Renal and cardiovascular protective effects of ARBs potentiated by dietary sodium moderation
Renal and cardiovascular protective effects of ARBs potentiated by dietary sodium moderationLambers Heerspink HJ, Holtkamp FA, et al.
Kidney Int doi:10.1038/ki.2012.74
Agents interfering with the renin-angiotensin-aldosterone system (RAASi) are considered a cornerstone in the prevention of end-stage renal and cardiovascular disease in patients with diabetes, both early and late stage [1-4]. To further optimize the efficacy of RAASi, dietary sodium restriction might be useful, as this might enhance the response of both blood pressure and albuminuria to ARBs in diabetic and nondiabetic patients with chronic kidney disease [5,6].
The goal of this study was to investigate if a low-sodium diet (= low urinary sodium excretion) increases the efficacy of an ARB on hard renal and cardiovascular end points in type 2 diabetic patients with nephropathy. Therefore, data of the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) and Irbesartan Diabetic Nephropathy Trial (IDNT) trials were merged and analyzed.
Long-term effects on renal and cardiovascular events were biggest in the lowest tertile of sodium intake with ARB therapy compared to non-RAASi-therapy. The effects on renal and cardiovascular events attenuated in subjects with higher sodium consumption; in the highest tertile the protective effects were completely offset. In the lowest tertile, a trend toward greater relative risk reductions for hospitalization for heart failure events was observed.
ConclusionModerately low dietary sodium intake enhances the effect of RAAS intervention on renal and CV outcome. These data support calls for population-wide intervention to reduce dietary salt intake, not only for its beneficial effect on renal/CV morbidity/mortality, but also for its beneficial effect on therapy response to RAAS intervention
The results of this study demonstrate unequivocally that salt reduction is essential for protection against heart disease and progression of kidney damage in patients dependent on RAAS blockade. Moreover, the study shows that the beneficial effect already occurs with only mild salt restriction, which corresponds to recent results from short term studies and in patients with non-diabetic kidney disease. These results demonstrate the importance of lifestyle correction in addition to optimal pharmacological treatment. Based on these results, in the future many health benefits may be expected.
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