Serum Phosphate and Left Ventricular Hypertrophy in Young Adults: The Coronary Artery Risk Development in Young Adults Study

BACKGROUND/AIMS: A relationship with vascular dysfunction in chronic kidney disease suggests a possible association of phosphate level with left ventricular hypertrophy development in people with normal kidney function. We aimed to determine whether such an association exists in community-dwelling young adults. METHODS: This is a cohort study of participants in the ongoing, community-based, prospective Coronary Artery Risk Development in Young Adults study (n = 4,055). Phosphate levels were measured at year 0, and left ventricular hypertrophy assessed by echocardiography at year 5. RESULTS: The mean age was 25.0 years. Mean values were: estimated glomerular filtration rate 118.5 ml/min/1.73 m(2); phosphate 3.7 mg/dl; left ventricular mass indexed to body surface area 80.5 g/m(2), and indexed to height(2.7) 35.2 g/m(2.7). Left ventricular hypertrophy was present in 4.5% of the population. As a continuous variable, the phosphate level was associated with left ventricular hypertrophy (odds ratio per standard deviation 1.27; 95% confidence interval 1.09-1.47; p = 0.0020). This association persisted after covariate adjustment (odds ratio per standard deviation 1.30; 95% confidence interval 1.10-1.54; p = 0.0018), and was most pronounced for fifth quintile phosphate levels (>4.0 mg/dl). CONCLUSION: Phosphate level may be a risk factor for left ventricular hypertrophy in community-dwelling young adults. As phosphate levels may be modifiable, the causality of this association can be addressed with controlled trials.