International Collaboration for the Epidemiology of eGFR in Low and Middle Income Populations - Rationale and core protocol for the Disadvantaged Populations eGFR Epidemiology Study (DEGREE).

BACKGROUND: There is an increasing recognition of epidemics of primarily tubular-interstitial chronic kidney disease (CKD) clustering in agricultural communities in low- and middle-income countries (LMICs). Although it is currently unclear whether there is a unified underlying aetiology, these conditions have been collectively termed CKD of undetermined cause (CKDu). CKDu is estimated to have led to the premature deaths of tens to hundreds of thousands of young men and women over the last 2 decades. Thus, there is an urgent need to understand the aetiology and pathophysiology of these condition (s). International comparisons have provided the first steps in understanding many chronic diseases, but such comparisons rely on the availability of standardised tools to estimate disease prevalence. This is a particular problem with CKD, since the disease is asymptomatic until the late stages, and the biases inherent in the methods used to estimate the glomerular filtration rate (GFR) in population studies are highly variable across populations. METHOD: We therefore propose a simple standardised protocol to estimate the distribution of GFR in LMIC populations - The Disadvantaged Populations eGFR Epidemiology (DEGREE) Study. This involves the quantification of renal function in a representative adult population-based sample and a requirement for standardisation of serum creatinine measurements, along with storage of samples for future measurements of cystatin C and ascertainment of estimates of body composition, in order to obtain valid comparisons of estimated GFR (eGFR) within and between populations. DISCUSSION: The methodology we present is potentially applicable anywhere, but our particular focus is on disadvantaged populations in LMICs, since these appear to be most susceptible to CKDu. Although the protocol could also be used in specific groups (e.g. occupational groups, thought to be at excess risk of CKDu) the primary aim of the DEGREE project is characterise the population distribution of eGFR in multiple regions so that international comparisons can be performed. It is only with a standardised approach that it will be possible to estimate the scale of, and variation in, impaired kidney function between affected areas. These data should then provide insights into important social, demographic and environmental risk factors for this increasingly recognised disease

Heat stress, hydration and uric acid: a cross-sectional study in workers of three occupations in a hotspot of Mesoamerican nephropathy in Nicaragua.

OBJECTIVES: To study Mesoamerican nephropathy (MeN) and its risk factors in three hot occupations. DESIGN: Cross-sectional. SETTING: Chinandega and León municipalities, a MeN hotspot on the Nicaraguan Pacific coast, January-February 2013. PARTICIPANTS: 194 male workers aged 17-39 years: 86 sugarcane cutters, 56 construction workers, 52 small-scale farmers. OUTCOME MEASURES: (1) Differences between the three occupational groups in prevalences/levels of socioeconomic, occupational, lifestyle and health risk factors for chronic kidney disease (CKD) and in biomarkers of kidney function and hydration; (2) differences in prevalences/levels of CKD risk factors between workers with reduced estimated glomerular filtration rate (eGFRCKD-EPI construction > farming, p=0.003). Significant trends (cane > construction > farming) were also observed for high serum urea nitrogen (blood urea nitrogen (BUN) >20 mg/dL), high serum creatinine (SCr >1.2 mg/dL), low urinary pH (≤5.5) and high BUN/SCr ratio (>20) but not for high urinary specific gravity (≥1.030). Sugarcane cutters also more often had proteinuria and blood and leucocytes in the urine. Workers with eGFR <80 mL/min/1.73 m2 reported a higher intake of water and lower intake of sugary beverages. Serum uric acid levels related strongly and inversely to eGFR levels (adj β -10.4 mL/min/1.73 m2, 95% CI -12.2 to -8.5, p<0.001). No associations were observed for other metabolic risk factors, pesticides, non-steroidal anti-inflammatory drugs or alcohol. Among cane cutters, consumption of electrolyte hydration solution appeared preventive (adj β 8.1 mL/min/1.73 m2, p=0.09). CONCLUSIONS: Heat stress, dehydration and kidney dysfunction were most common among sugarcane cutters. Kidney dysfunction also occurred to a lesser extent among construction workers, but hardly at all among small-scale farmers. High serum uric acid was associated with reduced kidney function

