Correction of hypomagnesemia by dapagliflozin in patients with type 2 diabetes: A post hoc analysis of 10 randomized, placebo-controlled trials

SGLT2 Inhibitors Blunt Kidney Magnesium Wasting in Acute Cisplatin-Induced Hypomagnesemia with Effects on the Thick Ascending Limb and Distal Convoluted Tubule

Key Points

Background

Cisplatin, a chemotherapeutic agent, induces kidney magnesium wasting and hypomagnesemia. Recent studies suggest that sodium-glucose cotransporter 2 inhibitors elevate serum magnesium concentration in patients with or without diabetes. We hypothesized that the sodium-glucose cotransporter 2 inhibitor empagliflozin attenuates acute cisplatin-induced hypomagnesemia by acting on the thick ascending limb (TAL) and distal convoluted tubule (DCT), key sites of magnesium reabsorption.

Methods

Adult male Wistar rats received weekly treatments of cisplatin (2.5 mg/kg) or saline (vehicle) for 5 weeks. After 3 weeks, rats were randomized to receive empagliflozin (10 mg/kg per day) or water (vehicle) for the next 15 days.

Results

Cisplatin-treated rats developed significant hypomagnesemia with increased fractional excretion of magnesium. Empagliflozin treatment reduced fractional excretion of magnesium and restored serum magnesium levels. In the TAL, cisplatin-treated rats had higher Na+-K+-Cl− cotransporter 2 (NKCC2) abundance but lower phosphorylated NKCC2 and claudin-16 levels than empagliflozin-treated cisplatin rats, whose protein levels were similar to controls. By contrast, claudin-19 abundance in the TAL was higher in cisplatin-treated rats than in controls and unaffected by empagliflozin treatment. In the DCT, cisplatin-treated rats displayed reduced abundance of the NaCl cotransporter (NCC), the magnesium channel transient receptor potential melastatin 6, and NCC phosphorylation, all of which were rescued by empagliflozin. Unexpectedly, cisplatin-treated rats exhibited higher mRNA expression and protein abundance of TRPM7 compared with empagliflozin-treated cisplatin rats, whose levels were similar to controls. Diuretic challenge tests with furosemide or hydrochlorothiazide confirmed reduced NKCC2 and NCC activity in cisplatin-treated rats. However, the natriuretic response to furosemide or hydrochlorothiazide did not differ between control and empagliflozin-treated cisplatin rats. Immunohistochemistry suggested that empagliflozin reversed cisplatin-induced DCT remodeling.

Conclusions

Empagliflozin reduces kidney magnesium wasting and restores serum magnesium in cisplatin-treated rats, likely through reversing NKCC2 inhibition and claudin-16 downregulation in the TAL while normalizing NCC function and restoring transient receptor potential melastatin 6 expression in the DCT.

SGLT2 inhibitors increase low serum magnesium levels in patients with chronic kidney disease immediately after treatment

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown in clinical trials to increase serum Mg2+ levels in patients with type 2 diabetes mellitus. However, it is unclear whether this effect is similarly observed in patients with chronic kidney disease (CKD) and whether such an increase is observed immediately after treatment.

METHODS

Our retrospective observational study included the 62 patients with CKD who started SGLT2 inhibitor therapy at our institution between 2017 and 2022 and who had complete data on serum Mg2+ measurements at baseline and at 1, 3, and 6 months after treatment. Patients were divided into three subgroups, stratified by serum Mg2+ levels at baseline. We evaluated the changes in serum Mg2+ levels from baseline to 6 months after treatment and the factors associated with these changes.

RESULTS

Median eGFR and mean serum Mg2+ at baseline were 33.5 mL/min/1.73 m2 and 2.03 mg/dL, respectively. Treatment with SGLT2 inhibitors significantly increased serum Mg2+ levels immediately from 1 month after treatment compared with those at baseline and persisted over 6 months, with an overall mean change of 0.13 mg/dL from baseline to 6 months. This increased effect was observed in the low and middle tertile subgroups, but not in the high tertile subgroup. Multivariate linear regression analysis revealed that baseline serum Mg2+ levels and sodium-chloride differences, as a parameter of acid-base status, were independently associated with these changes.

CONCLUSIONS

SGLT2 inhibitors increased serum Mg2+ levels in patients with CKD, particularly those with lower baseline Mg2+ levels, potentially improving their prognosis.

