Prospective Urban Rural Epidemiology Study Research Articles

Low-Fat Dietary Pattern and Health Outcomes in the Women's Health Initiative Randomized Clinical Trial

Background: Debate, stimulated recently by the Prospective Urban Rural Epidemiology study, concerns the preferred macronutrient dietary composition. Here we provide a comprehensive overview of health outcomes in the Women's Health Initiative Dietary Modification (DM) trial. Methods: The DM trial was a randomized, controlled trial conducted at 40 centres in the USA. 48,835 postmenopausal women, aged 50-79 years, with baseline intake of ≥32% energy from fat were randomly assigned by a computerized, stratified, permuted block algorithm to a low-fat dietary pattern intervention group (40%) or to a usual diet comparison group (60%) during 1993-8. Intervention goals were to reduce fat intake to 20% of total energy and increase vegetables, fruit, and grains. Invasive breast cancer and colorectal cancer were co-primary outcomes, and coronary heart disease was secondary, with other health outcomes also monitored. Findings: After the 8.5-year (mean) intervention period, intervention versus comparison group differences included lower fat by 8-10% of total energy and higher carbohydrate by 8-10% of total energy with increases in vegetables, fruit, and grains. Intervention and comparison group annual incidences were 0.42 and 0.46 (hazard ratio 0.92, 95% CI - 0.84 to 1.01) for invasive breast cancer, and 0.13 and 0.12 (HR, 1.07, 95% CI - 0.92 to 1.27) for colorectal cancer, with overall unchanged CHD incidence and total mortality. During 17.7-years (mean) cumulative follow-up, statistically significant reduction in deaths following breast cancer, diabetes requiring insulin, and CHD among women who were not hypertensive, emerged in intervention group, primarily among participants who were obese at enrollment. Interpretation: In postmenopausal women, reduction in total dietary fat with commensurate increase in carbohydrate did not increase all-cause mortality or have adverse health consequences, while having some health benefits. Clinical Trial Number: This study is registered with clinicaltrials.gov identifier: NC0611. Funding Statement: The development of this paper is partially supported by National Cancer Institute grants R01 CA119171 and R01 CA10921. The WHI program is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services through contracts HHSN268201600018C, HHSN268201600001C, HHSN268201600002C, HHSN268201600003C, and HHSN268201600004C, and these sources also partially support the development of this paper. Declaration of Interests: None of the authors report a conflict of interest related to this study. Ethics Approval Statement: Institutional review board approval was obtained at each individual center, and all participants provided written informed consent.

Characterizing exposure to household air pollution within the Prospective Urban Rural Epidemiology (PURE) study

BackgroundHousehold air pollution (HAP) from combustion of solid fuels is an important contributor to disease burden in low- and middle-income countries (LIC, and MIC). However, current HAP disease burden estimates are based on integrated exposure response curves that are not currently informed by quantitative HAP studies in LIC and MIC. While there is adequate evidence supporting causal relationships between HAP and respiratory disease, large cohort studies specifically examining relationships between quantitative measures of HAP exposure with cardiovascular disease are lacking. ObjectiveWe aim to improve upon exposure proxies based on fuel type, and to reduce exposure misclassification by quantitatively measuring exposure across varying cooking fuel types and conditions in diverse geographies and socioeconomic settings. We leverage technology advancements to estimate household and personal PM2.5 (particles below 2.5 μm in aerodynamic diameter) exposure within the large (N~250,000) multi-country (N~26) Prospective Urban and Rural Epidemiological (PURE) cohort study. Here, we detail the study protocol and the innovative methodologies being used to characterize HAP exposures, and their application in epidemiologic analyses. Methods/designThis study characterizes HAP PM2.5 exposures for participants in rural communities in ten PURE countries with >10% solid fuel use at baseline (Bangladesh, Brazil, Chile, China, Colombia, India, Pakistan, South Africa, Tanzania, and Zimbabwe). PM2.5 monitoring includes 48-h cooking area measurements in 4500 households and simultaneous personal monitoring of male and female pairs from 20% of the selected households. Repeat measurements occur in 20% of households to assess impacts of seasonality. Monitoring began in 2017, and will continue through 2019. The Ultrasonic Personal Aerosol Sampler (UPAS), a novel, robust, and inexpensive filter based monitor that is programmable through a dedicated mobile phone application is used for sampling. Pilot study field evaluation of cooking area measurements indicated high correlation between the UPAS and reference Harvard Impactors (r = 0.91; 95% CI: 0.84, 0.95; slope = 0.95). To facilitate tracking and to minimize contamination and analytical error, the samplers utilize barcoded filters and filter cartridges that are weighed pre- and post-sampling using a fully automated weighing system. Pump flow and pressure measurements, temperature and RH, GPS coordinates and semi-quantitative continuous particle mass concentrations based on filter differential pressure are uploaded to a central server automatically whenever the mobile phone is connected to the internet, with sampled data automatically screened for quality control parameters. A short survey is administered during the 48-h monitoring period. Post-weighed filters are further analyzed to estimate black carbon concentrations through a semi-automated, rapid, cost-effective image analysis approach. The measured PM2.5 data will then be combined with PURE survey information on household characteristics and behaviours collected at baseline and during follow-up to develop quantitative HAP models for PM2.5 exposures for all rural PURE participants (~50,000) and across different cooking fuel types within the 10 index countries. Both the measured (in the subset) and the modelled exposures will be used in separate longitudinal epidemiologic analyses to assess associations with cardiopulmonary mortality, and disease incidence. DiscussionThe collected data and resulting characterization of cooking area and personal PM2.5 exposures in multiple rural communities from 10 countries will better inform exposure assessment as well as future epidemiologic analyses assessing the relationships between quantitative estimates of chronic HAP exposure with adult mortality and incident cardiovascular and respiratory disease. This will provide refined and more accurate exposure estimates in global CVD related exposure-response analyses.

