Troponin I, but not BNP, is Associated with Phosphorus, Calcium and Vitamin D in Stable Coronary Artery Disease

Background: Elevated plasma cardiac troponin, elevated plasma phosphorus and decreased plasma vitamin D have been shown to be associated with negative outcomes. Methods and results: Troponin I, calcium, phosphorus and 25-OH vitamin D were studied in a cohort of 60 patients with stable coronary heart disease and preserved left ventricular function. Using a cut-off value of 0.012 ng/mL for plasma troponin I, patients with higher values (18 patients), when compared to the other patients (n=42), had higher mean values for plasma phosphorus (3.42+0.45 mg/dL vs 3.17+0.45 mg/dL, p= 0.041) and calcium (5.08+0.23 mEq/L vs 4.92+0.18 mEq/L, p= 0.016) and lower values for 25-OH vitamin D (14.2+5.6 ng/mL vs 19.4+8.8 ng/mL, p= 0.032). Binary logistic regression analysis showed that troponin I > 0.012 ng/ml is associated with increased phosphorus, increased calcium and decreased 25-OH vitamin D concentrations. A similar analysis using BNP >100 pg/mL failed to show signifcant associations with phosphorus, calcium and 25-OH vitamin D concentrations. Conclusions: In patients with stable coronary artery disease and preserved left ventricular function, those having cardiac troponin I > 0.012 ng/ml, but not those having BNP >100 pg/mL, had higher plasma phosphorus, higher plasma calcium and lower plasma 25-OH vitamin D concentrations than those having cardiac troponin I ≤ 0.012 ng/ml (or BNP ≤ 100 pg/mL).