Impact of SGLT2 Inhibitors on Magnesium in Kidney Transplant Patients with and Without Diabetes

Magnesium (Mg2+) is essential for cardiovascular and metabolic health, yet hypomagnesemia is common in kidney transplant recipients (KTRs) due to immunosuppressive therapy and renal dysfunction. Oral Mg2+ supplementation is often ineffective due to poor absorption and side effects. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have been shown to increase serum Mg2+ in chronic kidney disease, but their effects in KTRs, particularly patients without diabetes, remain unclear. This observational study assessed 63 KTRs treated with dapagliflozin, analyzing the serum Mg2+ levels at baseline and after 3 and 6 months. The hypomagnesemia prevalence, associations with oral supplementation, diabetes status, and diuretic use were evaluated. The results showed a significant Mg2+ increase with SGLT2i therapy, reducing hypomagnesemia regardless of the diabetes status. Oral supplementation did not correlate with improved Mg2+ levels, reinforcing its limited efficacy. Additional benefits included reductions in the body weight, blood pressure, and serum urate without compromising graft function. SGLT2i may offer a novel approach to managing hypomagnesemia in KTRs, potentially reducing the reliance on ineffective supplements while providing renal and cardiovascular benefits. Further research is needed to confirm these findings and elucidate the underlying mechanisms.

Calcium, Magnesium and Phosphate Disorders

A fundamental understanding of electrolyte disorders is a requisite skill for nephrology practitioners given the vital role kidneys play in maintenance of homeostasis. While disorders of sodium and potassium garner greater attention, calcium, magnesium, and phosphate are similarly essential for a variety of bodily functions. This article reviews the physiology and pathology of calcium, magnesium, and phosphate through a series of clinical vignettes designed to assist nephrologists preparing for boards and practitioners caring for patients with derangements in these electrolytes in clinical practice.

Hypomagnesaemia, an independent risk factor for the development of post-transplant diabetes mellitus in liver and renal transplant recipients? A systematic review

BACKGROUND

Post-transplantation diabetes mellitus (PTDM) is common after solid organ transplantation. In the past decade, there has been increasing interest in the association between hypomagnesaemia and the development of PTDM. This systematic review aimed to investigate the current knowledge regarding the association between hypomagnesaemia and PTDM in adult liver and renal transplant recipients.

METHODS

A literature search of five databases, Medline, Embase, ProQuest, Scopus and Google Scholar, as well as article reference lists, was performed. Eligible studies that focused on adult liver and renal transplant recipients without pretransplantation hyperglycaemia or diabetes were included. Other eligibility criteria included quantitative studies which reported magnesium concentrations, studies with at least 6 months of follow-up, and studies published in English. The Newcastle-Ottawa Assessment Tool was used for the quality assessment.

RESULTS

In total, 12 studies were included in the final analysis. Eleven focused on renal transplantation and one on liver transplantation. All studies were medium to high quality with eight out of 12 achieving the highest rating of nine. Eight studies found a negative association between either pretransplant or early post-transplant serum magnesium concentration and the risk of PTDM, three studies found no association between these two variables, and one study found a positive association between the magnesium concentration at 8 weeks after transplantation and glycosylated haemoglobin A1C.

CONCLUSIONS

Further large-scale prospective studies with at least 6 months of follow-up are needed to confirm these findings, particularly in liver transplantation, to further clarify and explore the relationship between hypomagnesaemia and PTDM.

The Role of Sodium-Glucose Co-transporter 2 Inhibitors in Patients With Hypomagnesemia: A Systematic Review

Sodium-glucose co-transporter 2 (SGLT2) inhibitors, initially developed for glycemic control in type 2 diabetes, have demonstrated benefits in reducing heart failure hospitalizations, slowing chronic kidney disease, and decreasing major cardiovascular events. Recent studies have shown that SGLT2 inhibitors can elevate serum magnesium levels in patients with type 2 diabetes, suggesting potential benefits in managing refractory hypomagnesemia. This systematic review analyzed relevant case reports, observational studies, and randomized controlled trials (RCTs) to investigate the association between SGLT2 inhibitors and hypomagnesemia. The review adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and study quality was assessed using the CAse REport (CARE) guidelines. It encompassed four case reports, one retrospective observational study, one post-hoc analysis of 10 RCTs, and one meta-analysis of 18 RCTs, with a total study population of 19,767 patients. The meta-analysis revealed that SGLT2 inhibitors significantly increased serum magnesium levels in patients with type 2 diabetes, with a linear dose-dependent increase noted particularly for canagliflozin. Additionally, the case reports and other studies suggested that SGLT2 inhibitors could exert extraglycemic effects, potentially enhancing magnesium balance beyond their impact on urinary magnesium excretion. This systematic review underscores the effectiveness of SGLT2 inhibitors in addressing refractory hypomagnesemia linked with urinary magnesium wasting. It also suggests promising avenues for the application of these drugs in diverse patient populations.

Sodium/Glucose Cotransporter 2 Inhibitors and Magnesium Homeostasis: A Review

Magnesium (Mg2+), also known as "the forgotten ion," is the second most abundant intracellular cation and is essential in a broad range of intracellular physiological and biochemical reactions. Its deficiency, hypomagnesemia (Mg2+<1.8mg/dL), is a prevalent condition and routinely poses challenges in its management in clinical practice. Sodium/glucose cotransporter 2 (SGLT2) inhibitors have emerged as a new class of drugs with treating hypomagnesemia as their unique extraglycemic benefit. The beneficial effect of SGLT2 inhibitors on magnesium balance in patients with diabetes with or without hypomagnesemia has been noted as a class effect in recent meta-analysis data from randomized clinical trials. Some reports have demonstrated their role in treating refractory hypomagnesemia in patients with or without diabetes. Moreover, studies on animal models have attempted to illustrate the effect of SGLT2 inhibitors on Mg2+homeostasis. In this review, we discuss the current evidence and possible pathophysiological mechanisms, and we provide directions for further research. We conclude by suggesting the effect of SGLT2 inhibitors on Mg2+homeostasis is a class effect, with certain patients gaining significant benefits. Further studies are needed to examine whether SGLT2 inhibitors can become a desperately needed novel class of medicines in treating hypomagnesemia.

