Carbohydrates and cardiovascular disease.

Carbohydrates and the postprandial state: have our cake and eat it too?

<p> </p> <p><strong>OBJECTIVE: </strong>High cereal fiber and low glycemic index (GI) diets are associated with reduced cardiovascular disease (CVD) risk in cohort studies. Clinical trial evidence on event incidence is lacking. Therefore, to make trial outcomes more directly relevant to CVD we compared the effect on carotid plaque development in diabetes of a low GI diet versus a whole grain wheat fiber diet. </p> <p><strong>RESEARCH DESIGN AND METHODS: </strong>169 men and women with well controlled type 2 diabetes were randomized to counseling on either low GI or whole grain wheat fiber diets for 3 years. Change in carotid vessel wall volume (VWV) (pre-specified primary endpoint) was assessed by magnetic resonance imaging as an indication of arterial damage. </p> <p><strong>RESULTS: </strong>134 of 169 randomized participants completed the study. No treatment differences were seen in VWV. However, on the whole grain wheat fiber diet, VWV increased significantly from baseline, 23 mm3 (95% CI 4, 41) (p=0.016), but not on the low GI diet, 8 mm3 (95% CI-10, 26) (p=0.381). The low GI diet resulted in preservation of renal function, as eGFR, compared to the reduction following the wheat fiber diet. HbA1c was modestly reduced over the first 9 months in the intention-to-treat analysis, and extended with greater compliance to 15 months in the per-protocol analysis. </p> <p><strong>CONCLUSION:</strong> Since the low GI diet was similar to the whole wheat fiber diet recommended for cardiovascular risk reduction, the low GI diet may also be effective for CVD risk reduction. </p>

<p> </p> <p><strong>OBJECTIVE: </strong>High cereal fiber and low glycemic index (GI) diets are associated with reduced cardiovascular disease (CVD) risk in cohort studies. Clinical trial evidence on event incidence is lacking. Therefore, to make trial outcomes more directly relevant to CVD we compared the effect on carotid plaque development in diabetes of a low GI diet versus a whole grain wheat fiber diet. </p> <p><strong>RESEARCH DESIGN AND METHODS: </strong>169 men and women with well controlled type 2 diabetes were randomized to counseling on either low GI or whole grain wheat fiber diets for 3 years. Change in carotid vessel wall volume (VWV) (pre-specified primary endpoint) was assessed by magnetic resonance imaging as an indication of arterial damage. </p> <p><strong>RESULTS: </strong>134 of 169 randomized participants completed the study. No treatment differences were seen in VWV. However, on the whole grain wheat fiber diet, VWV increased significantly from baseline, 23 mm3 (95% CI 4, 41) (p=0.016), but not on the low GI diet, 8 mm3 (95% CI-10, 26) (p=0.381). The low GI diet resulted in preservation of renal function, as eGFR, compared to the reduction following the wheat fiber diet. HbA1c was modestly reduced over the first 9 months in the intention-to-treat analysis, and extended with greater compliance to 15 months in the per-protocol analysis. </p> <p><strong>CONCLUSION:</strong> Since the low GI diet was similar to the whole wheat fiber diet recommended for cardiovascular risk reduction, the low GI diet may also be effective for CVD risk reduction. </p>

<p> </p> <p><strong>OBJECTIVE: </strong>High cereal fiber and low glycemic index (GI) diets are associated with reduced cardiovascular disease (CVD) risk in cohort studies. Clinical trial evidence on event incidence is lacking. Therefore, to make trial outcomes more directly relevant to CVD we compared the effect on carotid plaque development in diabetes of a low GI diet versus a whole grain wheat fiber diet. </p> <p><strong>RESEARCH DESIGN AND METHODS: </strong>169 men and women with well controlled type 2 diabetes were randomized to counseling on either low GI or whole grain wheat fiber diets for 3 years. Change in carotid vessel wall volume (VWV) (pre-specified primary endpoint) was assessed by magnetic resonance imaging as an indication of arterial damage. </p> <p><strong>RESULTS: </strong>134 of 169 randomized participants completed the study. No treatment differences were seen in VWV. However, on the whole grain wheat fiber diet, VWV increased significantly from baseline, 23 mm3 (95% CI 4, 41) (p=0.016), but not on the low GI diet, 8 mm3 (95% CI-10, 26) (p=0.381). The low GI diet resulted in preservation of renal function, as eGFR, compared to the reduction following the wheat fiber diet. HbA1c was modestly reduced over the first 9 months in the intention-to-treat analysis, and extended with greater compliance to 15 months in the per-protocol analysis. </p> <p><strong>CONCLUSION:</strong> Since the low GI diet was similar to the whole wheat fiber diet recommended for cardiovascular risk reduction, the low GI diet may also be effective for CVD risk reduction. </p>

Significance and Mechanistic Relevance of SIRT6-Mediated Endothelial Dysfunction in Cardiovascular Disease Progression.

