Effect of insulin resistance on postprandial elevations of remnant lipoprotein concentrations in postmenopausal women.

BACKGROUND: Questions remain as to why postmenopausal women are at a higher risk of coronary artery disease (CAD) than are premenopausal women. Studies have shown that plasma concentrations of remnant lipoproteins (RLPs) are elevated in patients with CAD and that increases in plasma RLP concentrations may be related to variations in insulin-mediated glucose disposal. OBJECTIVE: We sought to evaluate the possibility that postprandial accumulation of plasma RLPs will be accentuated in insulin-resistant, postmenopausal women. DESIGN: Postmenopausal women were divided into insulin-sensitive (n = 15) and insulin-resistant (n = 15) groups according to their steady state plasma glucose concentrations in response to a 180-min infusion of octreotide, insulin, and glucose. Plasma insulin, triacylglycerol, and RLP-cholesterol concentrations were measured either hourly (insulin) or every 2 h (triacylglycerol and RLP cholesterol) for 8 h, before and after breakfast (0800) and lunch (1200). RESULTS: By selection, insulin-resistant women had higher steady state plasma glucose concentrations than did insulin-sensitive women (10.8 +/- 0.5 compared with 4.1 +/- 5 mmol/L, respectively; P < 0.001), associated with higher fasting triacylglycerol (1.58 +/- 0.04 compared with 1.00 +/- 0.03 mmol/L; P = 0.01) and lower HDL-cholesterol (1.06 +/- 0.08 compared with 1.34 +/- 0.05; P = 0.01) concentrations. In addition, measurements of daylong concentrations of insulin, triacylglycerol, and RLP cholesterol were also significantly greater in insulin-resistant than in insulin-sensitive women (P < 0.001). CONCLUSIONS: Postprandial accumulation of RLPs is accentuated in insulin-resistant, postmenopausal women. This may contribute to the increased risk of CAD in these individuals.     

Postprandial lipemia in subjects with the threonine 54 variant of the fatty acid-binding protein 2 gene is dependent on the type of fat ingested

BACKGROUND: The alanine-for-threonine substitution at codon 54 (A54T polymorphism) in the fatty acid-binding protein 2 gene (FABP2) has been associated with hypertriglyceridemia and insulin resistance. Obese and diabetic T54 carriers have greater postprandial lipemia than do A54 homozygotes. The T54 protein isoform is also associated with increased triacylglycerol secretion in vitro. OBJECTIVE: We investigated diet-gene interactions by measuring postprandial lipids, glucose, insulin, and C-peptide in healthy, nonobese A54 homozygotes and T54 carriers after ingestion of 3 different fats. DESIGN: Eleven A54 homozygotes and 11 T54 carriers were given 3 oral-fat-tolerance tests (butter, safflower oil, and olive oil). Cholesterol and triacylglycerol were measured in plasma and in chylomicron fractions. RESULTS: There was no main effect of FABP2 genotype for chylomicron triacylglycerol, glucose, or C-peptide. The area under the insulin curve and the ratio of insulin to C-peptide were lower in T54 carriers than in A54 homozygotes [312 +/- 29 ( +/- SEM) compared with 425 +/- 31 pmol. h/L (P = 0.05) and 0.23 +/- 0.03 compared with 0.40 +/- 0.05 (P = 0.04), respectively], which suggests greater hepatic insulin clearance in T54 carriers. An association between genotype and chylomicron cholesterol was seen only after olive oil: values were higher (P = 0.02) in T54 carriers (0.087 +/- 0.006 mmol. h/L) than in A54 homozygotes (0.058 +/- 0.004 mmol. h/L). The main effect of fat was significant for the areas under the chylomicron cholesterol and chylomicron triacylglycerol curves [higher values for safflower (0.635 +/- 0.053 and 2.48 +/- 0.30 mmol. h/L, respectively) and olive (0.592 +/- 0.052 and 2.48 +/- 0.32 mmol. h/L, respectively) oils than for butter (0.425 +/- 0.043 and 1.69 +/- 0.20 mmol. h/L, respectively); P < 0.05]. CONCLUSIONS: The A54T polymorphism results in a diet-gene interaction: the T54 group had increased chylomicron cholesterol after olive oil only. Nevertheless, the greater hepatic insulin clearance in T54 carriers suggests that the polymorphism may not be deleterious in nonobese subjects.     

