Abstract 3491: Serum Phosphorus Levels are Associated with Increased Mortality in the General Population
Background: Elevated levels of serum phosphorus are associated with poor survival and increased atherosclerosis burden among patients with renal failure. Recently, an association between phosphorus and cardiovascular events has also been reported in the general population. The aim of our study was to examine whether serum phosphorus is associated with all-cause mortality in the general population.
Methods: We determined the association of baseline serum phosphorus levels with all-cause mortality in 13,998 subjects 45 to 64 years old without known coronary heart disease, stroke, or renal disease from the Atherosclerosis Risk in Communities (ARIC) study using public use data. The mean follow up was 12.5 years. Serum phosphorus was classified according to quintiles.
Results: Elevated phosphorus was significantly associated with increased age, female gender, current smoking, hypercholesterolemia, and fibrinogen levels (trend test p < 0.0001 for each), but was inversely associated with hypertension (trend test p = 0.003) and not associated with estimated glomerular filtration rate. A graded increase in mortality was noted across quintiles of serum phosphorus (trend test p < 0.0001). Individuals in the highest serum phosphorus quintile (> 3.9 mg/dl) experienced a 46% increase in mortality (age and sex adjusted HR 1.46; 95% CI: 1.22, 1.75) when compared to those with phosphorus levels of 3.1–3.3 mg/dl. This association remained significant after adjustment for traditional CVD risk factors and estimated glomerular filtration rate. We found significant interaction by gender (p < 0.0001), with men in the highest quintile experiencing a 48% increase in mortality (MV adjusted HR 1.48; 95% CI: 1.15, 1.92) but women experiencing a borderline significant 25% increase (MV adjusted HR 1.25; 95% CI: 0.94, 1.66).
Conclusion: In a population-based cohort of subjects free of overt cardiovascular and renal disease serum phosphorus was associated with decreased overall survival independent of traditional CVD risk factors and estimated glomerular filtration rate. This association appeared stronger among men than women.