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1.
Diabetes Res Clin Pract ; 151: 138-145, 2019 May.
Article in English | MEDLINE | ID: mdl-30959146

ABSTRACT

AIMS: Two medication change protocols were tested, both based on haemoglobin A1c (HbA1c), with one protocol also accounting for hypoglycaemic events. The aim was to compare the two protocols during intermittent energy restriction (5:2 diet). METHODS: Forty-two adults with type 2 diabetes (HbA1c ≥ 7% [53 mmol/mol], BMI of ≥27 kg/m2) treated with sulphonylureas and/or insulin were recruited and randomised 1:1 to fixed or adjusted medication protocols. Participants experiencing hypoglycaemia during a 2-week usual diet period then followed the 5:2 diet for 2 weeks (2 non-consecutive very-low-calorie days [500-600 kcal] and 5 habitual eating days/week), following the allocated medication protocol. The primary outcome was to determine if the adjusted protocol was superior to the fixed protocol at reducing hypoglycaemic events during the 5:2 diet. Flash glucose monitoring was used throughout to detect hypoglycaemia. RESULTS: There was a significant difference in change in the number of hypoglycaemic events between fixed and adjusted protocols (-1.0 vs. -3.5; P = 0.04). Over 60% of participants on the adjusted protocol had no hypoglycaemic events. CONCLUSIONS: This pilot study demonstrates the importance of assessing the risk of hypoglycaemia before starting a 5:2 diet and that the adjusted medication protocol is likely the best option for patients at risk. CLINICAL TRIAL REGISTRY: This study has been registered with the Australia New Zealand Clinical Trial Registry (ANZCTR) www.anzctr.org.au and given the registration number ACTRN12617000512325.


Subject(s)
Blood Glucose Self-Monitoring/methods , Diabetes Mellitus, Type 2/drug therapy , Hypoglycemia/therapy , Aged , Caloric Restriction/adverse effects , Caloric Restriction/methods , Diabetes Mellitus, Type 2/pathology , Female , Humans , Hypoglycemia/pathology , Male , Middle Aged , Pilot Projects
2.
Diabetes Res Clin Pract ; 151: 11-19, 2019 May.
Article in English | MEDLINE | ID: mdl-30902672

ABSTRACT

AIMS: We investigated the effects of intermittent compared to continuous energy restriction on glycaemic control in patients with type 2 diabetes mellitus. METHODS: Adults (N = 137) with type 2 diabetes (mean [SD] HbA1c level, 7.3% (56 mmol/mol) [1.3%] [14.2 mmol/mol]) were randomised to one of two diets for 12 months. The intermittent group (n = 70) followed a 2100-2500 kJ (500-600 kcal) diet 2 non-consecutive days/week and their usual diet for 5 days/week. The continuous group (n = 67) followed a 5000-6300 kJ (1200-1500 kcal) diet for 7 days/week. Follow-up occurred at 24 months, 12 months after the completed intervention. The primary outcome was change in HbA1c and the secondary outcome was weight loss. RESULTS: Intention-to-treat analysis showed an increase in mean [SEM] HbA1c level at 24 months in both the continuous and intermittent groups (0.4% [0.3%] vs 0.1% [0.2%] respectively; P = 0.32) (4.4 [3.3 mmol/mol] vs 1.1 [2.2 mmol/mol]; P = 0.32), with a between-group difference of 0.3% (90% CI, -0.31 to 0.83%) (3.3 mmol/mol [90% CI, -3.2 to 9.1 mmol/mol]) outside the prespecified boundary of ±â€¯0.5% (5.5 mmol/mol), so statistical equivalence was not shown. Weight loss was maintained (P < 0.001) at -3.9 kg [1.1 kg] in both groups at 24 months, with a between-group difference of 0.07 kg (90% CI, -2.5 to 2.6 kg) outside the prespecified boundary of ±2.5 kg. There were no significant differences between groups in body composition, fasting glucose levels, lipid levels, or total medication effect score at 24 months, which remained less than baseline. CONCLUSIONS: In this prospective analysis weight loss was maintained but despite this HbA1c increased to above baseline levels in both groups.


Subject(s)
Blood Glucose/metabolism , Caloric Restriction/methods , Diabetes Mellitus, Type 2/therapy , Weight Loss/physiology , Diabetes Mellitus, Type 2/pathology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Time Factors
3.
Nutr Metab Cardiovasc Dis ; 28(8): 830-838, 2018 08.
Article in English | MEDLINE | ID: mdl-29853429