Inequalities in the use of secondary prevention of cardiovascular disease by socioeconomic status: evidence from the PURE observational study.

SummaryBackgroundThere is little evidence on the use of secondary prevention medicines for cardiovascular disease by socioeconomic groups in countries at different levels of economic development.MethodsWe assessed use of antiplatelet, cholesterol, and blood-pressure-lowering drugs in 8492 individuals with self-reported cardiovascular disease from 21 countries enrolled in the Prospective Urban Rural Epidemiology (PURE) study. Defining one or more drugs as a minimal level of secondary prevention, wealth-related inequality was measured using the Wagstaff concentration index, scaled from −1 (pro-poor) to 1 (pro-rich), standardised by age and sex. Correlations between inequalities and national health-related indicators were estimated.FindingsThe proportion of patients with cardiovascular disease on three medications ranged from 0% in South Africa (95% CI 0–1·7), Tanzania (0–3·6), and Zimbabwe (0–5·1), to 49·3% in Canada (44·4–54·3). Proportions receiving at least one drug varied from 2·0% (95% CI 0·5–6·9) in Tanzania to 91·4% (86·6–94·6) in Sweden. There was significant (p<0·05) pro-rich inequality in Saudi Arabia, China, Colombia, India, Pakistan, and Zimbabwe. Pro-poor distributions were observed in Sweden, Brazil, Chile, Poland, and the occupied Palestinian territory. The strongest predictors of inequality were public expenditure on health and overall use of secondary prevention medicines.InterpretationUse of medication for secondary prevention of cardiovascular disease is alarmingly low. In many countries with the lowest use, pro-rich inequality is greatest. Policies associated with an equal or pro-poor distribution include free medications and community health programmes to support adherence to medications.FundingFull funding sources listed at the end of the paper (see Acknowledgments).

Nutritional knowledge amongst an adult South African sample of low socioeconomic status

The aim of this study was to determine the socioeconomic predictors of nutritional knowledge (NK) based on total household income, educational level and employment status. A secondary aim was to determine the relationship between NK and the body mass indexes (BMI) of children. Using a cross-sectional study, 39 participants enrolled in the Prospective Urban Rural Epidemiological (PURE) study were purposively sampled for data on their children’s age, gender, height and weight. A semi-structured researcher-generated questionnaire was used to collect sociodemographic information and assess NK. Pearson correlation assessed the relationship between the parent’s NK and their child’s BMI. Linear regression analysis was used to test predictive relationships. The Alpha level was set at p < 0.05. Regression analysis showed that 2.5% of the variance (R 2 = 0.25) was based on NK and was significant ( p < 0.05). Employment status was a significant predictor ( p = -0.038) of NK, when controlling for total household income and education level. Parents of underweight children had the lowest NK. In conclusion, there was a positive correlation between the children’s BMI and their parents NK, but this was not significant. Employment status was a significant predictor of NK. Public health practitioners should develop interventions based on NK, which might benefit black parents, especially those of low socioeconomic status. Keywords: Nutritional knowledge, socioeconomic status, South Africa, educational level, employment status

The Prospective Urban Rural Epidemiology (PURE) study: PURE Turkey.

