts with associated non-lethal effects, which raises the longstanding, yet unresolved question of how non-lethal effects of parasites compare with those of predators. We developed a framework for systematically answering this question for all types of predator-prey and host-parasite systems. Our framework reveals likely differences in non-lethal effects not only between predators and parasites, but also between different types of predators and parasites. Trait responses should be strongest towards predators, parasitoids and parasitic castrators, but more numerous and perhaps more frequent for parasites than for predators. In a case study of larval amphibians, whose trait responses to both predators and parasites have been relatively well studied, existing data indicate that individuals generally respond more strongly and proactively to short-term predation risks than to parasitism. Apart from studies using amphibians, there have been few direct comparisons of responses to predation and parasitism, and none have incorporated responses to micropredators, parasitoids or parasitic castrators, or examined their long-term consequences. Addressing these and other data gaps highlighted by our framework can advance the field towards understanding how non-lethal effects impact prey/host population dynamics and shape food webs that contain multiple predator and parasite species.

Oxidative stress links periodontal inflammation and renal function

Aims

Patients with chronic kidney disease (CKD) are also susceptible to periodontitis. The causal link between periodontitis and CKD may be mediated via systemic inflammation/oxidative stress. Using structural equation modelling (SEM), this cross‐sectional study aimed to explore the causal relationship between periodontal inflammation (PI) and renal function.

Materials and methods

Baseline data on 770 patients with stage 3–5 (pre‐dialysis) CKD from an ongoing cohort study were used. Detailed, bioclinical data on PI and renal function, as well as potential confounders and mediators of the relationship between the two, were collected. SEMs of increasing complexity were created to test the causal assumption that PI affects renal function and vice versa.

Results

Structural equation modelling confirmed the assumption that PI and renal function are causally linked, mediated by systemic oxidative stress. The magnitude of this effect was such that a 10% increase in PI resulted in a 3.0% decrease in renal function and a 10% decrease in renal function resulted in a 25% increase in PI.

Conclusions

Periodontal inflammation represents an occult source of oxidative stress in patients with CKD. Further clinical studies are needed to confirm whether periodontal therapy, as a non‐pharmacological approach to reducing systemic inflammatory/oxidative stress burden, can improve outcomes in CKD.

Cytomegalovirus seropositivity is independently associated with cardiovascular disease in non-dialysis dependent chronic kidney disease

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of early death in patients with chronic kidney disease (CKD). Previous work has described an association between Cytomegalovirus (CMV) seropositivity and CVD amongst patients with dialysis dependent end stage renal disease. Whether CMV seropositivity is associated with CVD in non-dialysis dependent CKD has not been established.

AIM

Investigate whether past CMV infection is associated with prevalent CVD in patients with non-dialysis dependent CKD.

DESIGN

A retrospective observational study using the Renal Impairment in Secondary Care cohort, a study evaluating bio-clinical determinants of outcomes in patients with progressive CKD.

METHODS

We assayed cryopreserved serum samples collected at inception for anti-CMV IgG antibodies from 764 patients with stages 2 to 5 CKD (pre-dialysis) and investigated its relationship with prevalent CVD.

RESULTS

Median estimated glomerular filtration was 24 ml/min/1.73 m2 (IQR 19-32). Sixty-eight percent of patients were CMV seropositive. CMV seropositivity was associated with older age, non-Caucasian ethnicity, diabetes and higher social deprivation index score. On univariable analysis, CMV seropositivity correlated with higher systolic blood pressure (P = 0.044), prevalent CVD (P < 0.001), ischaemic heart disease (P < 0.001) and cerebrovascular disease (P = 0.022). On multivariable analysis, CMV seropositive patients nearly twice as likely to have CVD compared to seronegative patients [Odds Ratio (OR) = 1.998, CI 1.231-3.242, P = 0.005].

CONCLUSIONS

In patients with non-dialysis CKD, CMV seropositivity is independently associated with a higher prevalence of CVD.

Association between non-malignant monoclonal gammopathy and adverse outcomes in chronic kidney disease: A cohort study

BACKGROUND

In studies including the general population, the presence of non-malignant monoclonal gammopathy (MG) can be causally associated with kidney damage and shorter survival. We assessed whether the presence of an MG is associated with a higher risk of kidney failure or death in individuals with chronic kidney disease (CKD).