Correction of anemia by dapagliflozin in patients with type 2 diabetes

Aims: Anemia is common in type 2 diabetes (T2D), particularly in patients with kidney impairment, and often goes unrecognized. Dapagliflozin treatment increases hemoglobin and serum erythropoietin levels. We investigated the effect of dapagliflozin 10-mg/day on hemoglobin in T2D patients with and without anemia. Methods: Data from 5325 patients from 14 placebo-controlled, dapagliflozin-treatment studies of at least 24-weeks duration were pooled. Dapagliflozin's effects (vs. placebo) on hemoglobin, serum albumin, estimated glomerular filtration rate (eGFR), systolic blood pressure, body weight, and safety in patients with and without anemia were evaluated. Results: At baseline, 13% of all T2D patients and 28% of those with chronic kidney disease (eGFR Conclusions: Treatment with dapagliflozin can correct and prevent anemia in T2D patients. A gradual increase in hemoglobin beyond week 4 may indicate an erythropoiesis-stimulating effect of sodium-glucose cotransporter 2 inhibition. (c) 2020 Published by Elsevier Inc

Baseline characteristics and enrichment results from the SONAR trial

Aim: The SONAR trial uses an enrichment design based on the individual response to the selective endothelin receptor antagonist atrasentan on efficacy (the degree of the individual response in the urinary albumin‐to‐creatinine ratio [UACR]) and safety/tolerability (signs of sodium retention and acute increases in serum creatinine) to assess the effects of this agent on major renal outcomes. The patient population and enrichment results are described here. Methods: Patients with type 2 diabetes with an estimated glomerular filtration rate (eGFR) within 25 to 75 mL/min/1.73 m2 and UACR between 300 and 5000 mg/g were enrolled. After a run‐in period, eligible patients received 0.75 mg/d of atrasentan for 6 weeks. A total of 2648 responder patients in whom UACR decreased by ≥30% compared to baseline were enrolled, as were 1020 non‐responders with a UACR decrease of &lt;30%. Patients who experienced a weight gain of &gt;3 kg and in whom brain natriuretic peptide exceeded ≥300 pg/mL, or who experienced an increase in serum creatinine &gt;20% (0.5 mg/dL), were not randomized. Results: Baseline characteristics were similar for atrasentan responders and non‐responders. Upon entry to the study, median UACR was 802 mg/g in responders and 920 mg/g in non‐responders. After 6 weeks of treatment with atrasentan, the UACR change in responders was −48.8% (95% CI, −49.8% to −47.9%) and in non‐responders was −1.2% (95% CI, −6.4% to 3.9%). Changes in other renal risk markers were similar between responders and non‐responders except for a marginally greater reduction in systolic blood pressure and eGFR in responders. Conclusions: The enrichment period has successfully identified a population with a profound UACR reduction without clinical signs of sodium retention in whom a large atrasentan effect on clinically important renal outcomes is possible. The SONAR trial aims to establish whether atrasentan confers renal protection

Translating the efficacy of dapagliflozin in chronic kidney disease to lower healthcare resource utilization and costs: a medical care cost offset analysis

AIMS: Dapagliflozin was approved for use in patients with chronic kidney disease (CKD) based on results of the DAPA-CKD trial, demonstrating attenuation of CKD progression and reduced risk of cardio-renal outcomes and all-cause mortality (ACM) versus placebo, in addition to standard therapy. The study objective was to assess the potential medical care cost offsets associated with reduced rates of cardio-renal outcomes across 31 countries and regions. MATERIALS AND METHODS: A comparative cost-determination framework estimated outcome-related costs of dapagliflozin plus standard therapy versus standard therapy alone over a 3-year horizon based on the DAPA-CKD trial. Incidence rates of end-stage kidney disease (ESKD), hospitalizations for heart failure (HHF), acute kidney injury (AKI), and ACM were estimated for a treated population of 100,000 patients. Associated medical care costs for non-fatal events were calculated using sources from a review of publicly available data specific to each considered setting. RESULTS: Patients treated with dapagliflozin plus standard therapy experienced fewer incidents of ESKD (7,221 vs 10,767; number needed to treat, NNT: 28), HHF (2,370 vs 4,684; NNT: 43), AKI (4,110 vs. 5,819; NNT: 58), and ACM (6,383 vs 8,874; NNT: 40) per 100,000 treated patients versus those treated with standard therapy alone. Across 31 countries/regions, reductions in clinical events were associated with a 33% reduction in total costs, or a cumulative mean medical care cost offset of $264 million per 100,000 patients over 3 years. LIMITATIONS AND CONCLUSIONS: This analysis is limited by the quality of country/region-specific data available for medical care event costs. Based on the DAPA-CKD trial, we show that treatment with dapagliflozin may prevent cardio-renal event incidence at the population level, which could have positive effects upon healthcare service delivery worldwide. The analysis was restricted to outcome-associated costs and did not consider the cost of drug treatments and disease management