ABSTRACT

BACKGROUND AND AIMS: The relationship between dietary intake and carotid intima media thickness (IMT) and pulse wave velocity (PWV) in individuals with type 1 and type 2 diabetes has not been well studied. We investigated the association between dietary intake and common carotid artery intima media thickness (CCA IMT) and PWV in a cohort with type 1 and type 2 diabetes. METHODS AND RESULTS: A one-year randomised controlled trial was conducted to investigate the effect of improving dietary quality on CCA IMT. These subjects were followed up again approximately 12 months after the completion of the trial (i.e. approximately 24 month since baseline). The study cohort included 87 subjects that had dietary intake and CCA IMT measured at baseline and after a mean of 2.3 years' follow-up. PWV was measured in a subsample of this cohort. Age and baseline mean CCA IMT were strongly associated with mean CCA IMT at 24 months. After adjustment for age and baseline mean CCA IMT, baseline consumption of carbohydrate (r = -0.28; p = 0.01), sugars (r = -0.27; p = 0.01), fibre (r = -0.26; p = 0.02), magnesium (r = -0.25; p = 0.02) and the Alternate Health Eating Index (AHEI) score (r = -0.23; p = 0.03) were inversely associated with mean CCA IMT at 24 months. Mixed linear modelling showed an interaction between mean CCA IMT and AHEI at baseline (p = 0.024). Those who were in the highest AHEI tertile at baseline had greater CCA IMT regression at 24 months compared to those in the lowest tertile, after adjustment for baseline age, BMI, smoking pack years, time since diabetes diagnosis, and mean arterial pressure at baseline (mean -0.043 mm; 95% CI -0.084, -0.003; p = 0.029). CONCLUSIONS: In this prospective analysis greater diet quality at baseline, as measured by the AHEI, was associated with greater CCA IMT regression after approximately two years. This suggests that greater diet quality is associated with better longer term vascular health in individuals with type 1 and type 2 diabetes.


Subject(s)
Carotid Artery Diseases/prevention & control , Carotid Intima-Media Thickness , Diabetes Mellitus, Type 1/diet therapy , Diabetes Mellitus, Type 2/diet therapy , Diet, Healthy , Nutritive Value , Risk Reduction Behavior , Aged , Carotid Artery Diseases/diagnostic imaging , Carotid Artery Diseases/etiology , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/diagnosis , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome
4.
Nutr Res Rev ; 31(1): 35-51, 2018 06.
Article in English | MEDLINE | ID: mdl-29037268

ABSTRACT

Animal studies indicate that the composition of gut microbiota may be involved in the progression of insulin resistance to type 2 diabetes. Probiotics and/or prebiotics could be a promising approach to improve insulin sensitivity by favourably modifying the composition of the gut microbial community, reducing intestinal endotoxin concentrations and decreasing energy harvest. The aim of the present review was to investigate the effects of probiotics, prebiotics and synbiotics (a combination of probiotics and prebiotics) on insulin resistance in human clinical trials and to discuss the potential mechanisms whereby probiotics and prebiotics improve glucose metabolism. The anti-diabetic effects of probiotics include reducing pro-inflammatory cytokines via a NF-κB pathway, reduced intestinal permeability, and lowered oxidative stress. SCFA play a key role in glucose homeostasis through multiple potential mechanisms of action. Activation of G-protein-coupled receptors on L-cells by SCFA promotes the release of glucagon-like peptide-1 and peptide YY resulting in increased insulin and decreased glucagon secretion, and suppressed appetite. SCFA can decrease intestinal permeability and decrease circulating endotoxins, lowering inflammation and oxidative stress. SCFA may also have anti-lipolytic activities in adipocytes and improve insulin sensitivity via GLUT4 through the up-regulation of 5'-AMP-activated protein kinase signalling in muscle and liver tissues. Resistant starch and synbiotics appear to have favourable anti-diabetic effects. However, there are few human interventions. Further well-designed human clinical studies are required to develop recommendations for the prevention of type 2 diabetes with pro- and prebiotics.


Subject(s)
Gastrointestinal Microbiome , Insulin Resistance , Insulin/metabolism , Intestines/microbiology , Prebiotics , Probiotics , Synbiotics , Animals , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/microbiology , Diabetes Mellitus, Type 2/prevention & control , Fatty Acids, Volatile/metabolism , Humans , Hypoglycemic Agents/therapeutic use , Inflammation/metabolism , Inflammation/microbiology , Inflammation/prevention & control , NF-kappa B/metabolism , Oxidative Stress
5.
Nutr Metab Cardiovasc Dis ; 27(12): 1060-1080, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29174025

ABSTRACT

AIMS: Over the last 7 years there has been intense debate about the advice to reduce saturated fat and increase polyunsaturated fat to reduce CVD risk. The aim of this review was to examine systematic reviews and meta-analyses since 2010 on this topic plus additional cohort studies and interventions not included in these reviews. DATA SYNTHESIS: High saturated and trans fat intake (which elevates LDL like saturated fat) in the Nurses and Health Professional Follow-Up Studies combined is associated with an 8-13% higher mortality and replacement of saturated fat with any carbohydrate, PUFA and MUFA is associated with lower mortality with PUFA being more effective than MUFA (19% reduction versus 11%). With CVD mortality only PUFA and fish oil replacement of saturated fat lowers risk with a 28% reduction in CVD mortality per 5% of energy. Replacing saturated fat with PUFA or MUFA is equally effective at reducing CHD events and replacement with whole grains will lower events while replacement with sugar and starch increases events. Replacement of saturated fat with carbohydrate has no effect on CHD events or death. Only PUFA replacement of saturated fat lowers CHD events and CVD and total mortality. Replacing saturated fat with linoleic acid appears to be beneficial based on the Hooper Cochrane meta-analysis of interventions although other analyses with fewer studies have shown no effect. CONCLUSIONS: Reducing saturated fat and replacing it with carbohydrate will not lower CHD events or CVD mortality although it will reduce total mortality. Replacing saturated fat with PUFA, MUFA or high-quality carbohydrate will lower CHD events.