The Prospective Urban Rural Epidemiology (PURE) study is a prospective cohort study that collects data on social, environmental, and individual risk factors and chronic diseases among residents of 25 countries in the range of 35 to 70 years of age, living in rural and urban areas. The PURE study is directed by the Population Health Research Institute of McMaster University in Canada. In Turkey, the study is conducted by the Metabolic Syndrome Society. In Turkey, the study is being conducted in 8 cities. The initial fieldwork began in 2008. Questionnaires were completed, and anthropometric measurements, blood and urine samples, handgrip strength evaluations, electrocardiogram readings, and spirometer and body composition measurements were obtained. Each year, participants were followed up via telephone. Every third year, questionnaires, field measurements, and biological data sampling were repeated. PURE Turkey has 4056 participants (female: 60.7%, male: 39.3%; mean age: 50±9.1 years). Among them, 43.9% had metabolic syndrome and 52.8% were obese. The prevalence of hypertension was 41.1% and proportion of controlled hypertension was 34%. A total of 2098 (51.7%) of the participants had a total cholesterol of ≥200 mg/dL or were using a lipid lowering agent. In patients with diabetes, 79.8% had low-density lipoprotein cholesterol levels ≥100 mg/dL. Although a dramatic change was not observed in those parameters in the follow-up years, the prevalence of diabetes mellitus increased from 13.7% in 2008 to 21% in 2015. The baseline and follow-up data of the PURE study were analyzed with the other countries participating in the study and reported for international publication. The PURE study is a large, ongoing, prospective epidemiological study that is investigating the "causes of the causes" of noncommunicable diseases in the world. In addition to revealing the health status of nations, the study also has the potential to affect health politics.

Adherence challenges encountered in an intervention programme to combat chronic non-communicable diseases in an urban black community, Cape Town

Background: Chronic non-communicable diseases (CNCD) have become the greatest contributor to the mortality rate worldwide. Despite attempts by Governments and various non-governmental organisations to prevent and control the epidemic with various intervention strategies, the number of people suffering from CNCD is increasing at an alarming rate in South Africa and worldwide.Objectives: Study's objectives were to explore perceived challenges with implementation of, and adherence to health messages disseminated as part of a CNCD intervention programme; to gain an understanding of participants' expectations of CNCD intervention programmes;, and to explore the acceptability and preference of health message dissemination methods. In addition, participants' awareness of, and willingness to participate inCNCDs intervention programmes in their community was explored.Methods: Participants were recruited from the existing urban Prospective Urban Rural Epidemiology study site in Langa, Cape Town. Focus group discussions were conducted with 47participants using a question guide. Summative content analysis was used to analyse the data.Results: Four themes emerged from the data analysis: practical aspects of implementation and adherence to intervention programmes; participants' expectations of intervention programmes; aspects influencing participants' acceptance of interventions; and their preferences for health message dissemination. The results of this study will be used to inform CNCDs intervention programmes.Conclusions: Our findings revealed that although participants found current methods of health message dissemination in CNCDs intervention acceptable, they faced real challenges with implementing and adhering to CNCDs to these messages.

Association between dietary patterns and cardiovascular risk factors in a selected population of Lower Silesia (PURE Study Poland).

Dietary pattern analysis is used to describe the dietary habits of a selected population. In many studies, dietary patterns (DPs) have been associated with risk factors for cardiovascular disease (CVD). The aim of the study was to assess the association between dietary patterns identified in the population of Lower Silesia, Poland, with anthropometric and biochemical risk factors for CVD. The study group included 2,025 participants of the Prospective Urban Rural Epidemiological (PURE) Study. Dietary intake was evaluated based on data from the Food Frequency Questionnaire (FFQ). Dietary patterns were derived using principal component analysis (PCA). The relationship between DPs and body mass index (BMI), waist circumference, waist-hip ratio, blood pressure, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides and fasting glucose level, was assessed. Three dietary patterns identified in the study explained 35.6% of total variance. The 'fruit, vegetables & dairy' DP, characterized by a high intake of vegetables, fruits, nuts, seeds, raisins, milk and low-fat dairy, was associated with improved lipid profile and anthropometric measures, lower diastolic blood pressure and lower fasting glucose concentration. 'Traditional' and 'fat & sugar' DPs were unfavourably associated with most of the risk factors for CVD presented in this study. Dietary patterns identified in this study were differently related to selected anthropometric and biochemical risk factors for CVD. 'Fruit, vegetables & dairy' DP was favourably associated with the biochemical and anthropometric CVD risk factors, and was characterized by higher nutritional value in comparison with 'traditional' and 'fat & sugar' DPs.

