The world still contains hundreds of guidelines that recommend screening at annual intervals, and regular testing of blood lipids in people taking statins. Fortunately, this practice is already dying out in the UK, but is very much alive and well in the USA, and as we know, in Canada.
Two Canadian groups, with a primary care focus have published interesting guidelines, backed by detailed discussion. We have included links to both of these guidelines in our Quick Links section.
CFPC Simplifed Lipid Guidelines
The College of Family Physicians of Canada (CFPC) published guidelines in 2015 with the purpose of “increasing the contribution of primary care professionals, seeking participants with little or no conflict of interest, and focusing on the highest level of evidence.”
Toward Optimized Practice (TOP)
Cardiovascular Disease Risk Guidelines
This provincial organization in Alberta “helps Alberta physicians and the teams with whom they work implement evidence-based practices to enhance the care of their patient.”
Both organizations make recommendations that reflect the UK experience.
With respect to age of increasing CVD risk, starting screening for men at age 40 and women at age 50 is suggested as a prudent approach.
Although there is debate regarding screening all patients at age 40, most women would not typically be at CVD risk at this age and the recommendation to screen would then not follow the best available evidence. Screening may be considered at earlier ages for patients with known risk factors like hypertension or diabetes
It could be argued that as lipid levels change minimally over the long term, the initial lipid results could be used for ongoing (future) CV risk assessments.
Therefore, for those not on statin therapy, screening (repeat lipid levels and risk assessment) is not required
more often than every five years.
Do patients need to fast to have their cholesterol checked?
Minimal differences exist between fasting and non-fasting high density lipoprotein (HDL), LDL, and total cholesterol. The differences that occur are less than the “within person variability” from repeat lipid testing. Tests of non-fasting HDL and non-HDL levels correlate with future CVD events. Although triglycerides are most susceptible to change without fasting, triglycerides contribute minimally to total cholesterol levels and triglyceride levels are not consistently associated with CVD. Removing the fasting restriction should improve test uptake adherence and reduce potential patient harm (e.g., hypoglycemia in diabetic patients).
Next week, we will discuss the shift in thinking from treating the “number”, to assessing overall risk of vascular disease. In our Quick Links section, you will find a useful patient information handout from TOP, which can help begin the this discussion with patients.