Efficacy and Safety of Dapagliflozin in Patients with Chronic Kidney Disease across the Spectrum of Frailty

BACKGROUND: A sizeable proportion of patients with chronic kidney disease (CKD) are reported to be frail. Here we examined the safety and efficacy of dapagliflozin in patients with CKD by frailty level. METHODS: Adults with CKD, with/without type 2 diabetes, with estimated glomerular filtration rate (eGFR) 25-75 mL/min/1.73m 2 and urinary albumin-to-creatinine ratio 200-5000 mg/g were randomized to dapagliflozin (10 mg/day) or placebo. The primary endpoint was composite of sustained ≥50% eGFR decline, end-stage kidney disease (ESKD) or death from kidney or cardiovascular (CV) causes. RESULTS: Frailty index (FI), assessed by Rockwood cumulative deficit approach, was calculable in 4303/4304 (99.9%) patients: 1162 (27.0%) in not-to-mildly frail(FI≤0.210), 1642 (38.2%) in moderately frail(FI 0.211-0.310), and 1499 (34.8%) in severely frail categories (FI>0.311). Dapagliflozin reduced the risk of the primary composite endpoint across all FI categories (hazard ratios [95% CI]: 0.50 [0.33-0.76], 0.62 [0.45-0.85], and 0.64 [0.49-0.83], respectively (P-interaction =0.67). Results were similar for secondary outcomes including kidney composite outcome (sustained ≥50% eGFR decline, ESKD or death from kidney cause; P-interaction=0.44), CV endpoint (heart failure hospitalization or CV death; P-interaction=0.63), and all-cause mortality (P-interaction p=0.42). Results were consistent when using FI as a continuous variable. Occurrence of serious adverse events was numerically lower in patients receiving dapagliflozin vs. placebo in all FI categories (16.9% vs. 20.1%, 26.3% vs. 30.7%, and 42.9% vs 47.8%, in not-to-mildly, moderately and severely frail categories, respectively). CONCLUSIONS: The relative benefit of dapagliflozin for all outcomes was consistent across all frailty categories, with no difference in associated safety

Rationale and protocol of the Dapagliflozin And Prevention of Adverse outcomes in Chronic Kidney Disease (DAPA-CKD) randomized controlled trial.

BACKGROUND: Recent cardiovascular outcome trials have shown that sodium-glucose co-transporter 2 (SGLT2) inhibitors slow the progression of chronic kidney disease (CKD) in patients with type 2 diabetes at high cardiovascular risk. Whether these benefits extend to CKD patients without type 2 diabetes or cardiovascular disease is unknown. The Dapagliflozin and Prevention of Adverse Outcomes in CKD (DAPA-CKD) trial (NCT03036150) will assess the effect of the SGLT2 inhibitor dapagliflozin on renal and cardiovascular events in a broad range of patients with CKD with and without diabetes. METHODS: DAPA-CKD is a randomized, double-blind, placebo-controlled, trial in which ∼4300 patients with CKD Stages 2-4 and elevated urinary albumin excretion will be enrolled. The vast majority will be receiving a maximum tolerated dose of a renin-angiotensin system inhibitor at enrolment. RESULTS: After a screening assessment, eligible patients with a urinary albumin:creatinine ratio ≥200 mg/g and estimated glomerular filtration rate (eGFR) between 25 and 75 mL/min/1.73 m2 are randomly assigned to placebo or dapagliflozin 10 mg/day. Enrolment is monitored to ensure that at least 30% of patients do not have diabetes and that no more than 10% have an eGFR >60 mL/min/1.73 m2. The primary endpoint is a composite of a sustained decline in eGFR of ≥50%, end-stage renal disease, renal death or cardiovascular death. The trial will conclude when 681 primary renal events have occurred, providing 90% power to detect a 22% relative risk reduction (α level of 0.05). CONCLUSION: DAPA-CKD will determine whether the SGLT2 inhibitor dapagliflozin, added to guideline-recommended therapies, safely reduces the rate of renal and cardiovascular events in patients across multiple CKD stages with and without diabetes

