Vitamin D deficiency parallels inflammation and immune activation, the Ludwigshafen Risk and Cardiovascular Health (LURIC) study

BACKGROUND: Low vitamin D concentrations are detected in patients suffering from various clinical conditions which are characterized also by inflammation and immune activation.We investigated whether vitamin D levels in patients with coronary artery disease (CAD) are related to markers of immune activation. METHODS: Serum concentrations of 25-hydroxyvitamin D[25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH) 2 D] and the immune activation markers neopterin and high sensitivity C-reactive protein (hsCRP) were measured in 2015 patients derived from the LUdwigshafen RIsk and Cardiovascular Health (LURIC) study, a cohort study among patients referred for coronary angiography. RESULTS: Serum concentrations of 25(OH)D and 1,25(OH) 2 D did not differ between patients with CAD [mean } SD:25(OH)D: 17.4 } 9.4 μ g/L; 1,25(OH) 2 D: 34.4 } 13.3 ng/L] and controls [25(OH)D: 18.4 } 11.7 μ g/L; 1,25(OH) 2 D: 35.3 } 12.7ng/L; Welch ’ s t-test: p = n.s.] but CAD patients had higher neopterin (8.6 } 7.4 nmol/L) and hsCRP (9.6 } 19.6 mg/L) concentrations compared to controls (neopterin: 7.5 } 4.8 nmol/L;p = 0.0004; hsCRP: 5.4 } 10.0 mg/L; p < 0.0001). There was an inverse correlation between serum 25(OH)D or 1,25(OH) 2 D concentrations and serum neopterin [Spearman ’ s rank correlation:25(OH)D: r s = – 0.183; 1,25(OH)2D: r s = – 0.230] and hsCRP [25(OH)D: r s = – 0.142; 1,25(OH) 2 D: r s = – 0.130; allp < 0.0001] concentrations. CONCLUSIONS: Our results indicate increased inflammatory processes in patients with low vitamin D status. Further studies should clarify the underlying mechanisms for the observed associations of vitamin D status and inflammatory parameters.