Subject(s)
Diet, High-Fat/adverse effects , Fatty Acids, Unsaturated , Fatty Acids/adverse effects , Heart Diseases/epidemiology , Diet, Fat-Restricted , Diet, Healthy , Dietary Carbohydrates/administration & dosage , Evidence-Based Medicine , Fatty Acids/administration & dosage , Fatty Acids, Unsaturated/administration & dosage , Fatty Acids, Unsaturated/adverse effects , Feeding Behavior , Heart Diseases/diagnosis , Heart Diseases/mortality , Heart Diseases/prevention & control , Humans , Meta-Analysis as Topic , Protective Factors , Risk Assessment , Risk Factors , Risk Reduction Behavior
6.
Diabetes Res Clin Pract ; 122: 106-112, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27833048

ABSTRACT

AIMS: Weight loss improves glycaemic control in type 2 diabetes mellitus (T2DM). However, as achieving and maintaining weight loss is difficult, alternative strategies are needed. Our primary aim was to investigate the effects of intermittent energy restriction (IER) compared to continuous energy restriction (CER) on glycated haemoglobin A1c (HbA1c). Secondary aims were to assess effects on weight loss, body composition, medication changes and subjective measures of appetite. Using a 2-day IER method, we expected equal improvements to HbA1c and weight in both groups. METHOD: Sixty-three overweight or obese participants (BMI 35.2±5kg/m2) with T2DM (HbA1c 7.4±1.3%) (57mmol/mol) were randomised to a 2-day severe energy restriction (1670-2500kJ/day) with 5days of habitual eating, compared to a moderate CER diet (5000-6500kJ/day) for 12weeks. RESULTS: At 12weeks HbA1c (-0.7±0.9% P<0.001) and percent body weight reduction (-5.9±4% P<0.001) was similar in both groups with no group by time interaction. Similar reductions were also seen for medication dosages, all measures of body composition and subjective reports of appetite. CONCLUSIONS: In this pilot trial, 2days of IER compared with CER resulted in similar improvements in glycaemic control and weight reduction offering a suitable alternative treatment strategy.


Subject(s)
Body Composition , Caloric Restriction/methods , Diabetes Mellitus, Type 2/diet therapy , Energy Metabolism/physiology , Glycated Hemoglobin/metabolism , Obesity/diet therapy , Weight Loss , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/metabolism , Female , Humans , Male , Middle Aged , Obesity/complications , Obesity/physiopathology , Pilot Projects
8.
Atherosclerosis ; 247: 7-20, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26854971

ABSTRACT

AIM: To conduct a systematic review and meta-analysis of clinical trials involving adults, to determine the effect of weight loss induced by energy restriction with or without exercise, anti-obesity drugs or bariatric surgery on measures of arterial stiffness and compliance. METHODS: A systematic search of Pubmed, EMBASE, MEDLINE and the Cochrane Library was conducted to find intervention trials (randomised/non-randomised) that aimed to achieve weight loss and included the following outcome measures: cardio-ankle vascular index (CAVI), direct measures of area/diameter related to pressure change (including ß-stiffness index, brachial or carotid artery compliance, aortic, carotid or brachial artery distensibility and strain), measures derived from peripheral pulse wave analysis (including augmentation index, augmentation pressure, distal oscillatory, proximal capacitive and systemic compliance) and pulse pressure. Data were analysed using Comprehensive Meta Analysis V2 using random effects analysis. Standardised mean difference (SMD) is reported with negative values indicating an improvement. RESULTS: A total of 43 studies, involving 4231 participants, were included in the meta-analysis. Mean weight loss was approximately 11% of initial body weight. Weight loss improved CAVI (SMD -0.48; p = 0.04), ß-stiffness index (SMD = -0.98; p = 0.001), arterial compliance (SMD = -0.61; p = 0.0001) and distensibility (SMD -1.10; p = 0.005), distal oscillatory compliance (SMD = -0.41; p = 0.03), proximal capacitive compliance (SMD -0.66; p = 0.009), systemic arterial compliance (SMD -0.71; p = 0.003) and reflection time (SMD -0.51; p = 0.001). Augmentation index, strain, augmentation pressure and pulse pressure were not significantly changed with weight loss. CONCLUSION: Weight loss induced by energy restriction improves some measures of arterial compliance and stiffness.


