Hyperlipidemias: Castro Cabezas M

Alipour A, Elte JW, van Zaanen HC, Rietveld AP, Castro Cabezas M. · Department of Internal Medicine, Sint Franciscus Gasthuis, Rotterdam, The Netherlands. · Atheroscler Suppl. · Pubmed #18595782 No free full text.

Abstract: Postprandial hyperlipidemia is considered to be a substantial risk factor for atherosclerosis. Interestingly, this concept has never been supported by randomized clinical trials. The difficulty lies in the fact that most interventions aimed to reduce postprandial lipemia, will also affect LDL-C levels. The atherogenic mechanisms of postprandial lipids and lipoproteins can be divided into direct lipoprotein-mediated and indirect effects; the latter, in part, by inducing an inflammatory state. Elevations in postprandial triglycerides (TG) have been related to the increased expression of postprandial leukocyte activation markers, up-regulation of pro-inflammatory genes in endothelial cells and involvement of the complement system. This set of events is part of the postprandial inflammatory response, which is one of the recently identified potential pro-atherogenic mechanisms of postprandial lipemia. Especially, complement component 3 levels show a close correlation with postprandial lipemia and are also important determinants of the metabolic syndrome. In clinical practice, fasting TG are frequently used as reflections of postprandial lipemia due to the close correlation between the two. The use of serial capillary measurements in an out-of-hospital situation is an alternative for oral fat loading tests. Daylong TG profiles reflect postprandial lipemia and are increased in conditions like the metabolic syndrome, type 2 diabetes and atherosclerosis. Studies are needed to elucidate the role of postprandial inflammation in atherogenesis and to find new methods in order to reduce selectively the postprandial inflammatory response. Future studies are needed to find new methods in order to reduce selectively the postprandial inflammatory response.

Castro Cabezas M. · Department of Vascular Medicine F02.126, University Medical Center Utrecht, P.O Box 85500, 3508 GA Utrecht, The Netherlands. · Biochem Soc Trans. · Pubmed #14505486 No free full text.

Abstract: FCHL (familial combined hyperlipidaemia) is the most frequent inherited disorder of lipid metabolism leading to premature atherosclerosis. The usual phenotype in FCHL is elevated fasting plasma triacylglycerols, low HDL (high-density lipoprotein)-cholesterol concentrations and elevated plasma apolipoprotein B concentrations. The metabolic basis for this phenotype is hepatic overproduction of VLDL (very-low-density lipoprotein), which is only partly linked to the insulin resistance associated with FCHL. At this stage the molecular basis for this VLDL overproduction is not known, but emerging evidence points to a disturbed trapping of peripheral fatty acids, resulting in enhanced hepatic flux of NEFA [non-esterified ('free') fatty acids]. Postprandial hyperlipidaemia with accumulation of lipoprotein remnants and NEFA have been implicated in the development of atherosclerosis in this disorder. It has been proposed that, by VLDL overproduction, fasting hypertriglyceridaemia may lead to 'overflow' of the catabolic cascade for triacylglycerol-rich particles, thereby explaining the delayed catabolism of remnants in FCHL. Delayed clearance of remnants of VLDL and chylomicrons leads to enhanced interaction of these highly atherogenic particles with the endothelium, and enhanced trans-endothelial migration of the particles, resulting in a chronic inflammatory response that is the initiation of the atherosclerotic lesion. In this process, activated leucocytes (either directly by the remnants or indirectly by released NEFA) play an important role by adherence to the endothelium and migration into the subendothelial space, where the uptake of atherogenic remnants results in a vicious cycle of activation of endothelium, leucocytes and production of cytokines.

Sniderman AD, Ribalta J, Castro Cabezas M. · Mike Rosenbloom Laboratory for Cardiovascular Research, Room H7.22, Royal Victoria Hospital, 687 Pine Avenue West, Montreal, Quebec H3A 1A1, Canada. · Nutr Metab Cardiovasc Dis. · Pubmed #11831111 No free full text.

