Postprandial lipemia: an under-recognized atherogenic factor in patients with diabetes mellitus

Postprandial Dysmetabolism and Its Medical Implications

An unbalanced diet increases the risk of developing a variety of chronic diseases and cancers, leading to higher morbidity and mortality rates worldwide. Low-grade systemic chronic inflammation mediated by the activation of the innate immune system is common to all these pathologies. Inflammation is a biological response of the body and a normal part of host defense to combat the effects of bacteria, viruses, toxins and macronutrients. However, when the innate immune system is constantly activated, it can promote the development of low-grade systemic chronic inflammation, which could play an important role in the development of chronic diseases and cancer. Since most chronic inflammatory diseases are associated with diet, a balanced healthy diet high in anti-inflammatory food components could prevent chronic diseases and cancer. The cells of the body's immune system produce chemokines and cytokines which can have pro-inflammatory and tumor-promoting as well as anti-inflammatory and tumor-fighting functions. A challenge in the future will be to assess whether polymorphisms in immune-related genes may play a role in promoting pro-inflammatory activity. Thanks to this duality, future research on immune regulation could focus on how innate immune cells can be modified to convert a pro-inflammatory and tumor-friendly microenvironment into an anti-inflammatory and anti-tumor one. This review describes inflammatory responses mediated by the innate immune system in various diseases such as hyperglycemia and/or hyperlipemia, obesity, type II diabetes, cardiovascular disease and cancer.

Salsalate Improves Postprandial Glycemic and Some Lipid Responses in Persons With Tetraplegia: A Randomized Clinical Pilot Trial With Crossover Design

Objectives

To investigate the effects of salsalate on fasting and postprandial (PP) glycemic, lipidemic, and inflammatory responses in persons with tetraplegia.

Methods

This study was a randomized, double-blind, cross-over design. It was conducted at a university laboratory. Ten males aged 25 to 50 years with SCI at C5-8 levels for ≥1 year underwent 1 month of placebo and salsalate (4 g/day) treatment. Blood samples were drawn before and 4 hours after breakfast and lunch fast-food meal consumption.

Results

Descriptive statistics indicate that fasting and PP glucose values were reduced with salsalate (pre-post mean difference, 4 ± 5 mg/dL and 8 ± 8 mg/dL, respectively) but largely unchanged with placebo (0 ± 6 mg/dL and -0 ± 7 mg/dL, respectively). Insulin responses were generally reciprocal to glucose, however less pronounced. Fasting free fatty acids were significantly reduced with salsalate (191 ± 216 mg/dL, p = .021) but not placebo (-46 ± 116 mg/dL, p = .878). Results for triglycerides were similar (25 ± 34 mg/dL, p =.045, and 7 ± 29 mg/dL, p = .464). Fasting low-density lipoprotein (LDL) levels were higher after salsalate (-10 ± 12 mg/dL, p = .025) but not placebo (2 ± 9 mg/dL, p = .403) treatment. Inflammatory markers were largely unchanged.

Conclusion

In this pilot trial, descriptive values indicate that salsalate decreased fasting and PP glucose response to fast-food meal challenge at regular intervals in persons with tetraplegia. Positive effects were also seen for some lipid but not for inflammatory response markers. Given the relatively "healthy" metabolic profiles of the participants, it is possible that salsalate's effects may be greater and more consistent in people with less favorable metabolic milieus.

Deacetylation of Caveolin-1 by Sirt6 induces autophagy and retards high glucose-stimulated LDL transcytosis and atherosclerosis formation

BACKGROUND

Atherosclerosis (AS) is the basis of diabetic macrovascular complications. The plasma low-density lipoprotein (LDL) particles transcytosis across endothelial cells (ECs) and deposition under the endothelium is the initiation step of AS. We previously reported that high glucose inhibits the autophagic degradation of Caveolin-1 and promote LDL transcytosis across ECs, which in turn accelerates atherosclerotic progression. Since Sirt6 is a chromatin-associated protein with deacetylation activity, whether it can regulate Caveolin-1 acetylation and regulating the autophagic degradation of Caveolin-1 remains elusive.

METHODS

Autophagy and histone acetylation were assessed in the umbilical cords of patients with gestational diabetes mellitus (GDM) by immunohistochemistry. An in vitro model of LDL transcytosis was established, and the role of Sirt6 in LDL transcytosis across endothelial cells was clarified. The effect of Sirt6 on the autophagic degradation of Caveolin-1 under hyperglycemic conditions was explored in a streptozotocin (STZ)-induced diabetic AS model established using the ApoE^-/- mice.

RESULTS

Caveolin-1 and acetylated histone H3 levels were significantly increased, while LC3B and Sirt6 were downregulated in the monolayer of the vascular wall from GDM and type 2 diabetes mellitus (T2DM) patients. Immunoprecipitation assays showed that Sirt6 interacts with Caveolin-1 and specifically mediated its acetylation levels. Immuno-electron microscopy (EM) further indicated that Sirt6 overexpression triggered the autophagic lysosomal degradation of Caveolin-1. ECs-specific overexpression of Sirt6 by adeno-associated viral vector serotype 9 (AAV9) induced autophagy, reduced Caveolin-1 expression, and ameliorated atherosclerotic plaque formation in STZ-induced diabetic ApoE^-/- mice.

CONCLUSION

Sirt6-mediated acetylation of Caveolin-1 activates its autophagic degradation and inhibits high glucose-stimulated LDL transcytosis. Thus, the Sirt6/Caveolin-1 autophagic pathway plays a crucial role in diabetic AS, and the overexpression or activation of Sirt6 is a novel therapeutic strategy.

Lipemia in the Plasma Sample Affects Fentanyl Measurements by Means of HPLC-MS2 after Liquid-Liquid Extraction

Examination of fentanyl levels is frequently performed in certain scientific evaluations and forensic toxicology. It often involves the collection of very variable blood samples, including lipemic plasma or serum. To date, many works have reported the methods for fentanyl detection, but none of them have provided information about the impact on the assay performance caused by an excessive amount of lipids. This aspect may be, however, very important for highly lipophilic drugs like fentanyl. To address this issue, we developed the liquid chromatography method with mass spectrometry detection and utilized it to investigate the impact of lipids presence in rabbit plasma on the analytical method performance and validation. The validation procedure, conducted for normal plasma and lipemic plasma separately, resulted in good selectivity, sensitivity and linearity. The limits of detection and quantification were comparable between the two matrices, being slightly lower in normal plasma (0.005 and 0.015 µg/L) than in lipemic plasma (0.008 and 0.020 µg/L). Liquid–liquid extraction provided a low matrix effect regardless of the lipid levels in the samples (<10%), but pronounced differences were found in the recovery and accuracy. In the normal plasma, this parameter was stable and high (around 100%), but in the lipemic matrix, much more variable and less efficient results were obtained. Nevertheless, this difference had no impact on repeatability and reproducibility. In the present work, we provided reliable, convenient and sensitive method for fentanyl detection in the normal and lipemic rabbit plasma. However, construction of two separate validation curves was necessary to provide adequate results since the liquid-liquid extraction was utilized. Therefore, special attention should be paid during fentanyl quantification that involves lipemic plasma samples purified by this technique.

Multicompartmental non-invasive sensing of postprandial lipemia in humans with multispectral optoacoustic tomography

OBJECTIVE

Postprandial lipid profiling (PLP), a risk indicator of cardiometabolic disease, is based on frequent blood sampling over several hours after a meal, an approach that is invasive and inconvenient. Non-invasive PLP may offer an alternative for disseminated human monitoring. Herein, we investigate the use of clinical multispectral optoacoustic tomography (MSOT) for non-invasive, label-free PLP via direct lipid-sensing in human vasculature and soft tissues.

METHODS

Four (n = 4) subjects (3 females and 1 male, age: 28 ± 7 years) were enrolled in the current pilot study. We longitudinally measured the lipid signals in arteries, veins, skeletal muscles, and adipose tissues of all participants at 30-min intervals for 6 h after the oral consumption of a high-fat meal.

