Apolipoprotein E genetic variation, atherogenic index and cardiovascular disease risk assessment in an African population: An analysis of HIV and malaria patients in Ghana

Abstract

Background Apolipoprotein E is involved in lipid transport and clearance of lipoprotein through low-density lipoprotein receptors (LDLR). ApoE variation has been linked to cardiovascular disease (CVD) risk. There are 3 isoforms of ApoE which originate from two non-synonymous single nucleotide polymorphisms denoted as ϵ2, ϵ3 and ϵ4. The ϵ2 isoform is implicated in higher levels of atherogenic lipoprotein with the ϵ4 isoform causing LDLR downregulation. This leads to variable effects and differential CVD risk. Malaria and HIV are life-threatening diseases affecting several countries globally especially in sub-Saharan Africa. Parasite and viral activities have been implicated in lipid dysregulation leading to dyslipidaemia. This study examined ApoE variation and CVD risk assessment in malaria and HIV patients. Methods We compared 76 malaria-only, 33 malaria-HIV coinfected, 21-HIV-only and 31 controls from a tertiary health facility in Ghana. Fasting venous blood samples were taken for ApoE genotyping and lipid measurements. Clinical and laboratory data were collected with ApoE genotyping performed using Iplex Gold microarray and PCR-RFLP. Cardiovascular disease risk was calculated using the Framingham BMI and cholesterol risk and Qrisk3 tools. Results The frequency of C/C genotype for rs429358 was 9.32%, whiles T/T genotype for rs7412 was found in 2.48% of all participants. ϵ3/ϵ3 was the most distributed ApoE genotype accounting for 51.55% of the total participants whiles ϵ2/ϵ2 was found in 2.48% of participants, with 1 in malaria-only and 3 in HIV-only patients. There was a significant association between ϵ4+ and high TG (OR = 0.20, CI; 0.05-0.73; p = 0.015), whiles ϵ2+ was significantly associated with higher BMI (OR; 0.24, CI; 0.06-0.87; p = 0.030) and higher Castelli Risk Index II in females (OR = 11.26, CI; 1.37-92.30; p = 0.024). A higher proportion of malariaonly participants had a moderate to high 10-year CVD risk. Conclusion Overall malaria patients seem to have a higher CVD risk though the means through which this occurs may be poorly understood. ϵ2/ϵ2 genotypes was observed in our population at a lower frequency. Further studies are vital to determine CVD risk in malaria and how this occurs.