Hypertriglyceridemia: a review of clinical relevance and treatment options: focus on cerivastatin.
The triglyceride (TG) level is one of several lipid parameters that can aid prediction of coronary heart disease (CHD) risk. An elevated plasma TG level is strongly associated with an increased risk of CHD. Hypertriglyceridemia, the second most common dyslipidemic abnormality in hypertensive subjects after increased low-density lipoprotein cholesterol (LDL-C), is defined by the National Cholesterol Education Programme (NCEP) as a fasting TG level of > 2.26 mmol/l (> 200 mg/dl) and is recognised as a primary indicator for treatment in type IIb dyslipidemia. Raised TG levels can be present in individuals at risk for CHD when the total cholesterol is normal. However, not all individuals with raised TG levels have increased risk of CHD. Factors such as: diet, age, lifestyle, and a range of medical conditions, drug therapy and metabolic disorders, can all affect the TG level. In some of these circumstances, other factors protect against the risk of CHD, and can minimise or negate the effect of the risk factors present. Although TG reducing therapy has been shown to be associated with an improved clinical outcome, more research is needed to determine whether this is an independent effect of TG reduction or an effect of normalising the overall lipid profile in hypertriglyceridemic patients. Further trials are required to quantify the clinical benefits of lowering TG to 'target' levels and to confirm targets defined by NCEP-II (shown in Table 1). The role of TG in CHD pathogenesis is thought to involve several direct and indirect mechanisms, such as effects on the metabolism of other lipoproteins, transport proteins, enzymes, and on coagulation and endothelial dysfunction. More research is required to fully elucidate the role of TG, the ways in which it can influence other risk factors and the mechanism of its own more direct role in the atherogenic process. Patients with hypertriglyceridemia have been shown to respond well to dietary control and to the use of lipid lowering drugs such as 3-hydroxy-3-methylglutaryl-Coenzyme A (HMG CoA) reductase inhibitors (known as statins), fibrates and nicotinic acids. However, recent retrospective real-life clinical studies show that only 38% of patients receiving some form of lipid-lowering therapy achieved NCEP-defined LDL-C target levels, demonstrating the need for the use of more aggressive treatment. In hypertriglyceridemic patients, the newer statins, cerivastatin and atorvastatin, have shown comparable efficacy in reducing TG compared with the older statins. Achieving NCEP target lipid levels has been shown to reduce the risk of cardiovascular disease in dyslipidemic individuals, including high-risk patient groups such as those with additional risk factors, existing heart disease, diabetes mellitus and metabolic syndrome. Although the latest clinical studies investigating combination therapies, i.e. dual therapy with both a statin and a fibrate, have demonstrated them to be effective for overall control of lipid parameters and reducing coronary events, it is not yet clear whether this offers any significant advantage over monotherapy. Results from ongoing longer-term end-point clinical studies may provide further information in this area and consequent reviews of primary care management policies for dyslipidemia. Statin monotherapy may be a reliable option for primary care treatment of dyslipidemia (including hypertriglyceridemia).