RESULTS

Optoacoustic lipid-signal analysis showed on average a 63.4% intra-arterial increase at ~ 4 h postprandially, an 83.9% intra-venous increase at ~ 3 h, a 120.8% intra-muscular increase at ~ 3 h, and a 32.8% subcutaneous fat increase at ~ 4 h.

CONCLUSION

MSOT provides the potential to study lipid metabolism that could lead to novel diagnostics and prevention strategies by label-free, non-invasive detection of tissue biomarkers implicated in cardiometabolic diseases.

Non-HDL-C Is More Stable Than LDL-C in Assessing the Percent Attainment of Non-fasting Lipid for Coronary Heart Disease Patients

This study aimed to compare the percentage attainment of fasting and non-fasting LDL-C and non-HDL-C target levels in coronary heart disease (CHD) patients receiving short-term statin therapy. This study enrolled 397 inpatients with CHD. Of these, 197 patients took statins for <1 month (m) or did not take any statin before admission (CHD1 group), while 204 patients took statins for ≥1 m before admission (CHD2 group). Blood lipid levels were measured at 0, 2, and 4 h after a daily breakfast. Non-fasting LDL-C and non-HDL-C levels significantly decreased after a daily meal (P < 0.05). Both fasting and non-fasting LDL-C or non-HDL-C levels were significantly lower in the CHD2 group. The percentage attainment of LDL-C <1.4 mmol/L at 2 and 4 h after a daily breakfast was significantly higher than that during fasting (P < 0.05), but the percent attainment of non-fasting non-HDL-C <2.2 mmol/L was close to its fasting value (P > 0.05). Analysis of c-statistic showed that non-fasting cut-off points for LDL-C and non-HDL-C were 1.19 and 2.11 mmol/L, corresponding to their fasting goal levels of 1.4 and 2.2 mmol/L, respectively. When post-prandial LDL-C and non-HDL-C goal attainments were re-evaluated using non-fasting cut-off points, there were no significant differences in percentage attainment between fasting and non-fasting states. Non-HDL-C is more stable than LDL-C in assessing the percent attainment of non-fasting lipid for coronary heart disease patients. If we want to use LDL-C to assess the percent attainment of post-prandial blood lipids, we may need to determine a lower non-fasting cut-off point.

Neurogenic Obesity and Skeletal Pathology in Spinal Cord Injury

Spinal cord injury (SCI) results in dramatic changes in body composition, with lean mass decreasing and fat mass increasing in specific regions that have important cardiometabolic implications. Accordingly, the recent Consortium for Spinal Cord Medicine (CSCM) released clinical practice guidelines for cardiometabolic disease (CMD) in SCI recommending the use of compartmental modeling of body composition to determine obesity in adults with SCI. This recommendation is guided by the fact that fat depots impact metabolic health differently, and in SCI adiposity increases around the viscera, skeletal muscle, and bone marrow. The contribution of skeletal muscle atrophy to decreased lean mass is self-evident, but the profound loss of bone is often less appreciated due to methodological considerations. General-population protocols for dual-energy x-ray absorptiometry (DXA) disregard assessment of the sites of greatest bone loss in SCI, but the International Society for Clinical Densitometry (ISCD) recently released an official position on the use of DXA to diagnose skeletal pathology in SCI. In this review, we discuss the recent guidelines regarding the evaluation and monitoring of obesity and bone loss in SCI. Then we consider the possible interactions of obesity and bone, including emerging evidence suggesting the possible influence of metabolic, autonomic, and endocrine function on bone health in SCI.

Exercise Interventions Targeting Obesity in Persons With Spinal Cord Injury

Spinal cord injury (SCI) results in an array of cardiometabolic complications, with obesity being the most common component risk of cardiometabolic disease (CMD) in this population. Recent Consortium for Spinal Cord Medicine Clinical Practice Guidelines for CMD in SCI recommend physical exercise as a primary treatment strategy for the management of CMD in SCI. However, the high prevalence of obesity in SCI and the pleiotropic nature of this body habitus warrant strategies for tailoring exercise to specifically target obesity. In general, exercise for obesity management should aim primarily to induce a negative energy balance and secondarily to increase the use of fat as a fuel source. In persons with SCI, reductions in the muscle mass that can be recruited during activity limit the capacity for exercise to induce a calorie deficit. Furthermore, the available musculature exhibits a decreased oxidative capacity, limiting the utilization of fat during exercise. These constraints must be considered when designing exercise interventions for obesity management in SCI. Certain forms of exercise have a greater therapeutic potential in this population partly due to impacts on metabolism during recovery from exercise and at rest. In this article, we propose that exercise for obesity in SCI should target large muscle groups and aim to induce hypertrophy to increase total energy expenditure response to training. Furthermore, although carbohydrate reliance will be high during activity, certain forms of exercise might induce meaningful postexercise shifts in the use of fat as a fuel. General activity in this population is important for many components of health, but low energy cost of daily activities and limitations in upper body volitional exercise mean that exercise interventions targeting utilization and hypertrophy of large muscle groups will likely be required for obesity management.

Functional Status of Pancreatic α and β Cells in Type 2 Diabetes Mellitus Patients with Different Plasma Triglyceride Levels: A Retrospective Analysis

OBJECTIVE

To investigate the functional status of pancreatic α and β cells in Type 2 diabetes mellitus (T2DM) patients with different plasma triglyceride (TG) levels. TG levels can be prognostic markers for T2DM.

METHODS

A total of 328 patients with T2DM were divided into three groups according to different TG levels: the TGL group: TG < 1.7 mmol/L; TGM group: 1.7 mmol/L ≤ TG < 2.3 mmol/L; and TGH group: TG ≥ 2.3 mmol/L. An oral glucose tolerance test (OGTT), insulin release test, and glucagon release test were performed in each patient. The changes of glucagon, glucagon/insulin ratio, early insulin secretion index (ΔI ₃₀/ΔG ₃₀), and area under the insulin curve (AUC_I) were compared among each group. Also, the correlations between glucagon and pancreatic β-cell function, glycosylated hemoglobin (HbA1c), and other indices were analyzed.

RESULTS

With the increase of TG, the fasting and postprandial glucagon levels, the glucagon/insulin ratio, and the area under the glucagon curve (AUC_G) presented an increasing trend. The homeostasis model assessment of insulin resistance (HOMA-IR) of the TGH group was significantly increased compared to the TGL and TGM groups. In addition to the increase in TG levels, the insulin sensitivity index (ISI), homeostasis model assessment for β-cell function index (HOMA-β), ΔI ₃₀/ΔG ₃₀, and AUC_I displayed a reducing trend. Glucagon was negatively correlated with ΔI ₃₀/ΔG ₃₀, high-density lipoprotein (HDL), HOMA-β, body mass index (BMI), ISI, and AUC_I (P < 0.05) and positively correlated with fasting blood glucose (FPG), AUC_G, HOMA-IR, HbA1c, duration, TG, low-density lipoprotein (LDL), and total cholesterol (TC) (P < 0.05).

CONCLUSION

Hypertriglyceridemia aggravated the dysfunction of pancreatic α and β cells. A reasonable control of the TG level makes it easier for blood glucose to reach the standard.