Availability and affordability of blood pressure-lowering medicines and the effect on blood pressure control in high-income, middle-income, and low-income countries: an analysis of the PURE study data

Hypertension is considered the most important risk factor for cardiovascular diseases, but its control is poor worldwide. We aimed to assess the availability and affordability of blood pressure-lowering medicines, and the association with use of these medicines and blood pressure control in countries at varying levels of economic development. We analysed the availability, costs, and affordability of blood pressure-lowering medicines with data recorded from 626 communities in 20 countries participating in the Prospective Urban Rural Epidemiological (PURE) study. Medicines were considered available if they were present in the local pharmacy when surveyed, and affordable if their combined cost was less than 20% of the households' capacity to pay. We related information about availability and affordability to use of these medicines and blood pressure control with multilevel mixed-effects logistic regression models, and compared results for high-income, upper-middle-income, lower-middle-income, and low-income countries. Data for India are presented separately because it has a large generic pharmaceutical industry and a higher availability of medicines than other countries at the same economic level. The availability of two or more classes of blood pressure-lowering drugs was lower in low-income and middle-income countries (except for India) than in high-income countries. The proportion of communities with four drug classes available was 94% in high-income countries (108 of 115 communities), 76% in India (68 of 90), 71% in upper-middle-income countries (90 of 126), 47% in lower-middle-income countries (107 of 227), and 13% in low-income countries (nine of 68). The proportion of households unable to afford two blood pressure-lowering medicines was 31% in low-income countries (1069 of 3479 households), 9% in middle-income countries (5602 of 65 471), and less than 1% in high-income countries (44 of 10 880). Participants with known hypertension in communities that had all four drug classes available were more likely to use at least one blood pressure-lowering medicine (adjusted odds ratio [OR] 2·23, 95% CI 1·59-3·12); p<0·0001), combination therapy (1·53, 1·13-2·07; p=0·054), and have their blood pressure controlled (2·06, 1·69-2·50; p<0·0001) than were those in communities where blood pressure-lowering medicines were not available. Participants with known hypertension from households able to afford four blood pressure-lowering drug classes were more likely to use at least one blood pressure-lowering medicine (adjusted OR 1·42, 95% CI 1·25-1·62; p<0·0001), combination therapy (1·26, 1·08-1·47; p=0·0038), and have their blood pressure controlled (1·13, 1·00-1·28; p=0·0562) than were those unable to afford the medicines. A large proportion of communities in low-income and middle-income countries do not have access to more than one blood pressure-lowering medicine and, when available, they are often not affordable. These factors are associated with poor blood pressure control. Ensuring access to affordable blood pressure-lowering medicines is essential for control of hypertension in low-income and middle-income countries. Population Health Research Institute, the Canadian Institutes of Health Research, Heart and Stroke Foundation of Ontario, Canadian Institutes of Health Research Strategy for Patient Oriented Research through the Ontario SPOR Support Unit, the Ontario Ministry of Health and Long-Term Care, pharmaceutical companies (with major contributions from AstraZeneca [Canada], Sanofi Aventis [France and Canada], Boehringer Ingelheim [Germany amd Canada], Servier, and GlaxoSmithKline), Novartis and King Pharma, and national or local organisations in participating countries.

