Submitted to: Clinical Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/2/2010
Publication Date: 4/20/2010
Citation: Schaefer, E. 2010. Northern light: a commentary on the 2009 Canadian Guidelines for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease in adults. Clinical Chemistry. 56(4):502-504. Interpretive Summary: In the United States, national guidelines for cholesterol management have been generated three times, with the last set being promulgated in 2001. In that set of guidelines the focus was on assessing the ten-year risk of heart disease based on gender, age, systolic blood pressure, smoking, total cholesterol, and high density lipoprotein or HDL cholesterol levels. Thus the goal of treatment was getting low density lipoprotein (LDL) cholesterol levels to < 100 mg/dl in subjects with heart disease, diabetes or a > 20% heart disease risk, < 130 mg/dl in those with 10 – 20% heart disease risk, and < 160 mg/dl in those with a < 10% heart disease risk. In 2004 an optional goal of LDL cholesterol of < 70 mg/dl was recommended for those with heart disease. The Canadians have taken a somewhat different approach. They have accepted the concept that family history of heart disease below age 60 years and a C reactive protein level of over 2.0 mg/L are independent risk factors along with those previously identified by the Framingham Heart Study. They have recommended using the Reynolds Risk Score and for those with disease or > 20% ten year risk of heart disease, an LDL cholesterol goal of < 80 mg/dl. For other subjects they have recommended physician’s judgment. Their risk assessment approach is justified.
Technical Abstract: Coronary heart disease (CHD) remains a leading cause of death and disability in both Canada and the US. Major established independent risk factors for CHD include increased age, male sex, hypertension, smoking, diabetes, increased total cholesterol [>240 mg/dL (6.2 mmol/L)] associated with increased LDL cholesterol [_160 mg/dL (4.2 mmol/L)], and decreased HDL cholesterol [<40 mg/dL (1.0 mmol/L)]. Based on the long-term follow-up of participants in the Framingham Heart Study, point systems have been developed allowing for the calculation of the 10- year risk of CHD. Many other investigators have documented that family history of premature CHD and increased high sensitivity C-reactive protein (hsCRP) are also independent CHD risk factors, and a modified point system known as the Reynolds Risk Score has been developed that includes these factors for calculating 10-year risk of CHD. The recently released third iteration of the Canadian guidelines for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease includes both of these CHD risk prediction systems in their guidelines, and in part incorporates family history of premature heart disease (age <60 years in a first degree relative) and increased hsCRP (2 mg/L).