High Prevalence of Primary Dyslipidaemia in Black South African Patients at a Tertiary Hospital in Northern Gauteng; South Africa

ABSTRACT

BACKGROUND:The prevalence of cardiovascular disease is projected to be 38.7% for the USA in 2020; including coronary heart disease at 8.6% and stroke at 3.6%. In South Africa (SA); premature deaths due to heart and blood vessel diseases in people of working age (35 - 64 years) have been predicted to increase by 41% between 2007 and 2030; with enormous negative economic impact. Atherosclerosis underlies much of the pathogenesis; which involves risk factors including dyslipidaemia. Secondary dyslipidaemia associated with diabetes mellitus; hypothyroidism; chronic renal disease; cholestasis; nephrotic syndrome; alcohol excess; drugs such as thiazide diuretics and antiretroviral agents may respond to treatment of underlying causes; but residual dyslipidaemia may in such cases be due to primary disorders of metabolism. Primary dyslipidaemias are uncommon and to a large extent underdiagnosed; especially in the black population of SA; reflecting a lack of clinical and laboratory awareness or expertise. Specific diagnoses enable effective intervention in the patients as well as the families.OBJECTIVE:To assess the burden and prevalence of dyslipidaemia in the SA black population at Dr George Mukhari Hospital in the north region of Gauteng.METHOD:A retrospective data analysis of 12-month lipid profiles comprising triglyceride (TG); total cholesterol (TC); high-density lipoprotein cholesterol and directly measured low-density lipoprotein (LDL) cholesterol (LDLC).RESULTS:There were 24 656 requests for 6 348 patients. The lipid cut-off levels were somewhat arbitrary but were based on the commonly used decision-making levels in the treatment guidelines. Severe hypercholesterolaemia (etgt;7 mmol/L) was seen in 299 (4.7%) patients and extreme hypercholesterolaemia (etgt;12 mmol/L) was seen in 30 (0.5%) patients. LDLC (etgt;5 mmol/L) occurred in 80 (1.3%) patients and etgt;10 mmol/L in 19 (0.3%) patients. A predominant triglyceride problem was seen in 578 (9.1%) patients with TG (etgt;2 mmol/L) and TC (etlt;5 mmol/L); whereas moderate hypertriglyceridaemia (etgt;5 mmol/L) was present in 113 (1.8%) patients; and more severe hypertriglyceridaemia (etgt;10 mmol/L) in 10 (0.2%). TC (etgt;5 mmol/L) with LDL (etgt;3 mmol/L) but TG in the normal range was seen in 369 (5.8%) patients; indicating a cholesterol-predominant problem. In contrast; LDLC (etgt;3 mmol/L) and TG (etgt;1.7 mmol/L) was seen in 249 (3.87%) representing mixed hyperlipidaemia. Paediatric patients with severe dyslipidaemia mostly suffered from nephrotic syndrome.CONCLUSION:A significant burden and a high prevalence of dyslipidaemias were present in adults in whom a monogenic disorder should be considered. The extent and severity of dyslipidaemia justify a special clinic and laboratory to ensure accurate diagnosis with effective intervention for patients and their families