Association of dietary nutrients with blood lipids and blood pressure in 18 countries: a cross-sectional analysis from the PURE study

The relation between dietary nutrients and cardiovascular disease risk markers in many regions worldwide is unknown. In this study, we investigated the effect of dietary nutrients on blood lipids and blood pressure, two of the most important risk factors for cardiovascular disease, in low-income, middle-income, and high-income countries. We studied 125 287 participants from 18 countries in North America, South America, Europe, Africa, and Asia in the Prospective Urban Rural Epidemiology (PURE) study. Habitual food intake was measured with validated food frequency questionnaires. We assessed the associations between nutrients (total fats, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, carbohydrates, protein, and dietary cholesterol) and cardiovascular disease risk markers using multilevel modelling. The effect of isocaloric replacement of saturated fatty acids with other fats and carbohydrates was determined overall and by levels of intakes by use of nutrient density models. We did simulation modelling in which we assumed that the effects of saturated fatty acids on cardiovascular disease events was solely related to their association through an individual risk marker, and then compared these simulated risk marker-based estimates with directly observed associations of saturated fatty acids with cardiovascular disease events. Participants were enrolled into the study from Jan 1, 2003, to March 31, 2013. Intake of total fat and each type of fat was associated with higher concentrations of total cholesterol and LDL cholesterol, but also with higher HDL cholesterol and apolipoprotein A1 (ApoA1), and lower triglycerides, ratio of total cholesterol to HDL cholesterol, ratio of triglycerides to HDL cholesterol, and ratio of apolipoprotein B (ApoB) to ApoA1 (all ptrend<0·0001). Higher carbohydrate intake was associated with lower total cholesterol, LDL cholesterol, and ApoB, but also with lower HDL cholesterol and ApoA1, and higher triglycerides, ratio of total cholesterol to HDL cholesterol, ratio of triglycerides to HDL cholesterol, and ApoB-to-ApoA1 ratio (all ptrend<0·0001, apart from ApoB [ptrend=0·0014]). Higher intakes of total fat, saturated fatty acids, and carbohydrates were associated with higher blood pressure, whereas higher protein intake was associated with lower blood pressure. Replacement of saturated fatty acids with carbohydrates was associated with the most adverse effects on lipids, whereas replacement of saturated fatty acids with unsaturated fats improved some risk markers (LDL cholesterol and blood pressure), but seemed to worsen others (HDL cholesterol and triglycerides). The observed associations between saturated fatty acids and cardiovascular disease events were approximated by the simulated associations mediated through the effects on the ApoB-to-ApoA1 ratio, but not with other lipid markers including LDL cholesterol. Our data are at odds with current recommendations to reduce total fat and saturated fats. Reducing saturated fatty acid intake and replacing it with carbohydrate has an adverse effect on blood lipids. Substituting saturated fatty acids with unsaturated fats might improve some risk markers, but might worsen others. Simulations suggest that ApoB-to-ApoA1 ratio probably provides the best overall indication of the effect of saturated fatty acids on cardiovascular disease risk among the markers tested. Focusing on a single lipid marker such as LDL cholesterol alone does not capture the net clinical effects of nutrients on cardiovascular risk. Full funding sources listed at the end of the paper (see Acknowledgments).

Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study

The relationship between macronutrients and cardiovascular disease and mortality is controversial. Most available data are from European and North American populations where nutrition excess is more likely, so their applicability to other populations is unclear. The Prospective Urban Rural Epidemiology (PURE) study is a large, epidemiological cohort study of individuals aged 35-70 years (enrolled between Jan 1, 2003, and March 31, 2013) in 18 countries with a median follow-up of 7·4 years (IQR 5·3-9·3). Dietary intake of 135 335 individuals was recorded using validated food frequency questionnaires. The primary outcomes were total mortality and major cardiovascular events (fatal cardiovascular disease, non-fatal myocardial infarction, stroke, and heart failure). Secondary outcomes were all myocardial infarctions, stroke, cardiovascular disease mortality, and non-cardiovascular disease mortality. Participants were categorised into quintiles of nutrient intake (carbohydrate, fats, and protein) based on percentage of energy provided by nutrients. We assessed the associations between consumption of carbohydrate, total fat, and each type of fat with cardiovascular disease and total mortality. We calculated hazard ratios (HRs) using a multivariable Cox frailty model with random intercepts to account for centre clustering. During follow-up, we documented 5796 deaths and 4784 major cardiovascular disease events. Higher carbohydrate intake was associated with an increased risk of total mortality (highest [quintile 5] vs lowest quintile [quintile 1] category, HR 1·28 [95% CI 1·12-1·46], ptrend=0·0001) but not with the risk of cardiovascular disease or cardiovascular disease mortality. Intake of total fat and each type of fat was associated with lower risk of total mortality (quintile 5 vs quintile 1, total fat: HR 0·77 [95% CI 0·67-0·87], ptrend<0·0001; saturated fat, HR 0·86 [0·76-0·99], ptrend=0·0088; monounsaturated fat: HR 0·81 [0·71-0·92], ptrend<0·0001; and polyunsaturated fat: HR 0·80 [0·71-0·89], ptrend<0·0001). Higher saturated fat intake was associated with lower risk of stroke (quintile 5 vs quintile 1, HR 0·79 [95% CI 0·64-0·98], ptrend=0·0498). Total fat and saturated and unsaturated fats were not significantly associated with risk of myocardial infarction or cardiovascular disease mortality. High carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction, or cardiovascular disease mortality, whereas saturated fat had an inverse association with stroke. Global dietary guidelines should be reconsidered in light of these findings. Full funding sources listed at the end of the paper (see Acknowledgments).

