| For medical practitioners and the general public - Cholesterol Journal Article Catalog. |
| First Page | Previous Page | Next Page | Last Page |
| Insulin sensitivity after a reduced-fat diet and a monoene-enriched diet in subjects with elevated serum cholesterol and triglyceride concentrations Louheranta, A. M., U. S. Schwab, et al. (2000), Nutr Metab Cardiovasc Dis 10(4): 177-87. Abstract: BACKGROUND AND AIMS: To investigate the effect of a reduced-fat diet and a monoene-enriched diet (MUFA diet) on serum lipids, glucose and insulin metabolism in subjects with elevated cholesterol and triglyceride concentrations. METHODS AND RESULTS: Eighteen subjects with elevated serum cholesterol and triglyceride concentrations consumed the MUFA diet (39% of energy (E%) as fat and 21 E% monoenes) and the reduced-fat diet (34 E% fat, 16 E% monoenes) for 4 weeks according to a randomized cross-over design. Both periods were preceded by consumption of a standardized baseline diet for 2 weeks. Serum lipid and lipoprotein concentrations were determined at the beginning and end of each diet period. A frequently sampled intravenous glucose tolerance test was performed after the MUFA diet and the reduced-fat diet. Insulin sensitivity index (SI) was 40% higher after the reduced-fat diet than after the MUFA diet (2.42 +/- 0.42 vs 1.73 +/- 0.24 10(-4) min-1 U-1 ml-1, p = 0.018). This change in insulin sensitivity was seen in 13 subjects and was most evident in those who began with the MUFA diet. Compared to the baseline diet (high in saturated fat), both experimental diets lowered serum total and LDL cholesterol concentrations (6.6-6.9%, p < 0.05 and 7.4-8.0%, p < 0.05 respectively). CONCLUSIONS: Both diets were equally effective in lowering serum lipid concentrations, but the reduced-fat diet resulted in better insulin sensitivity. |
| Insulin, diabetes and cholesterol metabolism Monnier, L., C. Colette, et al. (1995), C R Seances Soc Biol Fil 189(5): 919-31. Abstract: Cholesterol metabolism is altered in diabetic states. Three main mechanisms seem to be involved in these alterations: a) an increased glycation of cholesterol-rich lipoproteins, b) an insulin-resistant state which is mainly present in overweight type 2 diabetic patients, and c) changes in insulin secretion which depends on the clinical type of diabetes. Insulin per se exerts beneficial effects on the metabolism of cholesterol binding lipoproteins. Despite insulin has a stimulatory influence on the endogenous cholesterol synthesis from Acetyl-CoA, this hormone tends to decrease the LDL cholesterol concentrations through two additional effects: a diminution in the ApoB VLDL synthesis and an increase in the LDL catabolism. In well controlled diabetic patients, plasma concentrations of cholesterol binding lipoproteins are generally found within the normal range. These patients exhibit usually a normal sensitivity to insulin in the liver and peripheral tissues. In this case, the VLDL production is generally decreased, the LDL catabolism is either increased or normal, and therefore the endogenous cholesterol synthesis from Acetyl-CoA remains setted at a normal level. In poorly controlled and/or in insulin resistant diabetic patients, both VLDL cholesterol production and cholesterogenesis are increased, mainly as a consequence of the insulin-resistant state. The excessive glycation of LDL results in a diminution of their catabolism and therefore in an increase of their plasma concentrations. The reverse cholesterol transport pathway is also altered, the modifications being characterized by a diminution in HDL cholesterol concentrations, especially in the HDL2 subfraction. All these changes are certainly involved in the accelerated development of cardio-vascular complications encountered in diabetic patients. |