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Castro Cabezas M, Halkes CJ, Erkelens DW. · Departments of Internal Medicine and Endocrinology, University Hospital F02.126, P.O. Box 85500, 3508 GA Utrecht, The Netherlands. · Nutr Metab Cardiovasc Dis. · Pubmed #11434190 No free full text.

Abstract: The socio-economic impact of obesity, one of the most prevalent medical disorders in Western society, is mainly due to its association with a higher risk of coronary heart disease. It is likely that atherosclerosis develops against a background of obesity as a result of the insulin resistance that is invariably present in overweight and obese subjects. Fasting plasma lipids may be normal in obese subjects, but they are usually affected by postprandial hyperlipidemia, which is probably due to competition between chylomicrons and VLDL for the same metabolic pathways. The basis for the impaired clearance of atherogenic chylomicron remnants is the fact that obesity causes hepatic apo B-VLDL overproduction, and thus leads to competition with chylomicrons and their remnants at the lipolytic pathway (lipoprotein lipase and hepatic lipase) and receptor level (LDL-receptor and remnant-receptor). The overproduction of VLDL is probably caused by an enhanced hepatic flux of free fatty acids in both the postprandial (from the lipolysis of triglyceride rich particles) and postabsorptive states (from adipocytes). Weight reduction by means of life-style changes, supported by medical interventions with inhibitors of intestinal fat absorption (e.g. Orlistat) or appetite suppressants (e.g. Sibutramine), is essential in order to decrease the risk of atherosclerosis. Furthermore, improvement of risk factors can be achieved by means of fibrate treatment to modulate fasting and postprandial triglyceride levels. Treatment with cholesterol synthesis inhibitors ("statins") may reduce hepatic VLDL production and increase the clearance of atherogenic remnants by upregulating LDL-receptors, thus leading to improved fasting lipid levels and enhanced clearance of chylomicron remnants. Finally, the use of thiazolidinedione derivatives to improve insulin sensitivity may be one of the options for reducing the risk of atherosclerosis in obese subjects.

Castro Cabezas M, Verseyden C, Meijssen S, Jansen H, Erkelens DW. · Department of Internal Medicine, St. Franciscus Gasthuis Rotterdam, 3004 BA Rotterdam, The Netherlands. · J Clin Endocrinol Metab. · Pubmed #15579746 links to  free full text

Abstract: Familial combined hyperlipidemia (FCHL) patients have an impaired catabolism of postprandial triglyceride (TG)-rich lipoproteins (TRLs). We investigated whether atorvastatin corrects the delayed clearance of large TRLs in FCHL by evaluating the acute clearance of Intralipid (10%) and TRLs after oral fat-loading tests. Sixteen matched controls were included. Atorvastatin reduced fasting plasma TG (from 3.6 +/- 0.4 to 2.5 +/- 0.3 mM; mean +/- SEM) without major effects on fasting apolipoprotein B48 (apoB48) and apoB100 in large TRLs. Atorvastatin significantly reduced fasting intermediate density lipoprotein (Svedberg flotation, 12-20)-apoB100 concentrations. After Intralipid, TG in plasma and TRL showed similar kinetics in FCHL before and after atorvastatin treatment, although compared with controls, the clearance of large TRLs was only significantly slower in untreated FCHL, suggesting an improvement by atorvastatin. Investigated with oral fat-loading tests, the clearance of very low density lipoprotein (Sf20-60)-apoB100 improved by 24%, without major changes in the other fractions. The most striking effects of atorvastatin on postprandial lipemia in FCHL were on hepatic TRL, without major improvements on intestinal TRLs. Fasting plasma TG should be reduced more aggressively in FCHL to overcome the lipolytic disturbance causing delayed clearance of postprandial TRLs.

