Lipoprotein abnormalities in the pathogenesis of cerebral infarction and transient ischemic attack

Lipoprotein (a) in chronic renal failure: effect of maintenance hemodialysis

BACKGROUND

Coronary artery disease accounts for significant morbidity and mortality in patients with chronic kidney disease (CKD). Besides the higher prevalence of traditional risk factors, several uremia-related factors may play a role in accelerated atherosclerosis, such as elevated levels of lipoprotein (a) (Lp(a)). The effect of maintenance hemodialysis (MHD) on Lp(a) levels is not well understood. The present work was carried out to study the Lp(a) levels in Stage 4 and Stage 5 CKD patients as well as the effect of MHD on Lp(a) levels in patients with Stage 5 CKD.

METHODS

The study subjects included 15 patients with Stage 4 CKD, 15 patients with Stage 5 CKD, and 15 age- and sex-matched healthy controls. Plasma Lp(a) was measured by ELISA in all the subjects at the time of entry into the study and after 4 weeks of MHD in patients with Stage 5 CKD. Patients on MHD were dialyzed two to three times weekly for 4 hr during each session.

RESULTS

Mean Lp(a) levels were significantly higher in patients with CKD than in control patients. In patients with Stage 4 CKD, the Lp(a) level was 34.0 +/- 19.5 mg/dL, whereas in Stage 5 CKD the level was 49.0 +/- 30.9 and in healthy controls it was 22.2 +/- 16.4. In patients with Stage 5 CKD, 4 weeks of MHD led to a significant fall in Lp(a) levels by 23.6% (P < 0.001).

CONCLUSIONS

The results of this study show that increases in Lp(a) levels start early during the course of CKD and become more pronounced with increased severity of disease. Initiation of MHD lowers Lp(a) levels and may have a long-term beneficial effect on cardiovascular morbidity and mortality.

Evaluation of atherosclerosis-associated factors and pulse wave velocity for predicting cerebral infarction: a hospital-based, case?control study in Japan

BACKGROUND

The mortality rate for cerebrovascular diseases is much higher in Japan than in North American and West European countries. The primary aim of this study was to elucidate from an epidemiological perspective, the associations between cerebral infarction and demographic factors, medical history and other clinical measurements including pulse wave velocity, a newly introduced non-invasive measurement procedure used to assess aortic stiffness.

METHODS

This was a hospital-based, matched case-control study in northern Japan where there is a high incidence of cerebrovascular disease. The study group consisted of 92 matched pairs of cerebral infarction patients (cases) and healthy individuals admitted for a thorough health check-up (controls) at the Southern Tohoku General Hospital in Fukushima Prefecture, Japan. A conditional logistic regression model was used in the statistical analysis.

RESULTS

In univariate analyses, 14 variables were significantly associated with cerebral infarction, of which four remained significant in the final multivariate model. These were family history of hypertension (odds ratio (OR) = 8.61), cerebrovascular diseases (OR = 13.70), high-density lipoprotein cholesterol of 40 mg/dL or higher (OR = 0.08), and pulse wave velocity over 1600 cm/s (OR = 2.92).

CONCLUSION

Findings from the study indicate that a high pulse wave velocity, in addition to other traditional risk factors, may be associated with a higher risk of cerebral infarction. Further prospective studies are necessary to evaluate the use of this measure as a predictor of the disease.

Hepatic lipase mutation may reduce vascular disease prevalence in hemodialysis patients with high CETP levels

BACKGROUND

Uremic dyslipidemia characterized by reduced high-density lipoprotein (HDL) cholesterol levels is one of the major contributors to the high incidence of cardiovascular disease in hemodialysis patients. Hepatic lipase (HL), together with cholesteryl ester transfer protein (CETP), may not only promote reverse cholesterol transport but also enhance production of small, dense, more atherogenic low-density lipoprotein (LDL). A common C-514T mutation of the promoter region of the HL gene reportedly increases HDL cholesterol levels. However, whether the HL mutation is antiatherogenic or proatherogenic has remained unknown in uremic patients and the general population.

METHODS

We investigated the influence of the mutation and its interaction with CETP on HDL cholesterol levels and the apparent atherosclerotic complications in 183 hemodialysis patients aged over 30 years who had received no antilipemic drugs.

RESULTS

In patients with CETP levels > or =2.2 microg/mL [high CETP (HCT) group, N = 97], subjects with the TT genotype had a significantly higher level of HDL cholesterol than those without TT genotype (56.8 +/- 15.9 mg/dL vs. 45.7 +/- 13.4 mg/dL, P < 0.001), but not in patients with CETP levels <2.2 microg/mL [low CETP (LCT) group]. Multiple linear regression analysis showed that the TT genotype was a major independent positive determinant for HDL cholesterol levels in the HCT not LCT group. Among the HCT group patients, subjects with the TT genotype (N = 25) had a tendency toward lower prevalence of vascular disease than those without TT genotype (N = 72) (4.0% vs. 22.2%, P < 0.07). In this subgroup, TT genotype had an independent odds ratio of 0.041 (95% CI 0.002 to 0.75, P < 0.05) after adjusting for other risk factors.

CONCLUSION

The TT genotype of HL mutation may serve as a protective factor against vascular disease by increasing HDL cholesterol levels in hemodialysis patients with higher CETP levels.