Effects of Acute Dietary Polyphenols and Post-Meal Physical Activity on Postprandial Metabolism in Adults with Features of the Metabolic Syndrome

Approximately 22% of U.S. adults and 25% of adults globally have metabolic syndrome (MetS). Key features, such as dysglycemia and dyslipidemia, predict type 2 diabetes, cardiovascular disease, premature disability, and death. Acute supplementation of dietary polyphenols and post-meal physical activity hold promise in improving postprandial dysmetabolism. To our knowledge, no published review has described the effects of either intervention on postprandial glucose, insulin, lipids, and markers of oxidative damage and inflammation in adults with features of MetS. Thus, we conducted this review of controlled clinical trials that provided dietary polyphenols from oils, fruits, teas, and legumes during a dietary challenge, or implemented walking, cycling, and stair climbing and descending after a dietary challenge. Clinical trials were identified using ClinicalTrials.gov, PubMed, and Google Scholar and were published between 2000 and 2019. Dietary polyphenols from extra virgin olive oil, grapes, blackcurrants, strawberries, black tea, and black beans improved postprandial glucose, insulin, and markers of oxidative damage and inflammation, but results were not consistent among clinical trials. Freeze-dried strawberry powder distinctly improved postprandial insulin and markers of oxidative damage and inflammation. Post-meal physical activity attenuated postprandial glucose, but effects on postprandial lipids and markers of oxidative damage and inflammation were inconclusive. Consuming dietary polyphenols with a meal and completing physical activity after a meal may mitigate postprandial dysmetabolism in adults with features of MetS.

Postprandial Lipemia Modulates Pancreatic Alpha-Cell Function in the Prediction of Type 2 Diabetes Development: The CORDIOPREV Study

Diabetes (T2DM) is a major global health issue, and developing new approaches to its prevention is of paramount importance. We hypothesized that abnormalities in lipid metabolism are involved in alpha-cell deregulation. We therefore studied the metabolic factors underlying alpha-cell dysfunction in T2DM progression after a dietary intervention (Mediterranean and low-fat). Additionally, we evaluated whether postprandial glucagon levels may be considered as a predictive factor of T2DM in cardiovascular patients. Non-T2DM participants from the CORDIOPREV study were categorized by tertiles of the area under the curve (AUC) for triacylglycerols and also by tertiles of AUC for glucagon. Our results showed that patients with higher triacylglycerols levels presented elevated postprandial glucagon (P = 0.009). Moreover, we observed higher risk of T2DM (hazard ratio: 2.65; 95% confidence interval: 1.56-4.53) in subjects with elevated glucagon. In conclusion, high postprandial lipemia may induce alpha-cell dysfunction in cardiovascular patients. Our results also showed that postprandial glucagon levels could be used to predict T2DM development.

Influence of upper-body continuous, resistance or high-intensity interval training (CRIT) on postprandial responses in persons with spinal cord injury: study protocol for a randomised controlled trial

Background

Chronic spinal cord injury (SCI) increases morbidity and mortality associated with cardiometabolic diseases, secondary to increases in central adiposity, hyperlipidaemia and impaired glucose tolerance. While upper-body Moderate Intensity Continuous Training (MICT) improves cardiorespiratory fitness, its effects on cardiometabolic component risks in adults with SCI appear relatively modest. The aim of this study is to assess the acute effects of Continuous Resistance Training (CRT), High Intensity Interval Training (HIIT), MICT and rest (CON) on fasting and postprandial systemic biomarkers and substrate utilisation.

Methods

Eleven healthy, chronic SCI (> 1 year, ASIA A-C) men will be recruited. Following preliminary testing, each will complete four experimental conditions, where they will report to the laboratory following an ~ 10-h overnight fast. A venous blood sample will be drawn and expired gases collected to estimate resting metabolic rate (RMR). In order to ensure an isocaloric exercise challenge, each will complete CRT first, with the remaining three conditions presented in randomised order: (1) CRT, ~ 45 min of resistance manoeuvres (weight lifting) interspersed with low-resistance, high-speed arm-crank exercise; (2) CON, seated rest; (3) MICT, ~ 45 min constant arm-crank exercise at a resistance equivalent to 30–40% peak power output (PPO) and; (4) HIIT, ~ 35 min arm-crank exercise with the resistance alternating every 2 min between 10% PPO and 70% PPO. After each ~ 45-min condition, participants will ingest a 2510-kJ liquid test meal (35% fat, 50% carbohydrate, 15% protein). Venous blood and expired gas samples will be collected at the end of exercise and at regular intervals for 120 min post meal.

Discussion

This study should establish the acute effects of different forms of exercise on fasting and postprandial responses in chronic SCI male patients. Measures of glucose clearance, insulin sensitivity, lipid and inflammatory biomarker concentrations will be assessed and changes in whole-body substrate oxidation estimated from expired gases.

Trial registration

ClinicalTrials.gov, ID: NCT03545867. Retrospectively registered on 1 June 2018. 

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3583-1) contains supplementary material, which is available to authorized users.

Exercise and Health-Related Risks of Physical Deconditioning After Spinal Cord Injury

A sedentary lifestyle occurring soon after spinal cord injury (SCI) may be in contrast to a preinjury history of active physical engagement and is thereafter associated with profound physical deconditioning sustained throughout the lifespan. This physical deconditioning contributes in varying degrees to lifelong medical complications, including accelerated cardiovascular disease, insulin resistance, osteopenia, and visceral obesity. Unlike persons without disability for whom exercise is readily available and easily accomplished, exercise options for persons with SCI are more limited. Depending on the level of injury, the metabolic responses to acute exercise may also be less robust than those accompanying exercise in persons without disability, the training benefits more difficult to achieve, and the risks of ill-considered exercise both greater and potentially irreversible. For exercise to ultimately promote benefit and not impose additional impairment, an understanding of exercise opportunities and risks if exercise is undertaken by those with SCI is important. The following monograph will thus address common medical challenges experienced by persons with SCI and typical modes and benefits of voluntary exercise conditioning.

Western Dietary Pattern Is Associated With Severe Coronary Artery Disease

The independent predictive value of an unhealthy diet on the severity of coronary artery disease (CAD) requires further investigation. We assessed the impact of dietary pattern on CAD severity. In this cohort study, we included 188 symptomatic stable patients with CAD. Patients were categorized as having severe CAD or nonsevere CAD by coronary angiography. Among several demographics and clinical characteristics, all patients were tested using a semiquantitative food frequency questionnaire. Concerning baseline demographic characteristics, there was no difference between patients with severe CAD and nonsevere CAD. Principal component analysis revealed 8 distinct dietary patterns. The first component Western dietary pattern (increased intake of fat, red meat, and carbohydrates and minimal consumption of fruits and green leafy vegetables) was predictive of severe CAD (area under the curve: 0.73, 95% confidence intervals: 0.64-0.83, P < .001). In conclusion, an unhealthy Western type of diet is associated with the severity of coronary artery lesions in patients with stable CAD. These findings highlight the role of dietary patterns when estimating cardiovascular risk for the management of patients with CAD.

Postmeal triglyceridemia and variability of HbA1c and postmeal glycemia were predictors of annual decline in estimated glomerular filtration rate in type 2 diabetic patients with different stages of nephropathy

BACKGROUND

This study examined associations of annual glycemic variability and postprandial dysmetabolism with annual decline in estimated glomerular filtration rate (eGFR) in type 2 diabetic patients with different stages of nephropathy.

METHODS

Intrapersonal mean and coefficient of variation (CV) of HbA1c, fasting and postmeal concentrations of plasma glucose (FPG and PMPG, respectively) and serum triglycerides (FTG and PMTG, respectively) during the first 12 months after enrollment were calculated in a cohort of 168 type 2 diabetic patients: 53 with optimal albumin/creatinine ratio (ACR < 10 mg/g), 62 with high normal ACR (10-29 mg/g) and 53 with elevated ACR (≧30 mg/g). Annual changes in eGFR were computed using 52 (median) creatinine measurements obtained over a median follow-up of 6.0 years. Multivariate linear regressions assessed the independent correlates of changes in eGFR.

RESULTS

Kidney function declined faster in patients with high normal and elevated ACR (-1.47 and -2.01 ml/min/1.73 m2/year, respectively) compared to patients with optimal ACR (0.08 ml/min/1.73 m2/year, p < 0.05). In patients with high normal ACR, age (standardized β、-0.30、p = 0.01), CV-HbA1c (standardized β、-0.66、p < 0.001) and CV-PMPG (standardized β、-0.27、p = 0.01) was associated with annual eGFR decline independently of mean HbA1c and PMPG, sex, BMI, waist circumference, diabetes duration and therapy, means and CVs of FPG and systolic blood pressure, baseline eGFR, log ACR and uses of anti-hypertensive medications (R2 = 0.47). In patients with elevated ACR, PMTG (standardized β、-0.408, p = 0.007) was associated with annual eGFR decline (R2 = 0.15).

