Effects of dapagliflozin on volume status and systemic haemodynamics in patients with chronic kidney disease without diabetes: Results from DAPASALT and DIAMOND

Sodium-Glucose Cotransporter 2 Inhibitor Combined with Conventional Diuretics Ameliorate Body Fluid Retention without Excessive Plasma Volume Reduction

We previously reported that sodium-glucose cotransporter 2 (SGLT2) inhibitors exert sustained fluid homeostatic actions through compensatory increases in osmotic diuresis-induced vasopressin secretion and fluid intake. However, SGLT2 inhibitors alone do not produce durable amelioration of fluid retention. In this study, we examined the comparative effects of the SGLT2 inhibitor dapagliflozin (SGLT2i group, n = 53) and the combined use of dapagliflozin and conventional diuretics, including loop diuretics and/or thiazides (SGLT2i + diuretic group, n = 23), on serum copeptin, a stable, sensitive, and simple surrogate marker of vasopressin release and body fluid status. After six months of treatment, the change in copeptin was significantly lower in the SGLT2i + diuretic group than in the SGLT2i group (-1.4 ± 31.5% vs. 31.5 ± 56.3%, p = 0.0153). The change in the estimated plasma volume calculated using the Strauss formula was not significantly different between the two groups. Contrastingly, changes in interstitial fluid, extracellular water, intracellular water, and total body water were significantly lower in the SGLT2i + diuretic group than in the SGLT2i group. Changes in renin, aldosterone, and absolute epinephrine levels were not significantly different between the two groups. In conclusion, the combined use of the SGLT2 inhibitor dapagliflozin and conventional diuretics inhibited the increase in copeptin levels and remarkably ameliorated fluid retention without excessively reducing plasma volume and activating the renin-angiotensin-aldosterone and sympathetic nervous systems.

Sodium-glucose co-transporter protein 2 (SGLT2) inhibitors for people with chronic kidney disease and diabetes

BACKGROUND

Diabetes is associated with high risks of premature chronic kidney disease (CKD), cardiovascular diseases, cardiovascular death and impaired quality of life. People with diabetes are more likely to develop kidney impairment, and approximately one in three adults with diabetes have CKD. People with CKD and diabetes experience a substantially higher risk of cardiovascular outcomes. Sodium-glucose co-transporter protein 2 (SGLT2) inhibitors have shown potential effects in preventing kidney and cardiovascular outcomes in people with CKD and diabetes. However, new trials are emerging rapidly, and evidence synthesis is essential to summarising cumulative evidence.

OBJECTIVES

This review aimed to assess the benefits and harms of SGLT2 inhibitors for people with CKD and diabetes.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 17 November 2023 using a search strategy designed by an Information Specialist. Studies in the Register are continually identified through regular searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled studies were eligible if they evaluated SGLT2 inhibitors versus placebo, standard care or other glucose-lowering agents in people with CKD and diabetes. CKD includes all stages (from 1 to 5), including dialysis patients.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed the study risk of bias. Treatment estimates were summarised using random effects meta-analysis and expressed as a risk ratio (RR) or mean difference (MD), with a corresponding 95% confidence interval (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The primary review outcomes were all-cause death, 3-point and 4-point major adverse cardiovascular events (MACE), fatal or nonfatal myocardial infarction (MI), fatal or nonfatal stroke, and kidney failure.