Report of the Japan Atherosclerosis Society (JAS) Guideline for Diagnosis and Treatment of Hyperlipidemia in Japanese adults

This paper described the Guideline for Diagnosis and Management of Hyperlipidemias for Prevention of Atherosclerosis proposed by The Japan Atherosclerosis Society (JAS) Guideline Investigating Committee (1,995-2,000) under the auspices of the JAS Board of Directors. 1) The guideline defines the diagnostic criteria for serum total cholesterol (Table 1), LDL-cholesterol (Table 1), triglycerides (Table 4) and HDL-cholesterol (Table 7). It also indicates the desirable range (Table 1), the initiation levels of management (Table 2) and the target levels of treatment (Table 2) for total and LDL-cholesterol. 2) Though both total and LDL-cholesterol are shown as atherogenic parameter in the guideline, the use of LDL-cholesterol, rather than total cholesterol, is encouraged in daily medical practice and lipid-related studies, because LDL-cholesterol is more closely related to atherosclerosis. 3) Elevated triglycerides and low HDL-cholesterol are included in the risk factors, since no sufficient data have been accumulated to formulate the guideline for these two lipid disorders. 4) Emphasis is laid on evaluation of risk factors of each subject before starting any kind of treatment (Table 2). 5) This guideline is applied solely for adults (age 20-64). Lipid abnormalities in children or the youth under age 19, and the elderly with an age over 65 have to be evaluated by their own standard. 6) This part of the guideline gives only the diagnostic aspects of hyperlipidemias. The part of management and treatment will follow in the second section of the guideline that will be published in future.

Relation of lipid and lipoprotein(a) to ischaemic stroke

The relationship of lipids and Lp(a) to ischemic stroke hasn't been established yet. Our aim was to determine lipid profile and vascular risk factors in stroke patients and compare them with control subjects. Seventy-nine consecutive patients with ischemic stroke were analyzed by total cholesterol, HDL-C, LDL-C, triglyceride, Lp(a) and doppler ultrasonography and vascular risk factors were recorded. Thirty control subjects of same ages were compared with the patient group. Lp(a) and lipids were correlated with stroke subtype and carotid atherosclerosis. There was no statistical significance between patients and control subjects related to total cholesterol, triglyceride, HDL-C, LDL-C and Lp(a) (P>0.05). Atherotrombotic and lacunar strokes didn't show any difference correlated with lipids and Lp(a). Hypertension and diabetes mellitus were important risk factors with (OR=4.50, 95% CI=1.25-16.22) and (OR=4.43, 95% CI=1.79-10.93) respectively. These results were statistically significant (P<0.05). Total cholesterol (308.67+/-85.82) and Lp(a) (32.10+/-17.30) values showed statistical significance (P<0.05) in patients with marked stenosis when compared with patients of normal doppler ultrasonography. Hypertension and diabetes mellitus were found as independent risk factors for ischemic stroke. Lipids and Lp(a) were not independent for atherotrombotic and lacunar stroke. Lp(a) concentration and carotid atherosclerosis in ultrasonography were associated significantly.

Cholesteryl ester transfer protein as a protective factor against vascular disease in hemodialysis patients

Cholesteryl ester transfer protein (CETP) may promote reverse cholesterol transport. An elevated concentration of high-density lipoprotein cholesterol (HDL-C) is a protective factor against atherosclerosis. However, the effects of CETP itself and its interaction with HDL-C have not been investigated in hemodialysis patients, who are at high risk for atherosclerosis and generally considered to have decreased reverse cholesterol transport. We investigated the independent or synergistic influence of postprandial serum CETP and HDL-C concentrations on apparent atherosclerotic complications in 202 hemodialysis patients aged 40 to 80 years. Patients with vascular disease (n = 39) had significantly lower concentrations of CETP than those without vascular disease (n = 163). When all study subjects were divided into four groups according to CETP and HDL-C concentrations based on median values, we found significant differences in the prevalence of vascular disease (test for trend, P < 0.005): 28.8% in group I (HDL-C < 48 mg/dL; CETP < 2.2 microgram/mL); 25.0% in group II (HDL-C < 48 mg/dL; CETP >/= 2.2 microgram/mL); 17.8% in group III (HDL-C >/= 48 mg/dL; CETP < 2.2 microgram/mL); and 6.9% in group IV (HDL-C >/= 48 mg/dL; CETP >/= 2.2 microgram/mL). Multiple logistic regression analysis retained the interaction term between HDL-C (in milligrams per deciliter) and CETP (in micrograms per milliliter), but not HDL-C or CETP itself, as inversely associated with vascular disease in the entire patient group. In patients with HDL-C levels at the median value or greater, CETP had an independent odds ratio of 0.31 (95% confidence interval, 0.1 to 0.97; P < 0.05) after adjusting for age. These results suggest that CETP may serve as a protective factor against vascular disease in hemodialysis patients, especially those with normal or elevated HDL-C concentrations.

Application of computer tomography-oriented criteria for stroke subtype classification in a prospective study

PURPOSE

To apply stroke subclassification criteria based on computer tomography (CT) to strokes in the Nurses' Health Study and to assess reliability and validity of the criteria.

METHODS

Among 121,701 women aged 30-55 years at entry, subclassification criteria were applied to 1369 incident strokes which occurred from 1976 to 1994. Reproducibility of the subclassification criteria was assessed in a systematic sample of 100 strokes reviewed by two independent reviewers. As a validation, relative risks (RR) for stroke subtypes were examined in a prospective analysis of 112,282 women aged 34 to 59 years, free of cardiovascular disease and cancer in 1980, with follow-up through 1994.