Verseyden C, Meijssen S, van Dijk H, Jansen H, Castro Cabezas M. · Department of Vascular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands. · J Lipid Res. · Pubmed #12923226 links to  free full text

Abstract: VLDL overproduction by enhanced hepatic FFA flux is a major characteristic of familial combined hyperlipidemia (FCHL). The postprandial complement component 3 (C3) response has been associated with impaired postprandial FFA metabolism in FCHL. We investigated the effects of 16 weeks of treatment with atorvastatin on postprandial C3 and lipid changes in 12 FCHL patients. Atorvastatin significantly lowered fasting plasma C3 and triglyceride (TG) in FCHL. Fasting TG and insulin sensitivity were the best predictors of fasting and postprandial C3. Postprandial triglyceridemia and C3 response, estimated as area under the curve (AUC), were significantly lowered by atorvastatin by 19% and 12%, respectively, albeit still elevated, compared with 10 matched controls. Postprandial FFA-AUC and postheparin plasma lipolytic activities remained unchanged after atorvastatin, suggesting no major effect on lipolysis. After atorvastatin, postprandial hydroxybutyric acid-AUC, which was elevated in untreated FCHL patients, was decreased, reaching values similar to those in controls. The present data show reduction of postprandial hepatic FFA flux in FCHL by atorvastatin, providing an additional mechanistic explanation for the reduction of VLDL secretion reported previously for atorvastatin. This was accompanied by a decrease in fasting plasma C3 concentrations and a blunted postprandial C3 response to an acute oral fat load.

van Oostrom AJ, Alipour A, Sijmonsma TP, Verseyden C, Dallinga-Thie GM, Plokker HW, Castro Cabezas M. · Department of Cardiology, St. Antonius Hospital, Nieuwegein, the Netherlands. · Neth J Med. · Pubmed #19155542 links to  free full text

Abstract: Postprandial hyperlipidaemia has been associated with coronary artery disease (CAD). We investigated which of the generally used methods to test postprandial lipaemia differentiated best between patients with premature CAD (50+/-4 years, n=20) and healthy controls. Furthermore, the effects of rosuvastatin 40 mg/day on postprandial parameters were assessed. Standardised oral fat-loading tests (OFLT) and ambulant self-measurements of daylong capillary triglycerides (TGc) were performed. Total responses of individual lipoproteins, plasma TG (TGp) and remnant-like particle cholesterol (RLP-C) were estimated as area under the curve (AUC). Most AUCs were highest in untreated patients and reached control levels after rosuvastatin. From all AUCs, RLP-C-AUC was best associated to TGp-AUC in untreated patients and controls (adjusted R2=0.84, beta=0.92, p.

Alipour A, van Oostrom AJ, Izraeljan A, Verseyden C, Collins JM, Frayn KN, Plokker TW, Elte JW, Castro Cabezas M. · Department of Internal Medicine, University Medical Center Utrecht, The Netherlands. · Arterioscler Thromb Vasc Biol. · Pubmed #18218988 links to  free full text

Abstract: OBJECTIVE: Postprandial lipemia has been linked to atherosclerosis and inflammation. Because leukocyte activation is obligatory for atherogenesis, leukocyte activation by triglyceride-rich lipoproteins (TRLs) was investigated. METHODS AND RESULTS: The expression of CD11b and CD66b after incubation with glucose and native and artificial TRLs (NTRL and ATRL) in vivo and in vitro was evaluated by flowcytometry. Oral fat loading tests showed an increased expression of CD11b on monocytes and neutrophils and CD66b on neutrophils. In 11 volunteers, postprandial leukocytes became enriched with meal-derived fatty acids ([1-(13)C]16:0) suggesting uptake of exogenous fat. ApoB binding on leukocytes measured by flowcytometry in 65 subjects was highest on neutrophils and monocytes suggesting adherence of apoB-containing lipoproteins. Physiological concentrations of TRLs showed 62% increased neutrophil CD11b and a dose-dependent increased monocyte CD11b up to 84% in vitro. Incubations with lipid emulsions in the hypertriglyceridemic range showed a 5-fold increased monocyte CD11b expression, which was higher than the positive control (fMLP), and a dose-dependent 2- to 3-fold increased neutrophil CD11b and CD66b. The oxidative scavenger DMTU decreased the neutrophil CD66b expression by 36%. CONCLUSIONS: Acute hypertriglyceridemia is a leukocyte activator most likely by direct interaction between TRLs and leukocytes and uptake of fatty acids. TG-mediated leukocyte activation is an alternative proinflammatory and proatherogenic mechanism of hypertriglyceridemia in part associated to the generation of oxidative stress.

