In pathogenesis of cerebrovascular disease (CVD), serum lipids and lipoproteins are considered as playing a minor role, since their blood concentrations are mostly within the normal range or, only slightly elevated. However, the recent developments in lipoprotein studies have revealed that dyslipoproteinemias due to qualitative changes in serum lipoproteins are atherogenic, even when their blood levels are in the normal range. This directed us to reinvestigate serum lipids and lipoproteins including their apolipoproteins in CVD.
Fifty three healthy control subjects (male 32, female 21) and 89 CVD patients (male 66, female 23) on rehabilitation therapy 2 to 9 months after stroke were studied. The patients were classified on the basis of clinical signs, brain CT and angiography as cerebral bleeding 34 (male 23, female 11) and cerebral infarction 55 (male 43, female 22). The latter was further subdivided into infarction in perforating arteries 23 (male 18, female 15) and in cortical arteires 32 (male 25, female 7). Their fasting plasma was measured for total cholesterol (TC), triglycerides (TG), very low density lipoproteins (VLDL), low density lipoproteins (LDL), high density lipoproteins (HDL), their subfraction of HDL2b, HDL2a, HDL3, apolipoprotein A-I and A-II.
TC, TG and HDL-c in CVD patients were as anticipated within the normal range, except for TG and HDL-c in female patients with cerebral infarction of cortical artery regions.
However, when compared with the control, TC and LDL-c were lower in cerebral bleeding and higher in cortical artery infarction. TG and VLDL-c were significantly higher in CVD, while HDL-c and HDL2 comprising of HDL2b and HDL2a significantly lower in the CVD patients. HDL3 remained unchanged throughout the CVD groups. Apo A-I and A-II were also significantly lower in the CVD, whereas cholesterol ratio of TC— HDL-c/HDL-c had no significant difference.
When compared among CVD groups, TC and LDL-c were lower in cerebral bleeding than in infarctions, and the cholesterol ratio tended to be greater in the order of bleeding, perforating artery infarction and cortical artery infarction.
These abnormalities, though not exceeded from the normal range, of elevated TG and VLDL-c accompanied by slightly increased LDL-c and of decreased HDL-c with unchanged HDL3 indicated that there were some metabolic disturbance in conversion of VLDL-c to HDL-c and HDL3 to HDL2. These disturbance may be associated with the alteration in lipoprotein lipase and lecithin: cholesterol acyltransferase activities which often cause the qualitative alterations in serum lipoproteins.