Effect of dapagliflozin on urinary albumin excretion in patients with chronic kidney disease with and without type 2 diabetes:a prespecified analysis from the DAPA-CKD trial

BACKGROUND: Reductions in albuminuria are associated with a subsequent lower risk of kidney failure in patients with chronic kidney disease. The SGLT2 inhibitor dapagliflozin significantly reduced albuminuria in patients with type 2 diabetes and normal or near-normal kidney function. Whether this effect persists in patients with chronic kidney disease with and without type 2 diabetes is unknown. We assessed the effects of dapagliflozin on albuminuria in patients with chronic kidney disease with and without type 2 diabetes in the dapagliflozin and prevention of adverse outcomes in chronic kidney disease (DAPA-CKD) trial. METHODS: DAPA-CKD was a multicentre, double-blind, placebo-controlled, randomised trial done at 386 sites in 21 countries. Patients were eligible for the trial if they had chronic kidney disease, defined as an estimated glomerular filtration rate (eGFR) between 25 mL/min per 1·73 m2 and 75 mL/min per 1·73 m2 and a urinary albumin-to-creatinine ratio (UACR) between 200 mg/g and 5000 mg/g (22·6 to 565·6 mg/mmol). Participants were randomly assigned to dapagliflozin 10 mg (AstraZeneca; Gothenburg, Sweden) once daily or matching placebo, in accordance with the sequestered, fixed randomisation schedule, using balanced blocks to ensure an approximate 1:1 ratio. Change in albuminuria was a pre-specified exploratory outcome of DAPA-CKD. Regression in UACR stage, defined as a transition from macroalbuminuria (≥300 mg/g) to microalbuminuria or normoalbuminuria (<300 mg/g), and progression in UACR stage, defined as a transition from less than 3000 mg/g to 3000 mg/g or greater, were additional discrete endpoints. The trial is registered with ClinicalTrials.gov, NCT03036150. FINDINGS: Between Feb 2, 2017, and April 3, 2020, 4304 patients were recruited and randomly assigned to either dapagliflozin (n=2152) or placebo (n=2152). Median UACR was 949 mg/g (IQR 477 to 1885). Overall, compared with placebo, dapagliflozin reduced geometric mean UACR by 29·3% (95% CI -33·1 to -25·2; p<0·0001); relative to placebo, treatment with dapagliflozin resulted in a geometric mean percentage change of -35·1% (95% CI -39·4 to -30·6; p<0·0001) in patients with type 2 diabetes and -14·8% (-22·9 to -5·9; p=0·0016) in patients without type 2 diabetes over the follow-up visits (pinteraction<0·0001) Among 3860 patients with UACR of 300 mg/g or greater at baseline, dapagliflozin increased the likelihood of regression in UACR stage (hazard ratio 1·81, 95% CI 1·60 to 2·05). Among 3820 patients with UACR less than 3000 mg/g at baseline, dapagliflozin decreased the risk of progression in UACR stage (0·41, 0·32 to 0·52). Larger reductions in UACR at day 14 during dapagliflozin treatment were significantly associated with attenuated eGFR decline during subsequent follow-up (β per log unit UACR change -3·06, 95% CI -5·20 to -0·90; p=0·0056). INTERPRETATION: In patients with chronic kidney disease with and without type 2 diabetes, dapagliflozin significantly reduced albuminuria, with a larger relative reduction in patients with type 2 diabetes. The similar effects of dapagliflozin on clinical outcomes in patients with or without type 2 diabetes, but different effects on UACR, suggest that part of the protective effect of dapagliflozin in patients with chronic kidney disease might be mediated through pathways unrelated to reduction in albuminuria. FUNDING: AstraZeneca