Subject(s)
Caloric Restriction , Diet, Reducing , Energy Metabolism , Obesity/diet therapy , Vascular Diseases/prevention & control , Vascular Stiffness , Weight Loss , Compliance , Humans , Obesity/complications , Obesity/diagnosis , Obesity/physiopathology , Recovery of Function , Risk Factors , Treatment Outcome , Vascular Diseases/diagnosis , Vascular Diseases/etiology , Vascular Diseases/physiopathology
9.
Endocrine ; 50(3): 811-5, 2015 Dec.
Article in English | MEDLINE | ID: mdl-25957668

ABSTRACT

Polycystic ovary syndrome (PCOS) is a common condition affecting reproductive-aged women with features including hyperandrogenism and menstrual irregularity frequently treated with hormonal steroidal contraceptives. Women with PCOS appear to have lower bone mineral density (BMD). While steroidal contraceptives may positively affect bone health, their effect on BMD in PCOS is not known. The aim of this study was to assess BMD in women with PCOS according to recent contraceptive use. A cross-sectional analysis of 95 pre-menopausal overweight or obese sedentary women with PCOS [age 29.4 ± 6.4 years, body mass index (BMI) 36.1 ± 5.3 kg/m(2)] who either recently took steroidal contraceptives (ceased 3 months prior) or were not taking steroidal contraceptives was conducted. Clinical outcomes included BMD, anthropometry, insulin, glucose, reproductive hormones, dietary intake and vitamin use. BMD was significantly lower for women who used contraceptives compared to those who did not (mean difference 0.06 g/cm(2) 95 % confidence interval -0.11, -0.02, p = 0.005). In regression models, lower BMD was independently associated with contraceptive use (ß = -0.05, 95 % CI -0.094, -0.002, p = 0.042), higher testosterone (ß = -0.03, 95 % CI -0.05, -0.0008, p = 0.043) and lower BMI (ß = 0.006, 95 % CI 0.002, 0.01, p = 0.007) (r (2) = 0.22, p = 0.001 for entire model). We report for the first time that overweight and obese women with PCOS with recent steroidal contraceptive use had lower BMD in comparison to non-users independent of factors known to contribute to BMD. Whether this observation is directly related to steroidal contraceptive use or other factors requires further investigation.


Subject(s)
Bone Density/drug effects , Contraceptives, Oral, Hormonal/adverse effects , Polycystic Ovary Syndrome/drug therapy , Adult , Cross-Sectional Studies , Female , Humans , Young Adult
10.
Appetite ; 91: 7-12, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25819603

ABSTRACT

BACKGROUND: There is evidence suggesting that the nutritional content of recipes promoted by celebrity chefs or television cooking programmes contradict healthy eating guidelines. This study aims to investigate people's attitudes and beliefs about popular television cooking programmes and celebrity chefs. METHODS: Males and females who watch television cooking programmes were recruited to participate in a self-administered online questionnaire (22-items) which included multiple-choice and rank order questions. RESULTS: A total of n = 207 participants undertook the questionnaire with fully completed questionnaires available for n = 150 participants (Males, n = 22; Females, n = 128; aged 38.4 ± 14 years). The majority of respondents watch ≤30 minutes of television cooking programming per day (total responses, n = 153/207; 74%) with almost three-quarters (total responses, n = 130/175; 74%) having attempted a recipe. New cooking ideas (total responses, n = 81/175; 46%) and entertainment (total responses, n = 64/175; 36.5%) were the two main reasons participants gave for watching these programmes. Significantly more respondents believed recipes use excessive amounts of unhealthy fat, sugar or salt (unhealthy: 24%; healthy: 7%; P < 0.0001). Almost half of all respondents (total responses, n = 67/151; 44%) believed these programmes have no impact on their habitual diet. DISCUSSION AND CONCLUSION: Our results suggest television cooking programmes and celebrity chefs are unlikely to impact habitual dietary intake; rather, vicarious viewing and entertainment appear important factors relating to why people watch these programmes. However results generated from the present study are descriptive and subjective and further investigation into the impact of television cooking programmes and celebrity chefs on behavioural change requires attention. Further investigation including a systematic investigation into the dietary quality of recipes promoted by celebrity chefs against national healthy eating benchmarks is also warranted.


Subject(s)
Attitude to Health , Cooking , Diet/adverse effects , Famous Persons , Nutrition Policy , Patient Compliance , Television , Adult , Consumer Behavior , Cross-Sectional Studies , Diet Surveys , Feeding Behavior , Female , Food Preferences , Humans , Internet , Male , Middle Aged , South Australia , Television/trends , Workforce , Young Adult
11.
Nutr Metab Cardiovasc Dis ; 25(3): 253-66, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25456155

ABSTRACT

AIM: To review the relationships between: 1) Potassium and endothelial function; 2) Fruits and vegetables and endothelial function; 3) Potassium and other measures of vascular function; 4) Fruits and vegetables and other measures of vascular function. DATA SYNTHESIS: An electronic search for intervention trials investigating the effect of potassium, fruits and vegetables on vascular function was performed in MEDLINE, EMBASE and the Cochrane Library. Potassium appears to improve endothelial function with a dose of >40 mmol/d, however the mechanisms for this effect remain unclear. Potassium may improve measures of vascular function however this effect may be dependent on the effect of potassium on blood pressure. The effect of fruit and vegetables on endothelial function independent of confounding variables is less clear. Increased fruit and vegetable intake may improve vascular function only in high risk populations. CONCLUSION: Increasing dietary potassium appears to improve vascular function but the effect of increasing fruit and vegetable intake per se on vascular function is less clear.