RESULTS

Strokes were subclassified as follows: 226 subarachnoid hemorrhages, 135 intraparenchymal hemorrhages, 103 embolic, 217 large-artery occlusive, 309 lacunar, and 97 other thrombotic infarctions, as well as 282 strokes of undetermined type. No intercoder discrepancies were found in classification of subarachnoid hemorrhage, intraparenchymal hemorrhage, or embolic infarction, whereas there were four discrepancies relative to subclassification of thrombotic infarction, mostly due to inconsistent documentation of CT findings. In multivariate models, associations of older age (> 60 years), current smoking, history of diabetes, and high cholesterol with stroke subtypes were consistent with previous epidemiologic, clinical, or pathologic findings.

CONCLUSIONS

Stroke diagnostic criteria based primarily on CT were found to have a high rate of reliability and validity. These stroke subclassification criteria may be useful in examining whether associations for various lifestyle and health behaviors differ with stroke subtypes.

LDL receptor mutations and ApoB mutations are not risk factors for ischemic cerebrovascular disease of the young, but lipids and lipoproteins are

BACKGROUND

The genetic background for ischemic cerebrovascular disease of the young and the role of lipids and lipoproteins as risk factors are not clear.

METHODS

We determined five LDL receptor mutations (Trp23Stop, Trp66Gly, Trp556Ser, 313+1G --> A, 1846-1G --> A) and three apolipoprotein B mutations (Arg3500Gln, Arg3500Trp, Arg3531Cys), and other risk factors for ischemic cerebrovascular disease in 80 patients (36 women, 44 men) with onset of disease before the age of 50 years compared with 3366 individuals from a general population sample within the same age range.

RESULTS

None of the patients were carriers of mutations in the LDL receptor (Trp23Stop, Trp66Gly, Trp556Ser, 313+1G --> A, 1846 - 1G --> A) or the apolipoprotein B gene (Arg3500Gln, Arg3500Trp, Arg3531Cys) associated with hypercholesterolemia. However, on univariate analysis as well as on logistic regression analysis allowing for age and gender, plasma cholesterol (OR 1.4; P < 0.0005), HDL-cholesterol (OR 0.4; P < 0.005), diabetes (OR 5.8; P < 0.0001), and hypertension (OR 3.9; P < 0.001) were significant predictors of ischemic cerebrovascular disease.

CONCLUSIONS

The five most common LDL receptor mutations in Danish patients with familial hypercholesterolemia and three mutations in the apolipoprotein B gene did not predispose to ischemic cerebrovascular disease of the young. However, cholesterol and HDL-cholesterol are important risk factors for ischemic cerebrovascular disease of the young in the present study. The elevation in cholesterol could in some patients be due to rare LDL receptor mutations not tested for, and could in other patients be multifactorial in origin.

A cholesteryl ester transfer protein gene mutation and vascular disease in dialysis patients

Among patients undergoing maintenance hemodialysis, a decreased high-density lipoprotein cholesterol (HDL-C) concentration is among the most common abnormalities of lipid metabolism and apparently is an independent risk factor for vascular disease. A common missense mutation of cholesteryl ester transfer protein gene, D442G (Asp 442 to Gly), increases HDL-C levels through the reduced activity of cholesteryl ester transfer from HDL to VLDL, but the mutation also may lead to reduced activity of reverse cholesterol transport. To investigate the effect of the D442G polymorphism on atherosclerotic complications in dialysis patients, the genotype and allele frequency of the polymorphism were determined in 414 unselected dialysis patients and 220 control subjects, and postprandial serum lipid levels were measured in the dialysis patients. A similar genotype distribution was found between hemodialysis patients and healthy control subjects, and in dialysis patients with and without vascular disease. Serum levels of total cholesterol and HDL-C did not differ between patients with and without the mutation and in patients with and without vascular disease. However, patients with sub-median HDL-C levels (<45 mg/dl) had an independent odds ratio of 1.8 for vascular disease (95% confidence interval, 1.04 to 3.2; P < 0.05). In this low-HDL-C subgroup, patients with the D442G mutation had a significantly higher prevalence of vascular disease than those with no mutation (54.5% versus 24.4%; P < 0.05), and an independent odds ratio of 4.9 (95% confidence interval, 1.05 to 22.65; P < 0.05). In conclusion, the D442G mutation is an independent risk factor for atherosclerotic complications in dialysis patients with HDL-C levels below 45 mg/dl.

Arterial Damage, Triglycerides, Apolipoprotein, and Lp-(a) Values in PVD Patients

The aim of the study was to provide a detailed apolipoproteic profile in stage II peripheral vascular disease (PVD) patients and to ascertain whether lower ankle/ arm pressure index (API) values were associated with a worse profile.

Apolipoproteins of 83 stage II PVD patients (average age 64.7 ± 9.3 years) were selected and compared with those of a group of 44 normal control subjects, similar in terms of age, sex, and smoking and eating habits. Neither PVD patients nor controls had ever received lipid-lowering agents or defined dietary treatment. A diagnosis of PVD was confirmed by an API of <0.85. Arteriopathic patients were also split into two groups, depending on their API values, similar in terms of age, sex and smoking habits: API values of one group (n = 38) were ≥0.6, those of the other group (n = 45) were <0.6. The following biohumoral parameters were considered: fasting glycemia, total cholesterol, triglycerides (TGs); high-density lipoprotein cholesterol (HDL-C); low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), total cholesterol (TC)/HDL-C (TC/ HDL-C), Apoproteins (Apos) AI, AII, B, CII, CIII, and E; and lipoprotein a [Lp(a)].

