Kerin O’Dea

The Mediterranean diet improves hepatic steatosis and insulin sensitivity in individuals with non-alcoholic fatty liver disease

BACKGROUND & AIMS Non-alcoholic fatty liver disease (NAFLD) affects up to 30% of the population and signifies increased risk of liver fibrosis and cirrhosis, type 2 diabetes, and cardiovascular disease. Therapies are limited. Weight loss is of benefit but is difficult to maintain. We aimed at examining the effect of the Mediterranean diet (MD), a diet high in monounsaturated fatty acids, on steatosis and insulin sensitivity, using gold standard techniques. METHODS Twelve non-diabetic subjects (6 Females/6 Males) with biopsy-proven NAFLD were recruited for a randomised, cross-over 6-week dietary intervention study. All subjects undertook both the MD and a control diet, a low fat-high carbohydrate diet (LF/HCD), in random order with a 6-week wash-out period in- between. Insulin sensitivity was determined with a 3-h hyperinsulinemic-euglycemic clamp study and hepatic steatosis was assessed with localized magnetic resonance (1)H spectroscopy ((1)H-MRS). RESULTS At baseline, subjects were abdominally obese with elevated fasting concentrations of glucose, insulin, triglycerides, ALT, and GGT. Insulin sensitivity at baseline was low (M=2.7 ± 1.0 mg/kg/min(-1)). Mean weight loss was not different between the two diets (p=0.22). There was a significant relative reduction in hepatic steatosis after the MD compared with the LF/HCD: 39 ± 4% versus 7 ± 3%, as measured by (1)H-MRS (p=0.012). Insulin sensitivity improved with the MD, whereas after the LF/HCD there was no change (p=0.03 between diets). CONCLUSIONS Even without weight loss, MD reduces liver steatosis and improves insulin sensitivity in an insulin-resistant population with NAFLD, compared to current dietary advice. This diet should be further investigated in subjects with NAFLD.

Can the Mediterranean diet lower HbA1c in type 2 diabetes? Results from a randomized cross-over study.

BACKGROUND AND AIMS To investigate the impact of a diet modeled on the traditional Cretan Mediterranean diet on metabolic control and vascular risk in type 2 diabetes. METHODS AND RESULTS Twenty-seven subjects (47-77 yrs) with type 2 diabetes were randomly assigned to consume either the intervention diet ad libitum or their usual diet for 12 weeks and then cross over to the alternate diet. Most of the meals and staple foods for the intervention diet were provided. Lipids, glycemic variables, blood pressure, homocysteine, C-reactive protein, plasma carotenoids and body composition (anthropometry and dual energy X-ray absorptiometry) were assessed at baseline, and at the end of both diet periods. Dietary adherence was monitored using plasma carotenoid and fatty acid (FA) analysis, complemented by diet diaries. Compared with usual diet, on the ad libitum Mediterranean intervention diet glycosylated haemoglobin fell from 7.1% (95% CI: 6.5-7.7) to 6.8% (95% CI: 6.3-7.3) (p=0.012) and diet quality improved significantly [plant:animal (g/day) food ratio increased from 1.3 (95% CI: 1.1-1.5) to 5.4 (95% CI: 4.3-6.6) (p<0.001)], plasma lycopene and lutein/zeaxanthin increased (36% and 25%, respectively), plasma saturated and trans FAs decreased, and monounsaturated FAs increased. CONCLUSION A traditional moderate-fat Mediterranean diet improves glycemic control and diet quality in men and women with well-controlled type 2 diabetes, without adverse effects on weight.

