Reduced cholesterol levels in African-American adults with sickle cell disease

In a recent study of boys and girls with sickle cell disease (SCD) in Nigeria, a common finding with this genetic hematologic disorder was a marked reduction in total cholesterol. Epidemiologic studies have identified a relation between low serum levels of total cholesterol (< 130 mg/dL) and increased mortality from all causes. We were interested in knowing if hypocholesterolemia was present in African-American adults with SCD. We therefore compared the plasma lipid profiles of the 16 men and 20 women with SCD who received care at the University of Texas Medical Branch at Galveston between 1996 and 2001 with those of 2,415 gender-matched African Americans who were seen at the same hospital but who did not have SCD. The age-adjusted mean total cholesterol concentrations of the SCD males and females were 147 +/- 42 mg/dL and 179 +/- 36 mg/dL, compared to male and female control values of 200 +/- 75 mg/dL and 216 +/- 61 mg/dL, respectively. These differences between SCD subjects and controls were statistically significant (p < 0.001). The LDL-cholesterol levels of the men and women with SCD (68 +/- 28 mg/dl and 95 +/- 33 mg/dl, respectively) were also significantly reduced relative to the controls (121 +/- 58 mg/dl and 128 +/- 54 mg/dl, respectively, p = 0.001). The triglyceride levels of the men with SCD were much reduced relative to the male controls (102 +/- 34 mg/dL versus 194 +/- 215 mg/dL, p = 0.02), but were not different between the SCD females and their control group. The HDL-cholesterol levels of the SCD subjects and the controls were not different. These results indicate that total cholesterol and LDL-cholesterol concentrations are significantly reduced in adult men and women with SCD in the United States, and should heighten interest in the implication that low levels of cholesterol might exacerbate the medical problems inherent in this genetic disease.