CONCLUSIONS

Consistency of glycemic control and management of postprandial glycemia and lipidemia are important to preserve kidney function in type 2 diabetic patients.

Impact of bromocriptine-QR therapy on cardiovascular outcomes in type 2 diabetes mellitus subjects on metformin

OBJECTIVES

Type 2 diabetes mellitus (T2DM) is associated with a substantially increased risk of cardiovascular disease (CVD). Bromocriptine-QR (B-QR), a quick release sympatholytic dopamine D₂ receptor agonist, is a FDA-approved therapy for T2DM which may provide CVD risk reduction. Metformin is considered to be an agent with a potential cardioprotective benefit. This large placebo controlled clinical study assessed the impact of B-QR addition to existing metformin therapy on CVD outcomes in T2DM subjects.

METHODS

1791 subjects (1208 B-QR; 583 placebo) on metformin ± another anti-diabetes therapy at baseline derived from the Cycloset Safety Trial, a 12-month, randomized, multicenter, placebo-controlled, double-blind study in T2DM, were included in this study. The primary CVD endpoint evaluated was treatment impact on CVD event rate, prespecified as a composite of time to first myocardial infarction, stroke, coronary revascularization, or hospitalization for unstable angina/congestive heart failure. Impact on glycemic control was evaluated as a secondary analysis.

RESULTS

The composite CVD end point occurred in 16/1208 B-QR treated (1.3%) and 18/583 placebo treated (3.1%) subjects resulting in a 55% CVD hazard risk reduction (intention-to-treat, Cox regression analysis; HR: 0.45 [0.23-0.88], p = 0.028). Kaplan-Meier curves demonstrated a significantly lower cumulative incidence rate of the CVD endpoint in the B-QR treatment group (Log-Rank p = 0.017). In subjects with poor glycemic control (HbA1c ≥ 7.5) at baseline, B-QR therapy relative to placebo resulted in a significant mean %HbA1c reduction of -0.59 at week 12 and -0.51 at week 52 respectively (p < 0.001 for both) and a 10 fold higher percent of subjects achieving HbA1c goal of ≤7% by week 52 (B-QR 30%, placebo 3%; p = 0.003).

CONCLUSION

These findings suggest that in T2DM subjects on metformin, BQR therapy may represent an effective strategy for reducing CVD risk. Cycloset Safety Trial registration: ClinicalTrials.gov Identifier: NCT00377676.

Association of Postbreakfast Triglyceride and Visit-to-Visit Annual Variation of Fasting Plasma Glucose with Progression of Diabetic Nephropathy in Patients with Type 2 Diabetes

Urinary albumin/creatinine ratio (ACR) was measured at baseline and after a median follow-up of 6.0 years in 161 patients with type 2 diabetes. Intrapersonal means and SD of HbA1c, systolic BP, fasting, and postmeal plasma glucose (FPG and PMPG, resp.) and serum triglycerides (FTG and PMTG, resp.) were calculated in each patient during the first 12 months after enrollment. Associations of these variables with nephropathy progression (15 patients with progression of albuminuric stages and 5 with ACR doubling within the microalbuminuric range) were determined by multivariate logistic regression analysis providing odds ratio with 95% confidential interval. Patients with nephropathy progression, compared with those without nephropathy progression, had higher HbA1c (p < 0.01). They also had higher means and SD of FPG (both p < 0.05), FTG (both p < 0.05), and PMTG (p = 0.001). Multivariate logistic regression analysis demonstrated that SD-FPG (1.036, 1.001-1.073, p = 0.04) and PMTG (1.013, 1.008-1.040, p = 0.001) were significant predictors of progression of nephropathy even after adjustment for mean FPG and SD-FTG, age, sex, BMI, waist circumference, diabetes duration and therapy, means and SDs of HbA1c, PPG, FTG and systolic BP, baseline ACR, smoking status, and uses of antihypertensive and lipid-lowering medications. Consistency of glycemic control and management of postmeal TG may be important to prevent nephropathy progression in type 2 diabetic patients.

Potential Drug Combinations to Reduce Cardiovascular Disease Burden in Diabetes

The major cause of death and complications in patients with type 2 diabetes (T2DM) is cardiovascular disease (CVD). More than 60% of all patients with T2DM die of CVD, and an even greater percentage have serious complications. The impact of glucose lowering on cardiovascular complications is a hotly debated issue and recent large clinical trials reported no significant decrease in cardiovascular events with intensive glucose control. Risk remains high even after correcting diabetes-associated dyslipidemia with drugs such as fibrates and niacin. Data from several clinical studies show that postprandial glucose and lipids have a strong predictive value on myocardial infarction (MI) and mortality. However, strategies to reduce postprandial hyperglycemia and/or lipemia through increased utilization of glucose and/or triglycerides (TG) have been shown to not be effective in reducing the CVD burden. In this review, I discus the preferred ways to reduce postprandial glucose and TG with combinations of currently marketed drugs with potential benefit in CVD.

Anti-Diabetic Effects of Madecassic Acid and Rotundic Acid

Anti-diabetic effects of madecassic acid (MEA) and rotundic acid (RA) were examined. MEA or RA at 0.05% or 0.1% was supplied to diabetic mice for six weeks. The intake of MEA, not RA, dose-dependently lowered plasma glucose level and increased plasma insulin level. MEA, not RA, intake dose-dependently reduced plasminogen activator inhibitor-1 activity and fibrinogen level; as well as restored antithrombin-III and protein C activities in plasma of diabetic mice. MEA or RA intake decreased triglyceride and cholesterol levels in plasma and liver. Histological data agreed that MEA or RA intake lowered hepatic lipid droplets, determined by ORO stain. MEA intake dose-dependently declined reactive oxygen species (ROS) and oxidized glutathione levels, increased glutathione content and maintained the activity of glutathione reductase and catalase in the heart and kidneys of diabetic mice. MEA intake dose-dependently reduced interleukin (IL)-1β, IL-6, tumor necrosis factor-α and monocyte chemoattractant protein-1 levels in the heart and kidneys of diabetic mice. RA intake at 0.1% declined cardiac and renal levels of these inflammatory factors. These data indicated that MEA improved glycemic control and hemostatic imbalance, lowered lipid accumulation, and attenuated oxidative and inflammatory stress in diabetic mice. Thus, madecassic acid could be considered as an anti-diabetic agent.

Obesity-Related Oxidative Stress: the Impact of Physical Activity and Diet Manipulation

Obesity-related oxidative stress, the imbalance between pro-oxidants and antioxidants (e.g., nitric oxide), has been linked to metabolic and cardiovascular disease, including endothelial dysfunction and atherosclerosis. Reactive oxygen species (ROS) are essential for physiological functions including gene expression, cellular growth, infection defense, and modulating endothelial function. However, elevated ROS and/or diminished antioxidant capacity leading to oxidative stress can lead to dysfunction. Physical activity also results in an acute state of oxidative stress. However, it is likely that chronic physical activity provides a stimulus for favorable oxidative adaptations and enhanced physiological performance and physical health, although distinct responses between aerobic and anaerobic activities warrant further investigation. Studies support the benefits of dietary modification as well as exercise interventions in alleviating oxidative stress susceptibility. Since obese individuals tend to demonstrate elevated markers of oxidative stress, the implications for this population are significant. Therefore, in this review our aim is to discuss (i) the role of oxidative stress and inflammation as associated with obesity-related diseases, (ii) the potential concerns and benefits of exercise-mediated oxidative stress, and (iii) the advantageous role of dietary modification, including acute or chronic caloric restriction and vitamin D supplementation.

