Short-term changes in lipoprotein subclasses and C-reactive protein levels of hypertriglyceridemic adults on low-carbohydrate and low-fat diets

Diets designed to promote weight loss and improve atherogenic lipid profiles traditionally include a reduction in total fat and, in particular, saturated fats. This study was designed to test the efficacy of a low-fat diet vs a carbohydrate (CHO)–restricted (low-CHO) diet in hypertriglyceridemic patients on lipid profile, weight loss, high-sensitivity C-reactive protein (hs-CRP), and satiety. Twenty-eight hypertriglyceridemic subjects (based on fasting triacylglycerol [TG] levels exceeding 1.69 mmol/L) were randomized to either the low-CHO or low-fat diet for 8 weeks. Fasting bloods were acquired at weeks 0 and 8 and analyzed for lipids and hs-CRP. Body weight and other anthropometric measures were also obtained. Three random 24-hour food recalls were used to assess compliance during the trial and 2 recalls before randomization to permit individualized dietary education. A significant time-by-treatment interaction was observed (P = .045), wherein the small low-density lipoprotein cholesterol concentrations were reduced by 46% in the low-CHO–assigned subjects and increased by 36% for those assigned the low-fat plan. The observed decrease in TG (18%) among low-CHO subjects, in contrast to the 4% increase for low-fat group, was not significant, nor were there significant differences in hs-CRP, overall dietary compliance, satiety, or the magnitude of body weight loss between groups (low-CHO group, −3.8% vs low-fat group, −1.6%). Favorable reductions in small low-density lipoprotein concentrations after 8 weeks suggest that a moderately restricted carbohydrate diet (20% CHO as energy) can promote a less atherogenic lipid profile when compared to the low-fat diet.     

生命早期使用头孢曲松对生命后期高脂饲料负荷小鼠糖脂代谢的影响

目的探究生命早期使用抗生素对生命后期高脂饲料负荷下的小鼠血糖、血脂等糖脂代谢指标的影响。方法将48只2周龄雌性BALB/c小鼠随机分为空白对照组、抗生素组、高脂组和联合作用组,每组12只,抗生素组和联合作用组以100 mg/kg头孢曲松灌胃,其余2组灌胃等量生理盐水,持续至4周龄后停止灌胃,接着高脂组和联合作用组以高脂饲料、其余2组以普通饲料喂养12周。最后1周测定空腹血糖并进行口服糖耐量实验,实验结束后测定血脂、肝脏脂质、胰岛素和瘦素水平,并计算胰岛素抵抗指数。结果与普通饲料相比,高脂饲料引起小鼠糖耐量受损,内脏脂肪、血糖、胰岛素抵抗指数、血脂、肝脏脂质和瘦素增加(P<0.05);与空白对照组相比,抗生素组小鼠糖耐量受损,内脏脂肪、血糖和肝脏甘油三酯水平增加(P<0.05);与高脂组相比,联合作用组小鼠的糖耐量受损、血糖、胰岛素抵抗指数和肝脏总胆固醇水平增加(P<0.05)。结论生命早期使用头孢曲松增加了机体内脏脂肪、血糖、胰岛素抵抗和肝脏脂质,且加剧了高脂饲料诱导的糖脂代谢紊乱,表明生命早期使用抗生素可能会提高机体对高脂饲料诱导糖脂代谢异常的易感性。     