SGLT2 Inhibitors in Management of Severe Hypomagnesemia in Patients Without Diabetes: A Report of 4 Cases

Sodium/glucose cotransporter 2 (SGLT2) inhibitors have demonstrated a class effect in improving serum magnesium levels in patients with diabetes. Additionally, recent reports have shown their promising beneficial effects in the treatment of refractory hypomagnesemia in patients with diabetes. However, their role in treating hypomagnesemia in patients without diabetes remains unexplored. Here, we report 4 cases of severe and refractory hypomagnesemia that showed dramatic improvement after initiating SGLT2 inhibitors in patients without diabetes. Case 1 had calcineurin inhibitor-associated severe hypomagnesemia. Cases 2, 3, and 4 had refractory hypomagnesemia associated with platinum-based chemotherapy with or without gastrointestinal losses. Case 1 was able to withdraw from high-dose oral magnesium supplementation. Cases 2 and 3 achieved independence from intravenous magnesium supplementation, whereas case 4 had decreased intravenous magnesium requirements. All the cases demonstrated sustainably improved serum magnesium levels. Withdrawal of SGLT2 inhibitors in case 4 resulted in worsening serum magnesium levels and intravenous magnesium requirements. The extraglycemic benefit of this group of medications not only suggests the need for further studies to better understand the effect of SGLT2 inhibitors on magnesium homeostasis but also supports expanded use in a larger patient population.

Sodium-glucose cotransporter-2 inhibitor therapy in kidney transplant patients with type 2 or post-transplant diabetes: an observational multicentre study

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2is) have cardioprotective and renoprotective effects. However, experience with SGLT2is in diabetic kidney transplant recipients (DKTRs) is limited.

METHODS

This observational multicentre study was designed to examine the efficacy and safety of SGLT2is in DKTRs. The primary outcome was adverse effects within 6 months of SGLT2i treatment.

RESULTS

Among 339 treated DKTRs, adverse effects were recorded in 26%, the most frequent (14%) being urinary tract infection (UTI). In 10%, SGLT2is were suspended mostly because of UTI. Risk factors for developing a UTI were a prior episode of UTI in the 6 months leading up to SGLT2i use {odds ratio [OR] 7.90 [confidence interval (CI) 3.63-17.21]} and female sex [OR 2.46 (CI 1.19-5.03)]. In a post hoc subgroup analysis, the incidence of UTI emerged as similar in DKTRs treated with SGLT2i for 12 months versus non-DKTRs (17.9% versus 16.7%). Between baseline and 6 months, significant reductions were observed in body weight [-2.22 kg (95% CI -2.79 to -1.65)], blood pressure, fasting glycaemia, haemoglobin A1c [-0.36% (95% CI -0.51 to -0.21)], serum uric acid [-0.44 mg/dl (95% CI -0.60 to -0.28)] and urinary protein:creatinine ratio, while serum magnesium [+0.15 mg/dl (95% CI 0.11-0.18)] and haemoglobin levels rose [+0.44 g/dl (95% CI 0.28-0.58]. These outcomes persisted in participants followed over 12 months of treatment.

CONCLUSIONS

SGLT2is in kidney transplant offer benefits in terms of controlling glycaemia, weight, blood pressure, anaemia, proteinuria and serum uric acid and magnesium. UTI was the most frequent adverse effect. According to our findings, these agents should be prescribed with caution in female DKTRs and those with a history of UTI.

Acquired Disorders of Hypomagnesemia

Magnesium disorders are common in clinical practice and when present can manifest clinically as cardiovascular, neuromuscular, or other organ dysfunction. Hypomagnesemia is far more common than hypermagnesemia, which is largely seen in patients with reduced glomerular filtration rates receiving magnesium-containing medications. In addition to inherited disorders of magnesium handling, hypomagnesemia is also seen with excessive gastrointestinal or renal losses and due to medications such as amphotericin B, aminoglycosides, and cisplatin. Laboratory assessment of body magnesium stores largely relies on the measurement of serum magnesium levels that are a poor proxy for total body stores but does correlate with the development of symptoms. Replacement of magnesium can be challenging, with oral replacement strategies being generally more effective at slowly replacing body stores but intravenous replacement being more effective at treating the more life-threatening and severe cases of hypomagnesemia. We conducted a thorough review of the literature using PubMed (1970-2022) and the search terms magnesium, hypomagnesemia, drugs, medications, treatment, and therapy. In the absence of clear data on optimal management of hypomagnesemia, we have made recommendations on magnesium replacement based on our clinical experience.

