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 m²; phosphate 3.7 mg/dl; left ventricular mass indexed to body surface area 80.5 g/m², 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.