Sun exposure influences the prognostic power of components of mineral metabolism in patients with coronary artery disease.

BACKGROUND AND AIM: Calcidiol (vitamin D metabolite) plasma levels vary with sun exposure (SE). However, it is not known if SE influences its prognostic ability. We have studied the effect of SE on plasma levels of the components of mineral metabolism (calcidiol, fibroblast growth factor-23 [FGF-23], parathormone [PTH], and phosphate [P]) and on their prognostic value in patients with coronary artery disease (CAD). METHODS AND RESULTS: We studied prospectively 704 patients with stable CAD. Clinical variables and baseline calcidiol, FGF-23, PTH, and P plasma levels were assessed. We divided the population in two subgroups, according to the period of plasma extraction: High SE (HSE) (April-September) and low SE (LSE) (October-March). The outcome was the development of acute ischemic events (acute coronary syndrome, stroke, or transient ischemic attack), heart failure, or death. Mean follow-up was 2.15 ± 0.99 years. Calcidiol and P levels were higher in HSE group. In the whole population, calcidiol (HR = 0.84 for each 5 ng/ml increase, 95% CI = 0.71-0.99; p = 0.038) and FGF-23 (HR = 1.14 for each 100 RU/ml increase, 95% CI = 1.05-1.23; p = 0.009) were predictors of the outcome, along with age, hypertension, body-mass index, peripheral artery disease, and P levels. In the LSE subgroup, calcidiol (HR = 0.75; 95% CI = 0.57-0.99; p = 0.034) and FGF-23 (HR = 1.34; 95% CI = 1.13-1.58; p = 0.003) remained as predictors of the outcome. In the HSE group calcidiol and FGF-23 had not independent prognostic value. CONCLUSIONS: In patients with stable CAD, low calcidiol and high FGF-23 plasma levels predict an adverse prognosis only when the sample is obtained during the months with LSE. SE should be taken into account in the clinical practice.

Parathormone Levels Are Independently Associated with the Presence of Left Ventricular Hypertrophy in Patients with Coronary Artery Disease.

BACKGROUND: Abnormalities of mineral metabolism and inflammation may affect the cardiovascular system. We have assessed the relationship of left ventricular hypertrophy (LVH) with inflammation and mineral metabolism. METHODS: LVH was measured in 146 outpatients with stable coronary artery disease (SCAD) using echocardiography. Calcidiol (a vitamin D metabolite), parathyroid hormone (PTH), fibroblast growth factor-23, high-sensitivity C-reactive protein, MCP-1 (monocyte chemoattractant protein-1), galectin-3, NGAL (neutrophil gelatinase-associated lipocalin), and sTWEAK (soluble TNF-related weak inducer of apoptosis) plasma levels were studied. RESULTS: LVH, defined as septal thickness ≥11 mm, was present in 19.9% of cases. These patients were older [75.0 (61.0-81.0) vs 64.0 (51.0-76.0) years; p=0.002], had higher prevalence of left ventricular ejection fraction (LVEF)>40%, and had higher PTH [84.7 (59.6-104.7) vs 63.2 (49.2-85.2) pg/ml; p=0.007], galectin-3 [9.6 (8.0-11.1) vs 8.3 (6.9-9.9) ng/ml; p=0.037], and NGAL (208.5±87.6 vs 173.9±73.4 ng/ml; p=0.031) plasma levels than those without LVH. Glomerular filtration rate was lower in patients with LVH than in those without it (65.1±20.0 vs 74.7±19.9 mL/min/1.73 m2; p=0.021). There were no significant differences in hypertension (79.3 vs 68.4%; p=0.363) or sex between both groups. Variables showing differences based on univariate analysis and hypertension were entered into a logistic regression analysis. Only age [odds ratio (OR) =1.052 (1.011-1.096); p=0.013], PTH plasma levels [OR=1.017 (1.003-1.031); p=0.021], and LVEF>40% [OR=7.595 (1.463-39.429); p=0.016] were independent predictors of LVH. CONCLUSIONS: In patients with SCAD, elevated PTH levels are independently associated with the presence of LVH. Further studies are needed to elucidate the role of PTH in the development of myocardial hypertrophy.