Magnesium reabsorption in the kidney

Mg²⁺ is essential for many cellular and physiological processes, including muscle contraction, neuronal activity, and metabolism. Consequently, the blood Mg²⁺ concentration is tightly regulated by balanced intestinal Mg²⁺ absorption, renal Mg²⁺ excretion, and Mg²⁺ storage in bone and soft tissues. In recent years, the development of novel transgenic animal models and identification of Mendelian disorders has advanced our current insight in the molecular mechanisms of Mg²⁺ reabsorption in the kidney. In the proximal tubule, Mg²⁺ reabsorption is dependent on paracellular permeability by claudin-2/12. In the thick ascending limb of Henle's loop, the claudin-16/19 complex provides a cation-selective pore for paracellular Mg²⁺ reabsorption. The paracellular Mg²⁺ reabsorption in this segment is regulated by the Ca²⁺-sensing receptor, parathyroid hormone, and mechanistic target of rapamycin (mTOR) signaling. In the distal convoluted tubule, the fine tuning of Mg²⁺ reabsorption takes place by transcellular Mg²⁺ reabsorption via transient receptor potential melastatin-like types 6 and 7 (TRPM6/TRPM7) divalent cation channels. Activity of TRPM6/TRPM7 is dependent on hormonal regulation, metabolic activity, and interacting proteins. Basolateral Mg²⁺ extrusion is still poorly understood but is probably dependent on the Na⁺ gradient. Cyclin M2 and SLC41A3 are the main candidates to act as Na⁺/Mg²⁺ exchangers. Consequently, disturbances of basolateral Na⁺/K⁺ transport indirectly result in impaired renal Mg²⁺ reabsorption in the distal convoluted tubule. Altogether, this review aims to provide an overview of the molecular mechanisms of Mg²⁺ reabsorption in the kidney, specifically focusing on transgenic mouse models and human hereditary diseases.

Improvement in Serum Magnesium Levels With Sodium-Glucose Cotransporter 2 Inhibitors

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are associated with a modest but significant increase in serum magnesium levels. This report describes improvement in serum magnesium and associated symptoms after initiating SGLT2i therapy in a patient with refractory hypomagnesemia. A 58-year-old woman presented with persistent hypomagnesemia refractory to oral magnesium supplements. She had history of type 2 diabetes mellitus, hypothyroidism, fibromyalgia, and degenerative disk disease. The cause of hypomagnesemia was attributed to excessive renal losses. Laboratory investigations revealed serum magnesium of 1.2 mg/dL with fractional excretion of magnesium of 8.9%. She was started on empagliflozin 10 mg daily. Within 4 weeks of therapy, her serum magnesium level corrected with symptomatic improvement, which was sustained a few weeks later. Subsequently, her oral magnesium supplements dose was reduced. SGLT2i has been shown to improve magnesium levels in patients with urinary magnesium wasting. Several mechanisms have been postulated, but the exact physiology remains unknown. SGLT2i have been efficacious for glycemic control, renal protection, decreasing the risk of atherosclerotic cardiovascular disease events, and cardiac mortality in patients with diabetes. In addition, renal and cardiac benefits are also demonstrated in patients without diabetes. This observation demonstrates that SGLT2i can improve the management of patients with otherwise intractable hypomagnesemia.

The effects of oral magnesium supplementation on glycaemic control in patients with type 2 diabetes: a systematic review and dose-response meta-analysis of controlled clinical trials

The current systematic review and meta-analysis were conducted to evaluate the effects of oral Mg supplementation on glycaemic control in type 2 diabetes mellitus (T2DM) patients. Related articles were found by searching the PubMed, SCOPUS, Embase and Web of Science databases (from inception to 30 February 2020). A one-stage robust error meta-regression model based on inverse variance weighted least squares regression and cluster robust error variances was used for the dose-response analysis between Mg supplementation and duration of intervention and glycaemic control factors. Eighteen eligible randomised clinical trials were included in our final analysis. The dose-response testing indicated that the estimated mean difference in HbA1c at 500 mg/d was -0·73 % (95 % CI: -1·25, -0·22) suggesting modest improvement in HbA1c with strong evidence (P value: 0·004). And in fasting blood sugar (FBS) at 360 mg/d was -7·11 mg/dl (95 % CI: -14·03, -0·19) suggesting minimal amelioration in FBS with weak evidence (P value: 0·092) against the model hypothesis at this sample size. The estimated mean difference in FBS and HbA1c at 24 weeks was -15·58 mg/dl (95 % CI: -24·67, -6·49) and -0·48 (95 % CI: -0·77, -0·19), respectively, suggesting modest improvement in FBS (P value: 0·034) and HbA1c (P value: 0·001) with strong evidence against the model hypothesis at this sample size. Oral Mg supplementation could have an effect on glycaemic control in T2DM patients. However, the clinical trials so far are not sufficient to make guidelines for clinical practice.

