Fluctuating plasma phosphorus level by changes in dietary phosphorus intake induces endothelial dysfunction

Area of Science:

• Nephrology
• Cardiovascular Science
• Nutritional Science

Background:

• High serum phosphorus (P) negatively impacts endothelial function, increasing oxidative stress and reducing nitric oxide production.
• Serum P levels can fluctuate due to daily rhythms, diet, or dialysis in chronic kidney disease (CKD) patients.

Purpose of the Study:

• To investigate if fluctuating plasma P levels, driven by dietary P intake variations, contribute to endothelial dysfunction and elevated cardiovascular risk.

Main Methods:

• Rats were assigned to a control group (0.6% P diet) or experimental groups (LH and HL) with alternating low (0.02% P) and high (1.2% P) diets every two days.
• Total P intake was equalized across all groups over 16 days.
• Endothelial function, plasma 8-(OH)dG levels, and inflammatory factor expression (MCP-1) were assessed.

Main Results:

• The LH and HL groups exhibited significantly decreased endothelial-dependent vasodilation compared to controls.
• Plasma 8-(OH)dG levels and endothelial MCP-1 expression were significantly increased in the fluctuating P groups.
• These findings indicate impaired endothelial function due to increased oxidative stress and inflammation.

Conclusions:

• Repetitive fluctuations in plasma P, caused by varying dietary P intake, impair endothelial function.
• Habitual dietary P fluctuation may be a contributing factor to cardiovascular disease, especially in CKD patients, via endothelial dysfunction.