Opposite pattern of MDR1 and caveolin-1 gene expression in human atherosclerotic lesions and proliferating human smooth muscle cells.Cholesterol esterification and smooth muscle cell (SMC) proliferation are the crucial events in the development of atherosclerotic lesions. The objective of this study was to analyse cholesterol esterification and the expression of MDR1 (multidrug resistance), ACAT (acyl-CoA:cholesterol acyltransferase) and caveolin-1 genes in atherosclerotic and healthy vascular walls, in SMCs obtained from atherosclerotic lesions and saphenous veins. Results demonstrated higher levels of cholesterol esters, ACAT and MDR1 mRNAs and lower levels of caveolin-1 mRNA in atherosclerotic segments compared to adjacent serial sections of the same artery and the corresponding non-atherosclerotic arteries from cadaveric donors. SMCs isolated from atherosclerotic plaques manifested an increased capacity to esterify cholesterol and to grow at a faster rate than SMCs isolated from saphenous veins. In addition, when SMCs from atherosclerotic plaques were cultured in the presence of progesterone, a potent inhibitor of cholesterol esterification, significant growth suppression was observed. An increase in ACAT and MDR1 expression and a concomitant decrease in caveolin-1 expression were also observed in SMCs isolated from atherosclerotic arteries as early as 12 h after serum stimulation. An opposite pattern was found when SMCs were treated with progesterone. These findings support the idea that cholesterol esterification plays a role both in early atherogenesis and in clinical progression of advanced lesions and raise the possibility that the cholesterol ester pathway might directly modulate the proliferation of SMCs.

HMG-CoA reductase and ACAT inhibitors act synergistically to lower plasma cholesterol and limit atherosclerotic lesion development in the cholesterol-fed rabbit.Given the beneficial effects of HMG-CoA reductase and ACAT inhibitors on hypercholesterolemia and atherosclerosis, we hypothesized that coadministration would improve the hypolipidemic response and not only limit lesion development but also alter the cellular composition of atherosclerotic lesions so as to induce a stable atherosclerotic lesion morphology. Plasma total cholesterol exposure was reduced 29 and 39% with Atorvastatin ( Lipitor ) (2.5 mg/kg) and CI-976 (5 mg/kg), respectively, and 60% upon coadministration due primarily to reductions in VLDL-cholesterol. Modest changes in liver cholesterol ester (CE) content were observed with Atorvastatin ( Lipitor ) or CI-976; however, a striking 48% reduction was noted upon coadministration. Liver HMG-CoA reductase mRNA levels were reduced 73% by cholesterol feeding and drug treatment did not prevent the reduction; however, Atorvastatin ( Lipitor ) alone and upon coadministration blunted the decrease in LDL receptor mRNA levels. The CE content of the iliac-femoral was unaffected by Atorvastatin ( Lipitor ) but was reduced 35% by CI-976 and 53% upon coadministration. Thoracic aortic CE content was reduced 38% by Atorvastatin ( Lipitor ), 48% by CI-976 and 80% upon coadministration. Iliac-femoral lesion and macrophage area were reduced 48 and 67% by Atorvastatin ( Lipitor ), respectively, and 68 and 81% by CI-976 but upon coadministration only an 85% reduction in macrophage area was noted. Aortic arch cross-sectional lesion and macrophage area were unaffected by Atorvastatin ( Lipitor ), decreased 72-80% by CI-976 and reduced 87-92% upon coadministration. We conclude that inhibition of HMG-CoA reductase and ACAT acts synergistically to lower plasma total and lipoprotein cholesterol levels and to limit the development of atherosclerotic lesions in the cholesterol-fed rabbit by presumably regulating cholesterol trafficking pathways within liver and vascular cells.

