The impact of excessive salt intake on human health

Cardiovascular Risk Related to Glomerular Hyperfiltration in Nondiabetic Individuals: Increasing Visibility is Crucial

Glomerular hyperfiltration (GHF), defined by different estimation formulas, has been widely studied as a predictor of proteinuria and progression to chronic kidney disease (CKD) in diabetic patients. GHF is also an important cardiovascular (CV) risk factor and is related to allcause mortality in non-diabetic populations; however, the upper limit of glomerular filtration rate (GFR) above which it indicates the presence of GHF is weakly defined. This higher risk is as high as in the intermediate stages of CKD and is greater than the presence of diabetes or smoking and is still present in non-albuminuria patients. The original Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimation GFR formula showed lower error at higher glomerular filtration (GF) values, was the most used in population studies, and behaved as a better risk predictor. In our review (including approximately 3.6 million individuals), higher GFR values related to increased mortality risk varied from 106.6 to 113.7 ml/min, which are usually not considered risk values for standard guidelines in non-albuminuric patients. However, the lack of consensus on a GF cutoff value, as well as its variability due to sex and progressive reduction with age, affect the knowledge of this serious phenomenon in clinical practice. Although the elderly population is not exempted from the effects of GHF, the search for this phenomenon should be intensified in middle-aged populations because of their lower disease burden, where this situation may be more evident, and the possibility of reversing the consequences is greater. A population group often considered healthy includes obese people, essential hypertensives, smokers, and carriers of fatty liver, where the GHF phenomenon is frequent and is associated with CV disease, kidney disease, and higher mortality. Increasing its visibility by the medical community is essential to reduce the effects of GHF, emphasizing more frequent controls and implementing general measures that include strict control of hypertension, Na restriction, rich in vegetables diets and increased physical activity. Initiatives to confirm the beneficial effects of sodium-glucose cotransporter-2 inhibitors to treat isolated GHF would be an important breakthrough in reducing the severe consequences of this phenomenon.

Higher Potassium Intake and Lower Sodium Intake May Help in Reducing CVD Risk by Lowering Salt Sensitivity of Blood Pressure in the Han Chinese Population

Sodium (Na) reduction with a parallel supplemental potassium (K) intake can prevent cardiovascular diseases (CVDs). The relationship of the urinary Na/K ratio and salt sensitivity of blood pressure (SSBP) with CVDs is not clearly explained. We assumed that the SSBP mediates the relationship between the Na/K ratio and CVDs. In total, 2055 subjects who had 24 h urine collected and SSBP determined were included in this study. CVD risk was estimated using the China-PAR equation. MediationMultivariate logistic regression was used to explore the associations between the Na/K ratio or SSBP with CVD risk. Mediation analysis using a logistic regression model was performed. Both the urinary Na/K ratio and SSBP were related to the estimated CVD risk (p < 0.05). The mediation analysis found that SSBP mediated approximately 12% of the association between Na/K ratio and CVD risk. Our findings indicate that higher K intake and lower Na intake may help in preventing CVD risk by reducing SSBP risk in individuals with normotension or stage-one hypertension.

Hypertension, Anxiety and Obstructive Sleep Apnea in Cardiovascular Disease and COVID-19: Mediation by Dietary Salt

This perspective paper used a grounded theory method to synthesize evidence proposing that sodium toxicity from excessive dietary salt intake is a potential common pathophysiological mechanism that mediates the association of hypertension, obstructive sleep apnea, and anxiety with cardiovascular disease and COVID-19. Increased anxiety in these conditions may be linked to a high-salt diet through stimulation of the sympathetic nervous system, which increases blood pressure while releasing catecholamines, causing a "fight or flight" response. A rostral shift of fluid overload from the lower to the upper body occurs in obstructive sleep apnea associated with COVID-19 and cardiovascular disease, and may be related to sodium and fluid retention triggered by hypertonic dehydration. Chronic activation of the renin-angiotensin-aldosterone system responds to salt-induced dehydration by increasing reabsorption of sodium and fluid, potentially exacerbating fluid overload. Anxiety may also be related to angiotensin II that stimulates the sympathetic nervous system to release catecholamines. More research is needed to investigate these proposed interrelated mechanisms mediated by dietary salt. Furthermore, dietary interventions should use a whole-food plant-based diet that eliminates foods processed with salt to test the effect of very low sodium intake levels on hypertension, anxiety, and obstructive sleep apnea in cardiovascular disease and COVID-19.

Sodium Content in Cereal-Based Products Sold in Italy: How Far Are We from the Global Benchmarks?

Reformulation of food products is one of the measures needed for reducing salt consumption. Accordingly, the World Health Organization (WHO) recently proposed global sodium benchmarks for different food categories to be used for setting national policies. Therefore, the sodium content of cereal-based products currently sold in Italy was compared with the WHO benchmarks, highlighting those categories primarily needing a reformulation. To this aim, the sodium content and several declarations (i.e., nutrition and health claims, organic or gluten free declaration) were retrieved from 2917 cereal-based products sold on the Italian market. All “minimally processed breakfast cereals” had a sodium content below the benchmark, while “flatbreads” and “leavened bread” had the highest percentage of items above the respective sodium benchmarks. Flatbreads and “crackers/savory biscuits” showed the highest median delta values from the respective benchmarks of 360 and 278 mg/100 g, respectively. Large variability in terms of percentage of products with sodium content above the benchmark was observed within the same categories, as well as among products with different declarations. A large number of food products currently sold on the Italian market have a sodium content above the benchmark. This result suggests the need to reformulate many food products currently on the market to achieve the WHO/United Nations (UN) objective of 30% global reduction in sodium intake by 2025.