| Insulin-like growth factor I and low-density-lipoprotein cholesterol in women during high- and low-fat feeding Prewitt, T. E., T. G. Unterman, et al. (1992), Am J Clin Nutr 55(2): 381-4. Abstract: In vitro studies suggest that insulin-like growth factor I (IGF-I) may modulate hepatic production and peripheral utilization of lipoproteins. We measured blood concentrations of IGF-I; total, high-density-lipoprotein, and low-density-lipoprotein (LDL) cholesterol; and apolipoproteins in 18 women with above average cholesterol after high- and low-fat diet periods. Total cholesterol fell 6% (P less than 0.02) during the low-fat diet because of reduced concentrations of LDL cholesterol (P less than 0.01). Serum concentrations of IGF-I were inversely correlated with total and LDL cholesterol and apolipoprotein B during both high-fat (r = -0.676, P less than 0.005; r = -0.745, P less than 0.001; and r = -0.504, P less than 0.04, respectively) and low-fat (r = -0.656, P less than 0.005; r = -0.757, P less than 0.001; and r = -0.695, P less than 0.001, respectively) diets. IGF-I increased with reduced fat intake in obese subjects only. Thus, IGF-I may contribute to the regulation of LDL cholesterol in mildly hypercholesterolemic women but may not mediate the beneficial response to reduced fat intake. |
| Insulin-like growth factor I enhancement of steroidogenesis by bovine granulosa cells and thecal cells: dependence on de novo cholesterol synthesis Spicer, L. J., T. D. Hamilton, et al. (1996), J Endocrinol 151(3): 365-73. Abstract: Studies were conducted to determine the importance of de novo cholesterol synthesis and cholesterol side-chain cleavage enzyme in the action of IGF-I in bovine granulosa and thecal cells. Granulosa and thecal cells from bovine follicles were cultured for 2 days in 10% fetal calf serum and then treated with luteinizing hormone (100 ng/ml) and IGF-I (0 or 100 ng/ml) for an additional 2 days in serum-free medium. During the last 24 h of treatment, cells were concomitantly treated with simvastatin (0, 0.5 or 5 micrograms/ml) or 25-hydroxycholesterol (0 or 10 micrograms/ml). Simvastatin, a potent inhibitor of the key enzyme controlling de novo cholesterol synthesis, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, completely inhibited (P < 0.05) progesterone production by granulosa cells and progesterone and androstenedione production by thecal cells. Simvastatin also inhibited (P < 0.05) granulosa cell and thecal cell proliferation. Concomitant treatment with mevalonate, an immediate product of HMG-CoA reductase, attenuated the inhibitory effect of simvastatin on progesterone and androstenedione production by thecal cells and blocked the inhibitory effect of simvastatin on cell proliferation. The addition of 25-hydroxycholesterol, a substrate for cholesterol side-chain cleavage enzyme, had no effect (P > 0.10) on IGF-I-stimulated progesterone or androstenedione production by thecal cells and actually inhibited (P < 0.05) IGF-I-stimulated progesterone production by granulosa cells. These results provide indirect evidence indicating that stimulation of HMG-CoA reductase is an important locus of IGF-I action in bovine granulosa and thecal cells, whereas IGF-I has little or no effect on side-chain cleavage enzyme activity in these same cell types under the culture conditions employed. |
| Insulin-like growth factor-binding protein-1 is correlated with low density lipoprotein cholesterol in normal subjects Hopkins, K. D., E. D. Lehmann, et al. (1994), J Endocrinol 140(3): 521-4. Abstract: Insulin-like growth factor-I (IGF-I) has been inversely associated with low-density lipoprotein (LDL) cholesterol in normal women with slightly elevated cholesterol levels and hypothyroid women. More than 95% of IGF-I circulates bound to binding proteins (IGFBPs); of these IGFBP-1 is of particular interest as it is inversely regulated by insulin and is thought to inhibit the action of IGF-I and IGF-II. We examined the relationship between IGFBP-1 and LDL cholesterol in 41 healthy adult subjects. LDL cholesterol correlated with the body mass index (r = 0.40, P < 0.01), sex (r = 0.51, P < 0.001) and IGFBP-1 levels (r = 0.36, P < 0.02). LDL cholesterol did not correlate with age (r = 0.25, P = not significant) or IGF-I (r = 0.06, P = not significant). Upon multivariate regression analysis, sex, body mass index and IGFBP-1 were all independent predictors of LDL cholesterol (all P < 0.05). Elevated IGFBP-1 levels have been associated with an inhibition of serum IGF-I bioactivity in children with insulin-dependent diabetes. IGFBP-1 also appears to inhibit IGF-I hexose-stimulated uptake. IGFBP-1 may also be inhibiting the effect of IGFs on the cellular metabolism of LDL cholesterol. |