MAIN RESULTS

Fifty-three studies randomising 65,241 people with CKD and diabetes were included. SGLT2 inhibitors with or without other background treatments were compared to placebo, standard care, sulfonylurea, dipeptidyl peptidase-4 (DPP-4) inhibitors, or insulin. In the majority of domains, the risks of bias in the included studies were low or unclear. No studies evaluated the treatment in children or in people treated with dialysis. No studies compared SGLT2 inhibitors with glucagon-like peptide-1 receptor agonists or tirzepatide. Compared to placebo, SGLT2 inhibitors decreased the risk of all-cause death (20 studies, 44,397 participants: RR 0.85, 95% CI 0.78 to 0.94; I2 = 0%; high certainty) and cardiovascular death (16 studies, 43,792 participants: RR 0.83, 95% CI 0.74 to 0.93; I2 = 29%; high certainty). Compared to placebo, SGLT2 inhibitors probably make little or no difference to the risk of fatal or nonfatal MI (2 studies, 13,726 participants: RR 0.95, 95% CI 0.80 to 1.14; I2 = 24%; moderate certainty), and fatal or nonfatal stroke (2 studies, 13,726 participants: RR 1.07, 95% CI 0.88 to 1.30; I2 = 0%; moderate certainty). Compared to placebo, SGLT2 inhibitors probably decrease 3-point MACE (7 studies, 38,320 participants: RR 0.89, 95% CI 0.81 to 0.98; I2 = 46%; moderate certainty), and 4-point MACE (4 studies, 23,539 participants: RR 0.82, 95% CI 0.70 to 0.96; I2 = 77%; moderate certainty), and decrease hospital admission due to heart failure (6 studies, 28,339 participants: RR 0.70, 95% CI 0.62 to 0.79; I2 = 17%; high certainty). Compared to placebo, SGLT2 inhibitors may decrease creatinine clearance (1 study, 132 participants: MD -2.63 mL/min, 95% CI -5.19 to -0.07; low certainty) and probably decrease the doubling of serum creatinine (2 studies, 12,647 participants: RR 0.70, 95% CI 0.56 to 0.89; I2 = 53%; moderate certainty). SGLT2 inhibitors decrease the risk of kidney failure (6 studies, 11,232 participants: RR 0.70, 95% CI 0.62 to 0.79; I2 = 0%; high certainty), and kidney composite outcomes (generally reported as kidney failure, kidney death with or without ≥ 40% decrease in estimated glomerular filtration rate (eGFR)) (7 studies, 36,380 participants: RR 0.68, 95% CI 0.59 to 0.78; I2 = 25%; high certainty) compared to placebo. Compared to placebo, SGLT2 inhibitors incur less hypoglycaemia (16 studies, 28,322 participants: RR 0.93, 95% CI 0.89 to 0.98; I2 = 0%; high certainty), and hypoglycaemia requiring third-party assistance (14 studies, 26,478 participants: RR 0.75, 95% CI 0.65 to 0.88; I2 = 0%; high certainty), and probably decrease the withdrawal from treatment due to adverse events (15 studies, 16,622 participants: RR 0.94, 95% CI 0.82 to 1.08; I2 = 16%; moderate certainty). The effects of SGLT2 inhibitors on eGFR, amputation and fracture were uncertain. No studies evaluated the effects of treatment on fatigue, life participation, or lactic acidosis. The effects of SGLT2 inhibitors compared to standard care alone, sulfonylurea, DPP-4 inhibitors, or insulin were uncertain.

AUTHORS' CONCLUSIONS

SGLT2 inhibitors alone or added to standard care decrease all-cause death, cardiovascular death, and kidney failure and probably decrease major cardiovascular events while incurring less hypoglycaemia compared to placebo in people with CKD and diabetes.

Water Conservation Overrides Osmotic Diuresis During SGLT2 Inhibition in Patients With Heart Failure

BACKGROUND

Sodium-glucose cotransporter 2 inhibitors are believed to improve cardiac outcomes due to their osmotic diuretic potential.

OBJECTIVES

The goal of this study was to test the hypothesis that vasopressin-driven urine concentration overrides the osmotic diuretic effect of glucosuria induced by dapagliflozin treatment.

METHODS

DAPA-Shuttle1 (Hepato-renal Regulation of Water Conservation in Heart Failure Patients With SGLT-2 Inhibitor Treatment) was a single-center, double-blind, randomized, placebo-controlled trial, in which patients with chronic heart failure NYHA functional classes I/II and reduced ejection fraction were randomly assigned to receive dapagliflozin 10 mg daily or placebo (1:1) for 4 weeks. The primary endpoint was change from baseline in urine osmolyte concentration. Secondary endpoints included changes in copeptin levels and solute free water clearance.