Subject(s)
Endothelium, Vascular/physiology , Fruit , Potassium, Dietary/administration & dosage , Vegetables , Biomarkers/blood , Databases, Factual , Humans , Potassium, Dietary/blood , Randomized Controlled Trials as Topic
12.
Nutr Metab Cardiovasc Dis ; 25(1): 3-8, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25156891

ABSTRACT

AIM: Evidence from epidemiological studies suggests that higher consumption of dairy products may be inversely associated with risk of type 2 diabetes and other components of the metabolic syndrome, although the evidence is mixed. Intervention studies that increase dairy intake often involve lifestyle changes, including weight loss, which alone will improve insulin sensitivity. The aim of this review was to examine weight stable intervention studies that assess the effect of an increased intake of dairy products or dairy derived supplements on glucose metabolism and insulin sensitivity. DATA SYNTHESIS: An electronic search was conducted using MEDLINE, EMBASE, the Cochrane Database and Web of Science for randomised controlled trials altering only dairy intake in humans with no other lifestyle or dietary change, particularly no weight change, and with measurement of glucose or insulin. Healthy participants and those with features of the metabolic syndrome were included. Chronic whey protein supplementation was also included. Ten studies were included in this systematic review. CONCLUSIONS: In adults, four of the dairy interventions showed a positive effect on insulin sensitivity as assessed by Homeostasis Model Assessment (HOMA); one was negative and five had no effect. As the number of weight stable intervention studies is very limited and participant numbers small, these findings need to be confirmed by larger trials in order to conclusively determine any relationship between dairy intake and insulin sensitivity.


Subject(s)
Dairy Products/adverse effects , Dietary Supplements/adverse effects , Insulin Resistance , Milk Proteins/adverse effects , Animals , Humans , Milk Proteins/therapeutic use , Randomized Controlled Trials as Topic , Reproducibility of Results , Whey Proteins
13.
Atherosclerosis ; 238(2): 175-81, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25528424

ABSTRACT

OBJECTIVE: To determine the dietary predictors of central blood pressure, augmentation index and pulse wave velocity (PWV) in subjects with type 1 and type 2 diabetes. METHODS: Participants were diagnosed with type 1 or type 2 diabetes and had PWV and/or pulse wave analysis performed. Dietary intake was measured using the Dietary Questionnaire for Epidemiological Studies Version 2 Food Frequency Questionnaire. Serum lipid species and carotenoids were measured, using liquid chromatography electrospray ionization-tandem mass spectrometry and high performance liquid chromatography, as biomarkers of dairy and vegetable intake, respectively. Associations were determined using linear regression adjusted for potential confounders. RESULTS: PWV (n = 95) was inversely associated with reduced fat dairy intake (ß = -0.01; 95% CI -0.02, -0.01; p = 0 < 0.05) in particular yoghurt consumption (ß = -0.04; 95% CI -0.09, -0.01; p = 0 < 0.05) after multivariate adjustment. Total vegetable consumption was negatively associated with PWV in the whole cohort after full adjustment (ß = -0.04; 95% CI -0.07, -0.01; p < 0.05). Individual lipid species, particularly those containing 14:0, 15:0, 16:0, 17:0 and 17:1 fatty acids, known to be of ruminant origin, in lysophosphatidylcholine, cholesterol ester, diacylglycerol, phosphatidylcholine, sphingomyelin and triacylglycerol classes were positively associated with intake of full fat dairy, after adjustment for multiple comparisons. However, there was no association between serum lipid species and PWV. There were no dietary predictors of central blood pressure or augmentation index after multivariate adjustment. CONCLUSION: In this cohort of subjects with diabetes reduced fat dairy intake and vegetable consumption were inversely associated with PWV. The lack of a relationship between serum lipid species and PWV suggests that the fatty acid composition of dairy may not explain the beneficial effect.


Subject(s)
Diabetes Mellitus, Type 1/epidemiology , Diabetes Mellitus, Type 2/epidemiology , Diabetic Angiopathies/epidemiology , Diet , Vascular Stiffness , Adult , Aged , Biomarkers/blood , Carotenoids/blood , Chromatography, High Pressure Liquid , Cross-Sectional Studies , Dairy Products , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 1/physiopathology , Diabetes Mellitus, Type 1/therapy , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/physiopathology , Diabetes Mellitus, Type 2/therapy , Diabetic Angiopathies/blood , Diabetic Angiopathies/diagnosis , Diabetic Angiopathies/physiopathology , Diabetic Angiopathies/prevention & control , Diet/adverse effects , Diet, Fat-Restricted , Dietary Fats/blood , Feeding Behavior , Female , Humans , Linear Models , Male , Middle Aged , Multivariate Analysis , Nutrition Assessment , Nutritional Status , Pulse Wave Analysis , Risk Factors , Risk Reduction Behavior , Spectrometry, Mass, Electrospray Ionization , Surveys and Questionnaires , Tandem Mass Spectrometry , Vegetables , Victoria/epidemiology
14.
Nutr Metab Cardiovasc Dis ; 24(9): 983-9, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24875671

