Trends and associations between maternal characteristics and infant birthweight among Indigenous and non-Indigenous people in Tasmania, Australia: a population-based study.

OBJECTIVE: This study aimed to investigate the trends and associations of maternal characteristics and birthweight among Indigenous and non-Indigenous infants. STUDY DESIGN: This was a retrospective population-based study. METHODS: Fourteen years (2005-2018) of birthweight and perinatal health data of live-born singletons and their mothers obtained from the Tasmanian Data Linkage Unit were used to assess the trends and associations between maternal characteristics and infant birthweight using regression modelling. RESULTS: Compared with non-Indigenous mothers (n = 76,750), Indigenous mothers (n = 3805) had a significantly higher prevalence of risk factors during the 14-year period. Although the prevalence of prepregnancy obesity and gestational diabetes mellitus (GDM) markedly increased in both groups, the rate of increase was higher (P < 0.001) for Indigenous than non-Indigenous mothers. Smoking, alcohol consumption and illegal drug use during pregnancy reduced over the years, and there was no significant difference in the rate of reduction between the groups. Large-for-gestational-age (LGA) births increased while small-for-gestational-age (SGA) births decreased in both groups over time. In addition, high birthweight (HBW) births decreased while low birthweight (LBW) births increased. The rates of increase in LGA and LBW births and the rates of decrease in SGA and HBW births were significantly higher in Indigenous mothers compared with non-Indigenous mothers (P < 0.001 for all). The association between Indigenous ethnicity and LBW and SGA births weakened after adjusting for other confounding maternal and perinatal variables. LBW and SGA were positively associated with Indigenous ethnicity, age <18 years, smoking, alcohol consumption and illegal drug use, pre-eclampsia, underweight prepregnancy body mass index and low socio-economic status. Women with higher parity, pre-existing diabetes and prepregnancy overweight or obesity were more likely to give birth to an infant with HBW or LGA. CONCLUSIONS: The prevalence of risk factors for abnormal birthweight is higher among Tasmanian Indigenous mothers, contributing to a gap in birthweight outcomes between Indigenous and non-Indigenous infants. The dramatic increase in prepregnancy obesity and GDM in both groups highlight the importance of screening and management of GDM during pregnancy. Comprehensive programmes co-designed and co-managed in consultation with Indigenous people are needed to support healthy lifestyle choices among Indigenous women to address the barriers to individuals adopting behaviour change and to help close the health outcomes-related gap between Indigenous and non-Indigenous mothers and infants.

Capsaicin and Zinc Signalling Pathways as Promising Targets for Managing Insulin Resistance and Type 2 Diabetes.

The global burden of type 2 diabetes (T2DM) has led to significant interest in finding novel and effective therapeutic targets for this chronic disorder. Bioactive food components have effectively improved abnormal glucose metabolism associated with this disease. Capsaicin and zinc are food components that have shown the potential to improve glucose metabolism by activating signalling events in the target cells. Capsaicin and zinc stimulate glucose uptake through the activation of distinct pathways (AMPK and AKT, respectively); however, calcium signal transduction seems to be the common pathway between the two. The investigation of molecular pathways that are activated by capsaicin and zinc has the potential to lead to the discovery of new therapeutic targets for T2DM. Therefore, this literature review aims to provide a summary of the main signalling pathways triggered by capsaicin and zinc in glucose metabolism.

Physical Activity and Food Environments in and around Schools: A Case Study in Regional North-West Tasmania.

A better understanding of the physical activity (PA) infrastructure in schools, the walkability of neighborhoods close to schools, and the food environments around schools, particularly in rural, socioeconomically challenged areas such as the North-West (NW) of Tasmania, could be important in the wider effort to improve the health of school-age children. Accordingly, this research aimed to assess PA resources, walkability, and food environments in and around schools in three socioeconomically disadvantaged, regional/rural Local Government Areas (LGAs) of Tasmania, Australia. A census of schools (including assessment of the PA infrastructure quality within school grounds), a walkability assessment, and a census of food outlets surrounding schools (through geospatial mapping) were executed. Most of the schools in the study region had access to an oval, basketball/volleyball/netball court, and free-standing exercise equipment. In all instances (i.e., regardless of school type), the quality of the available infrastructure was substantially higher than the number of incivilities observed. Most schools also had good (i.e., within the first four deciles) walkability. Numerous food outlets were within the walking zones of all schools in the study region, with an abundance of food outlets that predominantly sold processed unhealthy food.

