Sodium glucose cotransporter 2 inhibitor (SGLT2i) is a class of drugs that were originally intended for decreasing blood glucose in diabetes. However, recent trials have shown that there are other beneficial effects. Recent major SGLT2i landmark trials have demonstrated benefits for cardiovascular disease (reduce major adverse cardiovascular events (heart attack, stroke, cardiovascular death), hospitalization for heart failure, all-cause death), and renal disease (delay the onset of dialysis) regardless of diabetic status.
1. Introduction
Diabetes, cardiovascular disease, and renal disease are all clinically related disease states. Diabetes is a major cause of chronic kidney disease and renal failure. Diabetes increases the risk for cardiovascular disease and death
[1]. The top cause of death in diabetes is cardiovascular disease. In renal disease, a low estimated glomerular filtration rate (eGFR) is associated with higher mortality
[2].
The origin of sodium glucose cotransporter 2 inhibitors (SGLT2i) is traced back to phlorizin, which is an organic compound first discovered and extracted from apple tree bark in 1835 by De Koninck and Stas
[3]. It has played a role in diabetes research through its action of renal glucosuria and inhibition of glucose reabsorption. Originally intended for treating diabetes, SGLT2i has since intersected the fields of endocrinology, cardiology, and nephrology. In 2008, the United States Food and Drug Administration mandated the inclusion of cardiovascular outcomes in diabetes trials. Since this era of cardiovascular outcome trials, more benefits from SGLT2i have been discovered. The convergence of the treatment of diabetes, cardiovascular disease, and renal disease is a paradigm shift.
2. Sodium Glucose Cotransporter 2 Inhibitor Trials in Type 2 Diabetes
The initial large clinical trials were focused on patients with type 2 diabetes, the main inclusion criterion.
The EMPA-REG OUTCOME trial was the earliest SGLT2i cardiovascular outcome trial and showed major cardiovascular benefits
[5][4]. The trial studied 7020 patients with type 2 diabetes and patients received either empagliflozin or placebo. There was a reduction in major adverse cardiovascular events (MACE) (myocardial infarction, stroke, cardiovascular death) in the empagliflozin group (HR, 0.86; 95% CI, 0.74–0.99;
p = 0.04 for superiority). Additionally, a reduction in hospitalization for heart failure was observed in patients receiving empagliflozin (HR, 0.65; 95% CI, 0.50–0.85;
p = 0.002). This trial was the first positive cardiovascular outcome trial in type 2 diabetics.
The CANVAS Program trial compared canagliflozin to placebo in 10,142 patients with type 2 diabetes. A reduction in major adverse cardiovascular event was observed in the canagliflozin group (HR, 0.86; 95% CI, 0.75–0.97;
p = 0.02 for superiority)
[6,7][5][6]. Additionally, hospitalization for heart failure and cardiovascular death was reduced in the canagliflozin group (HR 0.78; 95% CI, 0.67–0.91). There was an increased risk of amputation, specifically at the toe or metatarsal in those that received canagliflozin.
The DECLARE-TIMI 58 trial evaluated dapagliflozin compared to placebo in 17,160 patients with type 2 diabetes
[8,9][7][8]. There was a reduction in heart failure-related death and hospitalization (HR, 0.83; 95% CI, 0.73–0.95;
p = 0.005). Notably, dapagliflozin did not reduce the rate of major adverse cardiovascular event (HR, 0.93; 95% CI, 0.84–1.03;
p = 0.17). Renal events occurred less frequently in the dapagliflozin group (HR, 0.76; 95% CI, 0.67 to 0.87).
The TIMI Study Group performed a meta-analysis which included the EMPA-REG OUTCOME, CANVAS Program, and DECLARE-TIMI 58 trials with a total of 34,322 patients
[10][9]. SGLT2i reduced hospitalization for heart failure (HR, 0.77; 95% CI 0.71–0.84;
p < 0.0001) and progression of renal disease (HR, 0.55; 95% CI 0.48–0.64,
p < 0.0001) in patients with or without cardiovascular disease or history of heart failure.
These trials showed the benefits of SGLT2i in reducing cardiovascular events in patients with type 2 diabetes (
Table 1). This led to trials focusing on primarily examining cardiovascular benefits.
Table 1. Sodium glucose cotransporter 2 inhibitors (SGLT2i) trials in type 2 diabetes.
Trial
(Medication) |
Main Outcome
HR (95% CI) (p-Value) |
Key Summary |
EMPA-REG OUTCOME [5][4]
(empagliflozin 10 or 25 mg) |
↓ MACE,
0.86 (0.74–0.99) (p = 0.04)
↓ HHF
↓ All cause death |
This was the first SGLT2i trial showing reduction of CV events. |
CANVAS Program [6,[511]][10] (canagliflozin 100 or 300 mg) |
↓ MACE
0.86 (0.75–0.97) (p = 0.02) |
Canagliflozin reduced CV events and HHF. |
DECLARE-TIMI 58 [8][7]
(dapagliflozin 10 mg) |
↓ CV death or HHF
0.83 (0.73–0.95) (p = 0.005) |
Dapagliflozin reduced CV death and HHF. MACE was not reduced. |
VERTIS CV [12][11]
(ertugliflozin 5 or 15 mg) |
MACE
0.97 (0.75–1.03)
(p < 0.001 for noninferiority) |
Ertugliflozin is non-inferior to placebo in reducing MACE. |