D-核糖对高脂喂饲小鼠胰岛素抵抗的影响

目的观察D-核糖对高脂喂饲的C57BL/6小鼠血糖、血脂及胰岛素等的影响,探讨D-核糖对改善高脂膳食引起的糖耐量异常和胰岛素抵抗的可能性。方法 8 w龄C57BL/6雄性小鼠36只,随机分成正常对照、高脂对照、低剂量的D-核糖+高脂组(高脂+2.5%核糖)和高剂量的D-核糖+高脂组(高脂+5%核糖),喂饲12 w,记录摄食量和体重变化。11w进行葡萄糖耐量试验(OGTT),并计算葡萄糖曲线下面积(AUC)。干预12w处死,进行血生化指标及胰岛素检测。结果高脂+5%核糖组小鼠的血糖水平低于高脂对照组(P<0.05);高脂+2.5%核糖和高脂+5%核糖组糖耐量曲线下面积(P<0.01)、血清胰岛素水平(P<0.05)及胰岛素抵抗指数HOMA-IR(P<0.01)均显著低于高脂对照组。血清胆固醇(CHO)、高密度脂蛋白胆固醇(HDL-C)在核糖干预后的变化并不明显(P>0.05);高脂+5%核糖组血清低密度脂蛋白胆固醇(LDL-C)、血清甘油三酯(TG)及游离脂肪酸(FFA)低于高脂对照组(P<0.05)。结论 D-核糖可以改善高脂饲料喂饲小鼠的糖耐量异常和胰岛素抵抗。[营养学报,2013,35(2):142-145]     

Lipid effects of a dietary supplement softgel capsule containing plant sterols/stanols in primary hypercholesterolemia

ObjectiveThis randomized, placebo-controlled, crossover trial assessed the lipid-altering efficacy of a softgel capsule dietary supplement, providing esterified plant sterols/stanols 1.8 g/d, in 28 participants (～75% women) with primary hypercholesterolemia (fasting low-density lipoprotein cholesterol [LDL-C] levels ≥130 and <220 mg/dL), a mean age of 58.4 y, and a mean body mass index of 27.9 kg/m².MethodsAfter a 5-wk National Cholesterol Education Program (NCEP) Therapeutic Lifestyle Changes (TLC) diet and a single-blinded placebo lead-in, subjects received double-blinded placebo or sterol/stanol softgel capsules for 6 wk and then crossed over to the opposite product for 6 wk while continuing the TLC diet. Fasting lipids were assessed in duplicate at the end of the diet lead-in (baseline) and the end of each treatment.ResultsThe mean baseline lipid concentrations (milligrams per deciliter) were 223 for total cholesterol (TC), 179 for non–high-density lipoprotein cholesterol (non-HDL-C), 154 for low-density lipoprotein cholesterol, 44 for HDL-C, 125 for triacylglycerols, and 5.2 for TC/HDL-C. Differences from the control responses (plant sterol/stanol minus control) in the per-protocol sample were significant (P < 0.05) for LDL-C (?9.2%), non-HDL-C (?9.0%), TC (?7.4%), TC/HDL-C (?5.4%), and triacylglycerols (?9.1%). The HDL-C responses were not significantly different between treatments.ConclusionThe incorporation of softgel capsules providing esterified plant sterols/stanols 1.8 g/d into the NCEP TLC diet produced favorable changes in atherogenic lipoprotein cholesterol levels in these subjects with hypercholesterolemia.     

The Canadian Trial of Carbohydrates in Diabetes (CCD), a 1-y controlled trial of low-glycemic-index dietary carbohydrate in type 2 diabetes: no effect on glycated hemoglobin but reduction in C-reactive protein

BACKGROUND: The optimal source and amount of dietary carbohydrate for managing type 2 diabetes (T2DM) are unknown. OBJECTIVE: We aimed to compare the effects of altering the glycemic index or the amount of carbohydrate on glycated hemoglobin (HbA1c), plasma glucose, lipids, and C-reactive protein (CRP) in T2DM patients. DESIGN: Subjects with T2DM managed by diet alone (n=162) were randomly assigned to receive high-carbohydrate, high-glycemic-index (high-GI), high-carbohydrate, low-glycemic-index (low-GI), or low-carbohydrate, high-monounsaturated-fat (low-CHO) diets for 1 y. RESULTS: The high-GI, low-GI, and low-CHO diets contained, respectively, 47%, 52%, and 39% of energy as carbohydrate and 31%, 27%, and 40% of energy as fat; they had GIs of 63, 55, and 59, respectively. Body weight and HbA1c did not differ significantly between diets. Fasting glucose was higher (P=0.041), but 2-h postload glucose was lower (P=0.010) after 12 mo of the low-GI diet. With the low-GI diet, overall mean triacylglycerol was 12% higher and HDL cholesterol 4% lower than with the low-CHO diet (P<0.05), but the difference in the ratio of total to HDL cholesterol disappeared by 6 mo (time x diet interaction, P=0.044). Overall mean CRP with the low-GI diet, 1.95 mg/L, was 30% less than that with the high-GI diet, 2.75 mg/L (P=0.0078); the concentration with the low-CHO diet, 2.35 mg/L, was intermediate. CONCLUSIONS: In subjects with T2DM managed by diet alone with optimal glycemic control, long-term HbA1c was not affected by altering the GI or the amount of dietary carbohydrate. Differences in total:HDL cholesterol among diets had disappeared by 6 mo. However, because of sustained reductions in postprandial glucose and CRP, a low-GI diet may be preferred for the dietary management of T2DM.     

