Dysbetalipoproteinaemia in genetically predisposed Ghanaians

Dysbetalipoproteinaemia (dysβ) is a genetic lipid disorder characterised by accumulated remnant lipoproteins, leading to mixed hyperlipidaemia and increased cardiovascular risk. It is primarily associated with apolipoprotein E (apoE) ε2/ε2 homozygosity, although variants, such as arginine 145 cysteine (R145C), may also contribute. In sub-Saharan Africa, including Ghana, dysβ remains underdiagnosed due to limited awareness and access to diagnostic testing. This study assessed the prevalence of the dysβ phenotype in adult Ghanaians and its association with the apo ε2/ε2 genotype and R145C variant.

A cross-sectional study was conducted among 1,032 Ghanaian adults, comprising healthy controls (n = 702), diabetic patients (n = 268), and patients with ischaemic heart disease (IHD) (n = 62). Anthropometry, blood pressure, and lipid profiles were assessed. LDL particle size and remnant lipoproteins were visualised using polyacrylamide gradient gel electrophoresis (PGGE), while polymerase chain reaction and restriction fragment length polymorphism were used for apoE genotyping. Group comparisons were conducted using chi-square, Kruskal-Wallis and Mann-Whitney U tests.

The prevalence of dysβ was 1.6%; 4.8% in IHD patients, 1.5% in diabetics and 1.3% in healthy controls (p = 0.80). The ε2/ε2 genotype was identified in 2.6% of participants, with 52% exhibiting the dysβ phenotype. The R145C variant was found in 4.0% of the participants: 6.0% in IHD patients, 5.9% in diabetics, and 2.5% in healthy controls, but none of these carriers developed dysβ. Among healthy controls with ε2/ε2 who had the dysβ phenotype, BMI, WHR, total cholesterol [4.10, IQR (3.27-4.75), and triglycerides [1.08, IQR (0.98-1.54), and lower HDL-C, were statistically comparable to those who did not have the dysβ phenotype.

This is the first report of dysβ prevalence in Ghana. Although the phenotype was generally mild, the findings highlight the need for further research into lipid disorders and the role of genetic screening in cardiovascular risk assessment in African nations.