Sodium-Glucose Cotransporter 2 Inhibitors and Management of Refractory Hypomagnesemia Without Overt Urinary Magnesium Wasting: A Report of 2 Cases

Sodium-glucose cotransporter 2 (SGLT2) inhibitor have become widely used in patients with diabetes, heart failure, and kidney disease to improve clinical outcomes and diminish hospitalizations. They have also been associated with increased serum magnesium levels in patients with type 2 diabetes. The use of SGLT2 inhibitors resulted in improved magnesium homeostasis in a series of patients with refractory hypomagnesemia with urinary magnesium wasting. However, the role of SLGT2 inhibitors in patients with hypomagnesemia without urinary magnesium wasting remains unexplored. We report 2 cases with refractory hypomagnesemia without significant urinary magnesium wasting and dramatically improved serum magnesium levels after the initiation of SGLT2 inhibitors. Case 1 achieved independence from weekly intravenous magnesium infusions and reached sustainably greater serum magnesium levels with decreased oral magnesium supplementation and increased urinary fractional excretion of magnesium. Case 2 demonstrated improved serum magnesium levels with reduced oral magnesium supplementation without significant reduction in urinary fractional excretion of magnesium. These findings not only expand the use of SGLT2 inhibitors but also open the door for further studies to better understand the pathophysiology of how magnesium homeostasis is altered with inhibition of SGLT2.

Comparative Effects of Sodium-Glucose Cotransporter 2 Inhibitors on Serum Electrolyte Levels in Patients with Type 2 Diabetes: A Pairwise and Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Previous studies have reported that sodium-glucose co-transporter 2 (SGLT2) inhibitors (SGLT2is) affect levels of serum electrolytes, especially magnesium. This study aimed to integrate direct and indirect trial evidence to maximize statistical power to clarify their overall and comparative effects in patients with type 2 diabetes (T2D).

METHODS

We systematically searched PubMed, EMBASE, CENTRAL, and ClinicalTrials.gov up to January 2021 to identify eligible randomized controlled trials (RCTs) of SGLT2is that reported mean changes in serum electrolytes, including magnesium, sodium, potassium, phosphate, and calcium. We performed both random-effects pairwise and network meta-analyses to calculate the weighted mean difference (WMD) and 95% confidence intervals (CI).

RESULTS

In total, we included 25 RCTs involving 28,269 patients with T2D and 6 SGLT2is. Compared with placebo, SGLT2is were significantly associated with elevations in serum magnesium by 0.07 mmol/L (95% CI, 0.06 to 0.08 mmol/L) and serum phosphate by 0.03 mmol/L (95% CI, 0.02 to 0.04 mmol/L). Our network meta-analysis showed no evidence of significantly superior efficacy of any specific SGLT2 inhibitor over the others, although dapagliflozin was associated with a larger increment in serum magnesium (WMD=0.16 mmol/L) compared with other SGLT2is. Similarly, no statistically detectable differences among the effects of SGLT2is on serum levels of other electrolytes were detected.

CONCLUSIONS

SGLT2is significantly increased serum magnesium and phosphate levels, consistent with a class effect of SGLT2 inhibition. However, further investigations of long-term efficacy and safety in patients with T2D with different clinical phenotypes are needed.

Sodium Glucose Cotransporter-2 Inhibitors: Spotlight on Favorable Effects on Clinical Outcomes beyond Diabetes

Sodium glucose transporter type 2 (SGLT2) molecules are found in proximal tubules of the kidney, and perhaps in the brain or intestine, but rarely in any other tissue. However, their inhibitors, intended to improve diabetes compensation, have many more beneficial effects. They improve kidney and cardiovascular outcomes and decrease mortality. These benefits are not limited to diabetics but were also found in non-diabetic individuals. The pathophysiological pathways underlying the treatment success have been investigated in both clinical and experimental studies. There have been numerous excellent reviews, but these were mostly restricted to limited aspects of the knowledge. The aim of this review is to summarize the known experimental and clinical evidence of SGLT2 inhibitors' effects on individual organs (kidney, heart, liver, etc.), as well as the systemic changes that lead to an improvement in clinical outcomes.

Effect of Dapagliflozin and Magnesium Supplementation on Renal Magnesium Handling and Magnesium Homeostasis in Metabolic Syndrome