Postprandial Dysmetabolism and Oxidative Stress in Type 2 Diabetes: Pathogenetic Mechanisms and Therapeutic Strategies

Postprandial dysmetabolism in type 2 diabetes (T2D) is known to impact the progression and evolution of this complex disease process. However, the underlying pathogenetic mechanisms still require full elucidation to provide guidance for disease prevention and treatment. This review focuses on the marked redox changes and inflammatory stimuli provoked by the spike in blood glucose and lipids in T2D individuals after meals. All the causes of exacerbated postprandial oxidative stress in T2D were analyzed, also considering the consequence of enhanced inflammation on vascular damage. Based on this in-depth analysis, current strategies of prevention and pharmacologic management of T2D were critically reexamined with particular emphasis on their potential redox-related rationale.

Daily stressors, past depression, and metabolic responses to high-fat meals: a novel path to obesity

BACKGROUND

Depression and stress promote obesity. This study addressed the impact of daily stressors and a history of major depressive disorder (MDD) on obesity-related metabolic responses to high-fat meals.

METHODS

This double-blind, randomized, crossover study included serial assessments of resting energy expenditure (REE), fat and carbohydrate oxidation, triglycerides, cortisol, insulin, and glucose before and after two high-fat meals. During two separate 9.5-hour admissions, 58 healthy women (38 breast cancer survivors and 20 demographically similar control subjects), mean age 53.1 years, received either a high saturated fat meal or a high oleic sunflower oil meal. Prior day stressors were assessed by the Daily Inventory of Stressful Events.

RESULTS

Greater numbers of stressors were associated with lower postmeal REE (p = .008), lower fat oxidation (p = .04), and higher insulin (p = .01), with nonsignificant effects for cortisol and glucose. Women with prior MDD had higher cortisol (p = .008) and higher fat oxidation (p = .004), without significant effects for REE, insulin, and glucose. Women with a depression history who also had more stressors had a higher peak triglyceride response than other participants (p = .01). The only difference between meals was higher postprandial glucose following sunflower oil compared with saturated fat (p = .03).

CONCLUSIONS

The cumulative 6-hour difference between one prior day stressor and no stressors translates into 435 kJ, a difference that could add almost 11 pounds per year. These findings illustrate how stress and depression alter metabolic responses to high-fat meals in ways that promote obesity.

Role of free radical in atherosclerosis, diabetes and dyslipidaemia: larger-than-life

During the past few decades, there have been numerous studies related to free radical chemistry. Free radicals including reactive oxygen species (ROS) and reactive nitrogen species are generated by the human body by various endogenous systems, exposure to different physiochemical conditions, or pathological states, and have been implicated in the pathogenesis of many diseases. These free radicals are also the common by-products of many oxidative biochemical reactions in cells. When free radicals overwhelm the body's ability to regulate them, a condition known as oxidative stress ensues. They adversely alter lipids, proteins, and DNA, which trigger a number of human diseases. In a number of pathophysiological conditions, the delicate equilibrium between free radical production and antioxidant capability is distorted, leading to oxidative stress and increased tissue injury. ROS which are mainly produced by vascular cells are implicated as possible underlying pathogenic mechanisms in a progression of cardiovascular diseases including ischemic heart disease, atherosclerosis, cardiac arrhythmia, hypertension, and diabetes. This review summarizes the key roles played by free radicals in the pathogenesis of atherosclerosis, diabetes, and dyslipidaemia. Although not comprehensive, this review also provides a brief perspective on some of the current research being conducted in this area for a better understanding of the role free radicals play in the pathogenesis of atherosclerosis, diabetes, and dyslipidaemia.

Marital discord, past depression, and metabolic responses to high-fat meals: Interpersonal pathways to obesity

BACKGROUND

Longitudinal studies have implicated both marital distress and depression in the development of the metabolic syndrome, a risk factor for diabetes and cardiovascular disease. This study addressed the impact of hostile marital interactions and a mood disorder history on obesity-related metabolic responses to high-fat meals.

METHODS

This double-blind, randomized crossover study included serial assessments of resting energy expenditure (REE), fat and carbohydrate oxidation, triglycerides, insulin, glucose, interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) before and after two high-fat meals. During two separate 9.5h visits, 43 healthy married couples, ages 24-61 (mean=38.22), received either a high saturated fat meal or a high oleic sunflower oil meal, both 930kcal and 60g fat. The Structured Diagnostic Interview for DSM-IV assessed mood disorder history. Couples discussed a marital disagreement during both visits; behavioral coding of these interactions provided data on hostile marital behaviors.

RESULTS

Men and women who displayed more hostile behaviors and who also had a mood disorder history had significantly lower post-meal REE, higher insulin, and higher peak triglyceride responses than other participants, with nonsignificant effects for fat and carbohydrate oxidation. Participants with a mood disorder history had a steeper rise in postprandial IL-6 and glucose than those without a past history. Higher levels of hostile behaviors were associated with higher post-meal TNF-α. The two meals did not differ on any outcome assessed.

CONCLUSIONS

People spend about 18 of every 24h in a postprandial state, and dining with one's partner is a common daily event. Among subjects with a mood disorder history, the cumulative 6.75-h difference between high and low hostile behaviors translates into 128kcal, a difference that could add 7.6pounds/year. Our findings illustrate novel pathways through which chronic marital stress and a mood disorder history synergistically heighten the risk for obesity, metabolic syndrome, and cardiovascular disease.

Placental fatty acid transfer: a key factor in fetal growth

The functionality of the placenta may affect neonatal adiposity and fetal levels of key nutrients such as long-chain polyunsaturated fatty acids. Fetal macrosomia and its complications may occur even in adequately controlled gestational diabetic (GDM) mothers, suggesting that maternal glycemia is not the only determinant of fetal glycemic status and wellbeing. We studied in vivo the placental transfer of fatty acids (FA) labeled with stable isotopes administered to 11 control and 9 GDM pregnant women (6 treated with insulin). Subjects received orally ¹³C-palmitic, ¹³C-oleic, and ¹³C-linoleic acids and ¹³C-docosahexaenoic acid (¹³C-DHA) 12 h before an elective caesarean section. FA were quantified by gas chromatography and ¹³C enrichments by gas chromatography-isotope ratio mass spectrometry. The ¹³C-FA concentration was higher in total lipids of maternal plasma in GDM patients versus controls, except for ¹³C-DHA. Moreover, ¹³C-DHA showed a lower placenta/maternal plasma ratio in GDM patients versus controls and a significantly lower cord/maternal plasma ratio. Other FA ratios studied were not different between GDM and controls. A disturbed ¹³C-DHA placental uptake occurred in GDM patients treated with diet or insulin, while the latter also had lower ¹³C-DHA levels in the venous cord. The tracer study pointed towards an impaired placental DHA uptake as a critical step, while the transfer of other ¹³C-FA was less affected. Patients with GDM treated with insulin could also have a greater fetal fat storage, which may have contributed to the reduced ¹³C-DHA in the venous cord observed. The DHA transfer to the fetus was reduced in GDM pregnancies compared to controls. This might have an influence on fetal neurodevelopment and long-term consequences for the child.

Postprandial lipemia as a cardiometabolic risk factor

High levels of fasting circulating triglycerides (TG) represent an independent risk factor for cardiovascular disease. In western countries, however, people spend most time in postprandial conditions, with continuous fluctuation of lipemia due to increased levels of TG-rich lipoproteins (TRLs), including chylomicrons (CM), very low density lipoproteins (VLDL), and their remnants. Several factors contribute to postprandial lipid metabolism, including dietary, physiological, pathological and genetic factors. The presence of coronary heart disease, type 2 diabetes, insulin resistance and obesity is associated with higher postprandial TG levels compared with healthy conditions; this association is present also in subjects with normal fasting TG levels. Increasing evidence indicates that impaired metabolism of postprandial lipoproteins contributes to the pathogenesis of coronary artery disease, suggesting that lifestyle modifications as well as pharmacological approaches aimed at reducing postprandial TG levels might help to decrease the cardiovascular risk.