A Spatial Analysis of Access to Physical Activity Infrastructure and Healthy Food in Regional Tasmania.

Prevalence of physical inactivity and obesity continues to increase in regional areas such as North-West (NW) Tasmania and show no signs of abating. It is possible that limited access to physical activity infrastructure (PAI) and healthier food options are exacerbating the low levels of habitual physical activity and obesity prevalence in these communities. Despite a burgeoning research base, concomitant exploration of both physical activity and food environments in rural and regional areas remain scarce. This research evaluated access (i.e., coverage, variety, density, and proximity) to physical activity resources and food outlets in relation to socioeconomic status (SES) in three NW Tasmanian communities. In all three study areas, the PAI and food outlets were largely concentrated in the main urban areas with most recreational tracks and natural amenities located along the coastline or river areas. Circular Head had the lowest total number of PAI (n = 43) but a greater proportion (30%) of free-to-access outdoor amenities. There was marked variation in accessibility to infrastructure across different areas of disadvantage within and between sites. For a considerable proportion of the population, free-to-access natural amenities/green spaces and recreational tracks (73 and 57%, respectively) were beyond 800 m from their households. In relation to food accessibility, only a small proportion of the food outlets across the region sells predominantly healthy (i.e., Tier 1) foods (~6, 13, and 10% in Burnie, Circular Head and Devonport, respectively). Similarly, only a small proportion of the residents are within a reasonable walking distance (i.e., 5-10 min walk) from outlets. In contrast, a much larger proportion of residents lived close to food outlets selling predominantly energy-dense, highly processed food (i.e., Tier 2 outlets). Circular Head had at least twice as many Tier 1 food stores per capita than Devonport and Burnie (0.23 vs. 0.10 and 0.06; respectively) despite recording the highest average distance (4.35 and 5.66 km to Tier 2/Tier 1 stores) to a food outlet. As such, it is possible that both food and physical activity environment layouts in each site are contributing to the obesogenic nature of each community.

TRPV1 Activation by Capsaicin Mediates Glucose Oxidation and ATP Production Independent of Insulin Signalling in Mouse Skeletal Muscle Cells.

BACKGROUND: Insulin resistance (IR), a key characteristic of type 2 diabetes (T2DM), is manifested by decreased insulin-stimulated glucose transport in target tissues. Emerging research has highlighted transient receptor potential cation channel subfamily V member (TRPV1) activation by capsaicin as a potential therapeutic target for these conditions. However, there are limited data on the effects of capsaicin on cell signalling molecules involved in glucose uptake. METHODS: C2C12 cells were cultured and differentiated to acquire the myotube phenotype. The activation status of signalling molecules involved in glucose metabolism, including 5' adenosine monophosphate-activated protein kinase (AMPK), calcium/calmodulin-dependent protein kinase 2 (CAMKK2), extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), protein kinase B (AKT), and src homology phosphatase 2 (SHP2), was examined. Finally, activation of CAMKK2 and AMPK, and glucose oxidation and ATP levels were measured in capsaicin-treated cells in the presence or absence of TRPV1 antagonist (SB-452533). RESULTS: Capsaicin activated cell signalling molecules including CAMKK2 and AMPK leading to increased glucose oxidation and ATP generation independent of insulin in the differentiated C2C12 cells. Pharmacological inhibition of TRPV1 diminished the activation of CAMKK2 and AMPK as well as glucose oxidation and ATP production. Moreover, we observed an inhibitory effect of capsaicin in the phosphorylation of ERK1/2 in the mouse myotubes. CONCLUSION: Our data show that capsaicin-mediated stimulation of TRPV1 in differentiated C2C12 cells leads to activation of CAMKK2 and AMPK, and increased glucose oxidation which is concomitant with an elevation in intracellular ATP level. Further studies of the effect of TRPV1 channel activation by capsaicin on glucose metabolism could provide novel therapeutic utility for the management of IR and T2DM.