Longitudinal displacement of the carotid wall and cardiovascular risk factors: associations with aging, adiposity, blood pressure and periodontal disease independent of cross-sectional distensibility and intima-media thickness

The recently discovered longitudinal displacement of the common carotid arterial wall (i.e., the motion along the same plane as the blood flow), may be associated with incident cardiovascular events and represents a novel and relevant clinical information. At present, there have only been a few studies that have been conducted to investigate this longitudinal movement. We propose here a method to assess noninvasively the wall bi-dimensional (two-dimensional [2-D], cross-sectional and longitudinal) motion and present an original approach that combines a robust speckle tracking scheme to guidance by minimal path contours segmentation. Our method is well suited to large clinical population studies as it does not necessitate strong imaging prerequisites. The aim of this study is to describe the association between the longitudinal displacement of the carotid arterial wall and cardiovascular risk factors, among which periodontal disease. Some 126 Indigenous Australians with periodontal disease, an emerging risk factor, and 27 healthy age- and sex-matched non-indigenous control subjects had high-resolution ultrasound scans of the common carotid artery. Carotid intima-media thickness and arterial wall 2-D motion were then assessed using our method in ultrasound B-mode sequences. Carotid longitudinal displacement was markedly lower in the periodontal disease group than the control group (geometric mean (IQR): 0.15 mm (0.13) vs. 0.42 mm (0.30), respectively; p < 0.0001), independent of cardiovascular risk factors, cross-sectional distensibility and carotid intima-media thickness (p < 0.0001). A multivariable model indicated that the strongest correlates of carotid longitudinal displacement in adults with periodontal disease were age (β-coefficient = -.235, p = .03), waist (β-coefficient = -.357, p = 0.001), and pulse pressure (β-coefficient = .175, p = 0.07), independent of other cardiovascular risk factors, cross-sectional distensibility and pulse wave velocity. Carotid longitudinal displacement, estimated with our approach, is impaired in the periodontal disease group, independent of established cardiovascular risk factors and other noninvasive measures of arterial stiffness, and may represent an important marker of cardiovascular risk.

Diet and exercise in the prevention of diabetes.

BACKGROUND Individuals with impaired fasting glucose or impaired glucose tolerance are at high risk of progression to type 2 diabetes. Lifestyle modification through change to diet and exercise habit has considerable potential to prevent or delay the onset of this disease. METHODS A systematic literature search was undertaken of Medline, EMBASE, the Cochrane library and the Cumulative Index to Nursing and Allied Health Literature for journal articles relevant to the question of whether type 2 diabetes can be prevented by lifestyle change. RESULTS Four cohort studies in a total of 4864 high risk individuals followed for a period of 2.5-6 years were identified. These showed that lifestyle change may reduce the incidence of type 2 diabetes by 28-59%. Moreover, follow-up studies also indicate that diabetes incidence rates continue to be depressed many years after the discontinuation of a lifestyle intervention. Evidence from a meta-analysis confirms this evidence and suggests that it would be necessary to treat 6.4 (95% confidence interval 5.0-8.4) individuals to prevent or delay one case of diabetes through lifestyle intervention. An examination of weight loss diets (low fat, high protein or Mediterranean) suggests each may be effective but each has limitations requiring care in food selection. Evidence also suggests that the maintenance of weight loss also requires regular exercise with an additional expenditure of approximately 8.4 MJ week(-1) (2000 kcal week(-1)). CONCLUSIONS Diabetes can be prevented by lifestyle change. The challenge is to develop public health approaches to support individuals with respect to incorporating the lifestyle changes needed to reduce the risk of diabetes into their everyday life.

Exploring the expression of depression and distress in aboriginal men in central Australia: a qualitative study

BackgroundDespite being at heightened risk of developing mental illness, there has been little research into the experience of depression in Australian Aboriginal populations. This study aimed to outline the expression, experience, manifestations and consequences of emotional distress and depression in Aboriginal men in central Australia.MethodsUtilizing a grounded theory approach, in depth semi-structured interviews were conducted with 22 theoretically sampled young, middle aged and senior Aboriginal men and traditional healers. Analysis was conducted by a single investigator using constant comparison methods.ResultsDepressive symptoms were common and identifiable, and largely consistent with symptom profiles seen in non-Aboriginal groups. For Aboriginal men, depression was expressed and understood as primarily related to weakness or injury of the spirit, with a lack of reference to hopelessness and specific somatic complaints. The primary contributors to depression related to the loss of connection to social and cultural features of Aboriginal life, cumulative stress and marginalisation.ConclusionsDepression and depressive symptomatology clearly exists in Aboriginal men, however its determinants and expression differ from mainstream populations. Emotions were understood within the construction of spirit, Kurunpa, which was vulnerable to repetitive and powerful negative social forces, loss, and stress across the life course, and served to frame the physical and emotional experience and expression of depression.