The prevalence of metabolic syndrome (MetS) is increasing, and patients with MetS are at an increased risk of cardiovascular disease and diabetes. There is a close link between hypomagnesemia and MetS. Administration of sodium-glucose transporter 2 (SGLT2) inhibitors has been reported to increase serum magnesium levels in patients with diabetes. We investigated the alterations in renal magnesium handling in an animal model of MetS and analyzed the effects of SGLT2 inhibitors. Adult rats were fed a fructose-rich diet to induce MetS in the first 3 months and were then treated with either dapagliflozin or magnesium sulfate-containing drinking water for another 3 months. Fructose-fed animals had increased insulin resistance, hypomagnesemia, and decreased urinary magnesium excretion. Dapagliflozin treatment improved insulin resistance by decreasing glucose and insulin levels, increased serum magnesium levels, and reduced urinary magnesium excretion. Serum vitamin D and parathyroid hormone levels were decreased in fructose-fed animals, and the levels remained low despite dapagliflozin and magnesium supplementation. In the kidney, claudin-16, TRPM6/7, and FXDY expression was increased in fructose-fed animals. Dapagliflozin increased intracellular magnesium concentration, and this effect was inhibited by TRPM6 blockade and the EGFR antagonist. We concluded that high fructose intake combined with a low-magnesium diet induced MetS and hypomagnesemia. Both dapagliflozin and magnesium sulfate supplementation improved the features of MetS and increased serum magnesium levels. Expression levels of magnesium transporters such as claudin-16, TRPM6/7, and FXYD2 were increased in fructose-fed animals and in those administered dapagliflozin and magnesium sulfate. Dapagliflozin enhances TRPM6-mediated trans-epithelial magnesium transport in renal tubule cells.

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

BACKGROUND

Dapagliflozin reduced the risk of kidney failure in patients with chronic kidney disease with and without type 2 diabetes in the DAPA-CKD trial. In this pre-specified analysis, we assessed the effect of dapagliflozin on the rate of change in estimated glomerular filtration rate (eGFR)-ie, the eGFR slope.

METHODS

DAPA-CKD was a randomised controlled trial that enrolled participants aged 18 years or older, with or without type 2 diabetes, with a urinary albumin-to-creatinine ratio (UACR) of 200-5000 mg/g, and an eGFR of 25-75 mL/min per 1·73m². Participants were randomly assigned (1:1) to oral dapagliflozin 10 mg once daily or placebo, added to standard care. In this pre-specified analysis, we analysed eGFR slope using mixed-effect models with different slopes from baseline to week 2 (acute eGFR decline), week 2 to end of treatment (chronic eGFR slope), and baseline to end of treatment (total eGFR slope). DAPA-CKD is registered with ClinicalTrials.gov, NCT03036150, and is now complete.

FINDINGS

Between Feb 2, 2017, and April 3, 2020, 4304 participants were recruited, of whom 2152 (50%) were assigned to dapagliflozin and 2152 (50%) were assigned to placebo. At baseline, the mean age was 62 years (SD 12), 1425 (33·1%) participants were women, 2906 (67·5%) participants had type 2 diabetes. The median on-treatment follow-up was 2·3 years (IQR 1·8-2·6). From baseline to the end of treatment, dapagliflozin compared with placebo slowed eGFR decline by 0·95 mL/min per 1·73 m² per year (95% CI 0·63 to 1·27) in the overall cohort. Between baseline and week 2, dapagliflozin compared with placebo resulted in an acute eGFR decline of 2·61 mL/min per 1·73 m² (2·16 to 3·06) in patients with type 2 diabetes and 2·01 mL/min per 1·73 m² (1·36 to 2·66) in those without type 2 diabetes. Between week 2 and end of treatment, dapagliflozin compared with placebo reduced the mean rate of eGFR decline by a greater amount in patients with type 2 diabetes (mean difference in chronic eGFR slope 2·26 mL/min per 1·73 m² per year [1·88 to 2·64]) than in those without type 2 diabetes (1·29 mL/min per 1·73 m² per year [0·73 to 1·85]; p_interaction=0·0049). Between baseline and end of treatment, the effect of dapagliflozin compared with placebo on the decline of total eGFR slope in patients with type 2 diabetes was 1·18 mL/min per 1·73 m² per year (0·79 to 1·56) and without type 2 diabetes was 0·46 mL/min per 1·73 m² per year (-0·10 to 1·03; p_interaction=0·040). The total eGFR slope was steeper in patients with higher baseline HbA_1c and UACR; the effect of dapagliflozin on eGFR slope was also more pronounced in patients with higher baseline HbA_1c and UACR.

INTERPRETATION

Dapagliflozin significantly slowed long-term eGFR decline in patients with chronic kidney disease compared with placebo. The mean difference in eGFR slope between patients treated with dapagliflozin versus placebo was greater in patients with type 2 diabetes, higher HbA_1c, and higher UACR.

FUNDING

AstraZeneca.

The diuretic effects of SGLT2 inhibitors: A comprehensive review of their specificities and their role in renal protection

Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are new oral glucose-lowering agents that provide cardiovascular and renal protection in both patients with and without type 2 diabetes. Because of their unique mechanism of action, increased glucosuria is associated with osmotic diuresis and some natriuresis, yet the latter seems mostly transient. The potential role of the diuretic effect in overall cardiovascular and renal protection by SGLT2is remains a matter of debate. Precise evaluation of the diuretic effect is not so easy and most studies relied upon indirect estimations that led to divergent results, presumably also explained by different study designs and population characteristics. Everybody agrees upon the fact that SGLT2is are different from other classical diuretics (thiazides and loop diuretics) as they present some favourable properties, i.e. reduced sympathetic activity, preserved potassium balance, lower risk of acute renal injury, decrease of serum uric acid level. The potential role of the diuretic effect of SGLT2is on renal outcomes is still unclear, yet their ability to reduce albuminuria and dampen the risk of heart failure may contribute to improve renal prognosis besides other complex underlying mechanisms. In this comprehensive review we first critically analyse the results obtained with indirect methods that assess a diuretic effect of SGLT2is, second we describe the specificities of the diuretic activity of SGLT2is compared with other classical diuretics, and third we discuss the potential mechanisms by which the diuretic effect of SGLT2is could contribute to the improvement of renal outcomes consistently reported with this innovative amazing pharmacological class.