Changes in plasma lipoproteins during low-fat, high-carbohydrate diets: effects of energy intake

BACKGROUND: Low-fat diets can increase plasma triacylglycerol and reduce HDL cholesterol. Changes in energy intake and body weight can influence the lipoprotein response. OBJECTIVE: We sought to prospectively examine the effects of euenergetic and ad libitum dietary fat restriction on plasma lipoproteins in healthy postmenopausal women. DESIGN: Participants first received a controlled euenergetic diet in which dietary fat was reduced stepwise from 35% to 25% to 15% over 4 mo. Thereafter, participants followed an ad libitum 15%-fat diet for 8 mo; 54 women completed the intervention. RESULTS: During the controlled euenergetic diet, plasma triacylglycerol increased from 1.70 +/- 0.10 to 2.30 +/- 0.16 mmol/L, total cholesterol decreased from 5.87 +/- 0.13 to 5.53 +/- 0. 13 mmol/L, LDL cholesterol decreased from 3.41 +/- 0.10 to 2.87 +/- 0.10 mmol/L, HDL cholesterol decreased from 1.76 +/- 0.08 to 1.50 +/- 0.08 mmol/L, and apolipoprotein (apo) A-I decreased from 5.11 +/- 0.14 to 4.78 +/- 0.14 mmol/L (P < 0.0001 for all changes). Hormone replacement therapy did not affect the relative change in HDL cholesterol. Plasma glucose, insulin, hemoglobin A(1C,) free fatty acid, and apo B concentrations did not change significantly. During the ad libitum 15%-fat diet, participants lost 4.6 +/- 0.4 kg. Plasma triacylglycerol and LDL cholesterol returned to baseline values (1.77 +/- 0.12 and 3.31 +/- 0.08 mmol/L, respectively), whereas HDL cholesterol and apo A-I remained low (1.40 +/- 0.08 and 4.82 +/- 0.18 mmol/L, respectively). HDL cholesterol and apo A-I concentrations stabilized in subjects who were not receiving hormone replacement therapy but continued to decline in women who were receiving hormone therapy. CONCLUSIONS: The ad libitum 15%-fat diet resulted in significant weight loss. The euenergetic but not the ad libitum diet caused hypertriacylglycerolemia. HDL cholesterol decreased during both low-fat diets.     

Dietary medium-chain triacylglycerol prevents the postprandial rise of plasma triacylglycerols but induces hypercholesterolemia in primary hypertriglyceridemic subjects

BACKGROUND: Previous studies showed divergent results concerning the influence of medium-chain triacylglycerol (MCT) on lipoprotein metabolism. OBJECTIVE: The objective of this study was to compare the effects of MCT and corn oil on plasma lipids in primary hypertriglyceridemic patients. DESIGN: Ten subjects ate different proportions of corn oil and MCT for 12 wk. The subjects first ate a low-fat diet for 2 wk and during the next 4 wk, corn oil was added as the sole source of fat. Thereafter, for 2-wk periods, the subjects were sequentially fed corn oil and MCT mixed in the following proportions: 3:1, 1:1, and 0:1. Fasting plasma total cholesterol, triacylglycerol, and HDL-cholesterol concentrations were measured at the end of each period. At the end of the 100%-corn oil and of the 100%-MCT periods, subjects were fed a test meal containing the respective oil (40 g fat/m(2) body surface area) and total cholesterol and triacylglycerols were measured at 2-h intervals over 8 h; fasting lipoprotein composition was also measured. RESULTS: Compared with corn oil, MCT was associated with a higher mean (+/-SD) fasting total cholesterol concentration (6.39 +/- 1.14 compared with 5.51 +/- 0.98 mmol/L, respectively; P < 0. 05); non-HDL-cholesterol concentrations were also higher with MCT (5. 36 +/- 1.11 mmol/L) than with corn oil (4.51 +/- 0.92 mmol/L; P < 0. 005). In response to the liquid test meal, plasma total cholesterol did not change with either diet but triacylglycerols increased with the 100%-corn oil diet. CONCLUSIONS: MCT prevents the risk of pancreatitis due to postprandial hypertriglyceridemia but has the inconvenience of raising total cholesterol concentrations in primary hypertriglyceridemic subjects.     