Castro Cabezas M, de Vries JH, Van Oostrom AJ, Iestra J, van Staveren WA. · St Franciscus Gasthuis Rotterdam, Department of Internal Medicine, University Medical Center Utrecht, the Netherlands. · J Am Diet Assoc. · Pubmed #17000189 No free full text.

Abstract: BACKGROUND: Plant stanols have been recommended in combination with individualized dietary interventions to reduce plasma cholesterol concentrations. It is unclear whether plant stanols in combination with dietary guidance in patients already using optimal doses of statins will further reduce fasting and postprandial lipids compared with standard care. STUDY DESIGN: This single-blind, randomized study investigated the effect of plant stanols in margarines, combined with a lipid-lowering dietary intervention, in patients already on lipid-lowering medications at maximal doses not reaching their target lipid levels. Nutrition education was based on the stages of change theory. The control group (which served as the standard care control group) was also taking optimal doses of statins. This group received a margarine without plant stanols and a leaflet with Dutch nutrition guidelines. Fasting lipids were measured once in venous samples and postprandial lipemia was assessed by self-measured triglycerides in an outpatient setting. All subjects were given a capillary triglyceride measuring device (Accutrend GCT, Roche Diagnostics, Mannheim, Germany) and were instructed to measure their capillary triglycerides at six fixed time-points throughout the day on three different days. The mean area under the triglyceride curve represented total daylong triglyceridemia, which has been shown to reflect postprandial triglyceridemia. Twenty patients were included, 11 in the intervention group and 9 in the control group. RESULTS: In the plant stanol group, low-density lipoprotein cholesterol decreased significantly by 15.6% compared with a reduction of only 7.7% in the control group. The daylong triglyceridemia was similar in both groups at the beginning and at the end of the study, and no change was observed by the intervention. CONCLUSION: Intensive dietary intervention with addition of plant stanols results in clinically relevant reduction of low-density lipoprotein cholesterol in patients optimally treated with statins, compared with similar patients on statins receiving only standard care. The use of a plant stanol-enriched margarine did not decrease postprandial triglyceridemia in these patients.

Bartual A, González C, Martínez Hervás S, Real JT, García García AB, Castro Cabezas M, Chaves FJ, Priego MA, Ascaso JF, Carmena R. · Servicio de Endocrinología y Nutrición, Hospital Clínico Universitario de Valencia, Departamento de Medicina, Universitat de Valencia, España. · Rev Clin Esp. · Pubmed #16750103 No free full text.

Abstract: INTRODUCTION: A new method based on self-measurement of diurnal capillary triglycerides (TG) facilitates the study of postprandial lipemia (PL). The objectives of our study are: to evaluate the effect of gender and obesity on PL measured by self-determination of diurnal capillary TG with Accutrend GCT in normolipidemic non-diabetic subjects and subjects with familial combined hyperlipidemia (FCH). MATERIAL AND METHODS: We studied 23 FCH subjects (10 males) and 45 normolipidemic non-diabetic subjects (29 males). All subjects self-determine 3 diurnal capillary TG profiles during a week. RESULTS: In normolipidemic non diabetic subjects significantly higher diurnal TG profiles and area under the curve of TG (AUCTGc) (25.25 +/-9.09 vs 19.71 +/- 6.16 mmolh/l) were found in males compared to females. In FCH subjects these differences were not found and the AUCTGc correlated with BMI (r = 0.510, p < 0.05) and waist circumference (r = 0.453, p < 0.05). Obese subjects (BMI >or= 27 kg/m2) showed diurnal TG profiles and AUCTGc significantly higher than the non-obese. DISCUSSION: Normolipidemic non diabetic females showed a lower PL compared to males, probably due to the effect of estrogens in PL metabolism. Obesity negatively influences PL in normolipidemic non diabetic subjects and subjects with FCH.

Barter PJ, Ballantyne CM, Carmena R, Castro Cabezas M, Chapman MJ, Couture P, de Graaf J, Durrington PN, Faergeman O, Frohlich J, Furberg CD, Gagne C, Haffner SM, Humphries SE, Jungner I, Krauss RM, Kwiterovich P, Marcovina S, Packard CJ, Pearson TA, Reddy KS, Rosenson R, Sarrafzadegan N, Sniderman AD, Stalenhoef AF, Stein E, Talmud PJ, Tonkin AM, Walldius G, Williams KM. · Heart Research Institute, Camperdown, Sydney, NSW, Australia. · J Intern Med. · Pubmed #16476102 No free full text.

Abstract: There is abundant evidence that the risk of atherosclerotic vascular disease is directly related to plasma cholesterol levels. Accordingly, all of the national and transnational screening and therapeutic guidelines are based on total or LDL cholesterol. This presumes that cholesterol is the most important lipoprotein-related proatherogenic risk variable. On the contrary, risk appears to be more directly related to the number of circulating atherogenic particles that contact and enter the arterial wall than to the measured concentration of cholesterol in these lipoprotein fractions. Each of the atherogenic lipoprotein particles contains a single molecule of apolipoprotein (apo) B and therefore the concentration of apo B provides a direct measure of the number of circulating atherogenic lipoproteins. Evidence from fundamental, epidemiological and clinical trial studies indicates that apo B is superior to any of the cholesterol indices to recognize those at increased risk of vascular disease and to judge the adequacy of lipid-lowering therapy. On the basis of this evidence, we believe that apo B should be included in all guidelines as an indicator of cardiovascular risk. In addition, the present target adopted by the Canadian guideline groups of an apo B <90 mg dL(-1) in high-risk patients should be reassessed in the light of the new clinical trial results and a new ultra-low target of <80 mg dL(-1) be considered. The evidence also indicates that the apo B/apo A-I ratio is superior to any of the conventional cholesterol ratios in patients without symptomatic vascular disease or diabetes to evaluate the lipoprotein-related risk of vascular disease.

van Oostrom AJ, Real JT, Carmena R, Ascaso JF, Castro Cabezas M. · Department of Vascular Medicine, Room F02.216, University Hospital Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands. · Neth J Med. · Pubmed #15588068 links to  free full text

Abstract: BACKGROUND: A Mediterranean eating pattern and diet enriched in monounsaturated fatty acids may result in a favourable daylong lipid profile. METHODS: 19 Spanish males (aged 32 +/- 8 years) and 28 females (34 +/- 8 years) were matched to Dutch subjects on the basis of fasting capillary triglycerides (TGc), gender and age. TGc were self-measured at six fixed time points over three days. Daylong TGc profiles were calculated as areas under the curve (TGc-AUC). RESULTS: Anthropometric parameters and fasting plasma lipids were comparable between Spanish participants and Dutch subjects. Insulin sensitivity (expressed as HOMA) was highest in the Dutch females (1.41 +/- 1.09 vs. 2.09 +/- 1.23 in the Spanish females, p < 0.05). Daylong TGc values were not different between Spanish and Dutch participants. Male Spanish subjects showed the largest daylong TGc increase after lunch, while in the Dutch males, the largest TGc increase was seen after dinner. Total daytime dietary energy and total fat intake were comparable when analysed by gender. However, the Spanish participants had a higher intake of monounsaturated and polyunsaturated fatty acids as percentage of energy. CONCLUSION: There are no major differences in daylong triglyceridaemia between Dutch and Spanish subjects, despite different eating habits and a diet enriched in monounsaturated and polyunsaturated fat in the latter.

Delawi D, Meijssen S, Castro Cabezas M. · Department of Vascular Medicine F02.126, University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands. · Clin Chim Acta. · Pubmed #12559610 No free full text.