BackgroundThe health benefits of consuming a low glycaemic index (GI) diet to reduce the risk of type 2 Diabetes are well recognized. In recent years the GI values of various foods have been determined. Their efficacy in constructing and consuming a low GI diet over 24 h in modulating glycaemic response has not been fully documented. The translation of using single-point GI values of foods to develop a 24 h mixed meal diet can provide valuable information to consumers, researchers and dietitians to optimize food choice for glycaemic control. By using GI values of foods to develop mixed meals, our study is the first to determine how both blood glucose and substrate oxidation may be modulated over 24 h.MethodsThe study included 11 Asian men with a BMI between 17–24 kg/m2 who followed both a 1-day low GI and 1-day high GI diet in a randomized, controlled cross-over design. Test meals included breakfast, lunch, snack and dinner. Glycaemic response was measured continuously for over 24 h and postprandial substrate oxidation for 10 h inside a whole body calorimeter.ResultsThe low GI diet resulted in lower 24 h glucose iAUC (860 ± 440 vs 1329 ± 614 mmol/L.min; p = 0.014) with lower postprandial glucose iAUC after breakfast (p < 0.001), lunch (p = 0.009), snack (p = 0.012) and dinner (p = 0.003). Moreover, 24 h mean amplitude of glycaemic excursion was lower during the low GI vs high GI diet (1.44 ± 0.63 vs 2.33 ± 0.82 mmol/L; p < 0.001). Simultaneously, decrease in 10 h fat oxidation was less during the low vs high GI diet (−0.033 ± 0.021 vs −0.050 ± 0.017 g/min; p < 0.001), specifically after breakfast (p < 0.001) and lunch (p < 0.001).ConclusionsOur study corroborates that using low GI local foods to construct a 24 h low GI diet, is able to reduce glycaemic response and variability as recorded by continuous glucose monitoring. Our observations also confirm that a low GI diet promotes fat oxidation over carbohydrate oxidation when compared to a high GI diet. These observations provide public health support for the encouragement of healthier nutrition choices by consuming low GI foods.Trial registrationNCT 02631083 (Clinicaltrials.gov).

Preeclampsia: Exposing Future Cardiovascular Risk in Mothers and Their Children

Prevention of Cardiovascular Disease in Persons with Type 2 Diabetes Mellitus: Current Knowledge and Rationale for the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Trial

BackgroundA low Glycaemic Index (GI) diet may decrease some long-term health risks in Polycystic Ovary Syndrome (PCOS) such as endometrial cancer. This study was performed to assess compliance to a low GI diet in women with PCOS. Food diaries prospectively collected over 6 months from women on a low GI diet or healthy eating diet were analysed retrospectively. The women were recruited for a pilot randomised control trial investigating whether a low GI diet decreased the risk of Endometrial Cancer. Nine women with PCOS completed 33 food diaries (17 from women on a low GI diet and 16 from women on a healthy eating diet) recording 3023 food items (low GI group:n = 1457; healthy eating group:n = 1566). Data was analysed using Foster-Powell international values inserted into an SPSS database as no scientifically valid established nutrition software was found. The main outcome measures were mean item GI and Glyacemic Load (GL), mean meal GL, percentage high GI foods and mean weight loss.FindingsWomen allocated the low GI diet had a statistically significant lower GI of food items (33.67 vs 36.91, p < 0.05), lower percentage of high GI foods (4.3% vs 12.1%, p < 0.05) and lower GL of food items and meals.ConclusionWomen with PCOS on a low GI diet consumed food items with a significantly lower mean GI and GL compared to the healthy eating diet group. Longer term compliance needs evaluation in subsequent studies to ascertain that this translates to reduced long term health risks.Trial RegistrationISRCTN: ISRCTN86420258

Introduction to the Compendium on Early Cardiovascular Disease.