The current global state of movement and physical activity - the health and economic costs of the inactive phenotype.

Physical inactivity is one of the major contributing factors to the global pandemic of non-communicable diseases. Unfortunately, low levels of habitual movement and physical activity (PA) are seen in an increasing proportion of populations across low- and middle-income countries and high-income countries alike. This new normal - the inactive phenotype - is a significant contributor to multiple health and economic costs. Here we provide a brief historical overview of societal declines in PA, roughly consistent with major transitions in PA and nutrition in recent decades. This is followed by a synthesis of research evidence linking inactivity with poor health outcomes and prevention approaches needed to impact a perpetuation of poor lifestyle behaviors. A major focus of the paper is on the economic/health costs and the reduction of the inactive phenotype. In summary, we demonstrate that the consequences of insufficient PA are manifold, and if sustained, impact short and long-term health and quality of life, along with substantial economic costs.

Bitter melon protects against ER stress in LS174T colonic epithelial cells.

BACKGROUND: Bitter Melon (BM) has been used as a functional food in traditional Chinese and Indian medicine for many generations and has gained a great deal of attention due to its apparent benefits in moderating some of the pathogenic processes in a variety of inflammatory conditions. BM extract (BME) has been shown to possess strong anti-oxidant properties. In addition, it can ameliorate oxidative stress and potentially ER stress. There is increasing evidence that oxidative and ER stress are major contributors for intestinal secretory cell dysfunction which leads to local inflammation and disease pathogenesis that are hallmarks of inflammatory bowel diseases (IBD). Hence, the search for potential therapeutics against ER stress and oxidative stress in intestinal epithelial secretory cells may provide valuable resources for the management of IBD. The aim of the present study was to investigate the effects of BME in ameliorating ER stress in colonic epithelial cells. METHODS: Human colonic adenocarcinoma LS174T cells were used for the assessment of BME effects on colonic epithelial cells in vitro. Cell viability was assessed using trypan blue exclusion and the effect of BME in ameliorating tunicamycin (TM)-induced ER stress was determined by analysing the mRNA expression of the common ER stress markers; ATF6, XBP1, GRP78, CHOP and PERK by quantitative RT-PCR and GRP78 and CHOP by western blot. RESULTS: In the absence of ER stress, BME exhibited no cell toxicity up to 2.0% w/v and no significant effect on the basal mRNA expression of ER stress markers in LS174T cells. In contrast, pre-treatment of LS174T cells with BME followed by induction of ER stress resulted in a significant decrease in mRNA expression of ATF6, XBP1, GRP78, CHOP and PERK and protein expression of GRP78 and CHOP. Co-treatment during induction of ER stress and post- treatment following induction of ER Stress in LS174T cells resulted in a lower but still significant reduction in mRNA expression levels of most ER stress markers. CONCLUSIONS: This is one of the first studies demonstrating the efficacy of BME in reducing expression of ER stress markers in colonic epithelial cells suggesting the potential of BME as a dietary intervention in ameliorating ER stress and oxidation in IBD. Interestingly, while the most significant effect was seen with pre-treatment of cells with BME there was a reduced but still significant effect when co-treated or even post-treated. This suggests that BME may even be effective in modulating ER stress in the face of an existing cell stress environment.

Obstetric and Perinatal Morbidity in Northern Tasmanian Aboriginal Population: A Retrospective Cohort Study.