| Insulin-mediated venodilation is impaired in patients with high cholesterol Sung, B. H., M. Ching, et al. (1998), Hypertension 31(6): 1266-71. Abstract: Recently we have reported that insulin attenuates norepinephrine (NE)-induced vasoconstriction via a cyclic GMP-NO synthase pathway. Because hypercholesterolemia has been associated with abnormal endothelial function, we investigated whether insulin-mediated vasodilation is impaired in hypercholesterolemia. To assess vasoreactivity, NE (12.5, 25, 50, and 100 ng/min), NE (100 ng/min) combined with insulin (8, 16, 24, and 32 microU/min), and NE (100 ng/min) combined with sodium nitroprusside (0.01, 0.1, 1, 10, and 100 ng/min) were infused into dorsal hand veins. Changes in venous diameter were measured by ultrasonography, using a 7.5-MHz transducer. Twenty-two healthy, normotensive hypercholesterolemic subjects (HC; mean total cholesterol 6.93 mmol/L, HDL 1.45 mmol/L, LDL 4.81 mmol/L) and 18 age-matched normal control subjects (NC; mean total cholesterol 4.81 mmol/L, HDL 1.16 mmol/L, LDL 3.18 mmol/L) were studied. All HC had normal glucose tolerance test results. Baseline vein diameters were similar between groups, and the vasoconstrictor response to NE was not significantly different between HC and NC. Insulin significantly attenuated NE-induced vasoconstriction in NC but not in HC (P<0.01). Both groups were able to venodilate with sodium nitroprusside. To investigate the effects of cholesterol reduction on vascular reactivity, venoreactivity studies were repeated in 12 HC after treatment with 20 to 40 mg/d lovastatin for 6 weeks. There were no significant venoreactivity changes with the treatment. Plasma LDL cholesterol concentration was inversely correlated to venodilator effect of insulin (r=-0.42, P<0.02). In conclusion, insulin-mediated vasodilation is impaired in patients with high cholesterol. Absence of normal insulin-mediated but not sodium nitroprusside-induced venodilation in hypercholesterolemia suggests that insulin-mediated vasodilation is endothelium dependent. |
| Intake and indicators of iron and zinc status in children consuming diets low in saturated fat and cholesterol: the STRIP baby study. Special Turku Coronary Risk Factor Intervention Project for Babies Niinikoski, H., P. Koskinen, et al. (1997), Am J Clin Nutr 66(3): 569-74. Abstract: A low-fat diet may predispose children to low meat consumption, low iron intake, and iron deficiency. In the randomized prospective Special Turku Coronary Risk Factor Intervention Project for Babies (STRIP baby study), families of 540 children were counseled to reduce exposure of children > 7 mo of age to known environmental risk factors for coronary heart disease. The control group consisted of 522 children whose families received no specific counseling concerning dietary fat. Iron and zinc intakes of 79 children aged 3-4 y (40 in the intervention group and 39 in the control group) were assessed with 4-d food records. The children in the intervention group consumed less saturated fat than those in the control group and had continuously higher ratios of dietary polyunsaturated to saturated fatty acids. Mean (+/- SD) daily iron intakes in the intervention and control groups were 8.8 +/- 4.2 mg and 8.6 +/- 2.8 mg, respectively. Laboratory findings in the intervention and control groups, respectively, were as follows: hemoglobin, 123 +/- 8 and 122 +/- 7 g/L; mean cell volume, 81.8 +/- 2.9 and 81.7 +/- 3.2 fL; mean corpuscular hemoglobin, 28.1 +/- 1.3 and 27.8 +/- 1.4 pg; ferritin, 21.8 +/- 11.6 and 19.2 +/- 12.4 microg/L; transferrin, 2.90 +/- 0.30 and 2.85 +/- 0.29 g/L; and transferrin receptor, 2.34 +/- 0.46 and 2.29 +/- 0.39 mg/L. There were no significant differences between the groups. Daily zinc intakes were 7.5 +/- 1.2 mg in the intervention group and 7.4 +/- 1.3 mg in the control group; respective serum zinc concentrations were 11.2 +/- 1.9 and 10.5 +/- 1.6 micromol/L (NS). In conclusion, long-term supervised use of a diet low in saturated fat and cholesterol did not influence intake or serum indicators of iron and zinc in children. |
