A comparative study of plasma high-density lipoprotein cholesterol in two groups of Nigerians of different socio-economic status.

Blood samples were obtained from two groups of Nigerians of different income and educational status. Group I subjects consisted of 178 males and females with high income and post-secondary-school education; and in group II were 332 males and females with low income and no secondary-school education. Plasma total cholesterol and high-density lipoprotein (HDL) cholesterol were determined in all samples. There was no significant increase in the mean plasma total cholesterol levels in group II subjects after the age of 20 years but the increase in the group I subjects was only significant in the males. The mean HDL cholesterol levels did not increase with age in both groups who were more than 20 years old. Group I males and females had significantly higher mean levels of plasma total and HDL cholesterol than the group II subjects. The female subjects in both groups had significantly higher mean plasma HDL cholesterol than their male counterparts. The mean ratios of HDL: total cholesterol for group I females were significantly higher than the mean for group I males only and not significantly different from values for group II subjects.