The current analysis extends the results of these previous studies
by separately investigating those who received LLT at baseline
and those who did not. All lipids except ApoA1 and HDL cholesterol
were independent predictors of CHD in those not taking any
LLT at baseline, indirectly corroborating the benefits of statin therapy
in reducing cardiovascular disease in elderly participants of the
PROSPER and the AFCAPS/TexCAPS trials [2,11].We also found that
lipids remained independent predictors of CHD under statin therapy,
possibly with a stronger association than that observed in the
absence of LLT. This result may reflect a lack of adherence to statin
treatment, which in itself may increase the risk of CHD [19]. A previous
analysis of the Three-City Study indicated, however, that drug
exposure and compliance with treatment were fairly good [15]. In
those under statins at baseline, we looked for differences in baseline
characteristics that could explain why some subjects still had
elevated lipid concentrations. In fact, the baseline characteristics
of those with LDL cholesterol above or below the median value
(3.7 mmol/L, approximating the usual target value of 130 mg/dl)
under statin therapy were not different with respect to age, gender,
sleep disturbances, mini mental state examination, depressive
symptoms, physical activity, number of drugs currently used or
renal function. More frequent side effects under statin therapy have
been described in women, possibly leading to more discontinuation
of treatment than in men [20]. In the current study however, the
proportion of normalized LDL cholesterol under statin therapy on the one hand, and the pattern of association between lipids and
CHD under statin therapy on the other hand, were comparable in
both genders. Alternatively, subjects under statin therapymayhave
a worse cardiovascular risk profile or an underlying chronic condition
(indication bias). However, the results remained unchanged
when adjustment for baseline characteristics was carried out or
when those who died within the first 2 years were excluded. Therefore,
the current study suggests that under statin therapy, there
remains a substantial residual risk of CHD that is attributable to
some extent to lipid levels.