Canagliflozin mitigates increased cardiovascular risk from low-normal sodium intake in type 2 diabetes and CKDCanagliflozin may protect hearts in patients with low sodium intake

This study is a post hoc analysis of a randomized controlled trial involving 2573 participants with type 2 diabetes and chronic kidney disease (CKD). The population was divided into groups based on sodium intake—low-normal sodium (LNS) or high sodium (HS)—and treatment with either canagliflozin (100 mg) or a placebo. The primary outcome measured was the composite of cardiovascular death or hospitalization for heart failure.

In the placebo group, participants with LNS showed an increased risk of cardiovascular death or hospitalization for heart failure compared to those in the HS group, with an effect size of 1.56 (95% CI 1.10, 2.23). However, among patients treated with canagliflozin, there was a significantly reduced risk of these events compared to the placebo's LNS effect, with an effect size of 0.48 (95% CI 0.33, 0.70). In the HS group receiving canagliflozin, no significant difference was observed compared to the HS group receiving placebo (effect size 1.05; 95% CI 0.73, 1.53).

Secondary outcomes provided additional insights into renal and mortality trends. For heart failure alone in the LNS group versus the HS group (placebo), an increased risk was noted, though specific effect sizes were not reported. Regarding renal outcomes, the study found no effect from sodium intake; however, canagliflozin successfully reduced risk in both the LNS and HS groups. In terms of all-cause mortality, the analysis showed no significant effect from either sodium intake or canagliflozin treatment.

Safety and tolerability data were not reported for this specific analysis. The study's methodology includes a notable limitation as it is a post hoc analysis, which may affect the generalizability of certain findings. Additionally, sodium intake was estimated via formula rather than direct measurement, which could introduce potential bias in the categorization of participants.

These results are clinically relevant because they suggest that canagliflozin mitigates the increased cardiovascular risk associated with low-normal sodium intake in patients with type 2 diabetes and CKD. Furthermore, the drug provided renal protection regardless of the patient's dietary sodium intake. While these findings provide a nuanced view of how SGLT2 inhibitors interact with dietary factors, the post hoc nature of the analysis means results should be interpreted with caution.

Several questions remain unanswered regarding the long-term durability of this protective effect and whether other SGLT2 inhibitors demonstrate similar interactions with sodium intake. Further prospective trials are needed to confirm these observations in a primary analysis setting.