Heritability of plasma noncholesterol sterols and relationship to DNA sequence polymorphism in ABCG5 and ABCG8.The plasma concentrations of cholesterol precursor sterols and plant sterols vary over a 5- to 10-fold range among normolipidemic individuals, and provide indices of the relative rates of cholesterol synthesis and fractional absorption. In the present study, we examined the relative contributions of genetic and environmental factors to variation in the plasma concentrations and sterol-cholesterol ratios of five noncholesterol sterols, including the 5alpha-saturated derivative of cholesterol (cholestanol), two precursors in the cholesterol biosynthesis pathway (desmosterol and lathosterol), and two phytosterols (campesterol and sitosterol). Plasma sterol concentrations were highly stable in 30 individuals measured over a 48 week period. Regression of offspring sterol levels on the parental values indicated that plasma levels of all five noncholesterol sterols were highly heritable. Analysis of monozygotic and dizygotic twin pairs also indicated strong heritability of all five sterols. Two common sequence variations (D19H and T400K) in ABCG8, an ABC half-transporter defective in sitosterolemia, were associated with lower concentrations of plant sterols in parents, and in their offspring.Taken together, these findings indicate that variation in the plasma concentrations of noncholesterol sterols is highly heritable, and that polymorphism in ABCG8 contributes to genetic variation in the plasma concentrations of plant sterols.

High-density lipoprotein particles are large in patients with variant angina.OBJECTIVE: Dyslipidemia in patients with coronary vasospasm may be characterized by low level of high-density lipoprotein (HDL)-cholesterol as well as apolipoprotein (apo) A-I but not high level of low-density lipoprotein-cholesterol. This study sought to examine the HDL particle size in patients with variant angina. METHODS: The HDL particle size was examined by analyzing serum lipid levels in 38 patients with variant angina to compare with those of 40 control subjects and 30 normocholesterolemic patients with stable effort angina. Also, actual HDL size distribution was assessed by electrophoresis. RESULTS: The HDL-cholesterol, apoA-I and apoA-II levels were all lower (P < 0.01 for each) in patients with variant angina and patients with stable effort angina as compared with control subjects. The apoA-II level was lower (P < 0.01) in patients with variant angina than in patients with stable effort angina. The apoA-I/apoA-II ratio was lower (P < 0.01) in patients with stable effort angina, but not in patients with variant angina as compared with control subjects. In contrast, the HDL-cholesterol/apoA-I ratio was higher in patients with variant angina than in control subjects (P < 0.01) and also patients with stable effort angina (P < 0.01). The slope of the regression line, comparing HDL-cholesterol and apoA-I levels, was greater in patients with variant angina than in control subjects (P < 0.05) and patients with stable effort angina (P < 0.05), suggesting an increase in larger HDL particles. Native polyacrylamide gel electrophoresis revealed that HDL particles in patients with variant angina were skewed towards larger sizes compared with control subjects (P < 0.01) and patients with stable effort angina (P < 0.01). The abnormal serum lipid values were normalized in the patients with variant angina after the medical treatment and inactivation of the coronary spasm. CONCLUSION: High HDL-cholesterol/apoA-I levels associated with low serum HDL-cholesterol and apoA-I levels were characteristic in patients with variant angina, in whom HDL particles were large, cholesterol-rich and possibly malfunctioning.

