Plasma lipids in Nigerians with systemic arterial hypertension

In a nationwide survey of Nigeria, residents of Kano were shown to have the highest prevalence of hypertension and the highest levels of plasma cholesterol. Because hypertension and high cholesterol together markedly increase the risk for cardiovascular disease, we examined lipid profiles among hypertensives and nonhypertensives in Kano. To determine the extent to which there were differences in lipid profiles based on therapy for blood pressure, we created three strata for comparison.

The study was conducted at Aminu Kano Teaching Hospital, Kano, Nigeria. Lipid levels were examined among randomly selected hypertensives on antihypertensive regimens (n = 70), treatment-naïve hypertensives (n = 70), and normotensive individuals (n = 70) matched for age and gender. Overall mean age for hypertensives was 50.5 ± 11.9 years, and 54.3% were female. For the control group, mean age was 49.3 ± 12.9 years, and 55.7% were female.

Mean total cholesterol of the hypertensives on therapy (group 1) was 5.69 ± 1.19 mmol/L. Total cholesterol was significantly higher than levels in the treatment-naïve hypertensives (group 2) (5.24 ± 0.76 mmol/L; P = 0.01) and the controls (group 3) (4.91 ± 0.72 mmol/L; P = 0.000). Significant differences were also evident between groups for low-density lipoprotein (LDL) cholesterol. For high-density lipoprotein (HDL) cholesterol, the difference between the hypertensives on therapy and the treatment-naïve was not significant. Difference in this index between each hypertensive group and control was significant. The difference between groups for triglycerides followed the same pattern as HDL cholesterol. Increased total cholesterol (>6.5 mmol/L) was found to be 20%, 4.4%, and 1.4% in the hypertensive on therapy, treatment-naïve hypertensive, and control groups, respectively.

High levels of total and LDL cholesterol were more prevalent in treated versus untreated hypertensives and normotensive individuals, suggesting co-occurrence of two important risk factors for cardiovascular disease that is not ameliorated by treatment for hypertension.