Concomitant intake of quercetin with a grain-based diet acutely lowers postprandial plasma glucose and lipid concentrations in pigs

Treatment goals of diabetes mellitus type 2 (DMT2) include glycemic control and reduction of nonglycemic risk factors, for example, dyslipidemia. Quercetin, a plant-derived polyphenol, often discussed for possible antidiabetic effects, was investigated for acute postprandial glucose- and lipid-lowering effects in healthy growing pigs. Male pigs (n = 16, body weight = BW 25–30 kg) were fed flavonoid-poor grain-based meals without (GBM) or with quercetin (GBMQ). In a first experiment, postprandial plasma concentrations of glucose, nonesterified fatty acids (NEFA), and triacylglycerols were analyzed in 8 pigs receiving 500 g of either GBM or GBMQ (10 mg/kg BW) in a cross-over design. Blood samples were collected before, and up to 5 h every 30 min, as well as 6 and 8 h after the feeding. In the second experiment, 2 h after ingestions of 1000 g of either GBM or GBMQ (50 mg/kg BW) animals were sacrificed; gastric content was collected and analyzed for dry matter content. Quercetin ingestion reduced postprandial glucose, NEFA, and TG concentration, but two hours after ingestion of the meal no effect on gastric emptying was observed. Our results point to inhibitory effects of quercetin on nutrient absorption, which appear not to be attributable to delayed gastric emptying.

Risk of cardiovascular, cardiac and arrhythmic complications in patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has emerged as a public health problem of epidemic proportions worldwide. Accumulating clinical and epidemiological evidence indicates that NAFLD is not only associated with liver-related morbidity and mortality but also with an increased risk of coronary heart disease (CHD), abnormalities of cardiac function and structure (e.g., left ventricular dysfunction and hypertrophy, and heart failure), valvular heart disease (e.g., aortic valve sclerosis) and arrhythmias (e.g., atrial fibrillation). Experimental evidence suggests that NAFLD itself, especially in its more severe forms, exacerbates systemic/hepatic insulin resistance, causes atherogenic dyslipidemia, and releases a variety of pro-inflammatory, pro-coagulant and pro-fibrogenic mediators that may play important roles in the pathophysiology of cardiac and arrhythmic complications. Collectively, these findings suggest that patients with NAFLD may benefit from more intensive surveillance and early treatment interventions to decrease the risk for CHD and other cardiac/arrhythmic complications. The purpose of this clinical review is to summarize the rapidly expanding body of evidence that supports a strong association between NAFLD and cardiovascular, cardiac and arrhythmic complications, to briefly examine the putative biological mechanisms underlying this association, and to discuss some of the current treatment options that may influence both NAFLD and its related cardiac and arrhythmic complications.

Materno-fetal transfer of docosahexaenoic acid is impaired by gestational diabetes mellitus

Better knowledge on the disturbed mechanisms implicated in materno-fetal long-chain polyunsaturated fatty acid (LC-PUFA) transfer in pregnancies with gestational diabetes mellitus (GDM) may have potentially high implications for later on in effective LC-PUFA supplementation. We studied in vivo placental transfer of fatty acids (FA) using stable isotope tracers administrated to 11 control and 9 GDM pregnant women (6 treated with insulin). Subjects received orally [(13)C]palmitic, [(13)C]oleic and [(13)C]linoleic acids, and [(13)C]docosahexaenoic acid ((13)C-DHA) 12 h before elective caesarean section. Maternal blood samples were collected at -12, -3, -2, and -1 h, delivery, and +1 h. Placental tissue and venous cord blood were also collected. FA were quantified by gas chromatography (GC) and (13)C enrichments by GC-isotope ratio mass spectrometry. [(13)C]FA concentration was higher in total lipids of maternal plasma in GDM vs. controls, except for [(13)C]DHA. Moreover, [(13)C]DHA showed lower placenta/maternal plasma ratio in GDM vs. controls and significantly lower cord/maternal plasma ratio. For the other studied FA, ratios were not different between GDM and controls. Disturbed [(13)C]DHA placental uptake occurs in both GDM treated with diet or insulin, whereas the last ones also have lower [(13)C]DHA in venous cord. The tracer study pointed toward impaired placental DHA uptake as critical step, whereas the transfer of the rest of [(13)C]FA was less affected. GDM under insulin treatment could also have higher fetal fat storage, contributing to reduce [(13)C]DHA in venous cord. DHA transfer to the fetus was reduced in GDM pregnancies compared with controls, which might affect the programming of neurodevelopment in their neonates.

Lifestyle impact on meal-induced insulin sensitization in health and prediabetes: A focus on diet, antioxidants, and exercise interventions

The augmented whole-body glucose uptake response to insulin during the postprandial state is described as meal-induced insulin sensitization (MIS). MIS occurs when the presence of food in the upper gastrointestinal tract activates 2 feeding signals (activation of hepatic parasympathetic nerves and elevation of hepatic glutathione level), and causes insulin to release hepatic insulin sensitizing substance (HISS), which stimulates glucose uptake in skeletal muscle, heart, and kidneys. HISS action results in nutrient storage, primarily as glycogen. Impairment of HISS release results in the absence of meal-induced insulin sensitization (AMIS), which causes postprandial hyperglycemia and hyperinsulinemia, and chronically leads to the progression to a cluster of metabolic, vascular, and cardiac dysfunctions, which we refer to as components of the AMIS syndrome. Manipulation of the MIS process in health and in disease, by pharmacological and nonpharmacological interventions, is outlined in this review. High fat or sugar supplemented diet reduces MIS; exercise elevates MIS; and antioxidants protect MIS against reductions associated with diet and age.

Postprandial Peaking and Plateauing of Triglycerides and VLDL in Patients with Underlying Cardiovascular Diseases Despite Treatment

BACKGROUND

Dyslipidemia is associated with cardiovascular morbidities and mortality. Currently, fasting lipid profile determination is used to monitor treatment response. Recently, postprandial lipemia is of increasing interest because of its atherogenic and thrombogenic potential and also was found to be more predictive for cardiovascular diseases.

OBJECTIVES

To demonstrate postprandial lipemia among patients with cardiovascular diseases despite low fat diet, normal fasting lipid profile and even statin regimen.

PATIENTS AND METHODS

Patients aged 40-80 years old with cardiovascular diseases (i.e. coronary artery disease and cerebrovascular disease) more than 6 months, on statin treatment for more than 6 months and normal fasting lipid profile (according to NCEP ATP III guidelines) were included. Study exclusion criteria were pregnancy, acute cardiovascular events < 6 months, hepatic or renal failure. Finally, twelve patients were included.

RESULTS

The triglyceride level showed a significant rise from fasting to 2 hours after breakfast with a mean difference of 23.86 mg/dL (P =0.012). The level peaked at 4 hours after breakfast with a mean difference (MD) of 72.02 mg/dL (P =0.002). Subsequent triglyceride levels plateaued and were significantly higher than the baseline (P <0.05) until the 12th hour of observation. VLDL levels showed a similar pattern. Levels increased significantly from fasting to 2h after breakfast (mean difference: 4.49 mg/dL, P = 0.007), then plateaued and further increased 4 hours after breakfast (MD: 14.01 mg/dL, P = 0.002). VLDL levels were significantly higher than fasting (P < 0.05) and did not return to baseline until the 12th hour of observation. In contrast, the levels of total cholesterol, HDL and LDL decreased postprandially.

CONCLUSIONS

Triglyceride and VLDL peaking and plateauing were observed in patients with cardiovascular diseases despite low fat diet, normal fasting lipid profile and statin regimen. These findings may raise more attentions in monitoring and management of dyslipidemia in patients with cardiovascular and cerebrovascular events.

Nonfasting lipids, lipoproteins, and apolipoproteins in individuals with and without diabetes: 58 434 individuals from the Copenhagen General Population Study

BACKGROUND

Whether lipid profiles should be collected from fasting or nonfasting individuals is controversial, particularly in the diabetic population. We examined the influence of normal food intake on lipid profiles in diabetic and nondiabetic individuals.