Cardiovascular disease in recent onset diabetes mellitus

Insufficient dietary intake of chromium as an essential nutrient leads to signs and symptoms that are similar to those observed for diabetes and cardiovascular diseases. We postulate that in healthy individuals, urinary chromium excretion following a high glycemic index diet is higher than after a low glycemic index diet. A sequential randomized controlled cross-over study was carried out at the Metabolic Unit of Nutrition Department of King's College London. Sixteen healthy individuals aged 18 - 60 years were recruited from 26 volunteers. A low or high glycemic index diet (as the main meals/day) was given to the volunteers over six days. Fasting blood glucose and insulin changes were determined and 24-hr urine samples were collected to measure chromium excretion before intervention and every second day within each treatment with a one wash-out period using Dynamic Reaction Cell Inductively Coupled Plasma Mass Spectrometer. During the six-day diet study, there were no significant differences in 24-hr urinary chromium losses between the two groups following the low glycemic index (0.58+/-0.08 microg/24 hr) and high glycemic index diets (0.48+/-0.06 microg/24 hr). However, during day six there was a trend towards greater loss of chromium after the high glycemic index diet (0.73+/-0.1 microg/24 hr) in comparison with the low glycemic index diet (0.54+/-0.07 microg/24 hr). Evidence that urinary chromium loses following the high glycemic index diets have not been clearly demonstrated in normal subjects. These results suggest that chromium excretion may need to be observed for longer than six days to address this question.

Approximately 25% of US adults are estimated to have hypertriglyceridemia (triglyceride [TG] level ≥150 mg/dL [≥1.7 mmol/L]). Elevated TG levels are associated with increased cardiovascular disease (CVD) risk, and severe hypertriglyceridemia (TG levels ≥500 mg/dL [≥5.6 mmol/L]) is a well-established risk factor for acute pancreatitis. Plasma TG levels correspond to the sum of the TG content in TG-rich lipoproteins (TRLs; ie, very low-density lipoproteins plus chylomicrons) and their remnants. There remains some uncertainty regarding the direct causal role of TRLs in the progression of atherosclerosis and CVD, with cardiovascular outcome studies of TG-lowering agents, to date, having produced inconsistent results. Although low-density lipoprotein cholesterol (LDL-C) remains the primary treatment target to reduce CVD risk, a number of large-scale epidemiological studies have shown that elevated TG levels are independently associated with increased incidence of cardiovascular events, even in patients treated effectively with statins. Genetic studies have further clarified the causal association between TRLs and CVD. Variants in several key genes involved in TRL metabolism are strongly associated with CVD risk, with the strength of a variant’s effect on TG levels correlating with the magnitude of the variant’s effect on CVD. TRLs are thought to contribute to the progression of atherosclerosis and CVD via a number of direct and indirect mechanisms. They directly contribute to intimal cholesterol deposition and are also involved in the activation and enhancement of several proinflammatory, proapoptotic, and procoagulant pathways. Evidence suggests that non-high-density lipoprotein cholesterol, the sum of the total cholesterol carried by atherogenic lipoproteins (including LDL, TRL, and TRL remnants), provides a better indication of CVD risk than LDL-C, particularly in patients with hypertriglyceridemia. This article aims to provide an overview of the available epidemiological, clinical, and genetic evidence relating to the atherogenicity of TRLs and their role in the progression of CVD.