Disorders of Divalent Ions (Magnesium, Calcium, and Phosphorous) in Patients With Cancer

Disorders of the divalent ions (magnesium, calcium, and phosphorous) are frequently encountered in patients with cancer. Of these, hypomagnesemia, hypocalcemia, hypercalcemia, and hypophosphatemia are seen most commonly. These electrolyte disturbances may be related to the underlying malignancy or due to side effects of anticancer therapy. When caused by a paraneoplastic process, these abnormalities may portend a poor prognosis. Importantly, the development of severe electrolyte derangements may be associated with symptoms that negatively impact quality of life, preclude the administration of critical chemotherapeutic agents, or lead to life-threatening complications that require hospitalization and emergent treatment. In accordance, prompt recognition and treatment of these disorders is key to improving outcomes in patients living with cancer. This review will discuss selected derangements of the divalent ions seen in this population, with a focus on paraneoplastic and therapy-associated etiologies.

Canagliflozin, serum magnesium and cardiovascular outcomes-Analysis from the CANVAS Program

BACKGROUND

Patients with type 2 diabetes (T2D) are predisposed to derangements in serum Magnesium (Mg), which may have implications for cardiometabolic events and outcomes. In clinical trials, participants with T2D randomized to sodium-glucose co-transporter 2 (SGLT2) inhibitors have shown mild to moderate increases in serum Mg from baseline levels. This post hoc analysis assesses the relation between serum Mg with cardiovascular outcomes in 10,140 participants of the Canagliflozin Cardiovascular Assessment Study (CANVAS) Program.

METHODS

We evaluated the association of baseline serum Mg with the primary composite end point of death from cardiovascular causes, non-fatal myocardial infarction, and non-fatal stroke, and tested whether this association is modified by baseline serum Mg. Using mediation analysis, we determined whether change in serum Mg post-randomization mediates the beneficial effect of canagliflozin on cardiovascular outcomes.

RESULTS

Mean serum Mg levels at baseline were 0.77 ± 0.09 mmol/L in both canagliflozin group and placebo groups. The canagliflozin group experienced an average increase in serum Mg by 0.07 mmol/L (95% CI, 0.065-0.072 mmol/L; p < .001) for the duration of the trial. We found no association between baseline serum Mg levels and the primary composite end point, and no evidence of effect modification by baseline Mg levels. Change in serum Mg post-randomization was not a mediator of the effects of canagliflozin on cardiovascular outcomes.

CONCLUSIONS

In participants of the CANVAS Program, baseline and post-randomization serum Mg levels are not associated with cardiovascular outcomes.

Hypomagnesemia in the Cancer Patient

Hypomagnesemia is a common medical problem that contributes to the morbidity and mortality of patients with cancer. This review summarizes magnesium physiology and highlights the mechanisms underlying magnesium disturbances due to cancer and cancer treatment. The causes of hypomagnesemia can be categorized according to the pathophysiologic mechanism: decreased intake, transcellular shift, gastrointestinal losses, and kidney losses. Patients with cancer are at risk for opportunistic infections, frequently experience cardiovascular complications, and often receive classes of medications that cause or exacerbate hypomagnesemia. Also, cancer-specific therapies are responsible for hypomagnesemia, including platinum-based chemotherapy, anti-EGF receptor mAbs, human EGF receptor-2 target inhibitors (HER2), and calcineurin inhibitors. Urinary indices, such as the fractional excretion of magnesium, can provide useful information about the etiology. The management of hypomagnesemia depends on the magnitude of hypomagnesemia and the underlying cause. We recommended checking serum magnesium at the beginning of treatment and as part of routine monitoring throughout cancer treatment. Opportunities exist for potential research and practice improvement, including further characterization of hypomagnesemia regarding the clinical effect on cancer outcomes, preventing hypomagnesemia in patients receiving high-risk anticancer agents, and developing effective therapeutic strategies.

Are the antidiabetic SGLT2 inhibitors a cardiovascular treatment?

