2008 Clinical Practice Guidelines - Canadian Diabetes Association

type 2 diabetes. Although originally designed as a secondary
prevention trial, the protocol underwent several changes,
including the addition of subjects without known CAD, and
the eventual switch of all patients with known CAD to openlabel
lipid-lowering medication. Mean LDL-C reduction over
4 years in the atorvastatin group was 29% vs. placebo
(p 90 000 statin-treated subjects
indicated that for every 1.0 mmol/L reduction in LDL-C
there was an approximately 20% reduction in CVD events,
regardless of baseline LDL-C. The proportional reductions
were very similar in all subgroups, including those with diabetes
without pre-existing vascular disease (28). Although
this linear relationship between the proportional CVD risk
reduction and LDL-C lowering would suggest that there is
no lower limit of LDL-C or specified LDL-C target (as the
authors suggest), the clinical trial evidence summarized
above would suggest that a target LDL-C of ≤2.0 mmol/L is
currently the most appropriate target for high-risk individuals.
This target is achievable in the vast majority of people
with either a statin alone or a statin in combination with a
second agent, such as a cholesterol absorption inhibitor. For
those with an on-treatment LDL-C of 2.0 to 2.5 mmol/L,
the physician should use clinical judgement as to whether
additional LDL-C lowering is required.
Table 1 summarizes recommended treatment targets.
Tables 2A and 2B summarize considerations that should guide
the choice of pharmacologic agent(s) to treat dyslipidemia.
People with impaired glucose tolerance (IGT) (particularly
in the context of the metabolic syndrome) are at significant
risk for the development of CVD. Indeed, some
studies suggest that their vascular risk is almost as high as
individuals with type 2 diabetes (29). No clinical trial of
lipid-lowering agents has been conducted exclusively in
people with IGT; however, given their increased CV risk,
one can consider treating this population to the same targets
as people with diabetes (30). To reduce the CV morbidity
Table 1. Lipid targets for individuals with
diabetes at high risk for CVD
Index Target value
Primary target: LDL-C ≤2.0 mmol/L*
Secondary target:TC/HDL-C ratio 80 years (especially
women); small body frame and frailty; higher dose of statin;
multisystem diseases (e.g. chronic renal insufficiency due to
diabetes); multiple medications; hypothyroidism; perioperative
periods; alcohol abuse; excessive grapefruit juice consumption;
and specific concomitant medications such as fibrates (especially
gemfibrozil) (refer to specific statin package inserts for
others) (47)
† Listed in alphabetical order
HDL-C = high-density lipoprotein cholesterol
LDL-C = low-density lipoprotein cholesterol
TG = triglyceride
Drugs of choice
to lower LDL-C.
At higher doses,
modest
TG-lowering
effects and
HDL-C–raising
effects
Note: Physicians should refer to the most current edition
of Compendium of Pharmaceuticals and Specialties (Canadian
Pharmacists Association, Ottawa, Ontario, Canada) for product
monographs and complete prescribing information.
S109
COMPLICATIONS AND COMORBIDITIES