Reduced cellular cholesterol content in peroxisome-deficient fibroblasts is associated with impaired uptake of the patient's low density lipoprotein and with reduced cholesterol synthesis.Mammalian cells acquire cellular cholesterol by de novo synthesis as well as by uptake of low density lipoprotein (LDL). Peroxisomes contain enzymes involved in the synthesis of cholesterol, and peroxisome-deficient (PD) patients have been shown to have hypocholesterolemia and abnormal LDL. We therefore decided to study whether cholesterol synthesis and cellular uptake of LDL are impaired in cultured PD fibroblasts. The present study demonstrates a significantly lower cellular cholesterol mass in fibroblasts from three PD patients, as compared to control cells (41-59% of controls). The rate of cholesterol synthesis was also reduced in all three PD cell lines, being 16-20% of the control values. LDL binding and degradation by fibroblasts were 3- to 5-fold higher in the PD cells as compared to control cells. Similarly, enrichment of normal fibroblasts with tetracosanoic acid (C-24:0), a situation that could mimic the in vivo accumulation of very long chain fatty acid (VLCFA) in PD cells, caused LDL binding and degradation to be 4-fold higher than in non-treated cells. On the other hand, the uptake of LDL derived from PD patients by normal fibroblasts was markedly reduced (by up to 67%) in comparison to the cellular uptake of normal LDL. Similar results were obtained in PD cells. This study demonstrates a lower cellular cholesterol content and reduced cholesterol synthesis rate in PD cell lines. In addition, we demonstrate that regulation of the uptake of normal LDL by cellular LDL receptors is operative in PD cells, whereas LDL derived from PD patients is not recognized normally by the LDL receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of dietary safflower phospholipid and soybean phospholipid on plasma and liver lipids in rats fed a hypercholesterolemic diet.The effect of dietary safflower phospholipid (Saf-PL) and soybean phospholipid (Soy-PL) on plasma, liver, and fecal lipids in rats fed a hypercholesterolemic diet was compared with that of triglyceride mixture (controls). Triglyceride mixture (SP-Oil) of safflower oil and palm oil (8:2) contained almost comparable amounts of linoleic acid to safflower phospholipid or soybean phospholipid. Concentration of total cholesterol in plasma of rats fed the Saf-PL and Soy-PL diets were significantly decreased in comparison with that of the SP-Oil diet. Similarly, both Saf-PL and Soy-PL induced a reduction in the concentration of liver cholesterol compared with SP-Oil; Saf-PL indicated the lowest value. Saf-PL only significantly increased the level of high density lipoprotein (HDL) cholesterol. The level of chylomicron plus very low density lipoprotein (VLDL) cholesterol was lower in rats fed the Saf-PL and Soy-PL diets than that of the SP-Oil diet. The activity of plasma lecithin-cholesterol acyltransferase (LCAT) was increased in rats fed Saf-PL and Soy-PL. Saf-PL and Soy-PL caused an enhanced excretion of fecal neutral steroids, but not acidic steroids compared with SP-Oil. These results suggest that, in addition to soybean phospholipid, safflower phospholipid suppresses the elevation of plasma and liver cholesterol and that this effect may be brought about by inhibiting the absorption of cholesterol in the small intestine.

High-density lipoprotein cholesterol strongly discriminates between healthy free-living and disabled octo-nonagenarians: a cross sectional study. Associazione Medica Sabin.Aging is frequently associated with a deterioration in health and functional status, which often induces important modifications in several biological parameters, including plasma lipids; as a consequence, the real "meaning" of lipoprotein parameters in old individuals is complex. A cross sectional study was carried out in order to investigate the lipoprotein profile in very old individuals with or without disability, and evaluate the possible influence of other biological variables on plasma lipids. One hundred selected healthy free-living (FL) and 62 disabled (DIS) subjects aged over 80 were enrolled; 91 healthy adults matched for origin were included as controls. Lipoprotein profile [total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, apoprotein A-I and B], anthropometric parameters, and ADL were measured. The FL octo-nonagenarians featured higher HDL-cholesterol levels than adult controls. DIS octo-nonagenarians showed lower total and HDL-C levels than FL. Discriminant analysis indicated that HDL-cholesterol and apoprotein A-I, but not total cholesterol, strongly discriminated between FL and DIS octo-nonagenarians. Multivariate analysis demonstrated that the waist/hip ratio, an index of visceral adiposity, was negatively associated with HDL-C levels in FL, but not in DIS elderly. We conclude that: 1) in very old individuals, the absence or presence of disability is strongly associated with high or low HDL-cholesterol values, respectively; 2) HDL-C and apo A-I are the parameters which better discriminate between FL and DIS octo-nonagenarians; and 3) the differences in HDL-C levels between FL and DIS are not due to modifications in anthropometric parameters. Prospective studies are needed to better understand the relationship between high-density lipoprotein levels, disability and aging.