METHODS AND FINDINGS

Data were used from 3 prospective cohorts of individuals with CKD (not on dialysis or with a kidney transplant): (1) Renal Impairment in Secondary Care (RIISC, Queen Elizabeth Hospital and Heartlands Hospital, Birmingham, UK, N = 878), (2) Salford Kidney Study (SKS, Salford Royal Hospital, Salford, UK, N = 861), and (3) Renal Risk in Derby (RRID, Derby, UK, N = 1,739). Participants were excluded if they had multiple myeloma or any other B cell lymphoproliferative disorder with end-organ damage. Median age was 71.0 years, 50.6% were male, median estimated glomerular filtration rate was 42.3 ml/min/1.73 m2, and median urine albumin-to-creatinine ratio was 3.4 mg/mmol. All non-malignant MG was identified in the baseline serum of participants of RIISC. Further, light chain MG (LC-MG) was identified and studied in participants of RIISC, SKS, and RRID. Participants were followed up for kidney failure (defined as the initiation of dialysis or kidney transplantation) and death. Associations with the risk of kidney failure were estimated by competing-risks regression (handling death as a competing risk), and associations with death were estimated by Cox proportional hazards regression. In total, 102 (11.6%) of the 878 RIISC participants had an MG. During a median follow-up time of 74.0 months, there were 327 kidney failure events and 202 deaths. The presence of MG was not associated with risk of kidney failure (univariable subhazard ratio [SHR] 0.97 [95% CI 0.68 to 1.38], P = 0.85; multivariable SHR 1.16 [95% CI 0.80 to 1.69], P = 0.43), and although there was a higher risk of death in univariable analysis (hazard ratio [HR] 2.13 [95% CI 1.49 to 3.02], P < 0.001), this was not significant in multivariable analysis (HR 1.37 [95% CI 0.93 to 2.00], P = 0.11). Fifty-five (1.6%) of the 3,478 participants from all 3 studies had LC-MG. During a median follow-up time of 62.5 months, 564 of the 3,478 participants progressed to kidney failure, and 803 died. LC-MG was not associated with risk of kidney failure (univariable SHR 1.07 [95% CI 0.58 to 1.96], P = 0.82; multivariable SHR 1.42 [95% CI 0.78 to 2.57], P = 0.26). There was a higher risk of death in those with LC-MG in the univariable model (HR 2.51 [95% CI 1.59 to 3.96], P < 0.001), but not in the multivariable model (HR 1.49 [95% CI 0.93 to 2.39], P = 0.10). An important limitation of this work was that only LC-MG, rather than any MG, could be identified in participants from SKS and RRID.

CONCLUSIONS

The prevalence of MG was higher in this CKD cohort than that reported in the general population. However, the presence of an MG was not independently associated with a significantly higher risk of kidney failure or, unlike in the general population, risk of death.

Imbalanced turnover of collagen type III is associated with disease progression and mortality in high-risk chronic kidney disease patients

Background

Tubulointerstitial fibrosis is a major pathological feature in chronic kidney disease (CKD) and collagen type III (COL3) is a major component of the renal fibrotic scar. We hypothesized that a dysregulated turnover of COL3 is an important determinant of CKD progression. We assessed the relationship between fragments reflecting active formation (PRO-C3) and degradation (C3M) of COL3 and CKD disease progression and mortality in a prospective cohort of CKD patients.

Methods

We measured PRO-C3 and C3M in urine (uPRO-C3 and uC3M) and serum (sPRO-C3 and sC3M) of 500 patients from the Renal Impairment in Secondary Care study. Disease progression was defined as a decline in estimated glomerular filtration rate >30% or the start of renal replacement therapy within 12 and 30 months.

Results

Levels of uC3M/creatinine decreased, whereas levels of uPRO-C3/creatinine and sPRO-C3 increased with increasing CKD stage. uC3M/creatinine was inversely and independently associated with disease progression by 12 months {odds ratio [OR] 0.39 [95% confidence interval (CI) 0.18-0.83]; P = 0.01 per doubling of uC3M/creatinine} with development of end-stage renal disease [hazard ratio (HR) 0.70 (95% CI 0.50-0.97); P = 0.03 per doubling of uC3M/creatinine]. sPRO-C3 at baseline was independently associated with increased mortality [HR 1.93 (95% CI 1.21-3.1); P = 0.006 per doubling of sPRO-C3] and disease progression by 30 months [OR 2.16 (95% CI 1.21-3.84); P = 0.009 per doubling of sPRO-C3].

