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.