| Intake of 25 g of soybean protein with or without soybean fiber alters plasma lipids in men with elevated cholesterol concentrations Bakhit, R. M., B. P. Klein, et al. (1994), J Nutr 124(2): 213-22. Abstract: Twenty-one mildly hypercholesterolemic men consumed a diet that was low in fat (< 30% of energy) and cholesterol (300 mg/d) and were given muffins containing 25 g protein + 20 g dietary fiber daily from either isolated soybean protein + soybean cotyledon fiber, isolated soybean protein + cellulose, casein + soybean cotyledon fiber or casein + cellulose. All subjects progressed through the low fat, low cholesterol baseline period, lasting 2 wk, and then through all four dietary treatments, lasting 4 wk each, according to a Latin square design. Plasma concentrations of total, LDL, HDL and VLDL cholesterol, total and VLDL triacylglycerols, and apolipoprotein A-I and B were measured at the end of each period. When data from all subjects were analyzed, dietary treatments did not influence lipemia; however, in subjects with initial total cholesterol concentrations > 5.7 mmol/L, both isolated soybean protein treatments resulted in significantly lower total cholesterol compared with the two casein treatments (P < 0.05). In addition, a negative linear relationship was observed when a subject's total or LDL cholesterol change after each of the soybean treatments was regressed against the subject's baseline cholesterol concentration (P < 0.05). Apolipoprotein A-I varied dependent on baseline cholesterol with no apparent pattern, whereas apolipoprotein B levels were not affected. Results indicate that consumption of 25 g soybean protein/d is associated with lower total cholesterol concentrations in individuals with initial cholesterol concentrations > 5.7 mmol/L. |
| Intake of dietary plant sterols is inversely related to serum cholesterol concentration in men and women in the EPIC Norfolk population: a cross-sectional study Andersson, S. W., J. Skinner, et al. (2004), Eur J Clin Nutr 58(10): 1378-85. Abstract: OBJECTIVE: We examined the relation between intake of natural dietary plant sterols and serum lipid concentrations in a free-living population. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional population-based study of 22,256 men and women aged 39-79 y resident in Norfolk, UK, participating in the European Prospective Investigation into Cancer (EPIC-Norfolk). MAIN EXPOSURE AND OUTCOME MEASURES: Plant sterol intake from foods and concentrations of blood lipids. RESULTS: Mean concentrations of total cholesterol and low-density lipoprotein cholesterol, adjusted for age, body mass index and total energy intake, decreased with increasing plant sterol intake in men and women. Mean total serum cholesterol concentration for men in the highest fifth of plant sterol intake (mean intake 463 mg daily) was 0.25 mmol/l lower and for low-density lipoprotein cholesterol 0.14 mmol/l lower than those in the lowest fifth of plant sterol consumption (mean intake 178 mg daily); the corresponding figures in women were 0.15 and 0.13 mmol/l. After adjusting for saturated fat and fibre intakes, the results for total cholesterol and low-density lipoprotein cholesterol were similar, although the strength of the association was slightly reduced. CONCLUSIONS: In a free-living population, a high intake of plant sterols is inversely associated with lower concentrations of total and low-density lipoprotein serum cholesterol. The plant sterol content of foods may partly explain diet-related effects on serum cholesterol concentration. |
| Intake of olive oil can modulate the transbilayer movement of human erythrocyte membrane cholesterol Muriana, F. J., J. Villar, et al. (1997), Cell Mol Life Sci 53(6): 496-500. Abstract: Transbilayer movement of erythrocyte membrane cholesterol is impaired in patients affected with essential hypertension. This is an inherited disorder, but environmental factors are also involved. Dietary fats might play a role in the prevention and/or treatment of such abnormality in the kinetic pools of membrane cholesterol. We tested this hypothesis by using a diet (in which 30% of the energy came from fat) rich in olive oil or in high-oleic sunflower oil (as natural sources of monounsaturated fatty acids, MUFAs) and determining their influence on the movement of cholesterol into the lipid bilayer of the erythrocyte membrane after a four-week period. We concluded that dietary olive oil is helpful in normalizing the impaired transbilayer movement of membrane cholesterol in erythrocytes of eight normocholesterolaemic and eight hypercholesterolaemic hypertensive patients. However, the effects cannot be attributed exclusively to the content of MUFAs (mainly oleic acid) in the diet, as high-oleic sunflower oil was unable to induce favourable changes. |