Behenic acid is a cholesterol-raising saturated fatty acid in humans

BACKGROUND: Dietary behenic acid (22:0) is poorly absorbed. Because of its low bioavailability compared with other fatty acids and because of its very long chain length, the effect of dietary behenic acid (behenate) on serum lipid concentrations in humans is assumed to be neutral. OBJECTIVE: The objective was to establish the cholesterol-raising potential of behenic acid by comparing the effects on lipid and lipoprotein concentrations of a specially formulated fat enriched with behenic acid with those of palm oil (rich in palmitic acid; 16:0) and high-oleic acid sunflower oil (rich in cis oleic acid; 18:1). DESIGN: In a randomized, crossover, metabolic-ward study, 7 mildly hypercholesterolemic men were fed 3 natural-food diets supplemented with behenate oil, palm oil, or high-oleic acid sunflower oil. Mean serum lipid and lipoprotein concentrations and plasma triacylglycerol fatty acid composition were determined from fasting blood drawn during the final 4 d of each 3-wk diet period. RESULTS: Behenate oil produced mean concentrations of total cholesterol (5.87+/-0.8 mmol/L) and LDL cholesterol (4.40+/-0.8 mmol/L) not significantly different from those produced by palm oil (5.84+/-0.7 and 4.42+/-0.7 mmol/L, respectively) but significantly higher than those produced by high-oleic acid sunflower oil (5.12+/-0.5 and 3.70+/-0.6 mmol/L, respectively). There were no significant differences in triacylglycerol or HDL-cholesterol concentrations. CONCLUSIONS: Despite its low bioavailability compared with oleic acid, behenic acid is a cholesterol-raising fatty acid in humans and is therefore not a suitable substitute for palmitic acid in manufactured triacylglycerols.     

Non-attendance at secondary prevention clinics: the effect on lipid management

BACKGROUND: Secondary prevention of coronary artery disease is effective in reducing morbitiy and mortality. Our aim was to assess lipid management following non-attendance to a hospital based secondary prevention clinic. METHODS: Data were collected over 5 years on statin usage and total cholesterol levels for patients with coronary artery disease following attendance at a cardiac nurse led outpatient clinic. Lipid levels were taken from a central laboratory database, for both patients discharged from clinic and non-attenders. RESULTS: From 935 inpatients discharged from hospital, 248 (29%) defaulted from outpatient follow up. Lipid lowering drug usage was similar (72% vs. 74% for non-attenders, p=NS). Attenders at the nurse led outpatient clinic were more likely to achieve a total cholesterol <5 mmol/L at discharge than non-attenders (70% vs. 43%; p < 0.001), with a lower mean total cholesterol (4.75 +/- 0.06 mmol/L vs. 5.33 +/- 0.08 mmol/L; p < 0.001). Non-attenders subsequently had a greater number of cholesterol measurements than those who were discharged from the hospital based clinic (range 0-12, c2 23.8 on 12 df p < 0.005). Lipid profiles in hospital non-attenders remained inferior with fewer achieving a total cholesterol <5 mmol/L (61% vs. 78%; p < 0.001), and having greater mean total cholesterol levels (4.85 +/- 0.06 mmol/L vs. 4.52 +/- 0.05 mmol/L; p < 0.001). CONCLUSIONS: Patients defaulting from hospital follow up have higher total cholesterols with fewer at target level compared to attenders. Though non-attenders receive subsequent lipid measurement, inferior lipid profiles persist compared to patients who completed hospital follow up to be discharged. Further implementation strategies are needed with regard to lipid management in this patient group.     

Carbohydrate and lipid metabolism in patients with non-insulin-dependent diabetes mellitus: effects of a low-fat, high-carbohydrate diet vs a diet high in monounsaturated fatty acids

Nineteen patients affected by non-insulin dependent diabetes mellitus (NIDDM), in good glycemic control (fasting plasma glucose 7.2 +/- 0.3 mmol/L, glycosylated hemoglobin 6.3 +/- 0.2%), underwent three isocaloric dietary phases. In phases 1 and 3 the diet was rich in complex carbohydrates (Carbo) whereas in phase 2 it was rich in monounsaturated fatty acids (Mono). Plasma glucose concentrations were 7.1 +/- 0.3 and 7.2 +/- 0.3 mmol/L for the two Carbo phases and 7.5 +/- 0.4 mmol/L for the Mono phase (NS). Plasma total cholesterol values for the Carbo phases were 6.2 +/- 0.2 and 6.4 +/- 0.2 mmol/L, respectively, and 6.5 +/- 0.2 mmol/L on the Mono phase (NS). Similarly, no significant changes were noticed for plasma triglycerides and high-density-lipoprotein (HDL) cholesterol. Thus, both diets were well-tolerated and did not alter glucose homeostasis or worsen plasma lipid concentrations. Consequently, these results suggest that a wider dietary choice can be made available to NIDDM patients without producing unwanted side effects.     