Variation in the low density lipoprotein receptor gene is associated with differences in plasma low density lipoprotein cholesterol levels in young and old normal individuals from Italy.We have used four restriction fragment length polymorphisms (RFLPs) of the human low density lipoprotein receptor (LDL-R) gene, detected by the restriction enzymes Ava II, Pvu II, and ApaLI (5' and 3'), to study the effect of variation at this gene locus in determining plasma cholesterol and LDL cholesterol levels. Two hundred eighty-nine normolipidemic individuals were studied from the Liguria region of Italy. The Pvu II RFLP was significantly associated with differences in plasma total and LDL cholesterol levels, explaining 9.6% of the sample variance in LDL cholesterol levels. The other RFLPs, which are in strong linkage disequilibrium with the Pvu II RFLP, were associated with smaller effects on LDL cholesterol. The Pvu II allele, distinguished by the presence of the variable cutting site (P2 allele), was associated with lower levels of total and LDL cholesterol, and the frequency of the P2 allele was significantly reduced in individuals with LDL cholesterol levels higher than the 75th percentile. The frequency of the P2 allele was significantly higher in the group of individuals over 65 years old, and in this group the P2 allele was also associated with a similar reduction in LDL cholesterol levels. Because of linkage disequilibrium, only four RFLP haplotypes were common in this sample. Of these, only the haplotype P2A2VI (relative frequency, 0.269) was associated with a reduction in LDL cholesterol (average excess, -11.5 mg/dl).(ABSTRACT TRUNCATED AT 250 WORDS)

Elderly people with hypothalamic-pituitary disease and untreated GH deficiency: clinical outcome, body composition, lipid profiles and quality of life after 2 years compared to controls.OBJECTIVE: Elderly patients with GH deficiency (GHD) have significant impairments in multiple aspects of quality of life (QOL) but similar lipid profiles compared to age-matched control subjects. There are, however, no data on changes in these parameters with time. This study assessed the impact of untreated GHD over a period of 2 years in a group of elderly patients with hypothalamic-pituitary disease in relation to new illnesses and differences in body composition, circulating lipid profile levels and QOL. Control subjects were also followed for 2 years. SUBJECTS: Twenty-seven elderly patients (> 65 years) with hypothalamic-pituitary disorders and GHD (mean peak stimulated GH response 1.6 mIU/l, range 0.6--5.0) were studied initially. Two years later 21 (13 males) agreed to attend for reassessment. Mean age was then 72.7 +/- 5.04 years (range 67--85). Eighteen patients had pituitary tumours, three had craniopharyngiomas. Twenty-seven control subjects were studied at baseline and 17 (7 males) agreed to attend for reassessment. Mean age was then 75.9 +/- 6.97 years (range 67--88). METHODS: Weight, body mass index (BMI), total fat mass (FM) (bioelectrical impedance), serum IGF-1 and fasting lipid profile (total cholesterol, triglyceride, HDL cholesterol, LDL cholesterol) were measured. QOL was assessed in both groups using five interviewer-administered self-rating questionnaires: the Nottingham Health Profile, Short Form-36, Hospital Anxiety and Depression Scale, Mental Fatigue Questionnaire and Life Fulfillment Scale. The GHD group also completed the Disease Impact Scale. RESULTS: Two of the 27 patients with GHD died during the 2-year follow-up (myocardial infarction and probable cerebrovascular accident). Four controls could not be traced but there were no deaths in the other 23. In the 21 GHD patients after 2 years, mean serum IGF-1 and BMI were unchanged (12.6 +/- 5.8 vs. 13.3 +/- 5.1 nmol/l, P = 0.5 and 28.3 +/- 4.3 vs. 29.1 +/- 4.2, P = 0.5, respectively) at the 2-year follow-up and there were no significant changes in the lipid profiles. However, there was a significant reduction in fat mass (31.7 +/- 11.2 vs. 28.5 +/- 10.9%, P = 0.04). In the 17 control subjects after 2 years, serum IGF-1 levels (17.2 +/- 4.0 vs. 15.7 +/- 5.6 nmol/l, P = 0.4), BMI and fat mass were unchanged. However, there was a significant fall in total cholesterol levels over the 2-year follow-up (6.3 +/- 0.9 vs. 5.7 +/- 0.9 mmol/l, P < 0.0001), although LDL cholesterol, triglycerides and HDL cholesterol were unchanged. Analysing the QOL data, the GHD patients had less energy (P < 0.05), more depression (P < 0.05), more pain (P < 0.05) and lower life fulfillment scores (P < 0.01) after 2 years. However, the control subjects also had less energy (P < 0.05), less vitality (P < 0.05) and lower self-esteem (P < 0.05), more depression (P < 0.05), worse mental health (P < 0.05), life fulfillment personal (P < 0.01), life fulfillment material (P < 0.02), physical functioning and role physical functioning (P < 0.05) after 2 years. Comparing the patients and controls at baseline, there were significant differences in IGF-1, BMI, FM, LDL cholesterol, personal life fulfillment, mental fatigue, general health and mental health. However, after 2 years, only BMI and depression scores were significantly different. CONCLUSION: These patients with untreated GHD did not have deterioration of body composition or lipid profiles when reassessed after a period of 2 years. In fact, fat mass fell. The control subjects did have a significant decrease in total cholesterol but no change in other lipids or body composition. Some quality of life domains did deteriorate in the patients with GHD. However, the control subjects also had worse quality of life scores after 2 years which were then little different from the GHD patients. These results raise doubts about the benefits of GH replacement in elderly people with GHD.