| Intake of unsaturated fatty acids and HDL cholesterol levels are associated with manifestations of atopy in adults Schafer, T., S. Ruhdorfer, et al. (2003), Clin Exp Allergy 33(10): 1360-7. Abstract: BACKGROUND: The increase in allergic diseases is still unexplained. It was hypothesized that the intake of unsaturated fatty acids is a contributing cause of this development. We investigated the relationship between serum cholesterol levels, intake of polyunsaturated fatty acids (PUFA) and manifestations of atopy in a population-based setting. METHODS: A nested case-control study was performed within the population of the 3rd MONICA survey in Augsburg (Germany). The serum levels of total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol of 1537 adults (aged 28-78 years, response 61.4%) and the estimated intake of PUFA in a subset of 139 men were compared with the frequency of a doctor's diagnosis of asthma, allergic rhinoconjunctivitis (AR), atopic eczema (AE) and allergic sensitization as measured by skin prick and Radio Allergo Sorbent Test. FINDINGS: In bivariate analyses, we obtained a negative linear association between total and LDL cholesterol levels and the frequency of AR and sensitization, which was no longer significant after adjustment for important confounders. In contrast, positive linear associations were found between HDL cholesterol levels and AR and AE and, furthermore, between the intake of PUFA and allergic sensitization in men (P<0.01). After adjustment, an increasing risk for atopic diseases with increasing levels of HDL cholesterol and an increasing risk for allergic sensitization with increasing intakes of PUFA remained statistically significant. INTERPRETATION: There is indication that HDL cholesterol also plays a role in the complex interaction of fat intake, metabolism and the manifestation of atopy in adults. These findings may contribute to the understanding of time trends and regional differences of allergies. |
| Intense cholesterol lowering therapy with a HMG-CoA reductase inhibitor does not improve nitric oxide dependent endothelial function in type-2-diabetes--a multicenter, randomised, double-blind, three-arm placebo-controlled clinical trial Balletshofer, B. M., S. Goebbel, et al. (2005), Exp Clin Endocrinol Diabetes 113(6): 324-30. Abstract: Disturbances in nitric oxide (NO) metabolism resulting in endothelial dysfunction play a central role in the pathogenesis of atherosclerosis in hypercholesterolemia and in individuals with type 2 diabetes. It is unclear whether lipid lowering therapy with HMG-CoA-reductase inhibitors might improve endothelial function in subjects with type 2 diabetes as it is demonstrated in non-diabetic subjects with hypercholesterolemia. We examined the influence of 0.2 mg and 0.8 mg cerivastatin on endothelial function in a multicenter, randomised, double-blind, and three-arm placebo-controlled clinical trial. Endothelial function was assessed by nitric oxide-dependent flow mediated vasodilatation (FMD) of the brachial artery. A total of 103 patients with type 2 diabetes were enrolled in the study. Bayer Company undertook a voluntary action to withdraw cerivastatin from market, therefore the study was terminated earlier. At this point 77 patients were randomised, of which 58 completed the study (mean age 60 +/- 8 years, HbA1c 7.4 +/- 0.9 %). At baseline mean FMD was disturbed in all three therapy arms (5.18 +/- 2.31 % in the placebo group, 3.88 +/- 1.68 in the 0.2-mg cerivastation group, and 4.86 +/- 2.25 in the 0.8-mg cerivastatin group). Despite a significant reduction in cholesterol and LDL-cholesterol-levels after 12 weeks of treatment (decrease in LDL-cholesterol - 26.8 +/- 13.9 % in the 0.2-mg group and - 40.3 +/- 16.0 % in the 0.8-mg group, p = 0.0001, ANCOVA) there was no difference in flow mediated vasodilatation (p = 0.52 and p = 0.56 vs. placebo, respectively, ANCOVA). HbA1c, CRP, and HDL-cholesterol did not change during the study. Furthermore no difference in safety profile between cerivastatin and placebo was found. Despite a significant improvement in lipid profile under statin therapy, no improvement of endothelial dysfunction in terms of nitric oxide bioavailability could be detected. |