Food subsidy programs and the health and nutritional status of disadvantaged families in high income countries: a systematic review.

BackgroundLess healthy diets are common in high income countries, although proportionally higher in those of low socio-economic status. Food subsidy programs are one strategy to promote healthy nutrition and to reduce socio-economic inequalities in health. This review summarises the evidence for the health and nutritional impacts of food subsidy programs among disadvantaged families from high income countries.MethodsRelevant studies reporting dietary intake or health outcomes were identified through systematic searching of electronic databases. Cochrane Public Health Group guidelines informed study selection and interpretation. A narrative synthesis was undertaken due to the limited number of studies and heterogeneity of study design and outcomes.ResultsFourteen studies were included, with most reporting on the Special Supplemental Nutrition Program for Women, Infants and Children in the USA. Food subsidy program participants, mostly pregnant or postnatal women, were shown to have 10–20% increased intake of targeted foods or nutrients. Evidence for the effectiveness of these programs for men or children was lacking. The main health outcome observed was a small but clinically relevant increase in mean birthweight (23–29g) in the two higher quality WIC studies.ConclusionsLimited high quality evidence of the impacts of food subsidy programs on the health and nutrition of adults and children in high income countries was identified. The improved intake of targeted nutrients and foods, such as fruit and vegetables, could potentially reduce the rate of non-communicable diseases in adults, if the changes in diet are sustained. Associated improvements in perinatal outcomes were limited and most evident in women who smoked during pregnancy. Thus, food subsidy programs for pregnant women and children should aim to focus on improving nutritional status in the longer term. Further prospective studies and economic analyses are needed to confirm the health benefits and justify the investment in food subsidy programs.

NMR-determined lipoprotein subclass profile predicts type 2 diabetes.

AIMS To determine whether nuclear magnetic resonance (NMR)-determined lipoprotein profiles predict type 2 diabetes. METHODS Subjects were 813 male and female participants in the Melbourne Collaborative Cohort Study, aged 40-69 years at baseline (1990-1994), and with a baseline fasting plasma glucose <7.0 mmol/L. Incident type 2 diabetes was identified in 1994-1998 by self-report and confirmation from doctors. Eligible cases and a random group of controls were selected, with NMR data available for 59 cases and 754 non-cases. RESULTS Concentration of very low density lipoprotein (VLDL) particles (positive) and high density lipoprotein (HDL) particle size (negative) were selected by stepwise regression as predictors of type 2 diabetes. These associations were independent of other non-lipid risk factors, but not plasma triglycerides. Factor analysis identified a factor from NMR variables, explaining 47% of their variation, and characterized by a positive correlation with VLDL, particularly large and medium sized; more low density lipoprotein (LDL) that were smaller; and relatively smaller, but not more HDL particles. This factor was positively associated with diabetes incidence, but not independently of triglycerides. CONCLUSIONS We identified an atherogenic NMR lipoprotein profile in people who developed diabetes, but this did not improve diabetes prediction beyond conventional triglyceride levels.

Stores Healthy Options Project in Remote Indigenous Communities (SHOP@RIC): a protocol of a randomised trial promoting healthy food and beverage purchases through price discounts and in-store nutrition education

BackgroundIndigenous Australians suffer a disproportionate burden of preventable chronic disease compared to their non-Indigenous counterparts – much of it diet-related. Increasing fruit and vegetable intakes and reducing sugar-sweetened soft-drink consumption can reduce the risk of preventable chronic disease. There is evidence from some general population studies that subsidising healthier foods can modify dietary behaviour. There is little such evidence relating specifically to socio-economically disadvantaged populations, even though dietary behaviour in such populations is arguably more likely to be susceptible to such interventions.This study aims to assess the impact and cost-effectiveness of a price discount intervention with or without an in-store nutrition education intervention on purchases of fruit, vegetables, water and diet soft-drinks among remote Indigenous communities.Methods/DesignWe will utilise a randomised multiple baseline (stepped wedge) design involving 20 communities in remote Indigenous Australia. The study will be conducted in partnership with two store associations and twenty Indigenous store boards. Communities will be randomised to either i) a 20% price discount on fruit, vegetables, water and diet soft-drinks; or ii) a combined price discount and in-store nutrition education strategy. These interventions will be initiated, at one of five possible time-points, spaced two-months apart. Weekly point-of-sale data will be collected from each community store before, during, and for six months after the six-month intervention period to measure impact on purchasing of discounted food and drinks. Data on physical, social and economic factors influencing weekly store sales will be collected in order to identify important covariates. Intervention fidelity and mediators of behaviour change will also be assessed.DiscussionThis study will provide original evidence on the effectiveness and cost-effectiveness of price discounts with or without an in-store nutrition education intervention on food and drink purchasing among a socio-economically disadvantaged population in a real-life setting.Trial registrationAustralian New Zealand Clinical Trials Registry: ACTRN12613000694718