Cardiovascular diseases (CVDs) remain to be the leading causes of morbidity and mortality in Hong Kong and worldwide. Among different modifiable risk factors, dietary pattern is on the major determinant for CVD and overall mortality. Other than pharmacological therapies for cardiovascular risk factors, such as hypertension, hyperlipidemia and diabetes, maintaining a healthy diet is a more sustainable method in general population to prevent CVDs. Current lifestyle intervention in the West countries focus on high intake of fruit and vegetables with more than 400g per day and limited saturated fats with less than 10% of energy, there is very limited data on impact of dietary pattern on CVDs in Chinese. Prior studies among Chinese in Hong Kong have shown that only half of the local population fell within these recommended ranges for fat, saturated fatty acid and cholesterol intakes.&#13;\n&#13;\nSeveral different dietary patterns have been recommended for CVDs prevention based on: i) food groups, such as Mediterranean diet, the Dietary Approaches to Stop Hypertension (DASH) diet; ii) macronutrients: the low-carbohydrate diet, low glycemic index diet, very-low- fat diet and iii) nutrition or vitamin supplement. However, the effect of different dietary patterns based on modulations of food group, macronutrients and particular micronutrients on vascular structure and function in Chinese subjects is unclear. In the first part of this thesis, the relationships between different dietary pattern and surrogate markers of subclinical atherosclerosis and vascular function in different high risk populations for CVDs were investigated.&#13;\n&#13;\nIn Chapter 3, we compared the assessment of dietary pattern in Chinese using different tool, including Food Frequency Questionnaire (FFQ); Dietary Record; and Dietitian assessment. In this study, we demonstrated that suitable dietary assessments tools should be chosen for the assessment of different dietary pattern, according to characteristics of assessments.&#13;\n&#13;\nIn Chapter 4, the relationship between the fruit intake and subclinical atherosclerosis as measured by carotid intimal thickness (IMT) was investigated in patient with type II diabetes mellitus (DM). Our results showed that high fruit intake was associated with lower burden of carotid atherosclerosis, independent of level of vitamin intake in patients with type II DM.&#13;\n&#13;\nIn Chapter 5, we compared the impact of high carbohydrate diet on arterial stiffness between control subjects without CVDs and patients with high risk for CVDs. Our findings showed that high carbohydrate diet mainly affected patients with established CVDs, and their increased arterial stiffness was associated with an elevation of blood pressure.&#13;\n&#13;\nIn Chapter 6, we determined the effect of dietary vitamin intake on oxidative stress in patients with high risk of CVDs. In those high risk patients for CVDs, we demonstrated that increased dietary intake of vitamin A, beta-carotene and alpha tocopherol were associated with decreased oxidative stress, but these relationships were not observed in those control subjects without CVDs. It is likely attributed to the higher systemic oxidative stress levels in patients with high risk of CVDs.&#13;\n&#13;\nOn the other hand, food intake may also affect the clinical efficacy of cardiovascular therapies. In particularly, it has been well established that herbal intake which is commonly used by Chinese can affect the anticoagulant effect of warfarin on patients with non-valvular atrial fibrillation (AF). Thus, in this second part of the thesis, we investigated the effect of concomitant herbal intake on anticoagulation control in patients with non-valvular AF treated with warfarin. Our results showed that patients with AF treated with warfarin had limited knowledge on potential interaction between herbal substances in foods and warfarin, in which increased herbal substances intake significantly reduced the percentage time of anticoagulant effect within the therapeutic range. Moreover, a single section of education on knowledge of herbal ingredients did not improve their percentage time of therapeutic range for these patients.&#13;\n&#13;\nIn conclusion, these findings suggest that dietary pattern in Chinese might have significant impact of vascular function in patients with type II DM and high risk for CVDs. Moreover, the herbal substances in the diet among Chinese could have significant impact of the therapeutic effects in some of the cardiovascular medications, such as warfarin. Future clinical studies will be needed to confirm these potential beneficial effects of particular diet intake on vascular function in patients with high risks of CVDs as well as potential interaction between herbal substances in Chinese diet and cardiovascular medications.

The glycaemic index (GI) is a physiological measure of the ability of a carbohydrate to affect blood glucose. Interest is growing in this area for the clinical management of people at risk of, or with, established cardiovascular disease. There is a need to review the current evidence from randomised controlled trials (RCTs) in this area. This is an update of the original review published in 2008. To assess the effect of the dietary GI on total mortality, cardiovascular events, and cardiovascular risk factors (blood lipids, blood pressure) in healthy people or people who have established cardiovascular disease or related risk factors, using all eligible randomised controlled trials. We searched CENTRAL, MEDLINE, Embase and CINAHL in July 2016. We also checked reference lists of relevant articles. No language restrictions were applied. We selected RCTs that assessed the effects of low GI diets compared to diets with a similar composition but a higher GI on cardiovascular disease and related risk factors. Minimum trial duration was 12 weeks. Participants included were healthy adults or those at increased risk of cardiovascular disease, or previously diagnosed with cardiovascular disease. Studies in people with diabetes mellitus were excluded. Two reviewers independently screened and selected studies. Two review authors independently assessed risk of bias, evaluated the overall quality of the evidence using GRADE, and extracted data following the Cochrane Handbook for Systematic Reviews of Interventions. We contacted trial authors for additional information. Analyses were checked by a second reviewer. Continuous outcomes were synthesized using mean differences and adverse events were synthesized narratively. Twenty-one RCTs were included, with a total of 2538 participants randomised to low GI intervention (1288) or high GI (1250). All 21 included studies reported the effect of low GI diets on risk factors for cardiovascular disease, including blood lipids and blood pressure.Twenty RCTs (18 of which were newly included in this version of the review) included primary prevention populations (healthy individuals or those at high risk of CVD, with mean age range from 19 to 69 years) and one RCT was in those diagnosed with pre-existing CVD (a secondary prevention population, with mean age 26.9 years). Most of the studies did not have an intervention duration of longer than six months. Difference in GI intake between comparison groups varied widely from 0.6 to 42.None of the included studies reported the effect of low GI dietary intake on cardiovascular mortality and cardiovascular events such as fatal and nonfatal myocardial infarction, unstable angina, coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, and stroke. The unclear risk of bias of most of the included studies makes overall interpretation of the data difficult. Only two of the included studies (38 participants) reported on adverse effects and did not observe any harms (low-quality evidence). There is currently no evidence available regarding the effect of low GI diets on cardiovascular disease events. Moreover, there is currently no convincing evidence that low GI diets have a clear beneficial effect on blood lipids or blood pressure parameters.