Sodium-Glucose Cotransporter-2 Inhibitor Immediately Decreases Serum Uric Acid Levels in Type 2 Diabetic Patients

Changes in the estimated glomerular filtration rate and predictors of the renal prognosis in Japanese patients with type 2 diabetes: A retrospective study during the 12 months after the initiation of tofogliflozin

BACKGROUND

The changes in the estimated glomerular filtration rate (eGFR) and predictors of the renal prognosis were retrospectively assessed over the 12 months after the initiation of tofogliflozin, which has the shortest half-life among sodium-glucose cotransporter 2 (SGLT2) inhibitors, in Japanese patients with type 2 diabetes and renal impairment.

METHODS

In total, 158 patients treated with tofogliflozin between 2019 and 2021 were studied as the safety analysis set. One hundred and thirty subjects whose medication was continued over 12 months were investigated as the full analysis set. The subjects were divided into two groups based on the eGFR: normal- (eGFR ≥60 mL/min/1.73 m2, n = 87) and low- (eGFR <60 mL/min/1.73 m2, n = 43) eGFR groups.

RESULTS

The body weight, blood pressure, urinary protein excretion, and serum uric acid concentration decreased from baseline in both eGFR groups while the hemoglobin level increased. The eGFR did not significantly differ over time, except for the initial dip (-4.3±9.6 mL/min/1.73 m2 in the normal-eGFR group and -1.5±5.3 mL/min/1.73 m2 in the low-eGFR group). The change in the eGFR at 12 months after the initiation of tofogliflozin was -1.9±9.0 mL/min/1.73 m2 and 0.2±6.0 mL/min/1.73 m2 in the normal- and low-eGFR group, respectively. In the normal-eGFR group, the change in the eGFR showed a significant negative correlation with the HbA1c and eGFR at baseline, according to a multiple regression analysis. In the low-eGFR group, the change in the eGFR showed a significant negative correlation with urate-lowering agent use. The frequencies of adverse events specific for SGLT2 inhibitors were not significantly different between the normal- and low-eGFR groups.

CONCLUSIONS

Tofogliflozin may preserve renal function in the medium term in patients with type 2 diabetes and kidney impairment without an increase in specific adverse events.

Update on Diabetic Kidney Disease (DKD): Focus on Non-Albuminuric DKD and Cardiovascular Risk

The classic description of diabetic kidney disease (DKD) involves progressive stages of glomerular hyperfiltration, microalbuminuria, proteinuria, and a decline in the estimated glomerular filtration rate (eGFR), leading to dialysis. In recent years, this concept has been increasingly challenged as evidence suggests that DKD presents more heterogeneously. Large studies have revealed that eGFR decline may also occur independently from the development of albuminuria. This concept led to the identification of a new DKD phenotype: non-albuminuric DKD (eGFR < 60 mL/min/1.73 m², absence of albuminuria), whose pathogenesis is still unknown. However, various hypotheses have been formulated, the most likely of which is the acute kidney injury-to-chronic kidney disease (CKD) transition, with prevalent tubular, rather than glomerular, damage (typically described in albuminuric DKD). Moreover, it is still debated which phenotype is associated with a higher cardiovascular risk, due to contrasting results available in the literature. Finally, much evidence has accumulated on the various classes of drugs with beneficial effects on DKD; however, there is a lack of studies analyzing the different effects of drugs on the various phenotypes of DKD. For this reason, there are still no specific guidelines for therapy in one phenotype rather than the other, generically referring to diabetic patients with CKD.

The effect of dapagliflozin on uric acid excretion and serum uric acid level in advanced CKD

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) exhibit renoprotective effect in patients with chronic kidney disease (CKD) and reduce serum uric acid (UA) in patients with diabetes mellitus. However, it is not clarified whether SGLT2i reduce serum UA levels in patients with advanced CKD. This study aimed to investigate the impact of SGLT2i on change in serum UA levels in patients with advanced CKD. Data of 121 Japanese patients with CKD who were newly administered 10 mg dapagliflozin in our department between August 2021 and August 2022 were analyzed. Changes in UA and fractional excretion of UA (FEUA) were analyzed using multiple regression analysis. Of 75 patients, 21 (28.0%) patients, 24 (32.0%) patients, 29 (38.7%) patients, and 1 (1.3%) patient were categorized as having CKD stage 3a, 3b, 4, and 5, respectively. The median age was 67 years, and 72.0% were male. 23 (30.7%) of patients had diabetes mellitus. The median estimated glomerular filtration rate, serum UA, and FEUA were 35.7 mL/min/1.73 m², 6.4 mg/dL, and 6.76%, respectively, at the time of dapagliflozin administration. After administration, serum UA decreased to 5.6 mg/dL and FEUA increased to 9.22%. Dapagliflozin increases FEUA and reduces serum UA levels in patients with advanced CKD.

Sodium-Glucose Cotransporter-2 Inhibitors Could Help Delay Renal Impairment in Patients with Type 2 Diabetes: A Real-World Clinical Setting

This study compared the renoprotective effects of sodium−glucose cotransporter-2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP-4) inhibitors in patients with type 2 diabetes mellitus (T2DM). We performed a retrospective cohort study using electronic medical records of patients with T2DM. The primary outcome was the first occurrence of an estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m2 after the index date. We analyzed changes in repeatedly measured laboratory data, such as eGFR and serum uric acid (SUA). We included 2396 patients (1198 patients in each group) in the present study. The rate of renal events was significantly lower in the SGLT2 inhibitors group than that in the DPP-4 inhibitors group (hazard ratio, 0.46; 95% CI, 0.29 to 0.72; p = 0.0007). The annual mean change in the eGFR was significantly smaller in the SGLT2 inhibitors group than that in the DPP-4 inhibitors group, with a between-group difference of 0.86 ± 0.18 mL/min/1.73 m2 per year (95% CI, 0.49 to 1.23; p < 0.0001). Moreover, the mean change in SUA was lower in the SGLT2 inhibitors group. Considering the lower incidence of renal impairment, the slower decline in eGFR, and reduced SUA, SGLT2 inhibitors could help delay renal impairment in patients with T2DM.

SGLT2is and Renal Protection: From Biological Mechanisms to Real-World Clinical Benefits

In recent years, following the publication of results from several RCTs, first on cardiovascular and more recently on renal outcomes, SGLT2is have become the standard of care to prevent diabetic kidney disease and slow its progression. This narrative review focuses on biological mechanisms, both renal and extrarenal, underlying kidney protection with SGLT2is. Furthermore, data from cardiovascular as well as renal outcome trials, mostly conducted in diabetic patients, are presented and discussed to provide an overview of current uses as well as the future therapeutic potential of these drugs.