We measured 25(
OH)D serum levels in outpatients with risk factors for DD or history of HF derived from the DIAST-CHF study. Participants were comprehensively phenotyped including physical examination, echocardiography, and 6 min walk test and were followed up to 5 years. Quality of life was evaluated by the Short Form 36 (SF-36) questionnaire. We included 787 patients with available 25(
OH)D levels. Median 25(
OH)D levels were 13.1 ng/mL, mean E/e' medial was 13.2, and mean left ventricular ejection fraction was 59.1%. Only 9% (n = 73) showed a left ventricular ejection fraction <50%. Fifteen per cent (n = 119) of the recruited participants had symptomatic HFpEF. At baseline, participants with 25(
OH)D levels in the lowest tertile (≤10.9 ng/L; n = 263) were older, more often symptomatic (oedema and
fatigue, all P ≤ 0.002) and had worse cardiac [higher N-terminal pro-
brain natriuretic peptide (
NT-proBNP) and left atrial volume index, both P ≤ 0.023], renal (lower glomerular filtration rate, P = 0.012), metabolic (higher
uric acid levels, P < 0.001), and functional (reduced exercise capacity, 6 min walk distance, and SF-36 physical functioning score, all P < 0.001) parameters. Increased
NT-proBNP,
uric acid, and left atrial volume index and decreased SF-36 physical functioning scores were independently associated with lower 25(
OH)D levels. There was a higher risk for lower 25(
OH)D levels in association with HF, DD, and
atrial fibrillation (all P ≤ 0.004), which remained significant after adjusting for age. Lower 25(
OH)D levels (per 10 ng/mL decrease) tended to be associated with higher 5 year mortality, P = 0.05, hazard ratio (HR) 1.55 [1.00; 2.42]. Furthermore, lower 25(
OH)D levels (per 10 ng/mL decrease) were related to an increased rate of cardiovascular hospitalizations, P = 0.023, HR = 1.74 [1.08; 2.80], and remained significant after adjusting for age, P = 0.046, HR = 1.63 [1.01; 2.64], baseline
NT-proBNP, P = 0.048, HR = 1.62 [1.01; 2.61], and other selected baseline characteristics and co-morbidities, P = 0.043, HR = 3.60 [1.04; 12.43].
CONCLUSIONS: