Body mass interacts with fat quality to determine the postprandial lipoprotein response in healthy young adults.

BACKGROUND AND AIMS: Postprandial lipemia predicts the evolution of cardiovascular disease. Obesity is associated with an increase in the magnitude of postprandial lipemia. Our objective was to evaluate the influence of body mass index (BMI) on the effects of acute ingestion of different types of fat on the postprandial lipemic response. METHODS AND RESULTS: Twenty-one healthy men followed a 4-week baseline diet and then consumed three fat-loaded meals that included 1g fat/kg body wt (65%fat) according to a randomized crossover design. The compositions of the three meals were olive oil meal (22% saturated fatty acids (SFA), 38% monounsaturated fatty acids (MUFA), 4% polyunsaturated fatty acids (PUFA)); butter meal (35% SFA, 22% MUFA, 4% PUFA); walnuts meal (20% SFA, 24% MUFA, 16% PUFA, and 4% α-linolenic acid). Higher-weight (HW) subjects (BMI greater than the median 26.18 kg/m(2), n = 11) presented higher incremental area under the curve (iAUC) for triglycerides (TG), both in large- and small-TG rich lipoproteins (TRL) than lower-weight (LW) subjects (BMI<26.18 kg/m(2), n = 10) (p<0.05), and a similar trend for plasma TG (p = 0.084). Moreover, HW subjects presented higher concentrations for small TRL-cholesterol and small TRL-TG in different timepoints of the postprandial lipemia after the intake of enriched walnuts or butter meals compared with the olive oil-enriched meal (p < 0.05) No significant differences were observed between the three types of meals in the postprandial response of LW subjects. CONCLUSION: HW subjects present a greater postprandial response than LW subjects, and they benefit from the consumption of monounsaturated fatty acids from olive oil, to lower their levels of TRL particles during the postprandial state.

Relationship of oxidative stress and endothelial dysfunction in sleep apnoea.

The aim of the present study was to evaluate ischaemic reactive hyperaemia (IRH) in obstructive sleep apnoea (OSA) and its relationship with oxidative stress. We studied 69 consecutive patients referred to our Sleep Unit (Reina Sofia University Hospital, Cordoba, Spain). Patients with chronic diseases or those taking medication were excluded. IRH was assessed before and after polysomnography. Morning IRH and oxidative stress markers were compared between patients with (apnoea-hypopnoea index (AHI) ≥ 5) and without (AHI < 5) OSA. Measurements were repeated in 25 severe OSA patients after continuous positive airway pressure (CPAP) therapy. We included 46 OSA patients (mean ± sd AHI 49 ± 32.1) and 23 non-OSA subjects (AHI 3 ± 0.9). The OSA patients showed a significant worsening of morning IRH, and a significant increase in malondialdehyde and 8-hydroxydeoxyguanosine levels. Only the oxygen desaturation index independently explained morning IRH, while malondialdehyde levels showed a weak effect on IRH. In severe OSA patients, IRH improved significantly after CPAP treatment, as did malondialdehyde, 8-hydroxydeoxyguanosine and protein carbonyl levels. In OSA patients, endothelial dysfunction and oxidative stress were observed, and IRH worsened after sleep. The increase in oxidative stress was not associated with IRH, while intermittent hypoxia was strongly associated with IRH. In severe OSA patients, CPAP treatment improved oxidative stress and endothelial function.

Consumption of diets with different type of fat influences triacylglycerols-rich lipoproteins particle number and size during the postprandial state.

BACKGROUND AND AIMS: Previous evidence suggests that dietary fat could influence the composition and size of triacylglycerols-rich lipoproteins (TRL). In a controlled intervention study on healthy subjects, we evaluated the influence of 3 dietary interventions, with different types of fat on postprandial TRL particle size and number. METHODS AND RESULTS: Volunteers followed three different diets for four weeks each, according to a randomized crossover design. Western diet: 15% protein, 47% carbohydrates (CHO), 38% fat (22% saturated fatty acid (SFA)); Mediterranean diet: 15% protein, 47% CHO, 38% fat (24% monounsaturated fatty acid (MUFA)); high CHO enriched with ALNA diet: 15% protein, 55% CHO, <30% fat (8% polyunsaturated fatty acid (PUFA)). After a 12-h fast, volunteers consumed a breakfast with 1g fat and 7 mg cholesterol per kg body weight and a fat composition similar to that consumed in each of the diets: Butter meal: 35% SFA; Olive oil meal: 36% MUFA; Walnut meal: 16% PUFA, 4% α-linolenic acid. Tryglicerides (TG) in TRL (large and small TRL) were determined by ultracentrifugation and size and number of lipoprotein particles were measured with Nuclear Magnetic Resonance Spectroscopy at different time points. The olive oil meal reduced the number of total TRL postprandial particles compared with the other meals (P=0.002). Moreover, the olive oil meal also increased the TRL particle size compared with the walnut meal (P=0.001). CONCLUSION: Our data showed that short-term intake of the Mediterranean diet and the acute intake of an olive oil meal lead to the formation of a reduced number and higher-size TRL particle compared with other fat sources. These novel findings have implications for understanding the postprandial lipoprotein mechanisms, and could favour the lower cardiovascular risk in Mediterranean countries.

Polymorphism at the TRIB1 gene modulates plasma lipid levels: insight from the Spanish familial hypercholesterolemia cohort study.

BACKGROUND AND AIMS: rs17321515 SNP has been associated with variation in LDL-C, high density lipoprotein cholesterol and triglycerides concentrations. This effect has never been studied in patients with severe hypercholesterolemia. Therefore, our aims were to assess the association of the rs17321515 (TRIB1) SNP with plasma lipids concentrations and anthropometric variables and to explore the interaction between this SNP and some classic risk factors in patients with familial hypercholesterolemia (FH). METHODS AND RESULTS: rs17321515 SNP was genotyped in 531 subjects with genetic diagnosis of FH. Homozygous A/A had significantly higher waist circumference compared with G/G subjects (P = 0.006) and carriers of the minor allele G (P = 0.039). Interestingly, smokers homozygous for the A allele displayed higher plasma triglycerides concentrations (P = 0.029), higher VLDL-C levels (P = 0.023) and higher TC/HDL-C ratio (P = 0.035) than carriers of the minor allele G. In addition, homozygous A/A with the presence of arcus cornealis displayed lower plasma ApoA-I levels (P = 0.024) and higher TC/HDL-C ratio (P = 0.046) than carriers of the minor allele G. CONCLUSIONS: Smoking status and presence of arcus cornealis modulate the effect of rs17321515 (TRIB1) polymorphism on plasma lipids levels in patients with FH. These results could explain the differences in the susceptibility to coronary heart disease in these patients.

Olive oil and health: summary of the II international conference on olive oil and health consensus report, Jaén and Córdoba (Spain) 2008.

Olive oil (OO) is the most representative food of the traditional Mediterranean Diet (MedDiet). Increasing evidence suggests that monounsaturated fatty acids (MUFA) as a nutrient, OO as a food, and the MedDiet as a food pattern are associated with a decreased risk of cardiovascular disease, obesity, metabolic syndrome, type 2 diabetes and hypertension. A MedDiet rich in OO and OO per se has been shown to improve cardiovascular risk factors, such as lipid profiles, blood pressure, postprandial hyperlipidemia, endothelial dysfunction, oxidative stress, and antithrombotic profiles. Some of these beneficial effects can be attributed to the OO minor components. Therefore, the definition of the MedDiet should include OO. Phenolic compounds in OO have shown antioxidant and anti-inflammatory properties, prevent lipoperoxidation, induce favorable changes of lipid profile, improve endothelial function, and disclose antithrombotic properties. Observational studies from Mediterranean cohorts have suggested that dietary MUFA may be protective against age-related cognitive decline and Alzheimer's disease. Recent studies consistently support the concept that the OO-rich MedDiet is compatible with healthier aging and increased longevity. In countries where the population adheres to the MedDiet, such as Spain, Greece and Italy, and OO is the principal source of fat, rates of cancer incidence are lower than in northern European countries. Experimental and human cellular studies have provided new evidence on the potential protective effect of OO on cancer. Furthermore, results of case-control and cohort studies suggest that MUFA intake including OO is associated with a reduction in cancer risk (mainly breast, colorectal and prostate cancers).

Chronic effects of a high-fat diet enriched with virgin olive oil and a low-fat diet enriched with alpha-linolenic acid on postprandial endothelial function in healthy men.

Traditional cardiovascular risk factors are associated with endothelial dysfunction. The vascular endothelium plays a key role in local vascular tone regulation and can be modulated by dietary fat. We propose to determine the chronic effect of three diets with different fat compositions on postprandial endothelial function and inflammatory biomarkers. Twenty healthy men followed three 4-week diets in a randomised cross-over design: a Western diet, rich in saturated fat (22% SFA, 12% MUFA and 0.4% alpha-linolenic acid (ALA), all fractions are % of energy); a Mediterranean diet, rich in MUFA ( < 10 % SFA, 24 % MUFA and 0.4% ALA); a low-fat diet enriched in ALA ( < 10% SFA, 12% MUFA and 2% ALA). At the end of each dietary period all subjects underwent a postprandial study. Plasma concentrations of lipid parameters, soluble intercellular cell-adhesion molecule-1, soluble vascular cell-adhesion molecule-1 (sVCAM-1), nitrates and nitrites (NOx) and endothelial function studied by laser Doppler were examined at 0, 2, 4, 6 and 8 h. The endothelium-dependent vasodilatory response was greater 4 h after the ingestion of the MUFA-rich diet than after the SFA or ALA low-fat diets (P = 0.031). The 4 h postprandial plasma sVCAM-1 levels were lower after the MUFA meals than after the ALA low-fat diet (P = 0.043). The bioavailability of NOx was higher following the MUFA diet than after the SFA and ALA low-fat diets (P = 0.027). We found no differences in the other parameters measured. Chronic ingestion of a Mediterranean diet avoids the postprandial deterioration of endothelial function associated with Westernised diets in healthy individuals.

Basal plasma concentrations of plant sterols can predict LDL-C response to sitosterol in patients with familial hypercholesterolemia.

BACKGROUND: Familial hypercholesterolemia (FH) is associated with a high risk of coronary heart disease. Pharmacological treatment and diet are both essential for the management of FH. Foods rich in plant sterols (PS) may play an important role in the treatment of patients with these disorders. OBJECTIVE: To test the effect of the intake of PS on low-density lipoprotein (LDL) concentration, endothelial function (EF) and LDL particle size in 30 patients with FH. DESIGN: Randomized and crossover dietary intervention study. SETTING: Tertiary outpatient care. SUBJECTS: Thirty-eight were recruited, but only 30 were subjected to four low-fat dietary intervention periods, each of 4 weeks. METHODS: Each intervention had a different content of cholesterol (<150 or 300 mg/day) and sitosterol (<1 or 2 g/day). Lipid response, EF and LDL particle size were analysed after the intervention. RESULTS: Plasma sitosterol/cholesterol ratio was higher during both plant sterol-rich periods than during the low plant sterols periods. Basal sitosterol concentrations predicted the LDL-cholesterol response during the intake of plant sterol-enriched diets. The change in LDL-cholesterol was significantly greater in subjects in the upper and intermediate tertiles of basal plasma sitosterol concentrations (-21+/-8 mg/dl, P=0.03; -19+/-7 mg/dl, P=0.04, respectively) than in subjects in the lower tertile (8+/-5 mg/dl) when they changed from a low cholesterol diet to a low cholesterol plus plant sterol diet. CONCLUSION: Our study demonstrates that basal sitosterol values can predict hypolipidemic response in patients with FH.

The -250G/A polymorphism in the hepatic lipase gene promoter influences the postprandial lipemic response in healthy men.

BACKGROUND AND AIM: The -250G/A promoter polymorphism of the hepatic lipase gene has been associated with changes in the activity of the enzyme. We investigated whether this polymorphism modifies the postprandial response of triacylglycerol-rich lipoproteins (TRL) in young normolipemic males. METHODS AND RESULTS: Fifty-one healthy apolipoprotein (apo) E3/E3 male volunteers (30 G/G and 21 carriers of the A allele) underwent a vitamin A fat-loading test and blood samples were drawn every hour until the 6th, and every 2h and 30 min until the 11th. Total plasma cholesterol and triacylglycerols (TG), as well as cholesterol, TG and retinyl palmitate (RP) in TRL, isolated by ultracentrifugation, were determined. Carriers of the A allele showed a higher response (P=0.008), a higher area under the curve (AUC; P=0.022) and a lower RP peak time (P=0.029) in small TRL during the postprandial response, as well as a lower peak time in total plasma TG levels (P=0.034) and large TRL-TG (P=0.033) than subjects who were homozygous for the G allele. CONCLUSION: Our data indicate that the presence of the A allele in the -250G/A promoter polymorphism of the hepatic lipase gene is associated with a higher postprandial lipemic response.

[Comparison of the functional outcomes of patients with arthroscopic repair of massive rotator cuff ruptures alone or combined with acromioplasty or biceps tenotomy]. / Comparación de los resultados funcionales de los pacientes con reparación artroscópica de rupturas masivas del manguito rotador sola o combinada con acromioplastía y/o tenotomía del bíceps.

BACKGROUND: The rotator cuff injury it is one of the most common causes of pain and functional disability of the shoulder with an annual reported incidence of 4.5 million cases in the United States. It is one of the leading causes of pain of shoulder in patients older than 60 years. In Mexico, there are no reports of the incidence or the results of arthroscopic repair of massive rotator cuff lesions alone or combined with other procedures. OBJECTIVE: To evaluate the clinical evolution of patients post-surgery of arthroscopic rotator cuff massive injury repair AR-RCMI alone or in combination with other techniques. METHODS: Evaluation of records of patients with AR-RCMI post-surgery, comparing the results of the scales: simple shoulder test and VAS before and after surgery with a follow up of 2.6 years. The combined procedures were acromioplasty, tenotomy of biceps or both. RESULTS: 65 patients with diagnosis of massive injury; with an average age of 62.8 years (SD ± 9. 42), 27.7% were men and 72.3% women. The evaluation was conducted in four groups: arthroscopic repair (AR); arthroscopic repair + biceps tenotomy (AR + BT); arthroscopic repair + acromioplasty (AR + A) and arthroscopic repair + biceps tenotomy + acromioplasty (AR + BTA). All groups showed significant reduction in pain: AR (-44.1%, p = 0.0001), AR + A (-36.9%, p = 0.001), AR + BT (-36.3%, p = 0.0001), AR + BT + A (-38.5%, p = 0.0001). All groups had significant improvement in function with the SST scale.

ANTECEDENTES: La lesión del manguito rotador (LMR) es una de las causas más comunes de dolor y discapacidad funcional del hombro con una incidencia anual reportada de 4.5 millones de casos en Estados Unidos. La LMR es una de las principales causas de dolor de hombro en pacientes mayores de 60 años. En México, no existen reportes de la incidencia ni de los resultados de la reparación artroscópica de las lesiones masivas de manguito rotador sola o combinada con otros procedimientos. OBJETIVO: Evaluar la evolución clínica de los pacientes postoperados de reparación artroscópica de lesión masiva del manguito rotador (RA-LMMR), sola o combinada con otras técnicas. MÉTODOS: Evaluación de expedientes de pacientes postoperados de RA-LMMR en la que se compararon los resultados de las escalas: simple shoulder test y EVA antes y después de la cirugía a un seguimiento promedio de 2.6 años. Los procedimientos combinados fueron acromioplastía, tenotomía de bíceps o ambas. RESULTADOS: 65 pacientes con diagnóstico de lesión masiva con edad promedio de 62.8 años (DE ± 9.42), 27.7% fueron hombres y 72.3% mujeres. La evaluación se realizó en cuatro grupos: reparación artroscópica (RA), reparación artroscópica + tenotomía del bíceps (RA + TB), reparación artroscópica + acromioplastía (RA + A) y reparación artroscópica + tenotomía del bíceps + acromioplastía (RA + TBA). Todos los grupos mostraron disminución significativa del dolor: RA (-44.1%, p = 0.0001), RA + A (-36.9%, p = 0.001), RA + TB (-36.3%, p = 0.0001), RA + TB + A (-38.5%, p = 0.0001). De igual forma todos los grupos mostraron mejoría significativa de la función evaluada con la escala SST.

[Intraarticular lesions associated with tibial fixation during anterior cruciate ligament reconstruction]. / Lesiones intraarticulares asociadas a la fijación tibial en la reconstrucción del ligamento cruzado anterior.

Anterior cruciate ligament reconstruction is a demanding procedure; complications may arise at any of its stages. This is the report of three cases in which the tibial fixation devices (IntraFix and Bio-IntraFix) led to intraarticular lesions. The complications were detected in one of the cases while the patient was still in the operating room and in the remaining two during the follow-up. All the patients had a stable knee, but all of them sustained chondral lesions resulting from the inadequate placement of the implants used for tibial fixation. Several suggestions to avoid the complications stemming from these devices are provided.

La reconstrucción del ligamento cruzado anterior es un procedimiento exigente; las complicaciones pueden presentarse en cualquiera de sus etapas. Presentamos tres casos en los cuales los dispositivos para la fijación tibial (IntraFix y Bio-IntraFix) condicionaron lesiones intraarticulares. Las complicaciones fueron detectadas, en uno de los casos, mientras el paciente se encontraba aún en la sala de operaciones, y en los otros dos, durante el seguimiento. Todos los pacientes contaban con una rodilla estable, pero tuvieron lesiones condrales causadas por la inadecuada colocación de los implantes para la fijación tibial. Se exponen algunas sugerencias para evitar complicaciones con estos dispositivos.

Cerivastatin improves insulin sensitivity and insulin secretion in early-state obese type 2 diabetes.

In a double-blind, placebo-controlled, randomized crossover study, 15 stable mild hyperglycemic patients without treatment and with features of metabolic syndrome were treated with cerivastatin (0.4 mg/day) or placebo for 3 months. The insulin sensitivity index during the euglycemic-hyperinsulinemic clamp (EHC; 5.4 mmol/l; 80 mU x m(-2) x min(-1)) was increased by cerivastatin treatment (66.39 +/- 3.9 nmol x lean body mass [LBM](-1) x min(-1) x pmol(-1) x l(-1)) as compared with placebo (58.37 +/- 3.69 nmol x LBM(-1) x min(-1) x pmol(-1) x l(- 1); P < 0.01) by 13.7%. Glucose oxidation during EHC was significantly higher with statin treatment (16.1 +/- 1.37 micromol x LBM(-1) x min(-1)) as compared with placebo (14.58 +/- 1.48 micromol x LBM(-1) x min(-1); P < 0.05). During hyperinsulinemia (approximately 800 pmol/l) in EHC steady-state, lipid oxidation was significantly decreased and respiratory quotient was significantly increased with statin treatment (0.33 +/- 0.05 mg x LBM(-1) x min(- 1), 0.94 +/- 0.01) as compared with placebo (0.48 +/- 0.06 mg x LBM(-1) x min(-1), 0.91 +/- 0.01; P < 0.01 and P < 0.05, respectively). During statin treatment, the first-phase insulin response increased from 2.07 +/- 0.28 to 2.82 +/- 0.38 pmol x l(-1) x pmol(-1) (P < 0.05). The second phase of insulin responses examined by C-peptide and insulin levels averaged during the hyperglycemic clamp (20 mmol/l) was unchanged. In conclusion, this study demonstrates that 0.4 mg cerivastatin therapy improves first-phase insulin secretion and increases insulin-mediated glucose uptake and respiratory quotient in the early state of obese type 2 diabetes.

A carbohydrate-rich diet reduces LDL size in QQ homozygotes for the Gln 192Arg polymorphism of the paraoxonase 1 gene.

Paraoxonase 1 (PON 1) is an esterase with antioxidant properties that is present in HDL. Gln192Arg polymorphism (also named Q192R or Q/R) of the PON 1 gene that encodes this protein defines two alleles (Q and R). The R allele has been associated with higher cardiovascular risk. LDL size and susceptibility to oxidation also have been identified as cardiovascular risk factors. Our objective was to determine whether genetic variations in the Gln192Arg polymorphism influence LDL size and susceptibility to oxidation after the consumption of diets with different fat content. In our experiments, the participants (n = 98) underwent three 4-wk diets--one, saturated fat-enriched (SAT); another, monounsaturated fat-enriched (MONO); and a third, carbohydrate-enriched (CHO). We observed that LDL were smaller in the QQ group after the CHO diet vs. the SAT (P < 0.01) and MONO diets (P < 0.03). No differences in LDL size were found in QR/RR subjects. When we analyzed lag time of oxidation of LDL, we found that when carriers of the R allele (QR/RR) received the MONO diet, the lag period of LDL oxidation was longer as compared with the CHO diet. Otherwise, we found no differences in QQ homozygotes when we evaluated the lag time of oxidation of LDL after the three diets. These results suggest that the Glnl92Arg polymorphism of the paraoxonase gene influences LDL size and susceptibility to oxidation in response to diet.

Salivary gamma-glutamyl transferase activity in internal diseases.

Salivary gamma-glutamyl transferase (GGT) activity was measured in 116 patients with several diseases that involved the hepatobiliary tract, pancreas, and miscellaneous disorders and in 20 normal subjects. We have found significantly elevated values of salivary GGT in cirrhosis of the liver (8.3 +/- 0.9 [mean +/- SEM] units/L), hepatic tumors (10.4 +/- 1.3 units/L), acute cholecystitis (18.3 +/- 2 units/L), acute pancreatitis (15.1 +/- 2.4 units/L), diabetic ketoacidosis (11.6 +/- 1 units/L), and Sjögren's syndrome (19.6 +/- 4.8 units/L). Salivary GGT activities were unmodified in fatty liver, infectious hepatitis, silent cholelithiasis, and mumps. Several mechanisms explain high salivary GGT activity. Measurement of salivary GGT activity in internal medicine merits further investigations to determine its potential diagnostic value.

Selective IgA deficiency and the HLA-B8 antigen. Report of two cases with familial data.

Two patients had IgA deficiency, giardiasis, and the HLA-B8 antigen. The family of patient 1 included members with juvenile-onset diabetes mellitus, adrenal insufficiency, pernicious anemia, and hypothyroidism, a combination of unusual diseases that has been reported previously to occur as a syndrome with IgA deficiency and the HLA-B8 antigen. This coincidence makes it likely that these two patients and the one family previously described have a common pathogenic base, the inheritance of an abnormal immune-response gene that is acquired with the HLA-B8 antigen as a result of genetic dysequilibrium.

Lipoprotein concentrations in normolipidemic males consuming oleic acid-rich diets from two different sources: olive oil and oleic acid-rich sunflower oil.

The effects on plasma lipid concentrations of two oleic acid-rich diets, prepared with two different plant oils--olive oil and sunflower oil high in monounsaturated fatty acids (MUFAs)-- were compared with a National Cholesterol Education Program (NCEP) I diet. Twenty-one healthy, normolipidemic, young males consumed an NCEP-I diet (30% of energy as fat) during a 25-d period. Subjects were then assigned to two 4-wk study periods, according to a randomized, crossover design. Group one was placed on an olive oil-enriched diet (40% fat, 22% MUFAs), followed by a 4-wk period of a sunflower oil-enriched diet (40% fat, 22% MUFAs). In group two, the order of the diets was reversed. Both MUFA dietary periods resulted in an increase in high-density-lipoprotein (HDL) cholesterol (7% for the olive oil diet and 4% for the sunflower oil diet) and in apolipoprotein (apo) A-I (9% for both) compared with the NCEP-I diet. Low-density-lipoprotein (LDL) cholesterol and apo B concentrations (x +/- SEM) were lower (P < 0.05) during the sunflower oil diet (2.40 +/- 0.11 mmol/L, 0.85 +/- 0.04 mg/L) than during the olive oil diet (2.64 +/- 0.15 mmol/L, 0.93 +/- 0.05 mg/L). No significant differences were observed in these variables between the sunflower oil and NCEP-I (2.48 +/- 0.13 mmol/L, 0.89 +/- 0.04 mg/L) diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Low-fat and high-monounsaturated fatty acid diets decrease plasma cholesterol ester transfer protein concentrations in young, healthy, normolipemic men.

BACKGROUND: Cholesterol ester transfer protein (CETP) mediates the transfer of cholesteryl esters from HDL to apolipoprotein (apo) B-containing lipoproteins. The possible atherogenic role of this protein is controversial. Diet may influence plasma CETP concentrations. OBJECTIVE: The objective was to determine whether the changes in plasma lipids observed after consumption of 2 lipid-lowering diets are associated with changes in plasma CETP concentrations. DESIGN: : We studied 41 healthy, normolipidemic men over 3 consecutive 4-wk dietary periods: a saturated fatty acid-rich diet (SFA diet: 38% fat, 20% saturated fat), a National Cholesterol Education Program Step I diet (NCEP Step I diet: 28% fat, 10% saturated fat), and a monounsaturated fatty acid-rich diet (MUFA diet: 38% fat, 22% monounsaturated fat). Cholesterol content (27.5 mg/MJ) was kept constant during the 3 periods. Plasma concentrations of total, LDL, and HDL cholesterol; triacylglycerol; apo A-I and B; and CETP were measured at the end of each dietary period. RESULTS: Compared with the SFA diet, both lipid-lowering diets significantly decreased plasma total and LDL cholesterol, apo B, and CETP. Only the NCEP Step I diet lowered plasma HDL cholesterol. Positive, significant correlations were found between plasma CETP and total (r = 0.3868, P < 0.0001) and LDL (r = 0.4454, P < 0.0001) cholesterol and also between changes in CETP concentrations and those of total (r = 0.4543, P < 0.0001) and LDL (r = 0.4554, P < 0.0001) cholesterol. CONCLUSIONS: The isoenergetic substitution of a high-saturated fatty acid diet with an NCEP Step I or a high-monounsaturated fatty acid diet decreases plasma CETP concentrations.

Influence of the SstI polymorphism at the apolipoprotein C-III gene locus on the plasma low-density-lipoprotein-cholesterol response to dietary monounsaturated fat.

The plasma lipid response to changes in dietary fat and cholesterol can vary between individuals. The SstI polymorphism, arising from a cytosine to guanosine substitution in the 3' untranslated region of the APOC3 gene distinguishes between two alleles--S1 and S2. The S2 allele has been associated with elevated plasma triacylglycerol, cholesterol, and apolipoprotein (apo) C-III concentrations. In 90 young men we examined the effect of the same mutation on the response of low-density-lipoprotein (LDL) cholesterol to dietary monounsaturated fat. The frequency for the S2 allele was 0.14. Subjects were fed a low-fat diet for 25 d, followed by a diet rich in monounsaturated fatty acid (22% MUFA, 38% total fat) for 28 d; lipoproteins were measured at the end of each diet. There were no significant differences in initial total cholesterol between subjects with the APOC3*S1/APOC3*S1 (S1/S1) and APOC3*S1/APOC3*S2 (S1/S2) genotypes. After consumption of the diet high in MUFA, significant increases in LDL cholesterol (0.13 mmol/L, P < 0.027) were noted in the S1/S1 subjects whereas a significant decrease was observed in the S1/S2 subjects (-0.18 mmol/L, P < 0.046). Significant genotypic effects were seen for diet-induced changes in LDL cholesterol (P < 0.00034), total cholesterol (P < 0.009), and apo B (P < 0.0014). A study of the effect of the interaction between this mutation with that present in position -76 of the APOA1 gene promoter region (G/A) revealed that both mutations had an additive effect on changes in total cholesterol, LDL cholesterol, and apo B induced by diets. Plasma LDL-cholesterol responsiveness to the diet may be explained, at least in part, by variation at the APOC3 gene locus.

Effects of different dietary cholesterol concentrations on lipoprotein plasma concentrations and on cholesterol efflux from Fu5AH cells.

BACKGROUND: The fatty acid composition of the diet can modulate the effect of dietary cholesterol on plasma lipoproteins. However, HDL composition and its capacity to promote cholesterol efflux can be influenced by the diet. OBJECTIVE: Modifications in plasma lipids and in the capacity of serum to stimulate the cholesterol efflux induced by a low-fat diet [National Cholesterol Education Program (NCEP) Step I diet], by a monounsaturated fatty acid (MUFA)-rich diet, and by addition of cholesterol to both diets was studied. DESIGN: Fifteen young, healthy men followed 2 NCEP Step I diets (<30% of fat as energy, with <10% saturated fat and 14% MUFAs) for 24 d, providing 0.027 or 0.068 mg cholesterol x kJ(-1) x d(-1), and 2 oleic acid-enriched diets (38% of energy as fat, with 24% MUFAs) providing the same amount of dietary cholesterol as the NCEP Step I diets. RESULTS: Total cholesterol, LDL cholesterol, apolipoprotein (apo) B, and apo A-I concentrations decreased after the NCEP Step I and MUFA diets compared with the usual diet. HDL cholesterol also decreased after the NCEP Step I diet. Total:HDL cholesterol, apo B, and apo B:apo A-I were lower after the MUFA diets than after the NCEP Step I diets. There were no significant differences between the lipid profiles obtained after the NCEP Step I and MUFA diets were enriched with cholesterol. The capacity of serum to promote cholesterol efflux was significantly higher after the cholesterol-enriched NCEP Step I diet than after the NCEP Step I diet. CONCLUSIONS: The MUFA diet induced a better lipid profile than the NCEP Step I diet; however, the increase in the cholesterol content of both diets produced similar plasma lipid changes. The cholesterol in the NCEP Step I diet increased the cholesterol efflux induced by total serum.