Diacylglycerol oil ingestion in type 2 diabetic patients with hypertriglyceridemia

OBJECTIVE: Coronary arteriosclerotic heart disease frequently develops in patients with diabetes. Decreases in [corrected] serum high-density lipoprotein cholesterol (HDL-C) [corrected] concentration and low-density lipoprotein (LDL) particle size, accompanied by hypertriglyceridemia, are associated with the onset of atherosclerosis. We recently reported that hypertriglyceridemia was significantly improved in patients with type 2 diabetes who ingested diacylglycerol (DAG) oil. The effect on variables, including LDL particle size related to lipid metabolism, however, was not examined. The present study investigated the effects on these variables in more detail. METHODS: Patients with type 2 diabetes (n = 24) were assigned to receive DAG oil or triacylglycerol oil, and a 3-mo, single-blind, controlled study was performed. Patients replaced cooking oil in their daily diet with DAG or triacylglycerol oil, and anthropometry and blood sampling were performed at monthly intervals. RESULTS: There were no significant differences in calorie intake or amount of test oil ingested between groups. Waist circumference and serum triacylglycerol concentrations were significantly lower and serum concentrations of high-density lipoprotein cholesterol and apolipoprotein-AI were significantly higher in the DAG oil group than in the triacylglycerol oil group. Plasma plasminogen activator inhibitor-1 concentrations were significantly lower in the DAG oil group. LDL particle size tended to increase in the DAG oil group and was significantly larger in patients who had a small initial LDL particle size (<25.5 nm). There were no significant differences in variables related to glucose metabolism or in serum concentration of free fatty acids or total ketone bodies. CONCLUSIONS: These results indicate that DAG oil may be useful for patients who have type 2 diabetes in the management of obesity and lipid abnormalities.     

Dietary counselling effectively improves lipid levels in patients with endogenous hypertriglyceridemia: emphasis on weight reduction and alcohol limitation.

OBJECTIVE: To evaluate the short-term effect of dietary counselling in patients with endogenous hypertriglyceridemia and evaluate the effects of advised nutrient changes. DESIGN: A prospective dietary intervention study in patients with endogenous hypertriglyceridemia from January I st 1988 to December 31 st 1996 according to the Dutch guidelines for a healthy diet. Before and after the dietary intervention period of 12 weeks, 24h food recalls were used to assess dietary intake and macronutrient composition. Effectiveness was evaluated by assessment of body weight, serum lipids, lipoproteins and insulin resistance parameters. SETTING: Leiden outpatient Lipid Clinic. SUBJECTS: Forty-five newly diagnosed, untreated patients with endogenous hypertriglyceridemia. RESULTS: A significant reduction in energy intake and body weight as well as changes in macronutrient composition were observed. Total serum triacylglycerol and cholesterol levels decreased by 31% and 15%, respectively. No effects were observed on serum glucose and insulin levels. Weight reduction was significantly correlated with reduction of total plasma triacylglycerol levels and inversely correlated with changes in HDL cholesterol levels. Of all nutrients assessed, only reduction of alcohol intake correlated with improvement of total serum triacylglycerol. CONCLUSIONS: Short-term dietary counselling in patients with endogenous hypertriglyceridemia can effectively improve serum lipid and lipoprotein levels. With regard to the advised nutrient changes, weight loss and limitation of alcohol intake prove to be the best predictors of triacylglycerol reduction.     

Effect of an energy-restricted, high-protein, low-fat diet relative to a conventional high-carbohydrate, low-fat diet on weight loss, body composition, nutritional status, and markers of cardiovascular health in obese women

BACKGROUND: Limited evidence suggests that a higher ratio of protein to carbohydrate during weight loss has metabolic advantages. OBJECTIVE: The objective was to evaluate the effects of a diet with a high ratio of protein to carbohydrate during weight loss on body composition, cardiovascular disease risk, nutritional status, and markers of bone turnover and renal function in overweight women. DESIGN: The subjects were randomly assigned to 1 of 2 isocaloric 5600-kJ dietary interventions for 12 wk according to a parallel design: a high-protein (HP) or a high-carbohydrate (HC) diet. RESULTS: One hundred women with a mean (+/-SD) body mass index (in kg/m(2)) of 32 +/- 6 and age of 49 +/- 9 y completed the study. Weight loss was 7.3 +/- 0.3 kg with both diets. Subjects with high serum triacylglycerol (>1.5 mmol/L) lost more fat mass with the HP than with the HC diet (x +/- SEM: 6.4 +/- 0.7 and 3.4 +/- 0.7 kg, respectively; P = 0.035) and had a greater decrease in triacylglycerol concentrations with the HP (-0.59 +/- 0.19 mmol/L) than with the HC (-0.03 +/- 0.04 mmol/L) diet (P = 0.023 for diet x triacylglycerol interaction). Triacylglycerol concentrations decreased more with the HP (0.30 +/- 0.10 mmol/L) than with the HC (0.10 +/- 0.06 mmol/L) diet (P = 0.007). Fasting LDL-cholesterol, HDL-cholesterol, glucose, insulin, free fatty acid, and C-reactive protein concentrations decreased with weight loss. Serum vitamin B-12 increased 9% with the HP diet and decreased 13% with the HC diet (P < 0.0001 between diets). Folate and vitamin B-6 increased with both diets; homocysteine did not change significantly. Bone turnover markers increased 8-12% and calcium excretion decreased by 0.8 mmol/d (P < 0.01). Creatinine clearance decreased from 82 +/- 3.3 to 75 +/- 3.0 mL/min (P = 0.002). CONCLUSION: An energy-restricted, high-protein, low-fat diet provides nutritional and metabolic benefits that are equal to and sometimes greater than those observed with a high-carbohydrate diet.     