RESULTS

Thirty-three randomized, sodium-glucose cotransporter 2 inhibitor-naïve participants completed the study, 29 of whom (placebo: n = 14; dapagliflozin: n = 15) provided accurate 24-hour urine collections (mean age 59 ± 14 years; left ventricular ejection fraction 31% ± 9%). Dapagliflozin treatment led to an isolated increase in urine glucose excretion by 3.3 mmol/kg/d (95% CI: 2.51-4.04; P < 0.0001) within 48 hours (early) which persisted after 4 weeks (late; 2.7 mmol/kg/d [95% CI: 1.98-3.51]; P < 0.0001). Dapagliflozin treatment increased serum copeptin early (5.5 pmol/L [95% CI: 0.45-10.5]; P < 0.05) and late (7.8 pmol/L [95% CI: 2.77-12.81]; P < 0.01), leading to proportional reductions in free water clearance (early: -9.1 mL/kg/d [95% CI: -14 to -4.12; P < 0.001]; late: -11.0 mL/kg/d [95% CI: -15.94 to -6.07; P < 0.0001]) and elevated urine concentrations (late: 134 mmol/L [95% CI: 39.28-229.12]; P < 0.01). Therefore, urine volume did not significantly increase with dapagliflozin (mean difference early: 2.8 mL/kg/d [95% CI: -1.97 to 7.48; P = 0.25]; mean difference late: 0.9 mL/kg/d [95% CI: -3.83 to 5.62]; P = 0.70).

CONCLUSIONS

Physiological-adaptive water conservation eliminated the expected osmotic diuretic potential of dapagliflozin and thereby prevented a glucose-driven increase in urine volume of approximately 10 mL/kg/d · 75 kg = 750 mL/kg/d. (Hepato-renal Regulation of Water Conservation in Heart Failure Patients With SGLT-2 Inhibitor Treatment [DAPA-Shuttle1]; NCT04080518).

Dapagliflozin and Blood Pressure in Patients with Chronic Kidney Disease and Albuminuria

BACKGROUND AND AIMS

Sodium-glucose cotransporter 2 inhibitors decrease blood pressure in patients with type 2 diabetes, but the consistency and magnitude of blood pressure lowering with dapagliflozin in patients with chronic kidney disease (CKD) is unknown. We conducted a prespecified analysis of the DAPA-CKD trial to investigate the effect of dapagliflozin on systolic blood pressure (SBP) in patients with CKD, with and without type 2 diabetes.

METHODS

A total of 4304 adults with baseline estimated glomerular filtration rate (eGFR) 25-75 mL/min/1.73m2 and urinary albumin-to-creatinine ratio (UACR) 200-5000 mg/g were randomized to either dapagliflozin 10 mg or placebo once daily; median follow-up was 2.4 years. The primary endpoint was a composite of sustained ≥50% eGFR decline, end-stage kidney disease, or death from a kidney or cardiovascular cause. Change in SBP was a prespecified outcome.

RESULTS

Baseline mean (SD) SBP was 137.1 mmHg (17.4). By Week 2, dapagliflozin compared to placebo reduced SBP by 3.6 mmHg (95% CI 2.8-4.4 mmHg), an effect maintained over the duration of the trial (2.9 mmHg, 2.3-3.6 mmHg). Time-averaged reductions in SBP were 3.2 mmHg (2.5-4.0 mmHg) in patients with diabetes and 2.3 mmHg (1.2-3.4 mmHg) in patients without diabetes. The time-averaged effect of dapagliflozin on diastolic blood pressure (DBP) was 1.0 mmHg (0.6-1.4 mmHg); 0.8 mmHg (0.4-1.3 mmHg) in patients with diabetes and 1.4 mmHg (0.7-2.1 mmHg) in patients without diabetes. Benefits of dapagliflozin on the primary composite and secondary endpoints were evident across the spectrum of baseline SBP and DBP.