| Intense dietary counseling lowers LDL cholesterol in the recruitment phase of a clinical trial of men who had coronary artery bypass grafts Shenberger, D. M., R. J. Helgren, et al. (1992), J Am Diet Assoc 92(4): 441-5. Abstract: Intense dietary counseling lowered low-density-lipoprotein (LDL) cholesterol levels during the recruitment phase of a 5-year clinical trial of men who had undergone coronary artery bypass grafts. At visit 1, a 24-hour dietary recall was obtained and analyzed for intakes of total energy; total, saturated, monounsaturated, and polyunsaturated fat; and dietary cholesterol. Participants were then instructed to follow the National Cholesterol Education Program (NCEP) Step I diet. Additional dietary counseling was provided at 1-month intervals during visits 2 and 3. At visit 3, another 24-hour dietary recall was obtained and analyzed similarly. Of 59 men with an LDL cholesterol level greater than 4.5 mmol/L at visit 1, 52 decreased their level to 4.5 mmol/L or less to qualify for the 5-year study. Between visits 1 and 3, mean LDL cholesterol levels decreased significantly from 4.86 +/- 0.04 mmol/L to 4.27 +/- 0.05 mmol/L, which coincided with significant mean decreases in dietary intake of total fat from 33.4 +/- 1.3% to 25.2 +/- 1.4%, saturated fat from 11.1 +/- 0.6% to 7.0 +/- 0.4%, and dietary cholesterol from 122 +/- 6.1 to 90 +/- 6.3 mg/1,000 kcal. Overall, the dietary intake improved to more closely follow the NCEP Step II diet and resulted in a 10.7% decrease in total cholesterol level and a 12.4% decrease in LDL cholesterol level. |
| Intensive cholesterol reduction lowers blood pressure and large artery stiffness in isolated systolic hypertension Ferrier, K. E., M. H. Muhlmann, et al. (2002), J Am Coll Cardiol 39(6): 1020-5. Abstract: OBJECTIVES: We sought to investigate the effects of intensive cholesterol reduction on large artery stiffness and blood pressure in normolipidemic patients with isolated systolic hypertension (ISH). BACKGROUND: Isolated systolic hypertension is associated with elevated cardiovascular morbidity and mortality and is primarily due to large artery stiffening, which has been independently related to cardiovascular mortality. Cholesterol-lowering therapy has been efficacious in reducing arterial stiffness in patients with hypercholesterolemia, and thus may be beneficial in ISH. METHODS: In a randomized, double-blinded, cross-over study design, 22 patients with stage I ISH received three months of atorvastatin therapy (80 mg/day) and three months of placebo treatment. Systemic arterial compliance was measured noninvasively using carotid applanation tonometry and Doppler velocimetry of the ascending aorta. RESULTS: Atorvastatin treatment reduced total and low-density lipoprotein cholesterol and triglyceride levels by 36 +/- 2% (p < 0.001), 48 +/- 3% (p < 0.001) and 23 +/- 5% (p = 0.003), respectively, and increased high density lipoprotein cholesterol by 7 +/- 3% (p = 0.03). Systemic arterial compliance was higher after treatment (placebo vs. atorvastatin: 0.36 +/- 0.03 vs. 0.43 +/- 0.05 ml/mm Hg, p = 0.03). Brachial systolic blood pressure was lower after atorvastatin treatment (154 +/- 3 vs. 148 +/- 2 mm Hg, p = 0.03), as were mean (111 +/- 2 vs. 107 +/- 2 mm Hg, p = 0.04) and diastolic blood pressures (83 +/- 1 vs. 81 +/- 2 mm Hg, p = 0.04). There was a trend toward a reduction in pulse pressure (71 +/- 3 vs. 67 +/- 2 mm Hg, p = 0.08). CONCLUSIONS: Intensive cholesterol reduction may be beneficial in the treatment of patients with ISH and normal lipid levels, through a reduction in large artery stiffness. |