HDL-C and Apo AI were lower ( p < 0.01), while TC/ HDL-C ratios, Apo B, and Apo CII were higher ( p < 0.01) in PVD patients compared with controls. The comparison between the two PVD groups with different API values showed higher blood TG and VLDL-C values for the patients with lower API values (p < 0.05), indicating a relationship between hypertriglyceridemia and greater arterial damage. Key Words: Peripheral arterial occlusive disease-Triglyceride-Lipoprotein a.

Is family history an independent risk factor for stroke?

OBJECTIVE

To estimate the influence of family history on the occurrence of stroke.

METHODS

A case-control study was carried out from August 1992 to January 1994. The study population comprised 502 patients with a first stroke, aged between 20 and 70 years, who were treated at 48 affiliated hospitals. The same number of age and sex matched controls were selected from outpatients. Diagnoses were based on CT findings and clinical signs. There were 155 case-control pairs for subarachnoid haemorrhage, 158 for intracerebral haematoma, and 159 for cerebral infarction. Information about the patients and their families was obtained from a questionnaire which included the family histories of each subtype of stroke and other potential risk factors for stroke. The data were analysed focusing on the role of the family histories in the occurrence of stroke.

RESULTS

In univariate analysis, the family histories of subarachnoid haemorrhage and intracerebral haematoma were positively associated with each of the subtypes of stroke (odds ratios 11.24 for subarachnoid haemorrhage, 2.39 for intracerebral haematoma), whereas family history of cerebral infarction was not a significant risk factor for its occurrence (odds ratio 1.41). Family history of intracerebral haematoma was correlated with a personal history of hypertension and habitual alcohol consumption. After adjustment for potential risk factors (hypertension, diabetes, hyperlipidaemia, obesity, alcohol consumption, and regular smoking), family history of subarachnoid haemorrhage still remained the most powerful risk factor for subarachnoid haemorrhage, whereas family history of intracerebral haematoma no longer showed a significant association with haematoma.

CONCLUSION

Genetic factors play a major part in the pathogenesis of subarachnoid haemorrhage, and family history of subarachnoid haemorrhage is the strongest independent risk factor for the disease. On the other hand, family history of intracerebral haematoma was not an independent risk factor for haematoma, but it might be a good predictor, which indirectly influences the pathogenesis of intracerebral haematoma via certain hereditary components such as hypertension, and even lifestyle factors such as alcohol consumption. In cerebral infarction, genetic factors play a minor part in its pathogenesis.

Natural history, prognosis, and lipid abnormalities of idiopathic ischemic childhood stroke

A study was performed to assess the natural history, prognostic factors, and lipid and apolipoprotein abnormalities of idiopathic ischemic childhood stroke. A case series of 42 children, retrospectively identified with idiopathic ischemic strokes, were reassessed an average of 7.4 years (range, 1 to 19 years) after presentation. Patients were interviewed and examined, and fasting serum was obtained for lipid and apolipoprotein analysis. Poor outcome was defined as moderate to severe hemiparesis, special educational needs, epilepsy, recurrent stroke, or stroke-related death. Eighteen (43%) of the patients had a poor outcome. Among them were moderate to severe hemiparesis in 14 (78%), recurrent strokes in seven (39%), and one death. Poor outcome was evident early in their clinical course. Independent of outcome, lipid abnormalities including an elevated triglyceride and low-density lipoprotein cholesterol, and a depressed high-density lipoprotein cholesterol were seen in one third of all patients. A depressed ratio of apolipoprotein A-1 to apolipoprotein B (using adult normative values) was seen in half of the entire cohort. Clinical features of children with unexplained ischemic strokes at presentation and their subsequent course are described. Significant risk factors for a poor outcome include (1) persistence of hemiparesis 1 month after the stroke, (2) cortical as opposed to subcortical location, and (3) bilateral occlusive disease with telangiectasia on cerebral angiography. Previously described risk factors for an unfavorable prognosis, including occurrence during infancy and presentation with seizures, were not substantiated. Lipid abnormalities occur at an increased frequency in children after unexplained ischemic strokes. Prospective assessment of lipoprotein profiles are needed to further assess clinical significance. Assessing apolipoproteins may provide further insight than lipid values alone.

Thrombogenic and lipid risk factors in hypertension and coronary artery disease

Hypertension is not solely a phenomenon of elevation of systemic blood pressure. It frequently occurs in association with a great deal of metabolic derangement's and should never be regarded as coincidental only. Furthermore, a knowledge of these metabolic derangements may provide a clue to unveil the underlying mechanisms how essential hypertension and its associated complications arise. Therefore we devoted our attention to platelet dysfunction and dyslipidemia which are closely associated with atherosclerosis-the commonest complication of hypertension. We found there exists enhanced platelet aggregation in essential hypertension and a variety of its associated atherosclerotic diseases. Such an aberration in platelet function may be modified after administration of antihypertensive medications such as angiotensin converting enzyme (ACE) inhibitors, calcium channel blockades, beta blockades and dietary manipulation. We also demonstrated the close association between hypertension and its associated atherosclerotic complications and abnormal lipids profile. Hypertriglyceridemia which was initially regarded unimportant in the pathogenesis of atherosclerosis is found to be closely related to hypertension. In an intensive review, we found that people in Taiwan has experienced a huge increase in dietary calories and total fat consumption. In order to solve this emerging problem, a national guideline for diagnosis and management of lipid disorders in Taiwan was developed and announced. Through these efforts, we hope we can reduce the cardiovascular morbidity and mortality in Taiwan and even extend our experience to other countries.

