Granulocytes count may be mediator of high sodium intake and poor Renal and CV Outcomes

Netherlands: The relation between high-sodium intake and both cardiovascular and renal outcomes is mediated by granulocytes, reports large prospective cohort results published in The Journal of The American Heart Association.

Sodium, an electrolyte ( mineral) plays a key role in maintaining the right balance of fluids in our body. But, high sodium intake has been associated with a range of adverse outcomes. The WHO has recommended limiting dietary sodium to 2 g/day in healthy adults. Studies have shown that sodium has immune‐modulating properties, which leads to deleterious health outcomes but there is less evidence of the effects of high sodium consumption on neutrophilic granulocytes. Recently, granulocyte counts have been reported to be associated with hypertension, cardiovascular disease, renal outcomes, and all‐cause mortality. The role of increased sodium consumption in this association is a mystery.

Eliane F., University of Amsterdam, Netherlands and colleagues conducted a study to determine the association between (1) sodium intake and granulocytes on a population level; (2) granulocytes and the presence of hypertension and both cardiovascular and renal outcomes; and (3) role of granulocytes in mediating the relation between high‐sodium intake and these outcomes.

Investigators enrolled 13 804 participants from the prospective EPIC (European Prospective Investigation into Cancer)‐Norfolk cohort, with a mean age of 58 years and a median follow‐up of 19.3 years. Analyses were carried out using calculated estimated sodium intake and sodium‐to‐potassium ratios from spot urines at baseline. The main outcomes were set as hypertension at baseline and composite cardiovascular (mortality or cardiovascular events) and renal (mortality or renal events) outcomes during follow‐up.

Key findings of the analysis,

• Sodium intake and urine sodium‐to‐potassium ratio were positively associated with circulating granulocyte concentrations after adjustment for confounders (P=0.028 and P<0.001, respectively)

• Granulocytes significantly mediated the associations of sodium intake and urine sodium‐to‐potassium ratio with hypertension at baseline, and cardiovascular and renal outcomes, respectively

The authors conclude that the association of high sodium intake with worse cardiovascular and renal outcomes could be explained by alteration in immune cell counts. The study shows an association of estimated sodium intake and urine sodium‐to‐potassium levels with granulocytes at the population level, and a subsequent association of granulocytes with worse long‐term cardiovascular and renal outcomes. As a by-finding, the study revealed an independent negative association between estimated potassium intake and granulocytes that may exceed the effects of sodium.

The present study has established the immune‐modulating effects of sodium and the causal role of immune cells in both cardiovascular and renal disease, future studies need to investigate this potential causal pathway, the authors suggested.

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Eliane F. E. Wenstedt, Hessel Peters Sengers, S. Matthijs Boekholdt, Kay‐Tee Khaw, Nicholas J. Wareham, Bert‐Jan H. van den Born and Liffert Vogt

Originally published 22 Jun 2022https://doi.org/10.1161/JAHA.121.023727Journal of the American Heart Association. 2022;0:e023727