INTRODUCTION: Aboriginal and Torres Strait Islander women are at increased risk of maternal morbidity and mortality as compared to non-Aboriginals. Similarly, aboriginal babies are at increased risk of low birth weight and infant mortality. AIM: To investigate the independent association of aboriginality with Tasmanian maternal and neonatal morbidity. MATERIALS AND METHODS: A retrospective analysis of all the births (gestation more than 20 weeks) from June 2013 to May 2014 was conducted at the Launceston General Hospital, Tasmania. The study compared 66 Aboriginal (4.2% of the total births) to 1477 non-aboriginal births for maternal and neonatal morbidity. Comparisons were made using logistic regression. The outcome measures were maternal and neonatal morbidity. RESULTS: Significantly higher number of aboriginal women (49% vs 19%; OR 4.15 90%CI 2.52- 6.85) smoked and used illicit drugs (15% vs 2%; OR 9.24; 95%CI 4.28-19.96) than the non-aboriginal women (both p<0.001). Maternal morbidity was not significantly different between aboriginal compared to non-aboriginal women (OR 0.64; 95%CI 0.36-1.14; p=0.13; adjusted OR 1.00; 95%CI 0.52-1.93; p=0.99). Factors positively associated with maternal morbidity included: age (OR 1.28; 95%CI 1.13-1.46; p<0.01) and BMI (OR 1.50; 95%CI 1.33-1.70; p<0.01). The unadjusted OR of neonatal morbidity for aboriginality was 1.98 (95%CI 1.17-3.34; p=0.01) and adjusted was 1.45 (95%CI 0.77-2.72; p=0.25). Factors positively associated with neonatal morbidity included smoking (OR 2.24; 95%CI 1.59-3.14; p<0.01), illicit drug use 95%CI 1.49-(OR 3.26; 95%CI 1.49-7.13; p <0.01), hypertension (OR 2.49; 95%CI 1.61-3.84; p<0.01) and diabetes (OR 1.92; 95%CI 1.33-2.78; p<0.01). CONCLUSION: The composite Aboriginal maternal morbidity does not differ, however the increased rates of smoking and illicit drug use are largely responsible for neonatal morbidity. Along with strengthening strategies to decrease medical comorbidities in aboriginals, we recommend intensifying smoking and illicit drug cessation programs.

No Effects of a Short-Term Gluten-free Diet on Performance in Nonceliac Athletes.

PURPOSE: Implementation of gluten-free diets among nonceliac athletes has rapidly increased in recent years because of perceived ergogenic and health benefits. The aim of this study was to investigate the effects of a gluten-free diet (GFD) on exercise performance, gastrointestinal (GI) symptoms, perceived well-being, intestinal injury, and inflammatory responses in nonceliac athletes. METHODS: Thirteen competitive endurance cyclists (8 males, 5 females) with no positive clinical screening for celiac disease or history of irritable bowel syndrome (mean ± SD; age, 32 ± 7 yr; weight, 71.1 ± 13.4 kg; height, 177.0 ± 11.8 cm, VO2max 59.1 ± 8.0 mL·kg⁻¹·min⁻¹) were allocated to a 7-d gluten-containing diet (GCD) or GFD separated by a 10-d washout in a controlled, randomized, double-blind, crossover study. Cyclists ate a GFD alongside either gluten-containing or gluten-free food bars (16 g wheat gluten per day) while habitual training and nutrition behaviors were controlled. During each diet, cyclists completed the Daily Analysis of Life Demand for Athletes (DALDA) and GI questionnaires (postexercise and daily). On day 7, cyclists completed a submaximal steady-state (SS) 45-min ride at 70% Wmax followed by a 15-min time trial (TT). Blood samples were taken preexercise, post-SS, and post-TT to determine intestinal fatty acid binding protein (IFABP) and inflammatory markers (cytokine responses: interleukin [IL] 1ß, IL-6, IL-8, IL-10, IL-15, tumor necrosis factor α). Mixed effects logistic regression was used to analyze data. RESULTS: TT performance was not significantly different (P = 0.37) between the GCD (245.4 ± 53.4 kJ) and GFD (245.0 ± 54.6 kJ). GI symptoms during exercise, daily, and DALDA responses were similar for each diet (P > 0.11). There were no significant differences in IFABP (P = 0.69) or cytokine (P > 0.13) responses. CONCLUSIONS: A short-term GFD had no overall effect on performance, GI symptoms, well-being, and a select indicator of intestinal injury or inflammatory markers in nonceliac endurance athletes.