CONCLUSION

In patients with CKD and albuminuria, randomization to dapagliflozin was associated with modest reductions in systolic and diastolic BP.

Effects of Empagliflozin on Fluid Overload, Weight, and Blood Pressure in CKD

SIGNIFICANCE STATEMENT

SGLT2 inhibitors reduce risk of kidney progression, AKI, and cardiovascular disease, but the mechanisms of benefit are incompletely understood. Bioimpedance spectroscopy can estimate body water and fat mass. One quarter of the EMPA-KIDNEY bioimpedance substudy CKD population had clinically significant levels of bioimpedance-derived "Fluid Overload" at recruitment. Empagliflozin induced a prompt and sustained reduction in "Fluid Overload," irrespective of sex, diabetes, and baseline N-terminal pro B-type natriuretic peptide or eGFR. No significant effect on bioimpedance-derived fat mass was observed. The effects of SGLT2 inhibitors on body water may be one of the contributing mechanisms by which they mediate effects on cardiovascular risk.

BACKGROUND

CKD is associated with fluid excess that can be estimated by bioimpedance spectroscopy. We aimed to assess effects of sodium glucose co-transporter 2 inhibition on bioimpedance-derived "Fluid Overload" and adiposity in a CKD population.

METHODS

EMPA-KIDNEY was a double-blind placebo-controlled trial of empagliflozin 10 mg once daily in patients with CKD at risk of progression. In a substudy, bioimpedance measurements were added to the main trial procedures at randomization and at 2- and 18-month follow-up visits. The substudy's primary outcome was the study-average difference in absolute "Fluid Overload" (an estimate of excess extracellular water) analyzed using a mixed model repeated measures approach.

RESULTS

The 660 substudy participants were broadly representative of the 6609-participant trial population. Substudy mean baseline absolute "Fluid Overload" was 0.4±1.7 L. Compared with placebo, the overall mean absolute "Fluid Overload" difference among those allocated empagliflozin was -0.24 L (95% confidence interval [CI], -0.38 to -0.11), with similar sized differences at 2 and 18 months, and in prespecified subgroups. Total body water differences comprised between-group differences in extracellular water of -0.49 L (95% CI, -0.69 to -0.30, including the -0.24 L "Fluid Overload" difference) and a -0.30 L (95% CI, -0.57 to -0.03) difference in intracellular water. There was no significant effect of empagliflozin on bioimpedance-derived adipose tissue mass (-0.28 kg [95% CI, -1.41 to 0.85]). The between-group difference in weight was -0.7 kg (95% CI, -1.3 to -0.1).

CONCLUSIONS

In a broad range of patients with CKD, empagliflozin resulted in a sustained reduction in a bioimpedance-derived estimate of fluid overload, with no statistically significant effect on fat mass.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT03594110 ; EuDRACT: 2017-002971-24 ( https://eudract.ema.europa.eu/ ).

Fluid homeostatic action of dapagliflozin in patients with chronic kidney disease: the DAPA-BODY Trial

Sodium glucose cotransporter 2 (SGLT2) inhibitors have both glucose-lowering and diuretic effects. We recently reported that the SGLT2 inhibitor dapagliflozin exerts short-term fluid homeostatic action in patients with chronic kidney disease (CKD). However, the long-term effects of SGLT2 inhibitors on body fluid status in patients with CKD remain unclear. This was a prospective, non-randomized, open-label study that included a dapagliflozin treatment group (n = 73) and a control group (n = 24) who were followed for 6 months. Body fluid volume was measured using a bioimpedance analysis device. The extracellular water-to-total body water ratio (ECW/TBW), a predictor of renal outcomes, was used as a parameter for body fluid status (fluid retention, 0.400 ≤ ECW/TBW). Six-month treatment with dapagliflozin significantly decreased ECW/TBW compared with the control group (-0.65% ± 2.03% vs. 0.97% ± 2.49%, p = 0.0018). Furthermore, dapagliflozin decreased the ECW/TBW in patients with baseline fluid retention, but not in patients without baseline fluid retention (-1.47% ± 1.93% vs. -0.01% ± 1.88%, p = 0.0017). Vasopressin surrogate marker copeptin levels were similar between the control and dapagliflozin groups at 6 months (32.3 ± 33.4 vs. 30.6 ± 30.1 pmol/L, p = 0.8227). However, dapagliflozin significantly increased the change in copeptin levels at 1 week (39.0% ± 41.6%, p = 0.0010), suggesting a compensatory increase in vasopressin secretion to prevent hypovolemia. Renin and aldosterone levels were similar between the control and dapagliflozin groups at 6 months, while epinephrine and norepinephrine (markers of sympathetic nervous system activity) were significantly lower in the dapagliflozin group than in the control group. In conclusion, the SGLT2 inhibitor dapagliflozin ameliorated fluid retention and maintained euvolemic fluid status in patients with CKD, suggesting that SGLT2 inhibitors exert sustained fluid homeostatic actions in patients with various fluid backgrounds. Clinical trial registration: https://www.umin.ac.jp/ctr/, identifier [UMIN000048568].