Greater Total Antioxidant Capacity from Diet and Supplements Is Associated with a Less Atherogenic Blood Profile in U.S. Adults

Evidence from epidemiologic studies has shown that total antioxidant capacity (TAC) in the diet might be inversely associated with stroke, heart failure, and inflammatory biomarkers. However, studies on the association of TAC from both diet and supplements with cardiovascular disease (CVD) risk factors in the U.S. population are lacking. This cross-sectional population-based study aimed to investigate the association of TAC with both diet and supplements with CVD risk factors among 4039 U.S. adults in National Health and Nutrition Examination Survey (NHANES) 2007–2012. TAC from both food sources and dietary supplements was estimated from two 24-h dietary recalls using the NHANES supplement ingredient database, United States Department of Agriculture (USDA) proanthocyanidin, flavonoid, and isoflavone databases. Top contributors to TAC were tea, antioxidant supplements, vegetable mixture, orange juice, berries, and wine. Antioxidant supplement users had 1.6 times higher TAC than non-users. Greater TAC was associated with reduced triglycerides (TG) (−1.39% change; 95% CI = −2.56 to −0.21), TG to high-density lipoprotein cholesterol (HDL-C) ratio (−2.03% change; 95% CI = −3.45 to −0.60), HDL-C (0.65% change; 95% CI = 0.07 to 1.23), insulin (−1.37% change; 95% CI = −2.64 to −0.09), homeostasis model assessment of insulin resistance (HOMA-IR) (−1.57% change; 95% CI = −3.02 to −0.09) and C-reactive protein (CRP) (−0.83% change; 95% CI = −1.29 to −0.38) after adjusting for potential confounders. There was no significant association between TAC and waist circumference, BMI, blood pressure, low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and fasting glucose. The findings of this study support the hypothesis that an antioxidant-rich diet and intake of supplements are beneficial to reduce CVD risk.     

A Ketogenic Low-Carbohydrate High-Fat Diet Increases LDL Cholesterol in Healthy,Young, Normal-Weight Women: A Randomized Controlled Feeding Trial

Ketogenic low-carbohydrate high-fat (LCHF) diets are popular among young, healthy, normal-weight individuals for various reasons. We aimed to investigate the effect of a ketogenic LCHF diet on low-density lipoprotein (LDL) cholesterol (primary outcome), LDL cholesterol subfractions and conventional cardiovascular risk factors in the blood of healthy, young, and normal-weight women. The study was a randomized, controlled, feeding trial with crossover design. Twenty-four women were assigned to a 4 week ketogenic LCHF diet (4% carbohydrates; 77% fat; 19% protein) followed by a 4 week National Food Agency recommended control diet (44% carbohydrates; 33% fat; 19% protein), or the reverse sequence due to the crossover design. Treatment periods were separated by a 15 week washout period. Seventeen women completed the study and treatment effects were evaluated using mixed models. The LCHF diet increased LDL cholesterol in every woman with a treatment effect of 1.82 mM (p < 0.001). In addition, Apolipoprotein B-100 (ApoB), small, dense LDL cholesterol as well as large, buoyant LDL cholesterol increased (p < 0.001, p < 0.01, and p < 0.001, respectively). The data suggest that feeding healthy, young, normal-weight women a ketogenic LCHF diet induces a deleterious blood lipid profile. The elevated LDL cholesterol should be a cause for concern in young, healthy, normal-weight women following this kind of LCHF diet.     

