Exploring the likely effect of the introduction of drug eluting stents on requirements for coronary artery revascularisation procedures in Western Australia: a use of the CHD/CARP Markov Simulation Model

Background: Coronary artery revascularisation procedures (CARPs) include coronary artery bypass graft procedures (CABGs) and the less invasive percutaneous coronary interventions (PCIs) and they are common surgical interventions for coronary heart disease (CHD). The effectiveness of PCIs increased when stents were introduced and there was also a shift towards doing more PCIs and less CABGs, especially in older patients. More recently, PCIs have been further improved by the use of drug-eluting-stents (DES). In this study we used a recently developed CHD/CARP Markov model to explore the likely effect on CARP requirements due to the introduction of DES. Methods: This is achieved by considering the population of Western Australia aged 35 to 79 years at the beginning of 2001 (grouped according to history of CHD and CARPs) as the cohort, calculating the mean population risks for CHD/CARP events over three years 1998 to 2000, and using these population risks and certain modifications of them that incorporate the likely effect of the introduction of DES (in 2002) in the CHD/CARP Markov model to explore difference in total requirements for CABGs and PCIs over the period 2001 to 2010. The anticipated likely effect of DES on probabilities of CARP procedures was based on results of meta-analysis of randomized controlled trials comparing DES stents to ordinary stents and an anticipated further reduction in CABGs and increase in PCIs as was observed when (ordinary) stents were introduced. Results: The simulation results suggest that, over the period 2001 to 2010, the total number of CABGs will decline by up to 19% and the total number of PCIs will increase by up to 6%. Conclusion: The introduction of DES will have greater effect on the requirement of CABGs as compared to that on PCIs

Importance of time interval between repeated measurements of total or high-density lipoprotein cholesterol when estimating an individual's baseline concentrations

We studied intra-individual variation in total and high-density lipoprotein (HDL) cholesterol in healthy volunteers (22 men and 19 women, ages 19 to 62 years) on controlled natural diets. The within- person coefficient of variation (CV) depended on the interval between blood samples, increasing from about 2% to 3% for measurements made 24 h apart to 4% to 5% for measurements made at four-day intervals or longer. We conclude that within-subject fluctuations in total and HDL cholesterol have a time constant of several days. Multiple measurements are generally needed to decide whether an asymptomatic subject exceeds a certain concentration of total or HDL cholesterol; we recommend that such measurements be made at least four days apart

Understanding how dogs encourage and motivate walking: cross-sectional findings from RESIDE

Background Many people live with dogs but not all walk with them regularly. This study examines the demographic and behavioural factors that contribute towards owners reporting having a strong sense of encouragement and motivation to walk provided by their dogs, which we call ‘the Lassie effect’. Methods Data was collected from 629 dog owners participating in the RESIDE cross-sectional survey in Perth, Western Australia. Multivariable logistic regression analyses of factors associated with two separate outcome survey items ‘Dog encouragement to walk’ (how often dog encouraged me to go walking in last month) and ‘Dog motivation to walk’ (Having a dog makes me walk more). Results Owning a larger dog; having an increased level of attachment to dog; knowing dog enjoys going for a walk; believing walking keeps dog healthy; and having high social support from family to go walking, were positively associated with both outcomes ‘dog encouragement to walk’ and ‘dog motivation to walk’. Conversely, reporting the presence of children at home; that the child is the main person who walks with the dog; and perceiving dog-specific barriers to walking with dog daily; were negatively associated with both outcomes. In addition, ‘Dog motivation to walk’ only was positively associated with a belief walking reduces barking, and negatively with owning a dog that is overweight or a dog that is too old/sick. Reporting that the spouse/partner is main person who walks with the dog was also negatively associated with ‘dog motivation to walk’, as was increased perceived access to public open spaces with dog-supportive features. Conclusions There are both dog and owner factors that are associated with an owner’s sense of encouragement, and motivation to walk the dog, which in turn has been found to be associated with dog waking behaviour. These factors may be targeted in future interventions to increase and maintain physical activity levels of both people and pets

Serum lipids, apoproteins and nutrient intake in rural Cretan boys consuming high-olive-oil diets