| Intensive nutrition counseling enhances outcomes of National Cholesterol Education Program dietary therapy Rhodes, K. S., L. C. Bookstein, et al. (1996), J Am Diet Assoc 96(10): 1003-10; quiz 1011-2. Abstract: OBJECTIVE: To compare the effect of the addition of medical nutrition therapy administered by a registered dietitian with the usual physician counseling on nutrition knowledge, attitudes regarding dietary change, body mass index, dietary intake, and lipid and lipoprotein concentrations during initial management of persons at risk for cardiovascular disease. DESIGN: A 3-month prospective, randomized trial of subjects stratified by sex and assigned to one of four nested treatment groups, which were subsequently collapsed into two groups. SUBJECTS: Fifty-two men and 52 women classified at risk for cardiovascular disease. INTERVENTION: Two groups of subjects received dietary counseling from a physician or nurse; in one group the Grocery Shopping Guide was used. Two other groups received medical nutrition therapy from a registered dietitian (one or three visits) in addition to the instruction from a physician or nurse and the information provided by the Grocery Shopping Guide. STATISTICAL ANALYSES: Analyses of covariance were performed to determine differences between the groups. Paired t tests were performed to study changes within the groups. RESULTS: The group receiving medical nutrition therapy from a registered dietitian gained statistically significantly more nutrition knowledge; had significantly greater perceptions of the benefits and efficacy of following a cholesterol-lowering diet; consumed a significantly lower percentage of fat, higher percentage of carbohydrate, and less dietary cholesterol than subjects counseled only by a physician or nurse. They also had significantly greater improvement in body mass index. Both groups of subjects achieved statistically significant reductions in serum lipid levels. APPLICATIONS: Increased knowledge, benefits, and efficacy and lower-fat eating behaviors associated with additional nutrition therapy may have significant implications on the ability of persons to follow low-fat eating plans long term, which could reduce the need for costly medication intervention. |
| Interaction among molecules in mixtures of ceramide/stearic acid, ceramide/cholesterol and ceramide/stearic acid/cholesterol Ohta, N. and I. Hatta (2002), Chem Phys Lipids 115(1-2): 93-105. Abstract: To elucidate the interaction among the molecules which constitute intercellular lipids of stratum corneum, the phase diagrams in the binary mixtures of N-octadecanoyl-phytosphingosine (CER)/stearic acid (SA) and CER/cholesterol (CHOL) were studied by differential scanning calorimetry and by small- and wide-angle X-ray diffraction. These phase diagrams are mostly expressed by a eutectic type one. However, from their detailed analyses, it was revealed that in the phase diagram of CER/SA a new solid structure is formed just above the eutectic temperature. The lamellar spacing of the new structure is nearly equal to the length given by the sum of the two molecules of CER and/or SA, that is, in the lipid bilayer the hydrocarbon chains of CER and SA lie almost perpendicular to the lipid bilayer surface and the two kinds of molecules distribute homogeneously. On the other hand, in the binary mixture of CER/CHOL, CHOL molecules are apt to be isolated from the mixture. In a ternary mixture composed of equimolar lipids of CER, CHOL and SA, it was found that a pseudo-hexagonal structure takes place even in the solid state. This fact indicates that the three components are miscible and the hydrocarbon chains lie perpendicular to the lipid bilayer surface. We can draw the conclusion that the multi-component mixtures containing ceramide are apt to form the lamellar structure where even in the solid state the hydrocarbon chains lie perpendicular to the lipid bilayer surface and the components with hydrocarbon chains distribute homogeneously. |