METHODS

We assessed plasma concentrations of lipids, lipoproteins, apolipoproteins, and albumin as a function of time since the last meal in 58 434 individuals (participation rate 45%) from the general population, 2270 of whom had diabetes mellitus.

RESULTS

Similar patterns in the measured constituents were observed in the diabetic and nondiabetic populations. Triglycerides remained increased for 6-7 h in both populations after the last meal, whereas LDL cholesterol and albumin but not apolipoprotein B were reduced in both populations up to 5 h after normal food intake; after adjustment for hemodilution on the basis of albumin concentrations, the LDL cholesterol reductions were no longer present. Maximum observed mean differences from fasting concentrations in diabetic patients were -0.6 mmol/L, 0 mmol/L, 0.2 mmol/L, and 0.08 g/L (8 mg/dL) for LDL cholesterol, HDL cholesterol, triglycerides, and apolipoprotein B, respectively, and, correspondingly, -0.3 mmol/L, 0 mmol/L, 0.2 mmol/L, and 0.03 g/L (3 mg/dL) in individuals without diabetes.

CONCLUSIONS

Triglycerides increased up to 0.2 mmol/L after normal food intake in individuals with and without diabetes, whereas the postprandial reductions in LDL cholesterol observed in both populations likely were caused by hemodilution due to fluid intake. No statistically significant differences in postprandial apolipoprotein B concentrations were found. These data may be useful for discussion during revisions of guidelines for lipid measurements in individuals with or without diabetes.

Cholesterol and triglyceride management: "if I take my medication, can I eat what I want?"

The medications we use for cholesterol and triglyceride lowering are powerful and have substantial outcome data. However, even with aggressive statin therapy, there is residual risk for recurrent cardiovascular events. Strict dietary modification has been shown to reduce low-density lipoprotein (LDL) cholesterol by 20% to 30%. Low-fat and Mediterranean-type diets have also been associated with atherosclerosis regression and fewer coronary heart disease events. On the other hand, a high-fat diet can produce postprandial lipemia and an increase in cardiovascular disease risk. Patients with atherogenic dyslipidemia (low high-density lipoprotein cholesterol, increased triglycerides and non-high-density lipoprotein cholesterol, small dense low-density lipoprotein particles) and visceral adiposity are particularly prone to postprandial lipemia. These individuals typically have insulin resistance, which is associated with endothelial dysfunction and an increased risk for thrombosis. Lifestyle intervention is the key to reducing postprandial lipemia, specifically weight reduction and increased physical activity. Although medications can improve postprandial lipemia, poor dietary choices can overwhelm the effects of medication and negatively impact the health of arteries, thus promoting atherosclerosis. Therefore, patients who are treated with medications for dyslipidemia must be counseled on consuming a heart-healthy diet.

Effects of rosiglitazone on fasting and postprandial low- and high-density lipoproteins size and subclasses in type 2 diabetes

Rosiglitazone may increase cardiovascular risk in patients with type 2 diabetes. Yet, its effects on atherogenic dyslipidemia are still not fully elucidated. In a prospective open-label study rosiglitazone (4 mg/day for 12 weeks) was added to a maximum of 2 oral antidiabetic drugs in 18 diabetic patients. We evaluated the effects on plasma lipids before and after an oral fat load. The size and subclasses of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were also determined (by gradient gel electrophoresis). Rosiglitazone improved glycosylated hemoglobin ([HbA1c] P = .0023), without significant effects on fasting and postprandial plasma lipids. Fasting LDL size increased (+1.4%, P = .034), with less small, dense LDL-IIIA (-25.1%, P = .018). Postprandially, larger HDL-2b reduced (-8.7%, P = .006) and smaller HDL-3b increased (+12.2%, P = .05), without any effects on HDL size. Rosiglitazone led to antiatherogenic changes in LDL size and subclasses, with proatherogenic changes in HDL subclasses, despite no effects on plasma lipids. Their clinical relevance remains to be established.

The influence of major dietary fatty acids on insulin secretion and action

PURPOSE OF REVIEW

To briefly summarize recent advances towards understanding the influence of major dietary fatty acids on beta-cell function and evaluate their implications for insulin resistance.

RECENT FINDINGS

Studies in humans have shown that beta-cell function and insulin sensitivity improve progressively in the postprandial period as the proportion of monounsaturated fatty acids (MUFAs) with respect to saturated fatty acids (SFAs) in dietary fats increases. However, cell-culture experiments have revealed a dichotomy in the ability of fatty acids to moderate hyperactivity of, and induce lipotoxicity in, beta-cells. There are also some novel findings regarding the ability of HDL to protect beta-cells against oxidized LDL-induced apoptosis in vitro and of reconstituted HDL to attenuate insulin resistance in vivo. These findings raise new questions regarding the contribution of dietary fatty acids to insulin secretion and action.

SUMMARY

These new findings point to a critical role for major dietary fatty acids in the etiology and pathogenesis of diabetes, which appears to be of particular relevance during postprandial periods and mainly depends on the fatty acid type. This underscores the importance of dietary fatty acids in standard diabetes management.

Postprandial lipoproteins and cardiovascular disease risk in diabetes mellitus

Diabetes mellitus is associated with increased risk for atherosclerotic cardiovascular disease (CVD). Recent prospective studies in healthy individuals suggest that the postprandial triglyceride (TG) level is a better independent predictor for assessing future CVD events than fasting TG levels. In contrast, results have been more controversial among diabetic patients, as some studies report a positive association between postprandial TG and CVD. This raises the issue of to what extent postprandial TG levels may be of predictive value in the diabetic population. One possibility impacting on the predictive power of postprandial TG in identifying CVD risk may be the presence of other risk factors, including alterations in lipid and lipoprotein metabolism, which could make it more difficult to identify the impact of postprandial lipemia on cardiovascular risk. The findings provide a challenge to develop a better approach to assess the impact of postprandial lipemia on CVD risk under diabetic conditions.

Effects of a plant-based high-carbohydrate/high-fiber diet versus high-monounsaturated fat/low-carbohydrate diet on postprandial lipids in type 2 diabetic patients

OBJECTIVE

To search for a better dietary approach to treat postprandial lipid abnormalities and improve glucose control in type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

According to a randomized crossover design, 18 type 2 diabetic patients (aged 59 +/- 5 years; BMI 27 +/- 3 kg/m(2)) (means +/- SD) in satisfactory blood glucose control on diet or diet plus metformin followed a diet relatively rich in carbohydrates (52% total energy), rich in fiber (28 g/1,000 kcal), and with a low glycemic index (58%) (high-carbohydrate/high-fiber diet) or a diet relatively low in carbohydrate (45%) and rich in monounsaturated fat (23%) (low-carbohydrate/high-monounsaturated fat diet) for 4 weeks. Thereafter, they shifted to the other diet for 4 more weeks. At the end of each period, plasma glucose, insulin, lipids, and lipoprotein fractions (separated by discontinuous density gradient ultracentrifugation) were determined on blood samples taken at fasting and over 6 h after a test meal having a similar composition as the corresponding diet.

RESULTS

In addition to a significant decrease in postprandial plasma glucose, insulin responses, and glycemic variability, the high-carbohydrate/high-fiber diet also significantly improved the primary end point, since it reduced the postprandial incremental areas under the curve (IAUCs) of triglyceride-rich lipoproteins, in particular, chylomicrons (cholesterol IAUC: 0.05 +/- 0.01 vs. 0.08 +/- 0.02 mmol/l per 6 h; triglycerides IAUC: 0.71 +/- 0.35 vs. 1.03 +/- 0.58 mmol/l per 6 h, P < 0.05).

CONCLUSIONS

A diet rich in carbohydrate and fiber, essentially based on legumes, vegetables, fruits, and whole cereals, may be particularly useful for treating diabetic patients because of its multiple effects on different cardiovascular risk factors, including postprandial lipids abnormalities.