Conclusions

Dynamic products of COL3 formation and degradation were independently associated with CKD progression and mortality and may represent an opportunity to link pathological processes with targeted treatments against fibrosis.

Abstract PD8-07: Does resection of cavity shave margins result in lower positive margin and re-excision rates in patients with stage 0-III breast cancer? Results from a prospective multicenter randomized controlled trial

INTRODUCTION: Routine resection of cavity shave margins has been shown in single center studies to result in a significant reduction in positive margin and re-excision rates. In this prospective multicenter randomized controlled trial, we sought to validate these findings across practice settings.

METHODS: Nine centers across the United States, varying in practice setting and patient population, participated in this clinical trial of 398 stage 0-III breast cancer patients undergoing partial mastectomy (with or without resection of selective cavity margins). Participants were stratified by clinical stage and randomized 1:1 to either have routine cavity shave margins resected (“shave”) or not (“no shave”). Randomization group was revealed to the surgeon intraoperatively, after they had completed their standard partial mastectomy and were ready to close. Positive margins were defined as “tumor at ink” for invasive cancer or within 2 mm for ductal carcinoma in situ (DCIS). Adverse events were defined as seromas requiring percutaneous drainage, and/or hematomas or abscesses requiring operative intervention.

RESULTS: Median patient age was 65 (range; 29-94). 116 patients had invasive disease, 74 had DCIS, 179 had both, and 29 had no residual cancer at the time of partial mastectomy. The median invasive cancer size was 1.2 cm (range; 0.05-8.00 cm); the median extent of DCIS was 0.9 cm (range; 0.05-6.40 cm). The “shave” and “no shave” groups were well matched at baseline for clinicopathologic and demographic factors.

FactorShave (n=197)No Shave (n=201)p-valueAge (years); median (range)67 (36-94)64 (29-89)0.585Race  0.062-- White173 (87.8%)164 (81.6%) -- Black20 (10.2%)33 (16.4%) -- Asian2 (1.0%)2 (1.0%) -- Native American0 (0%)2 (1.0%) -- Unknown/Declined2 (1.0%)0 (0%) Hispanic ethnicity28 (14.2%)32 (15.9%)0.806Invasive tumor size (cm); median (range)1.30 (0.09-8.00)1.20 (0.05-7.50)0.282DCIS extent (cm); median (range)0.80 (0.10-6.40)1.00 (0.05-5.50)0.906Invasive histology  0.556-- Ductal177 (89.8%)186 (92.5%) -- Lobular16 (8.1%)13 (6.5%) -- Mucinous3 (1.5%)2 (1.0%) -- Other1 (0.5%)0 (0%) Neoadjuvant therapy15 (7.6%)19 (9.5%)0.592Palpable tumor57 (28.9%)56 (27.9%)0.825Node positive*24 (16.3%)16 (10.6%)0.175*Of the 298 patients who had lymph nodes evaluated

Prior to randomization, positive margin rates were similar in the “shave” and “no shave” groups (38.1% vs. 37.3%, respectively, p=0.918). After randomization, however, those in the “shave” group were significantly less likely than those in the “no shave” group to have positive margins (8.6% vs. 37.3%, respectively, p&lt;0.001). They were also less likely to require re-excision or mastectomy for margin clearance (8.6% vs. 23.9%, p&lt;0.001). There were no significant differences between the two groups in terms of adverse events (p=0.280). Rates of seroma (1.5% vs. 0.5%, p=0.368), hematoma (0.5% vs. 0.5%, p=1.000) and abscess (0.3% vs. 0%, p=0.495) were similar between the “shave” and “no shave” groups, respectively.

CONCLUSION: Resection of cavity shave margins significantly reduces positive margin and re-excision rates in patients with stage 0-III breast cancer undergoing partial mastectomy.

Citation Format: Chagpar AB, Tsangaris T, Garcia-Cantu C, Howard-McNatt M, Chiba A, Berger AC, Levine E, Gass JS, Gallagher K, Lum SS, Martinez RD, Willis AI, Pandya SV, Brown EA, Fenton A, Mendiola A, Murray M, Haddad V, Solomon NL, Senthil M, Bansil H, Ollila D, Snyder SK, Edmonson D, Lazar M, Namm JP, Li F, Butler M, McGowan NE, Herrera ME, Avitan YP, Yoder B, Dupont E. Does resection of cavity shave margins result in lower positive margin and re-excision rates in patients with stage 0-III breast cancer? Results from a prospective multicenter randomized controlled trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD8-07.