饮食干预对妊娠期糖尿病小鼠子代中远期瘦素及糖脂代谢的影响

目的 研究妊娠期糖尿病(GDM)子代小鼠在饮食干预下其瘦素水平及糖脂代谢的转归情况。方法 链脲霉素腹腔注射建立GDM模型,将其产下子鼠随机分为对照组、高脂组(G-HF)、高纤组(G-HX)、热量限制组(G-CR),非GDM子鼠建立空白对照组(C-CON);每组各7只。干预后测总胆固醇(TCH),甘油三酯(TG),低密度脂蛋白胆固醇(LDL-C),高密度脂蛋白胆固醇(HDL-C),胰岛素、瘦素水平。结果 （1）GDM子代血糖显著高于正常鼠子代（P<0.05）;TCH,TG,LDL-C显著升高(P<0.05）。（2）饮食干预后,热量限制组血糖体重趋于稳定;高脂组血脂代谢水平均显著降低(P<0.05）;高纤组HDL-C高于空白对照组 (P<0.05);热量限制组TCH,TG,LDL-C明显降低(P<0.001),瘦素、胰岛素改善。（3）血清瘦素水平与TG、TCH、LDL-C及胰岛素水平正相关(P<0.05)。结论 GDM子鼠有明显的不良结局。高脂饮食能加重GDM子代不良转归,高纤饮食作用较弱,热量限制可能通过改善瘦素抵抗,显著改善胰岛素抵抗及糖脂代谢。     

Impact of Lifestyle Modifications on Alterations in Lipid and Glycemic Profiles and Uric Acid Values in a Pediatric Population

Cardiometabolic risk factors are frequent in children and adolescents with excess weight. The aim of this study was to evaluate the effects of lifestyle modifications on alterations in lipid and glycemic profiles and uric acid values in a pediatric population at increased cardiovascular risk. The study involved 276 subjects with a mean age of 10.6 (2.3) years. Body mass index (BMI) z-score and biochemical parameters (serum low-density lipoprotein (LDL) cholesterol, triglycerides and uric acid and homeostasis model assessment to quantify insulin resistance (HOMA index)) were assessed at baseline and at the end of a median follow-up of 14.7 (12.4, 19.3) months. Throughout follow-up, all children received a non-pharmacological treatment based on increased physical activity, reduced sedentary activity and administration of a personalized, healthy and balanced diet. All children attended periodic quarterly control visits during follow-up. Multivariable statistical analyses showed that each BMI z-score point reduction at follow-up was associated with an 8.9 (95% CI −14.2; −3.6) mg/dL decrease in LDL cholesterol (p = 0.001), 20.4 (95% CI −30.0; −10.7) mg/dL in triglycerides (p < 0.001), 1.6 (95% CI −2.2; −1.0) in HOMA index (p < 0.001), and 0.42 (95% CI −0.66; −0.18) mg/dL in uric acid (p = 0.001) values. At each reduction of the BMI z-score by one point, the odds of presenting with insulin resistance and hyperuricemia at follow-up significantly decreased (OR 0.23, 95% CI 0.10–0.50, and OR 0.32, 95% CI 0.10–0.95, p < 0.001 and p < 0.05, respectively). Improvement of dietary habits and lifestyles may improve lipid and glycemic profiles and serum uric acid values in a pediatric population.     

The Beneficial Effects of Astaxanthin on Glucose Metabolism and Modified Low-Density Lipoprotein in Healthy Volunteers and Subjects with Prediabetes