ABSTRACT

BACKGROUND AND AIMS: Increased potassium intake is related to reduced blood pressure (BP) and reduced stroke rate. The effect of increased dietary potassium on endothelial function remains unknown. The aim was to determine the effect of increased dietary potassium from fruit and vegetables on endothelial function. METHODS AND RESULTS: Thirty five healthy men and women (age 32 ± 12 y) successfully completed a randomised cross-over study of 2 × 6 day diets either high or low in potassium. Flow mediated dilatation (FMD), BP, pulse wave velocity (PWV), augmentation index (AI) and a fasting blood sample for analysis of Intercellular Adhesion Molecule-1 (ICAM-1), E-selectin, asymmetric dimethylarginine (ADMA) and endothelin-1 were taken on completion of each intervention. Dietary change was achieved by including bananas and potatoes in the high potassium and apples and rice/pasta in the low potassium diet. Dietary adherence was assessed using 6 day weighed food diaries and a 24 h urine sample. The difference in potassium excretion between the two diets was 48 ± 32 mmol/d (P = 0.000). Fasting FMD was significantly improved by 0.6% ± 1.5% following the high compared to the low potassium diet (P = 0.03). There were no significant differences in BP, PWV, AI, ICAM-1, ADMA or endothelin-1 between the interventions. There was a significant reduction in E-selectin following the high (Median = 5.96 ng/ml) vs the low potassium diet (Median = 6.24 ng/ml), z = -2.49, P = 0.013. CONCLUSION: Increased dietary potassium from fruit and vegetables improves FMD within 1 week in healthy men and women but the mechanisms for this effect remain unclear. CLINICAL TRIAL REGISTRY: ACTRN12612000822886.


Subject(s)
Endothelium, Vascular/drug effects , Potassium, Dietary/administration & dosage , Adolescent , Adult , Aged , Arginine/analogs & derivatives , Arginine/blood , Blood Glucose/metabolism , Blood Pressure/drug effects , Body Mass Index , Cross-Over Studies , E-Selectin/blood , Endothelin-1/blood , Female , Fruit , Healthy Volunteers , Humans , Intercellular Adhesion Molecule-1/blood , Male , Middle Aged , Patient Compliance , Pulse Wave Analysis , Single-Blind Method , Urinalysis , Vegetables , Young Adult
15.
Nutr Metab Cardiovasc Dis ; 24(3): 224-35, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24472635

ABSTRACT

BACKGROUND: Meta analysis of short term trials indicates that a higher protein, lower carbohydrate weight loss diet enhances fat mass loss and limits lean mass loss compared with a normal protein weight loss diet. Whether this benefit persists long term is not clear. METHODS AND RESULTS: We selected weight loss studies in adults with at least a 12 month follow up in which a higher percentage protein/lower carbohydrate diet was either planned or would be expected for either weight loss or weight maintenance. Studies were selected regardless of the success of the advice but difference in absolute and percentage protein intake at 12 months was used as a moderator in the analysis. Data was analysed using Comprehensive Meta analysis V2 using a random effects analysis. As many as 32 studies with 3492 individuals were analysed with data on fat and lean mass, glucose and insulin from 18 to 22 studies and lipids from 28 studies. A recommendation to consume a lower carbohydrate, higher protein diet in mostly short term intensive interventions with long term follow up was associated with better weight and fat loss but the effect size was small-standardised means of 0.14 and 0.22, p = 0.008 and p < 0.001 respectively (equivalent to 0.4 kg for both). A difference of 5% or greater in percentage protein between diets at 12 mo was associated with a 3 fold greater effect size compared with <5% (p = 0.038) in fat mass (0.9 vs. 0.3 kg). Fasting triglyceride and insulin were also lower with high protein diets with effect sizes of 0.17 and 0.22, p = 0.003 and p = 0.042 respectively. Other lipids and glucose were not different. CONCLUSION: The short term benefit of higher protein diets appears to persist to a small degree long term. Benefits are greater with better compliance to the diet.


Subject(s)
Diet, Carbohydrate-Restricted , Dietary Carbohydrates/administration & dosage , Dietary Proteins/administration & dosage , Obesity/diet therapy , Weight Loss , Adiposity , Blood Glucose , Blood Pressure , C-Reactive Protein/metabolism , Diet, Fat-Restricted , Diet, Reducing , Humans , Insulin/blood , Lipids/blood , Observational Studies as Topic , Randomized Controlled Trials as Topic
16.
Nutr Metab Cardiovasc Dis ; 24(2): 148-54, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24119989

ABSTRACT

BACKGROUND AND AIMS: Endothelial dysfunction, as assessed by flow mediated dilatation (FMD) is an early event in atherosclerosis and an independent predictor of cardiovascular events. The effect of potassium supplementation on endothelial function and blood pressure (BP) in the postprandial state is not known. The aim of this study was to assess endothelial function using FMD in healthy volunteers. METHODS AND RESULTS: Thirty-two normotensive volunteers received a meal with 36 mmol potassium (High K) and a control 6 mmol potassium (Low K) meal on 2 separate occasions in a randomized order. FMD and BP were measured while participants were fasting and at 30, 60, 90 and 120 min after the meal. There was a postprandial decrease in FMD in both groups. FMD decreased overall less after the High K meal compared to the Low K meal (meal effect p < 0.05). Both meals produced a postprandial decrease in BP at 30 min which returned to baseline levels by 120 min. No significant differences in BP were observed between meals. FMD and systolic BP were negatively correlated at 90 (r = -0.54-0.55, p < 0.01) and 120 min (r = -0.42-0.56, p < 0.01) after both meals. CONCLUSIONS: A high potassium meal, which contains a similar amount of potassium as 2.5 serves of bananas, can lessen the postprandial reduction in brachial artery FMD when compared to a low potassium meal.