[Comparison between HDL and LDL cholesterol as risk factors for carotid atherosclerosis]

In order to find out whether there exists a relationship between HDL and LDL serum levels and atherosclerotic plaques in the carotid artery (CA), a prospective study was carried out involving 125 patients. They were aleatorily included, of both sexes and age between 45-75 years old. HDL and LDL serum levels were measured as well CA ultrasonographic mode B investigated. It was verified that the number of patients having atherosclerotic plaques in CA was inversely proportional to the HDL levels. We came up with the same ratio when the HDL levels were compared to the number of patients having CA stenosis. These results were statistically significant (x2 = 6.57 and x2 = 9.24 respectively; critical x2 = 5.99 to alpha = 5%). A direct ratio was also found out in the relationship between the presence of atherosclerotic plaques in the CA and the LDL serum levels (greater in patients with plaques). However no relationship between LDL levels and the occurrence or not of CA stenosis in patients having plaques was demonstrated. The results were not statistically significant (x2 = 0.97 and x2 = 0.41, respectively, critical x2 = 5.99 to alpha = 5%). The obtained results seem to be at least in part in agreement with literature findings. Statistically significative results in the comparison of HDL and LDL levels with the grade of stenosis of the CA were not found out (x2 = 11.78 and x2 = 4.03, respectively; critical x2 = 12.59 to alpha = 5%).

Influence of total cholesterol, high density lipoprotein cholesterol, and triglycerides on risk of cerebrovascular disease: the Copenhagen City Heart Study

OBJECTIVE

To estimate the influence of plasma total cholesterol, high density lipoprotein cholesterol, and triglycerides on risk of cerebrovascular disease.

DESIGN

The Copenhagen City Heart Study is a prospective observational survey with two cardiovascular examinations at five year intervals. Non-fasting plasma lipids were measured in participants once at each examination, along with other variables. The Cox regression model was used to establish the effect of the factors recorded on cerebrovascular events of mostly, but not exclusively, ischaemic origin.

SUBJECTS

19,698 women and men at least 20 years old, randomly selected after age stratification from an area of central Copenhagen.

MAIN OUTCOME MEASURES

Initial cases of stroke and transient ischaemic attack recorded from hospital records and death certificates from 1976 through 1988.

RESULTS

660 non-haemorrhagic and 33 haemorrhagic events were recorded. Total cholesterol was positively associated with risk of non-haemorrhagic events, but only for levels > 8 mmol/l, corresponding to the upper 5% of the distribution in the study population. For lower plasma cholesterol values the relative risk remained nearly constant. Plasma triglyceride concentration was significantly, positively associated with risk of non-haemorrhagic events. The relative risk corresponding to an increase of 1 mmol/l was 1.12 (95% confidence interval 1.07 to 1.16). There was a negative, log linear association between high density lipoprotein cholesterol and risk of non-haemorrhagic events (0.53 (0.34 to 0.83)). There was no indication that the effects of plasma lipids were different in women and men.

CONCLUSIONS

The pattern of the association between plasma cholesterol and risk of ischaemic cerebrovascular disease was not log linear, and the increased risk was confined to the upper 5% of the cholesterol distribution. Further studies should concentrate on the association between plasma cholesterol and verified haemorrhagic stroke.

The prevention of cardiovascular disease. Emphasis on secondary prevention

Atherosclerosis is a progressive disease affecting all major arteries. Clinical evidence of atherosclerosis increases the risk of subsequent morbid and mortal events fivefold to sevenfold over the next 5 to 10 years. The same risk factors contribute to the initial development of CVD events as to their recurrence. Both coronary and noncoronary events, such as stroke or PAD, reflect the severity of the underlying atherosclerotic process and strongly predict future excess CVD morbidity and mortality. Short-term and long-term survival depends on modifying the risk factors that contribute to CVD events. Although absolute proof of benefit for secondary prevention does not exist for all risk factors, the data from primary prevention trials and the secondary prevention trials that have been done argue strongly for aggressive intervention. Benefit has been demonstrated for smoking cessation, cholesterol reduction, and blood pressure control. Selected patients may benefit from additional medical, procedural, or surgical interventions to prolong life, such as beta-blocking agents, aspirin, or carotid endarterectomy. Many secondary prevention measures are a cost-effective way to reduce the substantial morbidity and mortality due to CVD. Contrary to primary prevention, even modest treatment effects from secondary prevention efforts can benefit large numbers of patients. Finally, secondary prevention may be more successful because patients with clinical evidence of CVD may be more highly motivated than their healthy counterparts to make and maintain lifestyle changes.

Subarachnoid hemorrhage, cerebral hemorrhage, and serum cholesterol concentration in men and women

The role of serum cholesterol in predicting the risk of stroke is unclear and may depend on the subtype of the disease. In 1964 to 1965, 54,385 Swedish men and women participated in a health survey with serum cholesterol and diastolic blood pressure determinations. The Swedish mortality register was used to identify causes of death in this cohort during 20.5 years of follow-up (1964 to 1985). A person-year-based Poisson model was used for multivariate analysis. Relative risk increased with decreasing serum cholesterol level for subarachnoid hemorrhage in men and for cerebral hemorrhage in women but not for subarachnoid hemorrhage in women. For cerebral hemorrhage in men, the risk function was U-shaped. Adjustment for diastolic blood pressure did not significantly change the relation between the risk for any of the different stroke types and the cholesterol level. A low cholesterol level predicts death from intracranial bleeding, but the data suggest that there is differing risk pattern for men and women.