Glucocorticoid activation by 11β-hydroxysteroid dehydrogenase enzymes in relation to inflammation and glycaemic control in chronic kidney disease: A cross-sectional study

OBJECTIVE

Patients with chronic kidney disease (CKD) have dysregulated cortisol metabolism secondary to changes in 11β-hydroxysteroid dehydrogenase (11β-HSD) enzymes. The determinants of this and its clinical implications are poorly defined.

METHODS

We performed a cross-sectional study to characterize shifts in cortisol metabolism in relation to renal function, inflammation and glycaemic control. Systemic activation of cortisol by 11β-HSD was measured as the metabolite ratio (tetrahydrocortisol [THF]+5α-tetrahydrocortisol [5αTHF])/tetrahydrocortisone (THE) in urine.

RESULTS

The cohort included 342 participants with a median age of 63 years, median estimated glomerular filtration rate (eGFR) of 28 mL/min/1.73 m2 and median urine albumin-creatinine ratio of 35.5 mg/mmol. (THF+5αTHF)/THE correlated negatively with eGFR (Spearman's ρ = -0.116, P = 0.032) and positively with C-reactive protein (ρ = 0.208, P < 0.001). In multivariable analysis, C-reactive protein remained a significant independent predictor of (THF+5αTHF)/THE, but eGFR did not. Elevated (THF+5αTHF)/THE was associated with HbA1c (ρ = 0.144, P = 0.008) and diabetes mellitus (odds ratio for high vs low tertile of (THF+5αTHF)/THE 2.57, 95% confidence interval 1.47-4.47). Associations with diabetes mellitus and with HbA1c among the diabetic subgroup were independent of eGFR, C-reactive protein, age, sex and ethnicity.

CONCLUSIONS

In summary, glucocorticoid activation by 11β-HSD in our cohort comprising a spectrum of renal function was associated with inflammation and impaired glucose control.

Glomerular filtration rate: new age- and gender- specific reference ranges and thresholds for living kidney donation

BACKGROUND

There is a need for a large, contemporary, multi-centre series of measured glomerular filtration rates (mGFR) from healthy individuals to determine age- and gender-specific reference ranges for GFR. We aimed to address this and to use the ranges to provide age- and gender-specific advisory GFR thresholds considered acceptable for living kidney donation.

METHODS

Individual-level data including pre-donation mGFR from 2974 prospective living kidney donors from 18 UK renal centres performed between 2003 and 2015 were amalgamated. Age- and gender-specific GFR reference ranges were determined by segmented multiple linear regression and presented as means ± two standard deviations.

RESULTS

Males had a higher GFR than females (92.0 vs 88.1 mL/min/1.73m2, P < 0.0001). Mean mGFR was 100 mL/min/1.73m2 until 35 years of age, following which there was a linear decline that was faster in females compared to males (7.7 vs 6.6 mL/min/1.73m2/decade, P = 0.013); 10.5% of individuals aged > 60 years had a GFR < 60 mL/min/1.73m2. The GFR ranges were used along with other published evidence to provide advisory age- and gender-specific GFR thresholds for living kidney donation.

CONCLUSIONS

These data suggest that GFR declines after 35 years of age, and the decline is faster in females. A significant proportion of the healthy population over 60 years of age have a GFR < 60 mL/min/1.73m2 which may have implications for the definition of chronic kidney disease. Age and gender differences in normal GFR can be used to determine advisory GFR thresholds for living kidney donation.

A novel biomarker of laminin turnover is associated with disease progression and mortality in chronic kidney disease

Background

Patients with chronic kidney disease (CKD) have increased risk of development of end-stage renal disease (ESRD) and early mortality. Fibrosis is the central pathogenic process in CKD and is caused by dysregulated extracellular matrix (ECM) remodeling. The laminin γ1 chain (LAMC1) is a core structural protein present in the basement membrane of several organs, including the kidneys. We hypothesized that dysregulation of LAMC1 remodeling could be associated with a higher risk of adverse clinical outcomes in patients with CKD.

Methods

A novel immunoassay targeting LG1M, a specific MMP-9-generated neo-epitope fragment of LAMC1, was developed and used to measure the levels of the fragment in urine and serum from 492 patients from the Renal Impairment in Secondary Care (RIISC) study, a prospective cohort of patients with high-risk CKD. Patients were monitored for a median follow-up time of 3.5 years. Associations between serum and urine LG1M levels and progression of CKD at 12 months were assessed by a multivariable logistic regression model. The association with ESRD or mortality was assessed by Kaplan-Meier survival curves and Cox proportional hazards regression.