Vanilloid-like agents inhibit aggregation of human platelets.

INTRODUCTION: Plant-derived and endogenous vanilloid-like agents exert their effects on cells through transient receptor potential vanilloid-1 (TRPV1). Little is known about the effects of these agents on platelet aggregation. We investigated the effect of various vanilloid-like agents on in-vitro platelet aggregation and tested whether this action is mediated through TRPV1. Understanding the mechanism of action of these compounds in platelets is important in that these compounds may be developed as novel anti-platelet agents. MATERIALS AND METHODS: The effects of plant-derived (capsaicin; dihydrocapsaicin, DHC) and endogenous vanilloid-like agents (N-oleoyldopamine, OLDA; N-arachidonoyl-dopamine, NADA) on platelet aggregation were investigated using ADP (5, 10µM), collagen (4, 8µg/mL) and arachidonic acid (AA, 300, 400µg/mL) as agonists. The direct effects of these agents on platelet viability were also determined using an LDH release assay. RESULTS: Capsaicin, OLDA and NADA inhibited ADP-induced platelet aggregation in a concentration-dependent manner. OLDA and NADA, but not capsaicin and DHC, inhibited collagen-induced aggregation, whereas AA-induced aggregation was inhibited by capsaicin, DHC and NADA, but not OLDA. Inhibition of aggregation was not due to direct toxicity of these agents towards platelets. The TRPV1 antagonist, SB-452533, did not affect inhibition of ADP-induced platelet aggregation by capsaicin and OLDA. CONCLUSIONS: These results demonstrate that the endovanilloids, OLDA and NADA, and plant-derived vanilloid, capsaicin, inhibit ADP-induced platelet aggregation. Collagen-induced aggregation was inhibited only by endovanilloids, whereas AA-induced aggregation was inhibited by capsaicin, DHC and NADA. This inhibition was not due to direct toxic effects of these agents, nor was inhibition of ADP-induced aggregation TRPV1 mediated.

Hypolipidaemic effect of crude extract from Carpobrotus rossii (pigface) in healthy rats.

Carpobrotus rossii (CR) was used by the Aboriginal population and early European settlers both as a food and therapeutic agent. Based on the presence of flavonoids in CR and results from our previous in vitro investigations, this study aimed to determine whether consumption of CR crude leaf extract: (a) affected lipoprotein profile, resting glucose, systolic blood pressure and vascular function, and (b) produced toxic effects (haematological measures, organ weight) in healthy rats. Male Hooded-Wistar rats (~230 g) were supplemented for 4 weeks with CR extract in their drinking water (35 mg/kg body weight daily). CR extract produced a significant decrease (18%, p=0.033) in atherogenic lipoproteins (but not high density lipoprotein). CR supplemented animals showed no signs of haematological toxicity and body and organ weight, daily fluid and food consumption and in vitro vascular responsiveness were similar for both groups. CR also increased (40%, p=0.049) the renal concentration of 3-hydroxy-3-methylglutaric acid (HMG), consistent with HMG-containing CR flavonoids being bioavailable, and therefore possessing the potential to interfere with cholesterol synthesis pathways. CR extract appears to be safe to ingest and may reduce cardiovascular risk.

Anti-ß2GP1 antibodies have variable effects on platelet aggregation.

AIM: To investigate the effects of affinity-purified rabbit anti-ß2GP1, and anti-ß2GP1 purified from patients with systemic lupus erythematosus (SLE), on adenosine diphosphate (ADP)-induced aggregation. METHODS: Whole blood was collected and processed to obtain platelet poor plasma (PPP) from normal controls (n = 15) and SLE patients (n = 15). Using PPP, anti-ß2GP1 titres were determined using an ELISA and IgG fractions isolated using a HiTrap protein G column. Anti-ß2GP1 was purified from two SLE patients using purified ß2GP1 coupled to a HiTrap NHS-activated HP column. RESULTS: The effect of rabbit and human derived anti-ß2GP1 (0-100 µg/mL), on ADP (2.5, 5 µM) induced platelet aggregation were investigated using light transmission aggregometry. Rabbit anti-ß2GP1 significantly inhibited all parameters of 5 µM ADP-induced platelet aggregation; %Max (p = 0.028), %AUC (p = 0.014) and slope (p < 0.001). In contrast, anti-ß2GP1 purified from SLE patients significantly enhanced the %Max (p = 0.031) and %AUC (p = 0.007) in a concentration dependent manner, but inhibited the slope (p < 0.05) of 5 µM ADP-induced platelet aggregation. CONCLUSION: Our data suggest anti-ß2GP1 purified from different species have variable effects on in vitro platelet aggregation. The disparity between rabbit and human anti-ß2GP1 may be due to the heterogeneous nature of anti-ß2GP1, varying avidity or different antibody binding specificities between species.