Astaxanthin (ASTX) is an antioxidant agent. Recently, its use has been focused on the prevention of diabetes and atherosclerosis. We examined the effects of astaxanthin supplementation for 12 weeks on glucose metabolism, glycemic control, insulin sensitivity, lipid profiles and anthropometric indices in healthy volunteers including subjects with prediabetes with a randomized, placebo-controlled trial. Methods: We enrolled 53 subjects who met our inclusion criteria and administered them with 12 mg astaxanthin or a placebo once daily for 12 weeks. Subsequently, their HbA1c levels, lipid profiles and biochemical parameters were determined. The participants also underwent a 75 g oral glucose tolerance test (OGTT), vascular endothelial function test and measurement of the visceral fat area. Results: After astaxanthin supplementation for 12 weeks, glucose levels after 120 min in a 75 g OGTT significantly decreased compared to those before supplementation. Furthermore, the levels of HbA1c (5.64 ± 0.33 vs. 5.57 ± 0.39%, p < 0.05), apo E (4.43 ± 1.29 vs. 4.13 ± 1.24 mg/dL, p < 0.05) and malondialdehyde-modified low-density lipoprotein (87.3 ± 28.6 vs. 76.3 ± 24.6 U/L, p < 0.05) were also reduced, whereas total cholesterol (TC), triglyceride (TG) and high-density lipoprotein-C (HDL-C) levels were unaltered. The Matuda index, which is one of the parameters of insulin resistance, was improved in the ASTX group compared to that before supplementation. Conclusions: our results suggest that ASTX may have preventive effects against diabetes and atherosclerosis and may be a novel complementary treatment option for the prevention of diabetes in healthy volunteers, including subjects with prediabetes, without adverse effects.     

Comparison of lycopene and fluvastatin effects on atherosclerosis induced by a high-fat diet in rabbits

OBJECTIVE: We evaluated the antiatherogenic effect of lycopene in rabbits fed a high-fat diet. METHODS: Forty adult male rabbits were divided into five groups that were fed a standard diet, a high-fat diet, a high-fat diet plus 4 mg/kg of lycopene, a high-fat diet plus 12 mg/kg of lycopene, and a high-fat diet plus 10 mg/kg of fluvastatin, respectively. Lycopene and fluvastatin were administered intragastrically. The level of serum total cholesterol, total triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total antioxidant capacity, and malondialdehyde were measured before and after 4 and 8 wk of experimental treatment. In addition, plasma levels of lycopene, oxidized low-density lipoprotein, serum nitric oxide, and interleukin-1 were measured after the experiment. The area of atherosclerotic plaque and pathologic changes of the aorta were evaluated. RESULTS: Compared with the control, levels of total cholesterol, total triacylglycerol, low-density lipoprotein cholesterol, malonaldehyde, oxidized low-density lipoprotein, and interleukin-1 were increased and total antioxidant capacity and nitric oxide were decreased in the animals with a high-fat diet (P < 0.05). Intragastric administration of lycopene counteracted the change in these parameters (P < 0.05). In this case, the data showed that lycopene in the used dose was better than the fluvastatin intervention. Morphologic analysis revealed that lycopene and fluvastatin markedly reduced the formation of atherosclerotic plaques in the aorta compared with the situation in rabbits on a high-fat diet alone. CONCLUSION: Lycopene, like fluvastatin, significantly attenuated atherogenesis in rabbits fed a high-fat diet.     

Extra Virgin Olive Oil Prevents the Age-Related Shifts of the Distribution of HDL Subclasses and Improves Their Functionality