Exercise therapy in type 2 diabetes

Structured exercise is considered an important cornerstone to achieve good glycemic control and improve cardiovascular risk profile in Type 2 diabetes. Current clinical guidelines acknowledge the therapeutic strength of exercise intervention. This paper reviews the wide pathophysiological problems associated with Type 2 diabetes and discusses the benefits of exercise therapy on phenotype characteristics, glycemic control and cardiovascular risk profile in Type 2 diabetes patients. Based on the currently available literature, it is concluded that Type 2 diabetes patients should be stimulated to participate in specifically designed exercise intervention programs. More attention should be paid to cardiovascular and musculoskeletal deconditioning as well as motivational factors to improve long-term treatment adherence and clinical efficacy. More clinical research is warranted to establish the efficacy of exercise intervention in a more differentiated approach for Type 2 diabetes subpopulations within different stages of the disease and various levels of co-morbidity.

Sarpogrelate protects against high glucose-induced endothelial dysfunction and oxidative stress

This study was designed to investigate the effect of sarpogrelate hydrochloride on impaired endothelium-dependent relaxation (EDR) induced by high glucose in isolated rat aorta. Both acetylcholine-induced EDR and sodium nitroprusside-induced endothelium-independent relaxation (EIR) were measured after the rings were exposed to high glucose in the absence and presence of sarpogrelate hydrochloride. Co-incubation of aortic rings with high glucose for 24h resulted in a significant inhibition of EDR, but had no effects on EIR. After incubation of the rings in the co-presence of sarpogrelate hydrochloride with high glucose for 24h, sarpogrelate hydrochloride significantly attenuated impaired EDR. This protective effect of sarpogrelate hydrochloride was abolished by N(G)-nitro-L-arginine methyl ester. Sarpogrelate hydrochloride significantly decreased superoxide anion (O(2)(-)) production and increased superoxide dismutase (SOD) activity and the nitric oxide (NO) release. These results suggest that sarpogrelate hydrochloride can restore impaired EDR induced by high glucose in isolated rat aorta, which may be related to scavenging oxygen free radicals and enhancing NO production.

Effect of oral acetyl L-carnitine arginate on resting and postprandial blood biomarkers in pre-diabetics

Background

Resting and postprandial oxidative stress is elevated in those with metabolic disorders such as diabetes. Antioxidant supplementation may attenuate the rise in oxidative stress following feeding. Therefore we sought to determine the effects of acetyl L-carnitine arginate (ALCA) on resting and postprandial biomarkers of glucose and lipid metabolism, as well as oxidative stress.

Methods

Twenty-nine pre-diabetic men and women were randomly assigned to either 3 g·day^-1 of ALCA (n = 14; 31 ± 3 yrs) or placebo (n = 15; 35 ± 3 yrs) in a double-blind design, to consume for eight weeks. Fasting blood samples were taken from subjects both pre and post intervention. After each fasting sample was obtained, subjects consumed a high fat, high carbohydrate meal and additional blood samples were taken at 1, 2, 4, and 6 hours post meal. Samples were analyzed for a variety of metabolic variables (e.g., glucose, HbA1c, lipid panel, C-reactive protein, nitrate/nitrite, and several markers of oxidative stress). Area under the curve (AUC) was calculated for each variable measured post meal, both pre and post intervention.

Results

ALCA, but not placebo, resulted in an increase in nitrate/nitrite (25.4 ± 1.9 to 30.1 ± 2.8 μmol·L^-1) from pre to post intervention, with post intervention values greater compared to placebo (p = 0.01). No other changes of statistical significance were noted (p > 0.05), although ALCA resulted in slight improvements in glucose (109 ± 5 to 103 ± 5 mg·dL^-1), HbA1c (6.6 ± 1.1 to 6.2 ± 1.2%), and HOMA-IR (3.3 ± 1.3 to 2.9 ± 1.2). AUC postprandial data were not statistically different between ALCA and placebo for any variable (p > 0.05). However, nitrate/nitrite demonstrated a moderate effect size (r = 0.35) for increase from pre (139.50 ± 18.35 μmol·L^-1·6 hr^-1) to post (172.40 ± 21.75 μmol·L^-1·6 hr^-1) intervention with ALCA, and the magnitude of decrease following feeding was not as pronounced as with placebo.

Conclusion

Supplementation with ALCA results in an increase in resting nitrate/nitrite in pre-diabetics, without any statistically significant change in other metabolic or oxidative stress variables measured at rest or post meal.

The role of exercise in minimizing postprandial oxidative stress in cigarette smokers

Cigarette smoking continues to pose a significant health burden on society. Two well-described mechanistic links associating smoking with morbidity and mortality include elevated blood lipids and increased oxidative stress. These variables have traditionally been measured while an individual is fasting, but evidence suggests that postprandial lipemia and oxidative stress provide more important information concerning susceptibility to disease, in particular cardiovascular disease. Cigarette smokers have elevated levels of biomarkers of oxidative stress at rest and experience impaired postprandial lipid and glucose metabolism. We have confirmed these findings while noting an exaggerated oxidative stress response to high-fat feeding. Smoking cessation is without question the best approach to minimizing smoking-induced ill health and disease, but success rates among those who attempt to quit are dismal. Other means to decrease a smoker's susceptibility to oxidative stress-related disease are needed. We propose that exercise may aid in attenuating postprandial oxidative stress, and we do so in 3 distinct ways. First, exercise stimulates an increase in endogenous antioxidant enzyme activity. Second, exercise improves blood triglyceride clearance via a reduced chylomicron-triglyceride half-life and an enhanced lipoprotein lipase activity. Third, exercise improves blood glucose clearance via an enhanced glucose 4 transport protein translocation and protein content, as well as insulin-insulin receptor binding and postreceptor signaling. Improvements in antioxidant status, as well as lipid and glucose processing, may aid greatly in minimizing feeding-induced oxidative stress in smokers. If so, and in accordance with the recent joint initiative of the American College of Sports Medicine and the American Medical Association, exercise may be viewed as a "medicine" for cigarette smokers at increased risk for postprandial oxidative stress. Research into this area may provide insight into the potential benefits of exercise for this purpose.

High-fat, energy-dense, fast-food-style breakfast results in an increase in oxidative stress in metabolic syndrome

The metabolic syndrome (MetS) is associated with an increased incidence of diabetes and coronary heart disease. Postprandial lipemia is a prominent feature of dyslipidemia in both type 2 diabetes mellitus and MetS and is also associated with coronary heart disease. Oxidative stress and inflammation are pivotal in all stages of atherosclerosis; however, there is a paucity of data on postprandial oxidative stress and inflammation in subjects with MetS. Thus, the primary aim of this study was to compare the postprandial effects of an energy-dense, high-fat, fast-food-style (FFS) meal with an American Heart Association (AHA)-recommended heart-healthy meal on biomarkers of oxidative stress and inflammation in subjects with MetS. A total of 11 subjects with MetS completed the study. Glucose levels were significantly increased 2 hours after both FFS and AHA diets (P < .0001), and high-density lipoprotein cholesterol levels significantly decreased in FFS diet but not in the AHA diet (P for interaction < .05). Total triglyceride levels significantly increased postprandially only in the FFS meal but not in the AHA meal (P for interaction = .03). Plasma thiobarbituric acid reactive substances and malondialdehyde + hydroxynonenal increased significantly with time in both dietary groups, and the postprandial increase was greater in the FFS diet compared to the AHA diet (P < .0005). Serum high-sensitivity C-reactive protein, interleukin 6, and tumor necrosis factor levels did not change with time or dietary treatment. The postprandial increase in interleukin 1b was significantly higher with the FFS meal, thus resulting in significant differences between both treatments (P for interaction = .03). Thus, in subjects with MetS, consumption of an energy-dense, fatty meal (FFS breakfast) results in increased postprandial oxidative stress compared to a heart-healthy meal (AHA).