Randomized controlled crossover study of the effect of a highly beta-glucan-enriched barley on cardiovascular disease risk factors in mildly hypercholesterolemic men

BACKGROUND: Soluble-fiber beta-glucan derived from oats can reduce cardiovascular disease (CVD) risk through reductions in total and LDL cholesterol. Barley-derived beta-glucan may also improve serum cholesterol, but large quantities are required for clinical significance. OBJECTIVE: This trial investigated whether a beta-glucan-enriched form of barley can favorably modify cholesterol and other markers of CVD and diabetes risk. DESIGN: Eighteen mildly hyperlipidemic ( +/- SD: 4.0 +/- 0.6 mmol LDL cholesterol/L) men with a mean (+/- SD) body mass index (in kg/m(2)) of 27.4 +/- 4.6 were randomly assigned in this single-blind, 2 x 4-wk trial to either the treatment arm [8.1-11.9 g beta-glucan/d (scaled to body weight)] or the control arm (isoenergetic dose of 6.5-9.2 g glucose/d). After a washout period of 4 wk, dietary regimens were crossed over. The trial took place in a long-stay metabolic facility, and all foods were provided (38% of energy from fat). Fasted blood samples were collected on days 0, 1, 7, 14, 21, 28, and 29 in both study arms. An oral-glucose-tolerance test was carried out on days 0 and 29. RESULTS: There was no significant change (Delta) in total (Delta = -0.08 mmol/L, -1.3%), LDL (Delta = -0.15 mmol/L, -3.8%), or HDL (Delta = 0 mmol/L) cholesterol or in triacylglycerol (Delta = 0.18 mmol/L), fasting glucose (Delta = -0.05 mmol/L), or postprandial glucose when analyzed between treatments (P > 0.05; ANOVA). CONCLUSION: The effect of beta-glucan-enriched barley on lipid profile was highly variable between subjects, and there was no evidence of a clinically significant improvement in CVD risk across this group of mildly hyperlipidemic men.     

Dietary echium oil increases plasma and neutrophil long-chain (n-3) fatty acids and lowers serum triacylglycerols in hypertriglyceridemic humans

A wealth of evidence indicates that consumption of fish or dietary fish oils containing long-chain (n-3) PUFA such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is associated with cardiovascular benefit, including a reduction in circulating triacylglycerol concentrations and reduced mortality from coronary heart disease. Shorter-chain dietary (n-3) PUFA such as alpha-linolenic acid from vegetable oils are inefficiently converted to EPA and DHA and do not possess the hypotriglyceridemic properties attributed to fish oils. The objective of this study was to investigate the effect of dietary Echium oil, a plant oil containing the 18-carbon (n-3) PUFA stearidonic acid, on tissue fatty acid content and serum triacylglycerol concentrations in hypertriglyceridemic humans. Asymptomatic subjects with mild-to-moderate hypertriglyceridemia were enrolled in an open-labeled study. Subjects underwent a 4-wk lead-in period and were then instructed to follow the National Cholesterol Education Program Step 1 diet. Subjects (n = 11) whose serum triacylglycerol concentrations remained between 3.4 and 5.1 mmol/L (300 and 450 mg/dL) were instructed to consume 15 g of Echium oil daily for 4 wk. During the treatment period, serum triacylglycerol concentrations decreased by 21%, or 0.87 +/- 0.26 mmol/L (mean +/- SD) compared with baseline (P < 0.05); 8 of 11 subjects had a decrease in serum triacylglycerols ranging from 13 to 52% with a decrease from baseline of 30%, or 1.26 +/- 0.41 mmol/L (mean +/- SD). There were no significant changes in any other clinical laboratory variables. Concentrations of long-chain (n-3) PUFA, including EPA, increased (P < 0.05) in plasma and neutrophils when subjects consumed Echium oil. In conclusion, dietary plant oils rich in stearidonic acid are metabolized to longer-chain, more unsaturated (n-3) PUFA. These oils appear to possess hypotriglyceridemic properties typically associated with fish oils.     