Abstract: BACKGROUND: The intra-individual variability of plasma lipids and apolipoproteins has not been studied systematically in familial combined hyperlipidemia (FCHL). METHODS: Intra-individual changes in fasting plasma lipids and apolipoproteins B and AI were determined in 18 untreated FCHL subjects and 16 unrelated, normolipidemic subjects. Participants were matched for gender, age and body mass index. The mean follow-up period of fasting plasma lipids was 48.91 +/- 35.46 (mean +/- S.D.) days. Postprandial lipemia was determined on 3 different days in 1 week in 90 healthy controls and 17 untreated FCHL subjects by the area under the diurnal capillary triglyceride curve (TGc-AUC). RESULTS: The coefficients of variation (CVs) for fasting plasma TG were similar between FCHL (23.2 +/- 10.2%) and controls (20.4 +/- 8.2%). The CVs for HDL-C, apo B and apo AI were the lowest of all fasting plasma measurements in both groups and there was no significant difference between FCHL (12.8 +/- 8.2%, 13.2 +/- 15.8% and 6.4 +/- 5.2%, respectively) and controls (11.4 +/- 4.3%, 11.3 +/- 10.6% and 7.8 +/- 4.6%, respectively). The CVs for postprandial lipemia were not different between FCHL (15.9 +/- 11.3%) and controls (15.1 +/- 11.0%), and were significantly lower than the CV of fasting capillary TG (TGc) in the same period (36.3 +/- 24.7% and 24.9 +/- 17.2%, respectively). CONCLUSIONS: Our study does not provide evidence for short-term major changes in fasting or postprandial lipemia or apolipoproteins in FCHL when systematically compared to healthy controls.

Ribalta J, Figuera L, Fernández-Ballart J, Vilella E, Castro Cabezas M, Masana L, Joven J. · Unitat de Recerca de Lípids i Arteriosclerosi, Institut de Recerca en Ciències de la Salut, Hospital Universitari de Sant Joan, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Spain. · Clin Chem. · Pubmed #12194944 links to  free full text

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Verseyden C, Meijssen S, Castro Cabezas M. · Department of Vascular Medicine F02.126, University Medical Center Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands. · J Lipid Res. · Pubmed #11861669 links to  free full text

Abstract: Impaired chylomicron (chylo) remnant clearance and small VLDL overproduction are major metabolic abnormalities in familial combined hyperlipidemia (FCHL). Quantitative data on postprandial apolipoprotein B-48 (apoB-48) and apolipoprotein B-100 (apoB-100) in TG rich lipoproteins (TRL) in FCHL have not been reported before. Eight untreated FCHL patients and 10 matched controls underwent a 24 h oral fat load. Fasting apoB-48 and apoB-100 were significantly higher in all TRL in FCHL. Maximal concentrations of chylo-[Svedberg's flotation rate (Sf) >400] apoB-48 and apoB-100 were reached later in FCHL (at t = 6 h), in contrast to controls (t = 4 h). Maximal VLDL1-(Sf60-400)-apoB-48 occurred at the same time point (t = 2 h) in both, whereas VLDL1-apoB-100 was maximal at t = 4 h in both, most likely representing delayed VLDL clearance by preferential clearance of chylo and their remnants by competition for the same clearance mechanisms. VLDL2-(Sf20-60)-apoB-48 and VLDL2- apoB-100 decreased in FCHL, in contrast to an increase of apoB-48, and no change of apoB-100 in controls, suggesting impaired conversion of VLDL1-apoB-48 into VLDL2-apoB-48 in FCHL, and partly also of VLDL1-apoB-100. In conclusion, in FCHL clearance of large postprandial Sf >400 apoB-48 and apoB-100 TRL is delayed. ApoB-100 accumulates in the VLDL1 range postprandially in both FCHL and controls, reaching higher levels in FCHL and thereby conferring a higher atherogenic burden in the postprandial situation in FCHL.

Sniderman AD, Castro Cabezas M, Ribalta J, Carmena R, de Bruin TW, de Graaf J, Erkelens DW, Humphries SE, Masana L, Real JT, Talmud PJ, Taskinen MR. · McGill University, Montreal, Quebec, Canada. · Eur J Clin Invest. · Pubmed #11895451 No free full text.

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