Blood Pressure Effects of SGLT2 Inhibitors: Mechanisms and Clinical Evidence in Different Populations

PURPOSE OF REVIEW

Sodium glucose transporter 2 inhibitors (SGLT2 inhibitors) are increasingly prescribed due to their considerable benefits on clinical outcomes in people with diabetes, heart failure, and chronic kidney disease (CKD). Hypertension is a common comorbidity in each of these disease states, increasing risk of cardiovascular morbidity and mortality. We herein review the effects of SGLT2 inhibitors on blood pressure in different populations, proposed mechanisms of action, and the contribution of blood pressure lowering to end-organ protection.

RECENT FINDINGS

A recognised effect of SGLT2 inhibitors in recent clinical trials is blood pressure lowering, with multiple postulated mechanisms. This advantageous effect was first identified in populations with type 2 diabetes mellitus, prior to expansion of these trials to broader cohorts. On our review, we identified that the blood pressure lowering effect of SGLT2 inhibitors appears to be a dose-independent class-effect, with a magnitude of effect comparable to that seen with a low dose hydrochlorothiazide. There is considerable evidence demonstrating that this effect is observed across populations including those with type 2 diabetes mellitus, chronic kidney disease, and resistant hypertension.

Cardiovascular outcomes and safety of SGLT2 inhibitors in chronic kidney disease patients

Background

Sodium-glucose co-transporter 2 (SGLT2) inhibitors provide cardiovascular protection for patients with heart failure (HF) and type 2 diabetes mellitus (T2DM). However, there is little evidence of their application in patients with chronic kidney disease (CKD). Furthermore, there are inconsistent results from studies on their uses. Therefore, to explore the cardiovascular protective effect of SGLT2 inhibitors in the CKD patient population, we conducted a systematic review and meta-analysis to evaluate the cardiovascular effectiveness and safety of SGLT2 inhibitors in this patient population.

Method

We searched the PubMed® (National Library of Medicine, Bethesda, MD, USA) and Web of Science™ (Clarivate™, Philadelphia, PA, USA) databases for randomized controlled trials (RCTs) of SGLT2 inhibitors in CKD patients and built the database starting in January 2023. In accordance with our inclusion and exclusion criteria, the literature was screened, the quality of the literature was evaluated, and the data were extracted. RevMan 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark) and Stata® 17.0 (StataCorp LP, College Station, TX, USA) were used for the statistical analyses. Hazard ratios (HRs), odds ratios (ORs), and corresponding 95% confidence intervals (CIs) were used for the analysis of the outcome indicators.

Results

Thirteen RCTs were included. In CKD patients, SGLT2 inhibitors reduced the risk of cardiovascular death (CVD) or hospitalization for heart failure (HHF) by 28%, CVD by 16%. and HHF by 35%. They also reduced the risk of all-cause death by 14% without increasing the risk of serious adverse effects (SAEs) and urinary tract infections (UTIs). However, they increased the risk of reproductive tract infections (RTIs).