A high intake of olive oil has produced high levels of high-density and low levels of low-density lipoprotein cholesterol in short-term dietary trials. To investigate long-term effects of olive oil we have studied the diet and serum lipids of boys in Crete, where a high olive oil consumption is the norm. Seventy-six healthy rural Cretan boys aged 7–9 years were studied. The diet was assessed by a 2-day dietary recall. Blood was collected according to a standardized protocol and sera were analyzed in a rigidly standardized laboratory. The mean daily intake of energy was 11.0 MJ (2629 kcal). The intake of fat (45.0% of energy) and oleic acid (27.2% of energy) was high, and that of saturated fat low (10.0% of energy), reflecting a high consumption of olive oil. The high consumption of olive oil was confirmed by a high proportion of oleic-acid (27.1 %) in serum cholesteryl fatty acids. Mean concentration of serum total cholesterol was 4.42 mmol 1−1 (171 mg dl−1 ), of HDL-cholesterol 1.40 mmol 1−1 (54 mg dl−1), of serum triglycerides 0.59 mmol I−1 (52 mg dl−1 ), of apo-A1 1210 mg 1−1 and of LDL apo-B 798 mg 1−1. The body mass index of the Cretan boys (18.2 kg m−2) was on average 2 kg m−2 higher than that of boys from other countries. Contrary to our expectation, the Cretan boys did not show a more favourable serum lipoprotein pattern than boys from more westernized countries studied previously using the same protocol. Our hypothesis that a typical, olive-oil-rich Cretan diet causes a relatively high HDL- to total cholesterol ratio is not supported by the present findings

Does getting a dog increase recreational walking?

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Tracking of pedometer-determined physical activity in adults who relocate: results from RESIDE

<p>Abstract</p> <p>Background</p> <p>This secondary analysis investigated the extent and pattern of one-year tracking of pedometer-determined physical activity in people who relocated within the same metropolitan area (T1: baseline and T2: post-relocation). Specifically, data were derived from the RESIDential Environment Project (RESIDE), a natural experiment of people moving into new housing developments.</p> <p>Methods</p> <p>1,175 participants (491 males, age = 42.6 ± 12.7 years, BMI = 27.2 ± 9.9 kg/m²; 684 females, age = 41.2 ± 11.3 years, BMI = 25.4 ± 5.2 kg/m²) wore a Yamax pedometer (SW-200-024) for seven days during the same season at both time points. Pearson's product-moment and Spearman's rank order correlations were used to evaluate the extent of tracking of mean steps/day. Age categories were set as youngest-29.9 (19 was the youngest in males, 20 in females), 30–39.9, 40–49.9, 50–59.9, and 60-oldest (78 was the oldest in males, 71 in females). Change in steps/day was also described categorically as: 1) stably inactive < 7,500 steps/day; 2) decreased activity (moved from ≥ 7,500 to < 7,500 steps/day between T1 and T2); 3) increased activity (moved from < 7,500 to ≥ 7,500 steps/day between T1 and T2); and, 4) stably active ≥ 7,500 steps/day at both time points. Stratified analyses were used to illuminate patterns by sex, age, and BMI-defined weight categories.</p> <p>Results</p> <p>Overall, there was a small (non-significant) decrease in steps/day between T1 and T2 (mean ± SD is -81 ± 3,090 with 95%CI -259 to 97). With few exceptions (i.e., older women), both Pearson's and Spearman's correlations were moderate (r = 0.30–0.59) to moderately high (r = 0.60–0.70). The relative change/stability in steps/day (cut at 7,500 steps/day) was not significant across age groups in males (χ²= 17.35, p = .137) but was in females (χ²= 50.00, p < .0001). In both males and females the differences across BMI categories was significant (χ²= 22.28, p = .001 and χ²= 15.70, p = .015, respectively). For both sexes, those in the obese category were more stably inactive (and less stably active) between assessment points compared with those who were categorized as normal weight.</p> <p>Conclusion</p> <p>Despite relocation, Western Australian adults held their rank position to a moderate to moderately high extent over one year. Categorized and expressed as relative stability/change over time, sex, age, and BMI patterns were evident.</p

Determinants of total and high density lipoprotein cholesterol in boys and men with special reference to diet

