High-phosphorus diets reduce aortic lesions and cardiomyocyte size and modify lipid metabolism in Ldl receptor knockout mice

Abstract

The consumption of phosphorus in Western populations largely exceeds the recommended intake, while vitamin D supply is often insufficient. Both situations are linked to an increased cardiovascular risk. A 17-week two-factorial study with Ldl receptor ^-/- mice was conducted to investigate the cardiovascular impact of dietary phosphorus [adequate (0.3%; P _0.3) vs. high (1.5%; P _1.5)] in combination with a low (50 IU/kg; D ₅₀) or adequate vitamin D diet (1000 IU/kg; D ₁₀₀₀). The data demonstrate that mice fed the P _1.5 vs. P _0.3 diets developed smaller vascular lesions ( p = 0.013) and cardiac hypotrophy ( p = 0.011), which were accompanied by diminished IGF1 and insulin signalling activity in their hearts. Vitamin D showed no independent effect on atherogenesis and heart morphology. Feeding P _1.5 vs. P _0.3 diets resulted in markedly reduced serum triacylglycerols ( p < 0.0001) and cholesterol ( p < 0.0001), higher faecal lipid excretion ( p < 0.0001) and a reduced mRNA abundance of hepatic sterol exporters and lipoprotein receptors. Minor hypocholesterolaemic and hypotriglyceridaemic effects were also found in mice fed the D ₁₀₀₀ vs. D ₅₀ diets ( p = 0.048, p = 0.026). To conclude, a high phosphorus intake strongly affected the formation of vascular lesions, cardiac morphology, and lipid metabolism, although these changes are not indicative of an increased cardiovascular risk.