Plasma lipoproteins in cortical infarction versus transient ischaemic attacks: a case control study

The authors investigated the relationship between plasma lipids and the risk for cortical infarction (61 cases) and transient ischaemic attacks (TIA) (35 cases) compared with matched controls. They observed a maximal increase of total cholesterol, of very low-density lipoprotein and low-density lipoprotein (LDL), triglycerides, total apolipoprotein (Apo), B,LDL-Apo B and Apo-A1, and small size high-density lipoprotein (HDL) and large size HDL whose separation was not possible. In contrast they observed a decrease of HDL-ApoE, a distribution of LDL in a single fraction and the presence of LDL of low weight in the group with cortical infarction with or without cardiac arrhythmias. For the first time, we describe a decrease of the HDL-ApoE/total ApoE ratio. TIA differed from the former group by a low level of HDL and the lack of abnormalities of Apo-A1, distribution of small and large size HDL, and in the distribution and the weight of LDL. These data suggest that previously demonstrated differences in LDL-cholesterol and HDL-cholesterol levels between patients with ischaemic stroke and control subjects may apply to patients with cortical infarction, and that in TIA there are changes in the distribution and the weight of LDL.

Plasma lipids and lipoproteins in subtypes of stroke

We determined plasma lipid and lipoprotein concentrations in 131 patients (95 males, 36 females, mean age 71 years) 6 months after acute stroke onset. Compared to a reference population, the alterations of plasma lipid concentrations in stroke patients were moderate. However, the stroke patients had higher levels of triglyceride and lipoprotein (a) and lower concentrations of cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol. Patients with different subtypes of stroke showed significant differences when compared with each other by analysis of covariance (with adjustment for age, sex, smoking, hypertension and diabetes). Patients with carotid or vertebral artery disease had the higher levels of cholesterol, triglyceride and apolipoprotein B, whereas high density lipoprotein triglyceride concentrations were higher in patients with cardioembolic infarcts.

Lipid profile in acute stroke: A prospective study

The dramatic decline in the risk of stroke is most likely secondary to a better control of risk factors, especially hypertension. An increase in low-density lipoprotein (LDL) cholesterol or a decrease in high-density lipoprotein (HDL) cholesterol may be additional risk factors for cerebrovascular diseases. In this study, we prospectively evaluated patients with ischemic stroke (except for cardioembolic) and age-matched controls for serum cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, very low-density lipoprotein cholesterol, and apoprotein A and B. Blood levels were determined at least 8 weeks after the acute stroke or transient ischemic attack. Between September 1989 and September 1990,59 patients and 60 controls were investigated. There were no differences among total cholesterol, triglycerides, LDL cholesterol, and apoproteins in the two groups. HDL cholesterol, however, was significantly higher in patients with stroke. In stroke patients, total cholesterol (p < 0.05), LDL cholesterol (p < 0.05), and apolipoprotein B (p < 0.05) were significantly higher in female patients compared to male patients. This study confirms that low HDL cholesterol may be a risk factor for stroke. Additionally, ally, we show that lipid abnormalities may appear to be more significant in women.

Ischemic stroke in young adults. II. Analysis of risk factors in the etiological subgroups

A prospective study on 386 consecutive patients affected of ischemic stroke (IS) has been analysed in relation to etiologies, comparing them with a control group of 100 people. The atherotrombotic etiology subgroups are associated with family history of stroke, risk factors, atheromatosis, occlusive peripheral arteriopathy, previous of stroke, high levels of hematocrit and hemoglobin, impaired lipid fractions and high levels of uric acid. The cardiac embolism etiology subgroups are associated with the presence of personal history of stroke, just as the mitral valva prolapse (MVP) patients group. The migraine group is significantly related with the intake of oral contraceptives.

Serum lipoprotein pattern variations in dementia and ischemic stroke

Blood levels of triglycerides, total cholesterol, isolated lipoprotein fractions (VLDL-LDL- and HDL-cholesterol) and apoproteins (Apo-A1 and Apo-B) were examined in multi-infarct dementia, senile dementia of the Alzheimer type, ischemic stroke associated with carotid atherosclerosis and in control subjects. Forty patients divided into 10 consecutive patients for each group were studied. Alzheimer patients showed mean total cholesterol and Apo-B values significantly higher than control subjects. Apo-B was significantly higher in stroke patients than in controls. The mean lowest HDL-cholesterol (HDL-c) value was observed in stroke patients. No significant differences in mean HDL-c levels were found between patients with multi-infarct and Alzheimer dementia.

Atherosclerosis: current concepts on pathogenesis and interventional therapies

Atherosclerosis, the primary pathological condition accounting for most stroke syndromes, has been the intense focus of epidemiological, basic, and clinical investigations. Since these studies have direct bearing on the prevention of atherothrombotic brain infarction, this review emphasizes those advances in treatment resulting from their findings. The two most prominent theories on the pathogenesis of atherosclerosis relate to aberrations in lipoprotein metabolism and to enhanced proliferation of smooth muscle cells; likely, the theories are complementary. As a practical guideline for preventive therapy, the importance of using the total cholesterol level is stressed, although finer distinctions must rely on the low-density and high-density lipoprotein concentrations and their normalization. Since prevention of stroke may ultimately be its most effective therapy, consideration of cholesterol level, akin to strategies for preventing coronary heart disease, and efforts to avert platelet adhesion or aggregation and coagulation are warranted.