High-density lipoproteins (HDL) maintain cholesterol homeostasis through the role they play in regulating reverse cholesterol transport (RCT), a process by which excess cholesterol is transported back to the liver for elimination. However, RCT can be altered in the presence of cardiovascular risk factors, such as aging, which contributes to the increase in the incidence of cardiovascular diseases (CVD). The present study was aimed at investigating the effect of extra virgin olive oil (EVOO) intake on the cholesterol efflux capacity (CEC) of HDL, and to elucidate on the mechanisms by which EVOO intake improves the anti-atherogenic activity of HDL. A total of 84 healthy women and men were enrolled and were distributed, according to age, into two groups: 27 young (31.81 ± 6.79 years) and 57 elderly (70.72 ± 5.6 years) subjects. The subjects in both groups were given 25 mL/d of extra virgin olive oil (EVOO) for 12 weeks. CEC was measured using J774 macrophages radiolabeled with tritiated cholesterol ((³H) cholesterol). HDL subclass distributions were analyzed using the Quantimetrix Lipoprint® system. The HDL from the elderly subjects exhibited a lower level of CEC, at 11.12% (p < 0.0001), than the HDL from the young subjects. The CEC of the elderly subjects returned to normal levels following 12 weeks of EVOO intake. An analysis of the distribution of HDL subclasses showed that HDL from the elderly subjects were composed of lower levels of large HDL (L-HDL) (p < 0.03) and higher levels of small HDL (S-HDL) (p < 0.002) compared to HDL from the young subjects. A multiple linear regression analysis revealed a positive correlation between CEC and L-HDL levels (r = 0.35 and p < 0.001) as well as an inverse correlation between CEC and S-HDL levels (r = −0.27 and p < 0.01). This correlation remained significant even when several variables, including age, sex, and BMI as well as low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and glucose levels (β = 0.28, p < 0.002, and β = 0.24, p = 0.01) were accounted for. Consuming EVOO for 12 weeks modulated the age-related difference in the distribution of HDL subclasses by reducing the level of S-HDL and increasing the level of intermediate-HDL/large-HDL (I-HDL/L-HDL) in the elderly subjects. The age-related alteration of the CEC of HDL was due, in part, to an alteration in the distribution of HDL subclasses. A diet enriched in EVOO improved the functionality of HDL through an increase in I-HDL/L-HDL and a decrease in S-HDL.     

Effects of a Self-Prepared Carbohydrate-Reduced High-Protein Diet on Cardiovascular Disease Risk Markers in Patients with Type 2 Diabetes

We previously observed beneficial effects of a carbohydrate-reduced, high-protein (CRHP) diet on cardiovascular risk markers in patients with type 2 diabetes mellitus (T2DM) in a crossover 2 × 6-week trial, when all food was provided to subjects as ready-to-eat meals. Here, we report the results from a 6-month open label extension: 28 patients with T2DM were instructed to self-prepare the CRHP diet with dietetic guidance. At weeks 0, 6, 12, and 36, fasting and postprandial (4-h meal test) blood samples were collected for measurements of total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, triacylglycerol (TG), apolipoproteins A1 and B, non-esterified fatty acids (NEFA), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6. Diurnal blood pressure and heart rate were also assessed. At the end of the study (week 36), concentrations of fasting total and LDL-cholesterol, fasting and postprandial NEFA and TG, and fasting apolipoprotein-B, CRP and TNF-α concentrations were significantly lower compared with week 0 (p < 0.05). A significant decrease in diurnal heart rate was also observed. From week 12 to 36, an increase in HDL-cholesterol and apolipoprotein-A1 concentrations and a further reduction in fasting and postprandial NEFA (p < 0.05) were found. These changes were independent of minor fluctuations in body weight. We conclude that the substitution of dietary carbohydrate for protein and fat has beneficial effects on several cardiovascular risk markers in patients with T2DM, which are maintained or augmented over the next 6 months when patients select and prepare the CRHP diet on their own in a dietitian-supported setting.     

Oral Supplement Containing Hydroxytyrosol and Punicalagin Improves Dyslipidemia in an Adult Population without Co-Adjuvant Treatment: A Randomized,Double-Blind,Controlled and Crossover Trial

Hydroxytyrosol (HT) and punicalagin (PC) exert cardioprotective and antiatherosclerotic effects. This study evaluated the effect of an oral supplement containing HT and PC (SAx) on dyslipidemia in an adult population. A randomized, double-blind, controlled, crossover trial was conducted over a 20-week period. SAx significantly reduced the plasma levels of triglycerides (TG) in subjects with hypertriglyceridemia (≥150 mg/dL) (from 200.67 ± 51.38 to 155.33 ± 42.44 mg/dL; p < 0.05), while no such effects were observed in these subjects after the placebo. SAx also significantly decreased the plasma levels of low-density lipoprotein cholesterol (LDL-C) in subjects with high plasma levels of LDL-C (≥160 mg/dL) (from 179.13 ± 16.18 to 162.93 ± 27.05 mg/dL; p < 0.01), while no such positive effect was observed with the placebo. In addition, the placebo significantly reduced the plasma levels of high-density lipoprotein cholesterol (HDL-C) in the total population (from 64.49 ± 12.65 to 62.55 ± 11.57 mg/dL; p < 0.05), while SAx significantly increased the plasma levels of HDL-C in subjects with low plasma levels of HDL-C (<50 mg/dL) (from 44.25 ± 3.99 to 48.00 ± 7.27 mg/dL; p < 0.05). In conclusion, the supplement containing HT and PC exerted antiatherosclerotic and cardio-protective effects by considerably improving dyslipidemia in an adult population, without co-adjuvant treatment or adverse effects.     