Serum total and fractionated cholesterol distribution and prevalence of hypercholesterolemia in urban and rural communities in Saudi Arabia.Hypercholesterolemia is recognized as an independent risk factor for cardiovascular diseases. Data on serum total cholesterol concentration distribution from Saudi Arabia are scarce. We have conducted a cross sectional, national, epidemiological randomized household survey to study the distribution of serum total cholesterol (TCC), low density lipoprotein (LDL) and high density lipoprotein (HDL) concentrations, total cholesterol/high density lipoprotein (CH/HDL) ratio and prevalence of hypercholesterolemia (HC) among subjects aged 25-64 years in urban and rural communities of Saudi Arabia. The sample was 2924 Saudi subjects which was adjusted in accordance with the national population distribution with respect to age, gender, regional and residency, urban vs. rural population distribution. Height and weight were measured with calculation of body mass index (BMI). Blood samples were drawn and assayed for total cholesterol, triglyceride, high density lipoprotein concentration and calculation of low density lipoprotein concentration. The mean of BMI was significantly higher among female subjects and significantly higher among urban subjects. The prevalence of obesity was higher among female subjects and higher, however, not significant, among urban subjects. Mean serum TCC was higher among rural subjects. Mean serum LDL concentration was higher among female subjects and higher among urban subjects. Mean serum HDL concentration was lower among female subjects and lower among urban subjects. Mean CH/HDL ratio was higher among female subjects and higher for urban subjects. Female and male subjects living in rural communities had the highest and lowest percentages of subjects with high concentrations of LDL, respectively. Female and male subjects, living in rural communities had the highest and lowest percentages of subjects with low concentration of HDL, respectively. Male and female subjects living in rural communities had the highest and lowest percentages of studied subjects with a high CH/HDL ratio. The age-adjusted prevalence of HC (5.2-6.2 mmol/l) was equal among all the four groups. The prevalence of HC (> 6.2 mmol/l) was significantly higher among rural male subjects, compared with their counterparts in urban areas, while it was equal among female subjects. There was an increase in age-specific prevalence of HC (> 6.2 mmol/l) with maximum prevalence achieved at an age of 56-64 years for urban subjects, while it was achieved a decade earlier for rural subjects. The prevalence of HC, in general, was higher among rural male and urban female subjects. In conclusion, among Saudi subjects, means of total, fractionated cholesterol concentration, CH/HDL ratio > 6.5 and prevalence of obesity were higher among urban female subjects. The prevalence of HC, whether > 5.2 or > 6.2 mmol/l was higher among rural subjects. The difference, however, reached significance among female subjects. There is a need to study the possible underlying factors for the increase in prevalence of HC among rural subjects with special emphasis on the food components and nutritional habits of rural communities in Saudi Arabia. There is also a need to establish a control program throughout the country with the aim of halting the upward trend in incidence of CVD through control of modifiable risk factor such as obesity and hypercholesterolemia.