The effect of atherosclerosis on endothelium-dependent relaxation in the aorta and intracranial arteries of rabbits

The effect of hypercholesterolemia on vascular responsiveness was studied in isolated rabbit arteries. The arteries of animals maintained on a cholesterol-rich (1%) diet for 6 months had more pronounced intimal lesion than those receiving the diet for 3 months. The aortas were more severely damaged than the carotid or basilar arteries. Segments of the arteries were mounted in organ chambers for isometric tension recording or for measurement of the endothelium-derived relaxing factor. Endothelium-independent relaxation induced by glyceryl trinitrate was not affected even in the most severely damaged arteries; endothelium-dependent relaxation in response to acetylcholine (ACh) and A23187 was progressively inhibited as the degree of fatty streak formation increased. In the carotid arteries, mean (+/- standard deviation) relaxation induced by 10(-5) M of ACh (expressed as a percentage of the maximum relaxation induced by 10(-4) M of papaverine) decreased from 87.33% +/- 6.30% in control tissues to 60.90% +/- 4.64% in vessels from animals subjected to 6 months of hypercholesterolemia (p less than 0.01); in the aortas, mean relaxation due to 10(-5) M of ACh was 85.08% +/- 8.03% in control tissues and 41.35% +/- 13.68% in hypercholesterolemic tissues (p less than 0.01). In the carotid arteries, mean relaxation induced by 10(-7) M of A23187 decreased from 95.81% +/- 3.58% in control tissues to 55.95% +/- 2.81% in hypercholesterolemic tissues (p less than 0.01); in the aortas, relaxation in response to 10(-7) M of A23187 was 73.73% +/- 4.35% in control tissues and 29.35% +/- 6.77% in hypercholesterolemic tissues (p less than 0.01). Intimal lesions were not produced in the basilar arteries even in rabbits with 12 months of hypercholesterolemia, and endothelium-dependent relaxation was preserved.

Individual variation in susceptibility to extracranial carotid atherosclerosis

Risk factors for coronary disease were assessed and noninvasive methods were used to quantitate the extent of extracranial carotid atherosclerosis in 382 patients free of cerebrovascular symptoms. The ages of the participants ranged from 27 to 80 years. There were 183 men and 199 women, 30 black and 352 white persons. All patients had heart disease symptoms and were hospitalized for coronary angiography. Correlation of risk factors with extent of extracranial carotid atherosclerosis in this series of patients undergoing coronary angiography uncovered individual variability in relationships between risk factors and carotid atherosclerosis that depended on coronary status. Risk factors for carotid atherosclerosis in patients with and without coronary disease differed. Age and hypertension were independently related to carotid atherosclerosis in patients with, as well as those without, coronary disease. However, other risk factors were related to carotid atherosclerosis in only one group or the other. Risk factors correlated strongly with carotid atherosclerosis in patients with coronary disease (r2 = 0.41) but poorly in those with no coronary disease (r2 = 0.21). Certain risk factors (age, pack years of smoking, left ventricular hypertrophy) related differently to the extent of carotid atherosclerosis in patients with, than in those without, coronary disease. Clarification of the role of coronary status in the carotid atherosclerosis response to risk factors may partly explain the results of certain population-based studies that have related race, gender, and other risk factors to carotid atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Lp(a) lipoprotein in cerebrovascular disease and dementia

Lp(a) lipoprotein has been considered an independent risk factor in the development of coronary heart disease (CHD). We examined the role of Lp(a) in patients with cerebrovascular disease (CVD) and those with dementia. The Lp(a) concentration in patients with CHD, those with cerebral infarction due to a large artery occlusion and those with vascular dementia (VD) was significantly higher than that of age-matched control subjects. However, the Lp(a) concentration was not high in cerebral infarction due to a small artery occlusion, intracerebral hemorrhage and dementia of the Alzheimer type (DAT). The present results suggest that Lp(a) should cause VD as well as CVD, and that Lp(a) should be one of the indicators that distinguish VD from DAT.

Lipoprotein abnormalities in survivors of cerebral infarction with a special reference to apolipoproteins and triglyceride-rich lipoproteins

Serum lipid and apolipoprotein concentrations were measured in 37 male survivors of cerebral infarction (CI) and in 30 healthy controls. Both groups had similar total cholesterol levels, but the HDL-cholesterol level was significantly lower and the serum triglyceride level was significantly higher in the CI patients than in the controls. The ApoB level was significantly higher in the CI patients but there was no significant difference between the 2 groups in the levels of the other apolipoproteins (ApoA-I, A-II, C-II, C-III, and E). The HDL-cholesterol/ApoA-I ratio was significantly lower in the CI patients. Both the VLDL-triglyceride and VLDL-cholesterol levels were higher in the CI patients but the VLDL-cholesterol especially its cholesterol ester level was conspicuously high. A population of VLDL particles that bound to heparin on heparin-Sepharose columns was increased in the CI patients. We suggest that cholesterol ester is excessively transferred from HDL to VLDL during the disturbed catabolism of VLDL in CI patients.

Hypercholesterolemia and the baboon cerebral circulation

We investigated cerebrovascular vasodilator responses to increased arterial CO2 and the cerebrovascular response to infused 5-hydroxytryptamine (5-HT) in normal and hypercholesterolemic baboons. After 6-8 weeks of feeding an atherogenic diet the plasma cholesterol levels were increased without change in the triglycerides. The hypercholesterolemic animals showed a higher basal systemic arterial blood pressure than the normal controls without significant decrease in cerebrovascular prostacyclin production, altered basal cerebral blood flow or altered cerebrovascular response to infused 5-HT. However, the vasodilator response to hypercapnia was significantly decreased from the control value of 2.78 ml/min per mmHg increase in PCO2, to 1.62 ml/min per mmHg. Thus functional impairment of cerebral hemodynamics occurred before atherosclerotic alteration in the cerebral vessels could have been present.

