Hypovitaminosis D in African Americans residing in Memphis, Tennessee with and without heart failure.

BACKGROUND: Factors contributing to heart failure (HF) in African Americans (AA) are under investigation. Reduced 25(OH)D confers increased cardiovascular risk, including HF.
METHODS: We monitored serum 25(OH)D, 1,25(OH)2D3, parathyroid hormone (PTH), and creatinine clearance in 102 AA residing in Memphis: 58 hospitalized with decompensated HF of >or=4 weeks in 34 (21 men; 53.3 +/- 1.8 years) or of 1 to 2 weeks in 24 (17 men; 49.6 +/- 2.4 years) and associated with a dilated cardiomyopathy and reduced ejection fraction (<35%); 19 outpatients with compensated HF (14 men; 52.6 +/- 2.7 years) with comparable ejection fraction; 16 outpatients (9 men; 55.4 +/- 2.9 years) with heart disease, but without HF; and 9 healthy volunteers (3 men; 35.8 +/- 3.5 years).
RESULTS: Serum 25(OH)D <or=30 ng/mL was found in 96% and 90% with protracted or short-term decompensated HF, where it was of moderate to marked severity (<20 ng/mL) in 83% and 76%, respectively. In patients with either compensated or no HF, 25(OH)D <30 ng/mL was found in 95% and 100%, respectively, and in 30% of volunteers. Normal serum 1,25(OH)2D3 did not differ between patients. Serum PTH >65 pg/mL was found in all AA with decompensated HF of >or=4 weeks (132.4 +/- 12.0 pg/mL) and 67% with 1 to 2 weeks duration (82.3 +/- 7.9 pg/mL), but only 11% with compensated HF (45.8 +/- 6.1 pg/mL), 12% without HF (29.6 +/- 5.4 pg/mL), and none of the volunteers (31.1 +/- 3.9 pg/mL). Creatinine clearance did not differ between patient groups.
CONCLUSIONS: Hypovitaminosis D is prevalent amongst AA residing in Memphis, with or without HF. Elevations in serum PTH in keeping with secondary hyperparathyroidism are only found in AA with decompensated HF, where hypovitaminosis D and other factors are contributory.