Article Text
Statistics from Altmetric.com
- CHD: coronary heart disease
- CRP: C reactive protein
- CT: computed tomography
- FH: familial hypercholesterolaemia
- HDL: high density lipoprotein
- LDL: low density lipoprotein
- NCEP: US National Cholesterol Education Program
- PAI-1: plasminogen activator inhibitor
Used properly, screening detects metabolic time bombs before they wreak havoc; used inappropriately, screening may transform an asymptomatic individual into a modern semblance of Damocles, perpetually anxious about the future. Hence, before undertaking screening it is important to first answer the question as to whether the results are likely to influence the future management of the person screened. If the answer is no or uncertain, then it might be better to desist.
Familial occurrence of risk factors such as a raised low density lipoprotein (LDL) cholesterol is sometimes caused by a dominantly inherited disorder—for example, familial hypercholesterolaemia (FH)—but more often reflects interaction between weaker genetic traits and shared environmental influences, especially a poor diet. This review focuses mainly on metabolic risk factors causally related to the premature onset of coronary heart disease (CHD) and modifiable by alterations in diet and lifestyle or by drug treatment. Increasing evidence that certain agents, notably statins, can prevent or delay the onset of CHD makes it imperative to screen for dyslipidaemia the relatives of all patients developing or dying from CHD before the age of 55 if male or 65 if female.
CATEGORIES OF RISK FACTOR
The essential criteria of a risk factor are that it shows an independent and quantitative relation with the disease in question, there is evidence of a causal mechanism and, most importantly, there is reversibility of risk. Depending on the strength of the supporting evidence risk factors can be divided into various categories, as discussed below. Factors associated with a disease which lack any of these three criteria, except age, should be regarded as risk markers rather than as true risk factors.
LDL: AN OBLIGATORY RISK FACTOR
Numerous prospective surveys have shown a positive correlation between serum cholesterol over a wide range of concentrations and the risk of developing CHD. The correlation between total cholesterol and CHD is …