Effects on blood lipids of a blood pressure-lowering diet: the Dietary Approaches to Stop Hypertension (DASH) Trial.

BACKGROUND: Effects of diet on blood lipids are best known in white men, and effects of type of carbohydrate on triacylglycerol concentrations are not well defined. OBJECTIVE: Our goal was to determine the effects of diet on plasma lipids, focusing on subgroups by sex, race, and baseline lipid concentrations. DESIGN: This was a randomized controlled outpatient feeding trial conducted in 4 field centers. The subjects were 436 participants of the Dietary Approaches to Stop Hypertension (DASH) Trial [mean age: 44.6 y; 60% African American; baseline total cholesterol: < or = 6.7 mmol/L (< or = 260 mg/dL)]. The intervention consisted of 8 wk of a control diet, a diet increased in fruit and vegetables, or a diet increased in fruit, vegetables, and low-fat dairy products and reduced in saturated fat, total fat, and cholesterol (DASH diet), during which time subjects remained weight stable. The main outcome measures were fasting total cholesterol, LDL cholesterol, HDL cholesterol, and triacylglycerol. RESULTS: Relative to the control diet, the DASH diet resulted in lower total (-0.35 mmol/L, or -13.7 mg/dL), LDL- (-0.28 mmol/L, or -10.7 mg/dL), and HDL- (-0.09 mmol/L, or -3.7 mg/dL) cholesterol concentrations (all P < 0.0001), without significant effects on triacylglycerol. The net reductions in total and LDL cholesterol in men were greater than those in women by 0.27 mmol/L, or 10.3 mg/dL (P = 0.052), and by 0.29 mmol/L, or 11.2 mg/dL (P < 0.02), respectively. Changes in lipids did not differ significantly by race or baseline lipid concentrations, except for HDL, which decreased more in participants with higher baseline HDL-cholesterol concentrations than in those with lower baseline HDL-cholesterol concentrations. The fruit and vegetable diet produced few significant lipid changes. CONCLUSIONS: The DASH diet is likely to reduce coronary heart disease risk. The possible opposing effect on coronary heart disease risk of HDL reduction needs further study.     

Effect of a high-carbohydrate vs a high–cis-monounsaturated fat diet on lipid and lipoproteins in individuals with and without type 2 diabetes

It is not known whether the extent of the improvement in lipids and lipoproteins on a high–cis-monounsaturated (high-mono) diet compared with a high-carbohydrate (high-carb) diet is different in patients with type 2 diabetes mellitus (T2DM) and nondiabetic subjects. The aim of this study is to compare the effect of a high-mono and a high-carb diet on lipids and lipoproteins in patients with T2DM and nondiabetic subjects.

Ten healthy nondiabetic men, 8 men with T2DM on dietary therapy alone, and 10 men with T2DM requiring insulin therapy were fed an isoenergic high-carb diet (60% energy as carbohydrate and 25% as fat) and a high-mono diet (50% energy as fat and 35% as carbohydrate) for 2 to 4 weeks in a randomized, crossover fashion. Dietary fiber, simple carbohydrates, and cholesterol were held constant across diets. The lipid and lipoprotein responses to these diets were compared in nondiabetic and T2DM subjects by repeated measures analysis of variance model. Patients with T2DM had 2.2 to 2.3 times greater reductions in plasma triacylglycerol, very low-density lipoprotein (VLDL) cholesterol, and total cholesterol/high-density lipoprotein cholesterol ratio (TC/HDLC) on the high-mono diet compared with the high-carb diet than the nondiabetic subjects (P = .02-.04). The reductions in triacylglycerol and VLDL cholesterol were 2.7 times greater (P = .009-.02) in T2DM subjects with high plasma triacylglycerol concentrations (>2.26 mmol/L) but only 1.4 to 2.0 times greater (P = .16-.52) in T2DM patients with low triacylglycerol concentrations (<2.26 mmol/L) compared with nondiabetic subjects who all had low triacylglycerol concentrations (<2.26 mmol/L). Patients with T2DM experienced greater decreases in plasma triacylglycerol, VLDL cholesterol, and TC/HDLC on a high-mono diet compared with a high-carb diet than nondiabetic subjects. The extents of the improvements were likely related to plasma triacylglycerol concentrations in patients with T2DM.     