Development and experimental application of an HPLC procedure for the determination of capsaicin and dihydrocapsaicin in serum samples from human subjects.

Total capsaicins are extracted from 2 mL aliquots of serum or plasma using methyl-isobutyl ketone, evaporation of the extract to dryness and reconstitution with 200 µL of acetonitrile. The HPLC mobile phase is 40:60 water:acetonitrile. The absorbance of the eluent is monitored at 205 nm. Standardisation uses a known mixture of pure capsaicin and dihydrocapsaicin. Accuracies are 98.9 and 100.6 % for capsaicin and dihydrocapsaicin respectively. Inter batch reproducibility for both is 15 %. The limits of detection are 2.6 and 3.8 ng/mL for capsaicin and dihydrocapsaicin respectively. Analyses of sera obtained previously from human subjects who had eaten chilli containing meals showed that in those that absorbed capsaicins (N = 30) then the median, mean and SD of their serum capsaicin were: 13.4, 18.9 and 16.3 ng/mL. The corresponding data for those sera (N = 13) that had measurable levels of dihydrocapsaicin were: 6.9, 7.5 and 3.6 ng/mL. This procedure is suitable for use in prospective studies of the metabolism of orally ingested chilli.

Effects of antiphospholipid antibodies on in vitro platelet aggregation.

Antiphospholipid antibodies contribute to the development of thrombosis, although precise mechanisms remain to be elucidated. We determined the effects of affinity-purified anti-beta(2)-glycoprotein 1 (anti-ß(2)GP1) and anti-prothrombin (anti-PT) antibodies on in vitro platelet aggregation. Adenosine diphosphate (ADP) and collagen-induced platelet aggregation were performed using platelet-rich plasma ([PRP] 250 × 10(9)/L). Antiphospholipid antibodies (1.25-10 µg/mL) were preincubated with PRP for 10 minutes at 37°C prior to the addition of agonist. Anti-ß(2)GP1 antibodies significantly reduced platelet aggregation (percentage area under the curve; %AUC) in a concentration-dependent manner using both 5 µmol/L (P < .001) and 2.5 µmol/L (P = .038) ADP but did not significantly affect the rate of aggregation. Anti-PT antibodies significantly enhanced 5 µg/mL collagen-induced platelet aggregation (%AUC; P = .034) but did not affect ADP-induced platelet aggregation. These results suggest (1) interactions and effects of antiphospholipid antibodies on platelets are agonist and concentration dependent and (2) anti-ß(2)GP1 antibodies may inhibit dense granule release and/or inhibition of the arachidonic acid pathway.