Italian multicenter study of reversible cerebral ischemic attacks. Part 5. Risk factors and cerebral atherosclerosis

As part of a prospective study, the influence of several premorbid and environmental factors on the presence, extent and severity of cerebral vessel atherosclerosis was studied in 462 patients with clinical diagnosis of RIA who underwent cerebral angiography. The extent and severity of atherosclerosis of the cerebral vessels was quantified using extracranial and intracranial cerebrovascular scores (ECS, ICS) based on the number and severity of the lesions in 11 extracranial and 21 intracranial arterial segments. Results of univariate and multivariate analyses indicate that the presence of atherosclerotic changes of cerebral vessels, as shown by angiography, was strongly related with age in both sexes. The lesions were more frequent in males, in particular under age 55. Elevated cholesterol was associated with a higher incidence of atherosclerotic lesions. Smoking was associated with a higher incidence of extracranial lesions. Age, smoking and history of hypertension were the best predictors of the extent and severity of cerebral vessel atherosclerosis.

A dominant role of lipoprotein(a) in the investigation and evaluation of parameters indicating the development of cervical atherosclerosis

The correlation of serum levels of lipoprotein (a) [Lp(a)] with the progression of cervical atherosclerosis was investigated and compared with the common risk factors. The carotid arteries of 100 subjects were examined by direct bi-directional Doppler ultrasonic imaging. A highly significant elevation of the mean values of Lp(a) in group 1 (P1, with smooth surface plaques) and in group 2 (P2, with exulcerations) vs the control (P0, with no detectable plaques) was established. Low density lipoprotein cholesterol (LDL-C) was highly significantly elevated in P1, but only significantly higher in P2. Total cholesterol (TC) was significantly higher in P1 and highly significantly elevated in P2. Diabetes was also found to be significantly associated with atherosclerotic plaque formation, in contrast to triglycerides (TG), high density lipoprotein cholesterol (HDL-C) and its ratio to TC, hypertension and cigarette smoking. In a smaller collective of 30 patients--40-60 years old--being equally divided into 3 groups (p0, p1, p2), Lp(a) showed again to be the most significant parameter. LDL-C, TC and its ratio to HDL-C were highly significantly altered in subgroup p1 and significantly altered in subgroup p2. In this selection there were 12 patients with and 18 without cerebral infarction (CI). The difference of the medians of Lp(a) serum levels between these 2 groups was also found to be highly significant.

Selective determination of cholesterol in high density lipoprotein subfractions (HDL2 and HDL3) in patients with cerebral and peripheral arteriosclerosis

Cholesterol levels in high density lipoprotein subfractions (HDL2 and HDL3) were evaluated in 69 patients (55 males, average age +/- SD 58.3 +/- 8.8, and 14 females, average age +/- SD 63.1 +/- 10.3) with extra-coronary arteriosclerosis (lower limbs, supraaortic trunks and both sites), and in 79 healthy age-matched control subjects. HDL cholesterol was significantly reduced in male and female patients. The HDL cholesterol decrease was due to a fall in both HDL2 and HDL3 cholesterols; nonetheless, an analysis of the HDL2-cholesterol/HDL3-cholesterol ratio disclosed that HDL2 cholesterol was the most reduced. Slightly higher plasma cholesterol and triglyceride levels were found in the patients as well as a higher plasma cholesterol/HDL-cholesterol ratio. On the contrary, the HDL2-cholesterol/HDL3-cholesterol ratio was significantly reduced in the patients. These preliminary findings suggest that, as in ischemic heart disease, the HDL cholesterol reduction in cerebral and peripheral arteriosclerosis is also mainly due to a reduction in the HDL2 subfraction. These results also lend further support to the proposal that determination of the HDL subfractions is useful for a better assessment of the risk profile for arteriosclerosis.

The role of plasma lipids in carotid bifurcation atherosclerosis

The severity of coronary artery atherosclerosis correlates with increased plasma concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides and with decreased plasma concentrations of high-density lipoprotein cholesterol (HDL-C). The role of plasma lipoproteins in the pathogenesis of cerebral atherosclerosis, however, is less clear. Several investigators report that lipoprotein abnormalities correlate inversely with the incidence of cerebral infarction. We analyzed risk factors for carotid bifurcation atherosclerosis in 121 consecutive patients who underwent cerebral angiography. This analysis revealed a significant positive correlation between the plasma TC/HDL-C ratio and the extent of carotid bifurcation atherosclerosis (p = 0.01). The extent of atherosclerosis correlated inversely with plasma concentrations of HDL-C (p = 0.02). Triglyceride concentration correlated positively with the extent of atherosclerosis with marginal significance (p = 0.07). LDL-C and TC concentrations did not correlate with bifurcation atherosclerosis (p greater than 0.1). Only 4% of the variation in the extent of bifurcation atherosclerosis was explicable on the basis of plasma lipoprotein concentrations.

Triglycerides as a risk factor in extracranial atherosclerotic cerebrovascular disease

A retrospective study was carried out on a group of 138 patients undergoing carotid endarterectomy for extracranial vascular disease. Risk factors of cerebrovascular disease and routine laboratory evaluations were assessed. Of the laboratory evaluations of blood lipids, only mean triglycerides were found to be significantly different from laboratory normals. Stroke as a clinical event has been suggested not to be correlated with blood lipids in a number of large studies, but the present investigation supports the notion that extracranial vascular disease may be associated with blood lipid concentrations. Previous studies of stroke and lipids have not separated out the anatomical site responsible for the cerebral infarction, and thus probably have underestimated the effect of lipids as a risk factor in cervical extracranial atherosclerosis and brain infarction.