Phytosterols/stanols lower cholesterol concentrations in familial hypercholesterolemic subjects: a systematic review with meta-analysis

BACKGROUND: To-date, reviews regarding the cholesterol lowering capacity of phytosterols/stanols have focused on normo- and hypercholesterolemic (HC) subjects. Familial hypercholestrolemia (FH) is characterized by very high low-density lipoprotein cholesterol (LDL-C) concentrations and is considered a world public health problem due to the high incidence of premature coronary heart disease (CHD) in these patients. OBJECTIVE: To conduct a systematic review that investigates the efficacy of phytosterols/stanols in lowering total cholesterol (TC) and LDL-C concentrations in FH subjects. DESIGN: Randomized controlled intervention trials with the primary objective to investigate the effects of phytosterols/stanols on lipid concentrations in FH subjects were identified through selected international journal databases and reference lists of relevant publications. Two researchers extracted data from each identified trial and only trials of sufficient quality (e.g. controlled, randomized, double-blind, good compliance, sufficient statistical power) were included in the review. The main outcome measures were differences between treatment and control groups for LDL-C, TC, high-density lipoprotein cholesterol (HDL-C) and triacylglycerol (TG). RESULTS: Six out of 13 studies were of sufficient quality. Two were excluded from the meta-analysis because the sterols were administered in the granulate form at very high dosages (12 g/day and 24 g/day) compared to the other studies that used fat spreads as vehicle with dosages ranging from 1.6-2.8 g/day. The subjects were heterozygous, aged 2-69 years with baseline TC and LDL-C concentrations of +/-7 mmol/L and +/-5.4 mmol/L, respectively. The duration of the studies ranged from 4 weeks to 3 months. Fat spreads enriched with 2.3 +/- 0.5 g phytosterols/stanols per day significantly reduced TC from 7 to 11% with a mean decrease of 0.65 mmol/L [95% CI -0.88, -0.42 mmol/L], p < 0.00001 and LDL-C from 10-15% with a mean decrease of 0.64 mmol/L [95% CI -0.86, -0.43 mmol/L], p < 0.00001 in 6.5 +/- 1.9 weeks compared to control treatment, without any adverse effects. TG and HDL-C concentrations were not affected. CONCLUSION: Phytosterols/stanols may offer an effective adjunct to the cholesterol lowering treatment strategy of FH patients.     

Cholecalciferol significantly increases 25-hydroxyvitamin D concentrations in adults with cystic fibrosis

BACKGROUND: Vitamin D deficiency is increasingly being recognized and treated in patients with cystic fibrosis, although the treatment guidelines are not proven and the effectiveness of vitamin D preparations is untested. OBJECTIVES: The aims of this study were to determine the prevalence of 25-hydroxyvitamin D [25(OH)D] deficiency in a large cohort of adults with cystic fibrosis and to evaluate the effectiveness of supplementation with cholecalciferol. DESIGN: In this retrospective cohort design, baseline 25(OH)D concentrations were measured, and the effects of clinical interventions that involved either counseling on compliance or increasing supplemental cholecalciferol on serum 25(OH)D concentrations in those subjects with baseline concentrations 相似文献   

Long-term ingestion of dietary diacylglycerol lowers serum triacylglycerol in type II diabetic patients with hypertriglyceridemia.

We examined the effect of daily consumption of dietary diacylglycerol (DG) oil on serum lipid concentrations in patients with diabetes whose serum triacylglycerol (TG) levels were persistently increased despite continuous nutritional counseling at the outpatient clinic. Patients (n = 16) were divided into DG and control groups (n = 8 each). DG was incorporated (target dose 10 g/d) by substituting DG oil (80 g DG/100 g oil) for the ordinary TG cooking oil used at home for 12 wk. The control group continued consuming ordinary TG cooking oil. Dietary records indicated that there were no differences between groups in total energy intake or percentage of energy from fat. In the DG group, TG intake decreased from 26.8 +/- 9.3 to 15.7 +/- 8.9 g/d, whereas DG intake increased from 0.3 +/- 0.1 to 10.6 +/- 3.9 g/d. No differences between groups were observed in body weight, total fat intake or total oil consumption throughout the study period. In the DG group, serum TG levels decreased 39.4% from 2.51 +/- 0.75 mmol/L to 1.52 +/- 0.28 mmol/L. Serum glycohemoglobin A(1c) (HbA(1c)) concentration also decreased 9.7%. In contrast, there were no changes in these variables in the control group. Serum total and HDL cholesterol were not affected in either group. These results indicate that DG oil may be useful as an adjunct to the standard diet therapy of fat restriction in the management of diabetics with hypertriglyceridemia.     