Conclusion

SGLT2 inhibitors have a cardiovascular protective effect on patients with CKD, which in turn can significantly reduce the risk of CVD, HHF, and all-cause death without increasing the risk of SAEs and UTIs but increasing the risk of RTIs.

Critical Analysis of the Effects of SGLT2 Inhibitors on Renal Tubular Sodium, Water and Chloride Homeostasis and Their Role in Influencing Heart Failure Outcomes

SGLT2 (sodium-glucose cotransporter 2) inhibitors interfere with the reabsorption of glucose and sodium in the early proximal renal tubule, but the magnitude and duration of any ensuing natriuretic or diuretic effect are the result of an interplay between the degree of upregulation of SGLT2 and sodium-hydrogen exchanger 3, the extent to which downstream compensatory tubular mechanisms are activated, and (potentially) the volume set point in individual patients. A comprehensive review and synthesis of available studies reveals several renal response patterns with substantial variation across studies and clinical settings. However, the common observation is an absence of a large acute or chronic diuresis or natriuresis with these agents, either when given alone or combined with other diuretics. This limited response results from the fact that renal compensation to these drugs is rapid and nearly complete within a few days or weeks, preventing progressive volume losses. Nevertheless, the finding that fractional excretion of glucose and lithium (the latter being a marker of proximal sodium reabsorption) persists during long-term treatment with SGLT2 inhibitors indicates that pharmacological tolerance to the effects of these drugs at the level of the proximal tubule does not meaningfully occur. This persistent proximal tubular effect of SGLT2 inhibitors can be hypothesized to produce a durable improvement in the internal set point for volume homeostasis, which may become clinically important during times of fluid expansion. However, it is difficult to know whether a treatment-related change in the volume set point actually occurs or contributes to the effect of these drugs to reduce the risk of major heart failure events. SGLT2 inhibitors exert cardioprotective effects by a direct effect on cardiomyocytes that is independent of the presence of or binding to SGLT2 or the actions of these drugs on the proximal renal tubule. Nevertheless, changes in the volume set point mediated by SGLT2 inhibitors might potentially act cooperatively with the direct favorable molecular and cellular effects of these drugs on cardiomyocytes to mediate their benefits on the development and clinical course of heart failure.

Signaling Pathways of Podocyte Injury in Diabetic Kidney Disease and the Effect of Sodium-Glucose Cotransporter 2 Inhibitors

Diabetic kidney disease (DKD) is one of the most important comorbidities for patients with diabetes, and its incidence has exceeded one tenth, with an increasing trend. Studies have shown that diabetes is associated with a decrease in the number of podocytes. Diabetes can induce apoptosis of podocytes through several apoptotic pathways or induce autophagy of podocytes through related pathways. At the same time, hyperglycemia can also directly lead to apoptosis of podocytes, and the related inflammatory reactions are all harmful to podocytes. Podocyte damage is often accompanied by the production of proteinuria and the progression of DKD. As a new therapeutic agent for diabetes, sodium-glucose cotransporter 2 inhibitors (SGLT2i) have been demonstrated to be effective in the treatment of diabetes and the improvement of terminal outcomes in many rodent experiments and clinical studies. At the same time, SGLT2i can also play a protective role in diabetes-induced podocyte injury by improving the expression of nephrotic protein defects and inhibiting podocyte cytoskeletal remodeling. Some studies have also shown that SGLT2i can play a role in inhibiting the apoptosis and autophagy of cells. However, there is no relevant study that clearly indicates whether SGLT2i can also play a role in the above pathways in podocytes. This review mainly summarizes the damage to podocyte structure and function in DKD patients and related signaling pathways, as well as the possible protective mechanism of SGLT2i on podocyte function.

Update on Hypertension Research in 2021

In 2021, 217 excellent manuscripts were published in Hypertension Research. Editorial teams greatly appreciate the authors' contribution to hypertension research progress. Here, our editorial members have summarized twelve topics from published work and discussed current topics in depth. We hope you enjoy our special feature, "Update on Hypertension Research in 2021".