The sodium-glucose co-transporter 2 inhibitors (SGLT2i) were first conceived to treat type 2 diabetes due to their hypoglycaemic effect. However, due to an increasing number of studies, SGLT2i are changing the way we treat, and understand, diabetes, and cardiovascular risk, in general. The EMPA-REG OUTCOME clinical trial, in 2015, showed for the first time that empagliflozine - a glucose lowering agent - lowers the risk of death from cardiovascular causes and death from any cause. Also, this SGLT2i lowered hospital admission for heart failure and delayed renal function worsening. From then on, other clinical trials with SGLT2i such as CANVAS (canagliflozin) and DECLARE-TIMI-58 (dapagliflozin) confirmed these positive effects. With a proven and non-related glucose-lowering effect on heart failure, overall death, cardiovascular death, and renal function, SGLT2i stands out among the rest of anti-diabetic drugs. Since its role in treating patients with heart failure and type 2 diabetes has been undoubtedly established, new studies are paving the way for non-diabetic patients as well. A potential paradigm shift is being witnessed and, probably, the dawn of a new field, cardio-endocrinology, which involves new and far-reaching pharmacological agents.

Sodium-glucose cotransporter type 2 inhibitors for the treatment of type 2 diabetes mellitus

The management of type 2 diabetes mellitus (T2DM) is becoming increasingly complex. Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are the newest antidiabetic agents for T2DM. By targeting the kidney, they have a unique mechanism of action, which results in enhanced glucosuria, osmotic diuresis and natriuresis, thereby improving glucose control with a limited risk of hypoglycaemia and exerting additional positive effects such as weight loss and the lowering of blood pressure. Several outcome studies with canagliflozin, dapagliflozin or empagliflozin reported a statistically significant reduction in major cardiovascular events, hospitalization for heart failure and progression to advanced renal disease in patients with T2DM who have established atherosclerotic cardiovascular disease, several cardiovascular risk factors, albuminuric mild to moderate chronic kidney disease or heart failure. Current guidelines proposed a new paradigm in the management of T2DM, with a preferential place for SGLT2is, after metformin, in patients with atherosclerotic cardiovascular disease, heart failure and progressive kidney disease. Ongoing trials might extend the therapeutic potential of SGLT2is in patients with, but also without, T2DM. This Review provides an update of the current knowledge on SGLT2is, moving from their use as glucose-lowering medications to their new positioning as cardiovascular and renal protective agents.

Mechanisms of Cardiorenal Effects of Sodium-Glucose Cotransporter 2 Inhibitors: JACC State-of-the-Art Review

Sodium-glucose cotransporter 2 inhibitors (SGLT2i), a new drug class approved for treatment of diabetes, have been shown to possess a favorable metabolic profile and to significantly reduce atherosclerotic events, hospitalization for heart failure, cardiovascular and total mortality, and progression of chronic kidney disease. Although initially considered to be only glucose-lowering agents, the effects of SGLT2i have expanded far beyond that, and their use is now being studied in the treatment of heart failure and chronic kidney disease, even in patients without diabetes. It is therefore critical for cardiologists, diabetologists, nephrologists, and primary care physicians to be familiar with this drug class. This first part of this 2-part review provides an overview of the current understanding of the mechanisms of the cardio-metabolic-renal benefits of SGLT2i. The second part summarizes the recent clinical trials of SGLT2i.

Evolving understanding of cardiovascular protection by SGLT2 inhibitors: focus on renal protection, myocardial effects, uric acid, and magnesium balance

Robust clinical data indicate that inhibitors of the sodium/glucose cotransporter 2 (SGLT2) dramatically improve clinical outcomes in diabetes, especially heart failure and progression of kidney disease. Factors that may contribute to these findings include: 1) improved glycemic control, 2) diuresis and reduced extracellular fluid volume, 3) reduced serum uric acid levels, 3) direct myocardial effects, 4) reduction in proteinuria and preservation of kidney function, and 5) correction of diabetic magnesium deficiency. Understanding the mechanisms by which SGLT2 inhibitors improve cardiovascular outcomes has the potential to improve clinical management not only of diabetes, but also of other cardiovascular disorders such as heart failure and chronic kidney disease.

SGLT2 Inhibitors for Treatment of Refractory Hypomagnesemia: A Case Report of 3 Patients

In patients with urinary magnesium wasting, oral and intravenous supplementation often fail to adequately improve serum magnesium levels. Glucose intolerance and diabetes mellitus frequently accompany hypomagnesemia. Clinical trials examining inhibitors of the type 2 sodium glucose cotransporter (SGLT2) show small but significant increases in serum magnesium levels in diabetic patients. This report describes dramatic improvement in serum magnesium levels and associated symptoms after initiating SGLT2 inhibitor therapy in 3 patients with refractory hypomagnesemia and diabetes. Each patient received a different SGLT2 inhibitor: canagliflozin, empagliflozin, or dapagliflozin. One patient discontinued daily intravenous magnesium supplements and exhibited higher serum magnesium levels than had been achieved by magnesium infusion. 2 of the 3 patients exhibited reduced urinary fractional excretion of magnesium, suggesting enhanced tubular reabsorption of magnesium. These observations demonstrate that SGLT2 inhibitors can improve the management of patients with otherwise intractable hypomagnesemia, representing a new tool in this challenging clinical disorder.