Depression in Aboriginal men in central Australia: adaptation of the Patient Health Questionnaire 9

BackgroundWhile Indigenous Australians are believed to be at a high risk of psychological illness, few screening instruments have been designed to accurately measure this burden. Rather than simply transposing western labels of symptoms, this paper describes the process by which a screening tool for depression was specifically adapted for use across multiple Indigenous Australian communities.MethodPotential depression screening instruments were identified and interrogated according to a set of pre-defined criteria. A structured process was then developed which relied on the expertise of five focus groups comprising of members from primary Indigenous language groups in central Australia. First, focus group participants were asked to review and select a screening measure for adaptation. Bi-lingual experts then translated and back translated the language within the selected measure. Focus group participants re-visited the difficult items, explored their meaning and identified potential ways to achieve equivalence of meaning.ResultsAll five focus groups independently selected the Primary Health Questionnaire 9, several key conceptual differences were exposed, largely related to the construction of hopelessness. Together with translated versions of each instrument for each of the five languages, a single, simplified English version for use across heterogeneous settings was negotiated. Importantly, the ‘code’ and specific conceptually equivalent words that could be used for other Indigenous language groups were also developed.ConclusionsThe extensive process of adaptation used in this study has demonstrated that within the context of Indigenous Australian communities, across multiple language groups, where English is often a third or fourth language, conceptual and linguistic equivalence of psychological constructs can be negotiated. A validation study is now required to assess the adapted instrument’s potential for measuring the burden of disease across all Indigenous Australian populations.

Dietary patterns as predictors of successful ageing

ObjectivesTo examine associations between dietary patterns identified by factor analysis, and successful ageing.DesignProspective cohort study with diet measured in 1990-4, and successful ageing in 2003-7. Ordered logistic regression with outcome determined as dead/usual ageing/successful ageing was used to examine associations with quintile groups of dietary factor scores.ParticipantsMen and women (n=6308), without history of major illness at baseline, and aged >70 years at follow-up, or who had died before follow-up but would have been aged >70 at the commencement of follow-up, from the Melbourne Collaborative Cohort Study.MeasurementsFrequencies of intake of 121 foods at baseline were collected in a food frequency questionnaire. Anthropometry and other health and lifestyle data were collected. At follow-up, questionnaire data relating to mental health, physical function and medical history were used to define successful ageing.ResultsFour dietary factors were identified, characterized by higher loadings for (1) vegetables; (2) fruit, (3) feta, legumes, salad, olive oil, and inverse loadings for tea, margarine, cake, sweet biscuits and puddings; (4) meat, white bread, savoury pastry dishes and fried foods. In models excluding body size, the second factor ‘Fruit’ was positively associated with successful ageing (OR in top 20% vs lowest 20% of score 1.31, 95%CI (1.05–1.63), p trend across quintile groups 0.001); while the fourth factor ‘Meat/fatty foods’ was inversely associated (OR in top 20% vs lowest 20% of score 0.69, 95%CI (0.55–0.86), p trend across quintile groups 0.001). Factors 1 and 3 did not show significant associations with successful ageing. The association for ‘Fruit’ was little altered after adjustment for body size, while for ‘Meat/fatty foods’ the association was somewhat attenuated.ConclusionA dietary pattern including plenty of fruit while limiting meat and fried foods may improve the likelihood of ageing successfully.