In vitro antioxidant, antiplatelet and anti-inflammatory activity of Carpobrotus rossii (pigface) extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Carpobrotus rossii (CR) has a history of use as a food and therapeutic agent by Australian indigenous peoples and early European settlers and is believed to contain a number of pharmacologically active polyphenolic compounds. AIMS OF THE STUDY: Oxidation of low density lipoprotein (LDL), platelet aggregation, and inflammation contribute to the development and progression of atherosclerosis. The aim of the present study was to investigate the antioxidant, antiplatelet and anti-inflammatory activity of CR extract using human blood components. MATERIALS AND METHODS: An assay employing in vitro copper-induced oxidation of serum lipids was used to assess antioxidant activity of CR extract (and tannin, flavonoid and pre- and post-flavonoid fractions). The effects of CR extract on ADP- and collagen-induced platelet aggregation, and on basal (unstimulated) and lipopolysaccharide (LPS)- and phytohaemagglutinin A (PHA)-stimulated cytokine release from peripheral blood mononuclear cells (PBMC) were also investigated. RESULTS: CR extract increased the lag time of serum oxidation (maximum of ∼4-fold at 20µg/ml) in a concentration-dependent manner. The antioxidant activity resided only in the tannin and post-flavonoid fractions. CR had no effect on ADP-induced platelet aggregation, but significantly decreased collagen-induced platelet aggregation. LPS, but not PHA, significantly increased the release of IL-1ß and TNF-α from PBMC. CR extract alone inhibited monocyte chemoattractant protein (MCP)-1 release and in the presence of LPS, inhibited IL-10, TNF-α and MCP-1 release compared to LPS alone. CONCLUSION: CR has significant in vitro antioxidant, antiplatelet and, potentially, anti-inflammatory activity.

Acute effect of a high-carbohydrate low-fat meal on platelet aggregation.

Conflicting information is available regarding patient preparation with respect to the fasting and feeding states prior to blood collection in order to conduct platelet aggregation tests. Some literature suggests avoidance of only high-fat foods and allowance of non-fat foods and clear liquids; others suggest a fast of 8-10 hours. We conducted a study in 16 healthy subjects aged 44.0 +/- 12.7 (mean +/- SD) years to investigate and compare the effects of fasting and a high-carbohydrate low-fat meal on measures of platelet aggregation. Blood samples collected after an overnight fast of 10-12 hours and those collected at 40 and 120 minute postprandially (post-high-carbohydrate low-fat meal; 1900 kJ energy; 69, 16 and 15% of energy from carbohydrate, protein and fat, respectively), were tested for platelet aggregation in response to adenosine diphosphate. There was a significant reduction in maximum aggregation and area under the aggregation curve from fasting to 120 minute post meal (overall p < 0.001). Serum triglyceride concentrations did not change significantly from fasting to postprandial state (p = 0.53). Although there was a significant association between serum insulin, plasma glucose and measures of platelet aggregation, correcting for the effects of these metabolic parameters did not alter the results, providing evidence that other, currently unknown, factors associated with food consumption affect postprandial platelet aggregation. We propose that protocols for control of pre-analytical variables in platelet aggregation studies should make a fasting sample mandatory rather than "preferable" unless the objective of the study is to measure acute effects in response to a medication or food.

Effects of olive oil and tomato lycopene combination on serum lycopene, lipid profile, and lipid oxidation.

OBJECTIVE: We compared the effect of two diets (a diet high in olive oil and a diet high in carbohydrate and low in olive oil) with high lycopene content and other controlled carotenoids on serum lycopene, lipids, and in vitro oxidation. METHODS: This was a randomized crossover dietary intervention study carried out in Launceston, Tasmania, Australia in healthy free-living individuals. Twenty-one healthy subjects who were 22 to 70 y old were recruited by advertisements in newspapers and a university newsletter. A randomized dietary intervention was done with two diets of 10 d each. One diet was high in olive oil and the other was high in carbohydrate and low in olive oil; the two diets contained the same basic foods and a controlled carotenoid content high in lycopene. RESULTS: Significant increases (P<0.001) in serum lycopene concentration on both diets were to similar final concentrations. Higher serum high-density lipoprotein cholesterol (P<0.01), lower ratio of total cholesterol to high-density lipoprotein (P<0.01), and lower triacylglycerols (P<0.05) occurred after the olive oil diet compared with the high-carbohydrate, low-fat diet. There was no difference in total antioxidant status and susceptibility of serum lipids to oxidation. CONCLUSIONS: Serum lycopene level changes with dietary lycopene intake irrespective of the amount of fat intake. However, a diet high in olive oil and rich in lycopene may decrease the risk of coronary heart disease by improving the serum lipid profile compared with a high-carbohydrate, low-fat, lycopene-rich diet.