High hydrostatic pressure extract of garlic increases the HDL-cholesterol level via up-regulation of apolipoprotein A-I gene expression in rats fed a high-fat diet

ABSTRACT: BACKGROUND: Cardiovascular disease (CVD) is the number one cause of mortality worldwide and a low high-density lipoprotein cholesterol (HDL-C) level is an important marker of CVD risk. Garlic (Allium sativum) has been widely used in the clinic for treatment of CVD and regulation of lipid metabolism. This study investigated the effects of a high hydrostatic pressure extract of garlic (HEG) on HDL-C level and regulation of hepatic apolipoprotein A-I (apoA-I) gene expression. METHODS: Male Sprague-Dawley rats were divided into two groups and maintained on a high-fat control diet (CON) or high-fat control diet supplemented with high hydrostatic pressure extract of garlic (HEG) for 5 weeks. Changes in the expression of genes related to HDL-C metabolism were analyzed in liver, together with biometric and blood parameters. RESULTS: In the HEG group, the plasma levels of triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) were significantly decreased by 19% and 24%, respectively, relative to the control group. The plasma HDL-C level was increased by 59% (P < 0.05). The HEG-supplemented diet lowered the atherogenic index (AI) by 45% as compared to the CON group. Hepatic TG and total cholesterol (TC) levels were reduced by 35% and 43%, respectively in comparison with the CON group. The HEG supplementation increased hepatic mRNA levels of apoA-I, which is one of primarily proteins of HDL-C particle (P < 0.05). The gene expression of ATP-binding cassette transporter A1 (ABCA1) and lecithin:cholesterol acyltransferase (LCAT), importantly involved in the biogenesis in HDL, were also up-regulated by dietary HEG. CONCLUSIONS: These results suggest that HEG ameliorates plasma lipid profiles and attenuates hepatic lipid accumulation in the high-fat fed rats. Our findings provides that the effects of HEG on the increase of the plasma HDL-C level was at least partially mediated by up-regulation of hepatic genes expression such as apoA-I, ABCA1, and LCAT in rats fed a high-fat diet.     

正常BMI腹型肥胖人群高脂液体膳餐后脂代谢研究

目的探讨正常体质指数(BMI)腹型肥胖人群餐后脂代谢与正常体型人群的差异性。方法按照中国肥胖问题工作组提出的建议,以男性腰围≥85 cm,女性腰围≥80 cm为腹型肥胖判断标准,将收集到的BMI在正常范围的111例志愿者分成体型正常组和腹型肥胖组,测定其空腹状态下的胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL-C)和载脂蛋白B(ApoB)等指标,进食高脂负荷流质混合膳后,于0.5、1、2、4、6和8h测定以上指标。结果腹型肥胖组餐后TG水平高于体型正常组(P<0.05),HDL-C显著低于体型正常组(P<0.01)。两组人群餐后TC和ApoB未见统计学差异。结论正常BMI腹型肥胖人群已经存在餐后脂代谢异常,应及时采取针对性措施,防止心血管等疾病的发生。     

Do beans and oat bran add to the effectiveness of a low-fat diet?

The effects of consuming an increased amount of soluble fibre as oat bran or beans were examined in 40 free-living hypercholesterolaemic men and women. The subjects were initially established on a low-fat background diet (29% of energy from fat) and then 55 g low-fibre oat bran, 55 g high-fibre oat bran or 80 g mixed cooked beans were added to their diet in random order for 6 week periods. Body weight and overall composition of the diet did not change. Plasma cholesterol and low-density lipoprotein cholesterol (LDL-C) were unchanged. High-density lipoprotein cholesterol (HDL-C) was significantly higher on all three intervention diets than on the lower fibre run-in diet. Supplementation of a moderately low-fat diet with palatable quantities of oat bran or beans without changing the overall fat intake does not appear to significantly lower cholesterol but may have a benefit by increasing HDL-C and reducing the ratio of LDL-C to HDL-C.     