Results

Forty-six (11%) of the 416 patients who reached 12-month follow-up had progression of CKD; during the study follow-up, 125 patients (25.4%) developed ESRD and 71 patients (14.4%) died. Serum and urine levels of LG1M correlated with baseline eGFR (r = -0.43, p<0.0001 and r = -0.17, p = 0.0002, respectively). Serum levels of LG1M were higher in patients with one-year progression of CKD compared to those who did not progress (p<0.01). Baseline serum levels of LG1M were associated with development of ESRD (HR 3.2, 95% CI 1.99–5.2 for patients in the highest LG1M tertile compared to patient in the lowest tertile). Baseline urinary levels of LG1M (uLG1M) were significantly associated with mortality (HR 5.0, 95% CI 2.8–8.9, p<0.0001 for patients in the highest LG1M tertile compared to patients in the lowest tertile). Urine LG1M was retained in the model for prediction of mortality (HR per standard deviation of uLG1M: 1.01, 95% CI 1.00–1.02, p = 0.001).

Conclusions

LG1M, a marker of basement membrane remodeling, is increased in serum and urine of patients with CKD and levels are associated with one-year disease progression, development of ESRD, and mortality.

Adult minimal-change disease: observational data from a UK centre on patient characteristics, therapies, and outcomes

Background

Minimal change disease (MCD) is a common cause of the nephrotic syndrome in adults with limited evidence on its treatment and prognosis. We examined the presenting characteristics, treatments, and outcomes of adult patients with MCD in our centre.

Methods

This was an observational cohort study using retrospectively-collected data. All patients who had a renal biopsy reported as MCD between 1996 and 2012 were included, and data were collected at baseline and during follow-up. Statistical analysis included Cox-regression analysis to examine which factors were associated with risk of relapse.

Results

Seventy-eight patients were included, and had a median age of 36 years, and were 60% male and 73% white. Median follow-up time was 72 months. 37% were in AKI at presentation, which was significantly associated with a lower serum albumin and older age. Although 10% were steroid-resistant, 98% achieved remission at a median time of 5 weeks. 61% relapsed, at a median time of 11 months, and patients had a median number of 2 relapses during follow-up. A higher eGFR was associated with an increased risk of relapse (hazard ratio 1.18 [1.03–1.36] per 10 mL/min increase in eGFR), and females were significantly more likely than males to have an early relapse. Nearly half of the cohort required an additional immunosuppressive agent on top of glucocorticoids, the most commonly used being calcineurin inhibitors. Five patients subsequently developed FSGS: these patients had a lower baseline creatinine, a higher serum albumin, a longer time to remission, and were more likely to be steroid-resistant. Follow-up renal function was generally preserved, but follow-up creatinine was higher in those who had presented with AKI, and in those who had been commenced on a RAS inhibitor after biopsy. Infection requiring admission, diabetes mellitus and venous thromboembolism developed in 14%, 12%, and 12% of patients respectively.

Conclusions

Nearly all adults with MCD achieve remission, but relapses and disease- and therapy-related complications are common. In our cohort, eGFR and gender were associated with risk of relapse, and these previously undescribed associations could be explored further in future work.

Infections on the move: how transient phases of host movement influence disease spread

Animal movement impacts the spread of human and wildlife diseases, and there is significant interest in understanding the role of migrations, biological invasions and other wildlife movements in spatial infection dynamics. However, the influence of processes acting on infections during transient phases of host movement is poorly understood. We propose a conceptual framework that explicitly considers infection dynamics during transient phases of host movement to better predict infection spread through spatial host networks. Accounting for host transient movement captures key processes that occur while hosts move between locations, which together determine the rate at which hosts spread infections through networks. We review theoretical and empirical studies of host movement and infection spread, highlighting the multiple factors that impact the infection status of hosts. We then outline characteristics of hosts, parasites and the environment that influence these dynamics. Recent technological advances provide disease ecologists unprecedented ability to track the fine-scale movement of organisms. These, in conjunction with experimental testing of the factors driving infection dynamics during host movement, can inform models of infection spread based on constituent biological processes.