At present it is assumed that atherosclerosis begins in childhood and that this process may ultimately result in the manifestations of coronary heart disease later in life. For this reason it is relevant to study the distribution of risk indicators for coronary heart disease (CHD) in children from different countries and to seek possible determinants of these risk indicators.In Chapter 1 a general overview is given of coronary heart disease and its determinants. The reasons and objectives for research on CHD and the risk indicators for CHD are also discussed.In Chapter 2 the results are presented of a study on the distributions of mean total and HDL cholesterol concentrations in boys aged 7 and 8 years from urban and rural regions in 16 countries. A standardized protocol was used for the collection of samples with the analyses being carried out in one laboratory. The results of this study showed that the concentrations of total cholesterol in Dutch boys are similar to those of boys from Denmark, Austria, Ireland and Sweden but are lower than those of Finnish boys and higher than those of African and Asian boys. The mean concentrations of HDL cholesterol of the boys appeared to increase linearly with that of total cholesterol. This would indicate that both the concentrations of total and HDL cholesterol increase under the influence of a westernized diet. It would also indicate that the mean concentration of HDL cholesterol would be positively related to the incidence of coronary heart disease when different populations are compared, provided that the findings in boys could be extrapolated to adults.Chapter 3 deals with the concentrations of total and HDL cholesterol in two age-categories of adult men from thirteen countries. The concentrations of total and HDL cholesterol were on average higher in the groups of men from the European countries than in those from Asia and Africa. Although the tendency for a concomitant increase of mean HDL cholesterol and total cholesterol concentrations was less clear in the adult men than it was in the boys, there was no tendency for lower HDL cholesterol concentrations in men with higher total cholesterol concentrations. The body mass index appeared to be positively related with the concentrations of total cholesterol and negatively with that of HDL cholesterol.Chapter 4 deals with the concentrations of total and HDL cholesterol in macrobiotic, vegetarian and non-vegetarian men and boys. The concentrations of both total and HDL cholesterol were lower in the macrobiotic men and boys than in the other groups except for the concentration of HDL cholesterol in the non-vegetarian men. The variation between groups in the concentration of HDL cholesterol appeared to be largely due to variations in the concentration of cholesterol in the HDL 2 fraction (1.063 &lt; ρ 20 &lt; 1.125).In Chapter 5 the results are described of a more in depth study on the determinants of total and HDL cholesterol in boys from Finland, the Netherlands, Italy, the Philippines and Ghana. Positive correlations were found between the intake of fat, saturated fatty acids, monounsaturated fatty acids and dietary cholesterol and the concentrations of total and HDL cholesterol within several groups. Using the regression coefficients from a multiple regression analysis on the pooled data, it could be calculated that on average 24 percent of the inter-country differences in the levels of total cholesterol is explained by differences in the intakes of saturated fatty acids. Differences between the groups of the different countries 'in the intakesof carbohydrate explained on average 29 percent of the differences in the concentrations of HDL cholesterol. The results support the hypothesis that higher concentrations of total and HDL cholesterol are associated with western types of diets which are rich in saturated fatty acids and relatively poor in complex carbohydrates.Chapter 6 contains a general discussion of the various studies. The main conclusions were the following:- young boys from countries like Finland, the Netherlands, Denmark, Austria and Sweden are likely to be at a higher risk of developing coronary heart disease than boys from Greece or Portugal and boys from Asian and African countries;- the negative relationship between HDL cholesterol concentration and mortality or incidence from coronary heart disease as found within populations is not incompatible with the absence of a negative or even the presence of a positive relationship between HDL cholesterol and mortality from coronary heart disease when different countries are compared;- the changes induced by diet in the concentrations of total and HDL cholesterol tend to be parallel;- high concentrations of HDL cholesterol associated with a high intake of animal fat probably reflect a higher capacity to handle large amounts of dietary fat;- low concentrations of HDL cholesterol associated with a high intake of animal fat probably reflect a lower capacity to handle large amounts of dietary fat or when associated with a low intake of fat a normal capacity to handle dietary fat;- diets with relatively high proportions of food from vegetable origin, especially those relatively rich in complex carbohydrates and relatively poor in saturated fat, together with a considerable proportion of physical activity and an optimum level of body fatness might be beneficial for the prevention of the development of atherosclerosis in childhood.Thus it has been shown that epidemiological studies can play an important role in elucidating the relationship between diet and coronary heart disease. In particular, it has been possible to develop hypotheses on the significance of the concentration of HDL cholesterol as a risk factor for coronary heart disease