Low HDL cholesterol is associated with increased atherogenic lipoproteins and insulin resistance in women classified with metabolic syndrome

Both metabolic syndrome (MetS) and elevated LDL cholesterol (LDL-C) increase the risk for cardiovascular disease (CVD). We hypothesized that low HDL cholesterol (HDL-C) would further increase CVD risk in women having both conditions. To assess this, we recruited 89 women with MetS (25-72 y) and LDL-C ≥ 2.6 mmol/L. To determine whether plasma HDL-C concentrations were associated with dietary components, circulating atherogenic particles, and other risk factors for CVD, we divided the subjects into two groups: high HDL-C (H-HDL) (≥ 1.3 mmol/L, n = 32) and low HDL-C (L-HDL) (< 1.3 mmol/L, n = 57). Plasma lipids, insulin, adiponectin, apolipoproteins, oxidized LDL, Lipoprotein(a), and lipoprotein size and subfractions were measured, and 3-d dietary records were used to assess macronutrient intake. Women with L-HDL had higher sugar intake and glycemic load (P < 0.05), higher plasma insulin (P < 0.01), lower adiponectin (P < 0.05), and higher numbers of atherogenic lipoproteins such as large VLDL (P < 0.01) and small LDL (P < 0.001) than the H-HDL group. Women with L-HDL also had larger VLDL and both smaller LDL and HDL particle diameters (P < 0.001). HDL-C was positively correlated with LDL size (r = 0.691, P < 0.0001) and HDL size (r = 0.606, P < 0.001), and inversely correlated with VLDL size (r = -0.327, P < 0.01). We concluded that L-HDL could be used as a marker for increased numbers of circulating atherogenic lipoproteins as well as increased insulin resistance in women who are already at risk for CVD.     

Oat Bran Concentrate Bread Products Improve Long-Term Control of Diabetes: A Pilot Study

Objective To evaluate the long-term effects of oat bran concentrate bread products in the diet of free-living subjects with non-insulin-dependent diabetes (NIDDM) via dietary, clinical, and biochemical methods.

Design A 24-week crossover study consisting of two 12-week periods.

Subjects/setting Eight men with NIDDM (mean AGE=45 years) who lived in the community. Glucose and insulin profiles were conducted in a clinical investigation unit.

Intervention Palatable, high-fiber, oat bran concentrate (soluble fiber [p-glucan] CONTENT=22.8%) bread products were developed. Four randomly chosen subjects ate oat bran concentrate breads first; the other subjects ate control white bread first.

Main outcome measures Dietary intake (four 48-hour dietary recalls per period) was assessed. Blood glucose and insulin (8-hour profiles) and lipid parameters after fasting were measured (at 0, 12, and 24 weeks).

Statistical analyses performed Analysis of variance and repeated-measures analysis of variance.

Results Total energy and macronutrient intakes were similar in both periods. Mean total dietary fiber intake was 19 g/day in the white bread period and 34 g/day (9 g soluble fiber per day from oat bran concentrate) in the oat bran concentrate period. Body weight remained stable. Mean glycemic and insulin response areas (area under the curve) were lower (P≤.05 and not significant, respectively) for the oat bran concentrate period than the white bread period. After breakfast, area under the curve for the oat bran concentrate period was lower for glucose CP≤.01) and insulin (P≤.05); insulin peak was reached earlier (P≤.05) than in the white bread period. Dietary fiber intake was correlated negatively with insulin area under the curve (P≤.05). Mean total plasma cholesterol and low-density lipoprotein cholesterol levels were lower (P≤.01) in the oat bran concentrate period than in the white bread period. In the oat bran concentrate period, the mean ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol was reduced by 24% (P≤.05).

Conclusions The well-accepted oat bran concentrate bread products improved glycemic, insulinemic, and lipidemic responses. J Am Diet Assoc. 1996; 96:1254-1261.