Association between urinary free light chains and progression to end stage renal disease in chronic kidney disease

Background

Patients with chronic kidney disease (CKD) are at an increased risk of developing end-stage renal disease (ESRD). We assessed for the first time whether urinary free light chains (FLC) are independently associated with risk of ESRD in patients with CKD, and whether they offer incremental value in risk stratification.

Materials and methods

We measured urinary FLCs in 556 patients with CKD from a prospective cohort study. The association between urinary kappa/creatinine (KCR) and lambda/creatinine (LCR) ratios and development of ESRD was assessed by competing-risks regression (to account for the competing risk of death). The change in C-statistic and integrated discrimination improvement were used to assess the incremental value of adding KCR or LCR to the Kidney Failure Risk Equation (KFRE).

Results

136 participants developed ESRD during a median follow-up time of 51 months. Significant associations between KCR and LCR and risk of ESRD became non-significant after adjustment for estimated glomerular filtration rate (eGFR) and albumin/creatinine ratio (ACR), although having a KCR or LCR >75^th centile remained independently associated with risk of ESRD. Neither KCR nor LCR as continuous or categorical variables provided incremental value when added to the KFRE for estimating risk of ESRD at two years.

Conclusions

Urinary FLCs have an association with progression to ESRD in patients with CKD which appears to be explained to a degree by their correlation with eGFR and ACR. Levels above the 75^th centile do have an independent association with ESRD, but do not improve upon a current model for risk stratification.

Urinary endotrophin predicts disease progression in patients with chronic kidney disease

Renal fibrosis is the central pathogenic process in progression of chronic kidney disease (CKD). Collagen type VI (COL VI) is upregulated in renal fibrosis. Endotrophin is released from COL VI and promotes pleiotropic pro-fibrotic effects. Kidney disease severity varies considerably and accurate information regarding CKD progression may improve clinical decisions. We tested the hypothesis that urinary endotrophin derived during COL VI deposition in fibrotic human kidneys is a marker for progression of CKD in the Renal Impairment in Secondary Care (RIISC) cohort, a prospective observational study of 499 CKD patients. Endotrophin localised to areas of increased COL VI deposition in fibrotic kidneys but was not present in histologically normal kidneys. The third and fourth quartiles of urinary endotrophin:creatinine ratio (ECR) were independently associated with one-year disease progression after adjustment for traditional risk factors (OR (95%CI) 3.68 (1.06–12.83) and 8.65 (2.46–30.49), respectively). Addition of ECR quartiles to the model for disease progression increased prediction as seen by an increase in category-free net reclassification improvement (0.45, 95% CI 0.16–0.74, p = 0.002) and integrated discrimination improvement (0.04, 95% CI 0.02–0.06, p < 0.001). ECR was associated with development of end-stage renal disease (ESRD). It is concluded that ECR predicts disease progression of CKD patients.

The Association of Serum Free Light Chains With Mortality and Progression to End-Stage Renal Disease in Chronic Kidney Disease: Systematic Review and Individual Patient Data Meta-analysis

OBJECTIVE

To clarify the associations between polyclonal serum free light chain (sFLC) levels and adverse outcomes in patients with chronic kidney disease (CKD) by conducting a systematic review and individual patient data meta-analyses.

PATIENTS AND METHODS

On December 28, 2016, we searched 4 databases (MEDLINE, Embase, CINAHL, and PubMed) and conference proceedings for studies presenting independent analyses of associations between sFLC levels and mortality or progression to end-stage renal disease (ESRD) in patients with CKD. Study quality was assessed in 5 domains: sample selection, measurement, attrition, reporting, and funding.

RESULTS

Five prospective cohort studies were included, judged moderate to good quality, involving 3912 participants in total. In multivariable meta-analyses, sFLC (kappa+lambda) levels were independently associated with mortality (5 studies, 3680 participants; hazard ratio [HR], 1.04 [95% CI, 1.03-1.06] per 10 mg/L increase in sFLC levels) and progression to ESRD (3 studies, 1848 participants; HR, 1.01 [95% CI, 1.00-1.03] per 10 mg/L increase in sFLC levels). The sFLC values above the upper limit of normal (43.3 mg/L) were independently associated with mortality (HR, 1.45 [95% CI, 1.14-1.85]) and ESRD (HR, 3.25 [95% CI, 1.32-7.99]).

CONCLUSION

Higher levels of sFLCs are independently associated with higher risk of mortality and ESRD in patients with CKD. Future work is needed to explore the biological role of sFLCs in adverse outcomes in CKD, and their use in risk stratification.