| Interaction between apo A-I-containing lipoproteins and lecithin:cholesterol acyltransferase Ikeda, Y., T. Ohta, et al. (1994), Biochim Biophys Acta 1215(3): 307-13. Abstract: HDL2 and HDL3 subfractions of two species of apo A-I-containing lipoprotein, one containing only apo A-I (LpA-I) and the other containing both apo A-I and apo A-II (LpA-I/A-II), were tested for reactivity to lecithin:cholesterol acyltransferase (LCAT). These subfractions and their mixtures were incubated with lipoprotein-deficient plasma (LCAT source), and the rate of cholesterol esterification and kinetic parameters were determined. Apparent Vmax (appVmax) and apparent Km (appKm) for HDL2 subfractions of LpA-I and LpA-I/A-II were significantly lower than those of their HDL3 counterparts. Differences between subfractions were much more prominent in LpA-I than in LpA-I/A-II. appVmax of the HDL2 subfraction of LpA-I (LpA-IHDL2) was one-fifth, and appKm was one-third of those for the HDL3 subfraction (LpA-IHDL3). appVmax and appKm of LpA-IHDL2 were both lowest among the apo A-I-containing lipoprotein subfractions. When LpA-IHDL2 was added to other subfractions, the molar rate of cholesterol esterification was suppressed. Since LpA-IHDL2 consists of a particle 11.1 nm in diameter, our observations suggest that LpA-IHDL2 suppresses cholesterol esterification in apo A-I-containing lipoprotein, possibly by displacing LCAT from other subfractions with higher appKm and higher appVmax to 11.1 nm LpA-I particles with lower appKm and lower appVmax. All of these data suggest that the relative amount of 11.1 nm LpA-I particles in plasma regulates the reactivity of apo A-I-containing lipoprotein to LCAT and may play a key role on the production of cholesteryl esters in plasma. |
| Interaction between factor V Leiden and serum LDL cholesterol increases the risk of atherosclerosis Volzke, H., B. Wolff, et al. (2005), Atherosclerosis 180(2): 341-7. Abstract: OBJECTIVES: We investigated the association between the factor V Leiden gene variant and carotid atherosclerosis in a cross-sectional study and explored possible associations between this gene variant and coronary artery disease (CAD) in a case-control study. METHODS: The presence (n=1696) or absence (n=703) of carotid atherosclerosis were sonographically assessed among participants of the population-based Study of Health in Pomerania (SHIP). The case-control study included 1021 patients with severe CAD and 2791 healthy SHIP participants. The factor V Leiden gene variant was determined by PCR and MnlI digestion. RESULTS: Multivariable analyses revealed no independent association between the factor V Leiden gene variant per se and carotid atherosclerosis or CAD. In the cross-sectional study, there was an interaction between the factor V Leiden gene variant and serum LDL cholesterol in non-diabetics with respect to the risk of carotid atherosclerosis. In the case-control study a similar interaction was found for CAD. In both studies the atherosclerotic risk increased with rising serum LDL cholesterol concentrations in carriers of the factor V Leiden gene variant. CONCLUSION: The co-existence between the factor V Leiden gene variant and high serum LDL cholesterol is independently associated with the risk of atherosclerosis. |
| Interaction between genes and diet as a determinant of the plasma levels of cholesterol Lopez Miranda, J., J. M. Ordovas, et al. (1998), Med Clin (Barc) 111(14): 546-51. |
| Interaction between protein kinase C and sphingomyelin/cholesterol Jiang, Y., Z. Pan, et al. (1999), Cell Biol Int 23(7): 457-63. Abstract: Physical characteristics of binding of protein kinase C with sphingomyelin/cholesterol lipid bilayers were analysed using three complementary approaches: acrylodan fluorescence, fluorescence energy transfer and quenching of tryptophan fluorescence. It was demonstrated that sphingomyelin/cholesterol lipid membranes were available for protein kinase C binding. The intensity of the binding was dependent on the sphingomyelin content. The results of quenching of intrinsic tryptophan fluorescence showed that the enzyme molecule penetrated the sphingomyelin/cholesterol lipid bilayer to the C-16 position of labeled fatty acid probes. Our results also showed sphingomyelin itself restrains protein kinase C activity. A possible explanation for our results is that caveolae function as signaling storage devices. |