Subject(s)
Blood Pressure/drug effects , Dietary Supplements , Potassium, Dietary/administration & dosage , Adolescent , Adult , Aged , Body Mass Index , Brachial Artery/drug effects , Cross-Over Studies , Double-Blind Method , Endothelium, Vascular/drug effects , Female , Humans , Male , Meals , Middle Aged , Postprandial Period , Young Adult
17.
Clin Obes ; 4(3): 150-6, 2014 Jun.
Article in English | MEDLINE | ID: mdl-25826770

ABSTRACT

Effective strategies are needed to help individuals lose weight and maintain weight loss. The primary aim of this study was to investigate the effect of intermittent energy restriction (IER) compared to continuous energy restriction (CER) on weight loss after 8 weeks and weight loss maintenance after 12 months. Secondary aims were to determine changes in waist and hip measurements and diet quality. In a randomized parallel study, overweight and obese (body mass index [BMI] ≥ 27 kg m(-2)) women were stratified by age and BMI before randomization. Participants undertook an 8-week intensive period with weight, waist and hip circumference measured every 2 weeks, followed by 44 weeks of independent dieting. A food frequency questionnaire was completed at baseline and 12 months, from which diet quality was determined. Weight loss was not significantly different between the two groups at 8 weeks (-3.2 ± 2.1 kg CER, n = 20, -2.0 ± 1.9 kg IER, n = 25; P = 0.06) or at 12 months (-4.2 ± 5.6 kg CER, n = 17 -2.1 ± 3.8 kg IER, n = 19; P = 0.19). Weight loss between 8 and 52 weeks was -0.7 ± 49 kg CER vs. -1 ± 1.1 kg IER; P = 0.6. Waist and hip circumference decreased significantly with time (P < 0.01), with no difference between groups. There was an increase in the Healthy Eating Index at 12 months in the CER compared with the IER group (CER 8.4 ± 9.1 vs. IER -0.3 ± 8.4, P = 0.006). This study indicates that intermittent dieting was as effective as continuous dieting over 8 weeks and for weight loss maintenance at 12 months. This may be useful for individuals who find CER too difficult to maintain.


Subject(s)
Caloric Restriction , Obesity/diet therapy , Weight Loss , Adult , Aged , Female , Humans , Male , Middle Aged , Obesity/metabolism , Obesity/physiopathology
18.
Nutr Metab Cardiovasc Dis ; 24(5): 554-62, 2014 May.
Article in English | MEDLINE | ID: mdl-24374004

ABSTRACT

BACKGROUND AND AIM: Diets where carbohydrate has been partially exchanged for protein have shown beneficial changes in persons with type 2 diabetes but no studies have enrolled people with albuminuria. We aim to determine if a high protein to carbohydrate ratio (HPD) in an energy reduced diet has a beneficial effect on metabolic control and cardiovascular risk factors without negatively affecting renal function. METHOD AND RESULTS: Adult, overweight participants with type 2 diabetes, with albuminuria (30-600 mg/24 h or an albumin-to-creatinine ratio of 3.0-60 mg/mmol), and estimated GFR of >40 ml/min/1.73 m(2) were enrolled. Participants were randomized to an HPD or an SPD. Protein:fat:carbohydrate ratio was 30:30:40% of energy for the HPD and 20:30:50% for the SPD. Main outcomes were renal function, weight loss, blood pressure, serum lipids and glycaemic control. We recruited 76 volunteers and 45 (35 men and 10 women) finished. There were no overall changes in renal function at 12 months and no significant differences in weight loss between groups (9.7 ± 2.9 kg and 6.6 ± 1.4 kg HPD and SPD group respectively; p = 0.32). Fasting blood glucose decreased significantly with no treatment effect. The decrease in HbA1c differed between treatments at 6 months (HPD -0.9 vs. SPD -0.3%; p = 0.039) but not at 12 months. HDL increased significantly with no treatment effects. There were no changes in LDL or blood pressure overall but DBP was lower in the HPD group (p = 0.024) at 12 months. CONCLUSION: Weight loss improved overall metabolic control in this group of well controlled participants with type 2 diabetes regardless of diet composition.