Dairy fat in cheese raises LDL cholesterol less than that in butter in mildly hypercholesterolaemic subjects

OBJECTIVE: To determine whether dairy fat in cheese raises low-density lipoprotein (LDL) cholesterol as much as in butter, since epidemiology suggests a different impact on cardiovascular disease. DESIGN: A randomised crossover trial testing the daily consumption of 40 g dairy fat as butter or as matured cheddar cheese, each of 4 weeks duration, was preceded by and separated by 2-week periods when dietary fat was less saturated. SETTING: Free-living volunteers. SUBJECTS: A total of 14 men and five women of mean age 56+/-8 y, with mean total cholesterol of 5.6+/-0.8 mmol/l. MAIN OUTCOME MEASURES: Plasma cholesterol, LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), triacylglycerol and glucose. RESULTS: Saturated fat intake was significantly lower during the run-in than during the cheese and butter periods. Mean lipid values did not differ significantly between the cheese and run-in periods, but total cholesterol and LDL-C were significantly higher with butter: total cholesterol (mmol/l): butter 6.1+/-0.7; run-in 5.6+/-0.8 (P < 0.05; ANOVA with Bonferroni adjustment); vs cheese 5.8+/-0.6 (P > 0.05); median LDL-C (mmol/l): butter 3.9 (3.5-4.1) vs run-in 3.4 (3.0-4.1) (P < 0.05; Tukey test); vs cheese 3.7 (3.3-3.9) (P > 0.05). Among 13 subjects whose initial LDL-C was >4 mmol/l, the difference between butter (4.4+/-0.3 mmol/l) and cheese (3.9+/-0.3 mmol/l) was significant (P = 0.014). HDL-C was highest with butter and triacylglycerol with cheese (neither was significant). CONCLUSION: A total of 40 g dairy fat eaten daily for 4 weeks as butter, but not as cheese, raised total and LDL cholesterol significantly compared with a diet containing significantly less saturated fat. Dietary advice regarding cheese consumption may require modification.     

Meta-analysis of the effects of soy protein containing isoflavones on the lipid profile

BACKGROUND: Convincing evidence shows that soy protein intake has beneficial effects on lipid changes, but it is unclear which components of soy protein are responsible. OBJECTIVE: We conducted a meta-analysis to identify and quantify the effects of soy protein containing isoflavones on the lipid profile. DESIGN: Twenty-three eligible randomized controlled trials published from 1995 to 2002 were identified from the PUBMED database (National Library of Medicine, Bethesda, MD). Weighted mean effect sizes were calculated for net changes in serum lipid concentrations by using fixed-effect or random-effect models. Pre-specified subgroup analyses were performed to explore the influence of covariates on net lipid change. RESULTS: Soy protein with isoflavones intact was associated with significant decreases in serum total cholesterol (by 0.22 mmol/L, or 3.77%), LDL cholesterol (by 0.21 mmol/L, or 5.25%), and triacylglycerols (by 0.10 mmol/L, or 7.27%) and significant increases in serum HDL cholesterol (by 0.04 mmol/L, or 3.03%). The reductions in total and LDL cholesterol were larger in men than in women. Initial total cholesterol concentrations had a powerful effect on changes in total and HDL cholesterol, especially in subjects with hypercholesterolemia. Studies with intakes >80 mg showed better effects on the lipid profile. The strongest lowering effects of soy protein containing isoflavones on total cholesterol, LDL cholesterol, and triacylglycerol occurred within the short initial period of intervention, whereas improvements in HDL cholesterol were only observed in studies of >12 wk duration. Tablets containing extracted soy isoflavones did not have a significant effect on total cholesterol reduction. CONCLUSIONS: Soy protein containing isoflavones significantly reduced serum total cholesterol, LDL cholesterol, and triacylglycerol and significantly increased HDL cholesterol, but the changes were related to the level and duration of intake and the sex and initial serum lipid concentrations of the subjects.     

Continuous glucose for treatment of patients with type 1 glycogen-storage disease: comparison of the effects of dextrose and uncooked cornstarch on biochemical variables

Responses to uncooked cornstarch (UCS), dextrose (Dex), and a 3:1 mixture (UCS:Dex) were determined in seven children with type 1 glycogen-storage disease (GSD-1). UCS maintained blood glucose (BG) and serum insulin concentrations between 3.5 +/- 0.3 and 4.0 +/- 0.4 mmol/L (mean +/- SEM) and 50 +/- 7 and 79 +/- 22 pmol/L, respectively, in six of the seven patients for 4 h. Only four of seven patients completed the 4-h test after UCS:Dex (BG 2.9 +/- 0.3 mmol/L): After Dex, tests had to be stopped in all patients by 150 min after initiation (BG 2.7 +/- 0.4 mmol/L). Two methods of providing dietary glucose overnight, continuous intragastric glucose infusion (COG) and intermittent UCS at 2100 and 0200, were compared by monitoring metabolites and glucoregulatory hormones. The use of UCS in amounts equal to the calculated glucose production rate is an effective method of providing a continuous dietary source of glucose overnight to patients with GSD-1.