Subject(s)
Diabetes Mellitus, Type 2/diet therapy , Diet, Reducing , Diet , Dietary Proteins/administration & dosage , Obesity/diet therapy , Weight Loss , Adolescent , Adult , Aged , Albuminuria/blood , Albuminuria/complications , Albuminuria/diet therapy , Blood Glucose/metabolism , Blood Pressure , Cardiovascular Diseases/blood , Cardiovascular Diseases/prevention & control , Cholesterol, LDL/blood , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/complications , Dietary Carbohydrates/administration & dosage , Dietary Fats/administration & dosage , Energy Intake , Fasting , Female , Glycated Hemoglobin/metabolism , Healthy Volunteers , Humans , Male , Middle Aged , Obesity/blood , Obesity/complications , Overweight/blood , Overweight/complications , Overweight/diet therapy , Risk Factors , Young Adult
19.
Nutr Metab Cardiovasc Dis ; 24(5): 495-502, 2014 May.
Article in English | MEDLINE | ID: mdl-24374005

ABSTRACT

AIMS: To review: 1) the correlation between individual dietary components and carotid intima media thickness (cIMT); 2) the relationship between dietary patterns and cIMT; 3) the effect of dietary interventions on cIMT progression. DATA SYNTHESIS: An electronic search for epidemiological and intervention trials investigating the association between dietary components or patterns of intake and cIMT was performed in PUBMED, EMBASE and the Cochrane Library. Epidemiological data shows that a higher intake of fruit, wholegrains and soluble fibre and lower consumption of saturated fat in favour of polyunsaturated fat is associated with lower cIMT. In people at high risk of cardiovascular disease >93 g/day of fruit is associated with lower cIMT. Lower cIMT has also been observed when >0.79 serves/day of wholegrains and >25 g/day of fibre, predominately in the soluble form is consumed. Saturated fat is positively associated with cIMT, for every 10 g/day increase in saturated fat cIMT is 0.03 mm greater. Olive oil is inversely associated with cIMT, with a benefit seen when >34 g/day is consumed. While there are many epidemiological studies exploring the association between dietary intake and cIMT there are few intervention studies. Intervention studies show that a Mediterranean diet may reduce cIMT progression, especially in those with a higher cIMT. CONCLUSIONS: A Mediterranean style dietary pattern, which is high in fruits, wholegrains, fibre and olive oil and low in saturated fat, may reduce carotid atherosclerosis development and progression. However further research from randomised controlled trials is required to understand the association between diet and cIMT and the underlying mechanisms.


Subject(s)
Carotid Intima-Media Thickness , Feeding Behavior , Carotid Artery Diseases/prevention & control , Dairy Products/analysis , Databases, Factual , Diet, Mediterranean , Diet, Reducing , Dietary Fats/administration & dosage , Dietary Fiber/administration & dosage , Disease Progression , Edible Grain/chemistry , Fruit/chemistry , Humans , Meta-Analysis as Topic , Observational Studies as Topic , Phytosterols/administration & dosage , Potassium, Dietary/administration & dosage , Randomized Controlled Trials as Topic , Risk Factors , Sodium, Dietary/administration & dosage , Glycine max/chemistry , Vegetables/chemistry
20.
J Endocrinol Invest ; 36(11): 1004-10, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23812344

ABSTRACT

BACKGROUND: Polycystic ovary syndrome (PCOS) is associated with hyperandrogenism and an increased risk of Type 2 diabetes and cardiovascular disease. Decreased SHBG and elevated testosterone are associated with metabolic syndrome and glucose intolerance in women. AIM: The aim of this study was to assess the relationship between SHBG and testosterone and metabolic syndrome and glucose intolerance in PCOS. MATERIAL/SUBJECTS AND METHODS: Cross-sectional study in overweight and obese premenopausal non-diabetic women with PCOS (no.=178: no.=55 metabolic syndrome, no.=16 glucose intolerance). Data were analyzed by multiple regression with metabolic syndrome, oral glucose tolerance test (OGTT) glucose or SHBG as dependent variables and reproductive hormones, insulin resistance, glucose tolerance, lipids or C-reactive protein as independent variables. RESULTS: Metabolic syndrome was independently associated with body mass index [odds ratio (OR) 1.084 95% confidence interval (CI) 1.034-1.170, p=0.015] and SHBG (OR 0.961 95% CI 0.932-0.995, p=0.018). Glucose tolerance was independently associated with OGTT insulin (ß=0.418, p<0.001), age (ß=0.154, p=0.033) and PRL (ß=-0.210, p=0.002). SHBG was independently associated with OGTT insulin (ß=-0.216, p=0.014) and PCOS diagnostic criteria (ß=0.197, p=0.010). CONCLUSIONS: SHBG, but not testosterone, is independently associated with metabolic syndrome in overweight women with PCOS and is associated with insulin resistance and PCOS diagnostic criteria.


Subject(s)
Sex Hormone-Binding Globulin/metabolism , Testosterone/blood , Adolescent , Adult , Body Mass Index , C-Reactive Protein/metabolism , Cross-Sectional Studies , Female , Glucose Intolerance/complications , Glucose Tolerance Test , Humans , Insulin Resistance/physiology , Metabolic Syndrome/complications , Middle Aged , Obesity/complications , Overweight/complications , Polycystic Ovary Syndrome/metabolism
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