Prevalence, awareness, treatment and control of hypertension in four Middle East countries.

We report the prevalence, awareness, treatment, and control of hypertension across four Middle Eastern countries (Iran, Occupied Palestinian Territory, Saudi Arabia, and United Arab Emirates), using a standardized and uniform method. The Prospective Urban Rural Epidemiology study enrolled participants from 52 urban and 35 rural communities from four countries in the Middle East. We report results using definitions of hypertension, prevalence, awareness, treatment, and control, and the standards for uniform reporting of hypertension in adults as recently recommended by the World Hypertension League expert committee. Data for analyses were available on 10 516 participants, of whom 5082 (48%) were men. The mean age was 49 (±9.4) years for men and 48 (±9.3) years among women. A total of 3270 participants had hypertension (age-standardized rates, 33%), and n = 1807 (49%) of these participants were aware of their diagnosis. Of those with hypertension, n = 1754, (47%) were treated and only n = 673, (19%) had controlled blood pressure levels. Only 17% (n = 541) of those treated for hypertension received two or more blood pressure-lowering medications and 15% (n = 499) received statins. The prevalence, awareness, treatment, and control of blood pressure were higher among women and older (50-69 years) participants compared with men and younger individuals (30-49 years) (P < 0.0001 for all). The prevalence was higher in rural communities; however, awareness, treatment, and control were significantly higher among urban dwellers. Findings from this study indicate the need for improvements in hypertension diagnosis and treatment in the Middle East, especially in rural communities, men and younger individuals.

The measurement of liver fat from single-energy quantitative computed tomography scans.

Studies of soft tissue composition using computed tomography (CT) scans are often semi-quantitative and based on Hounsfield units (HU) measurements that have not been calibrated with a quantitative CT (QCT) phantom. We describe a study to establish the water (H2O) and dipotassium hydrogen phosphate (K2HPO4) basis set equivalent densities of fat and fat-free liver tissue. With this information liver fat can be accurately measured from any abdominal CT scan calibrated with a suitable phantom. Liver fat content was measured by comparing single-energy QCT (SEQCT) HU measurements of the liver with predicted HU values for fat and fat-free liver tissue calculated from their H2O and K2HPO4 equivalent densities and calibration data from a QCT phantom. The equivalent densities of fat were derived from a listing of its constituent fatty acids, and those of fat-free liver tissue from a dual-energy QCT (DEQCT) study performed in 14 healthy Chinese subjects. This information was used to calculate liver fat from abdominal SEQCT scans performed in a further 541 healthy Chinese subjects (mean age 62 years; range, 31-95 years) enrolled in the Prospective Urban Rural Epidemiology (PURE) Study. The equivalent densities of fat were 941.75 mg/cm3 H2O and -43.72 mg/cm3 K2HPO4, and for fat-free liver tissue 1,040.13 mg/cm3 H2O and 21.34 mg/cm3 K2HPO4. Liver fat in the 14 subjects in the DEQCT study varied from 0-17.9% [median: 4.5%; interquartile range (IQR): 3.0-7.9%]. Liver fat in the 541 PURE study subjects varied from -0.3-29.9% (median: 4.9%; IQR: 3.4-6.9%). We have established H2O and K2HPO4 equivalent densities for fat and fat-free liver tissue that allow a measurement of liver fat to be obtained from any abdominal CT scan acquired with a QCT phantom. Although radiation dose considerations preclude the routine use of QCT to measure liver fat, the method described here facilitates its measurement in patients having CT scans performed for other purposes. Further studies comparing the results with magnetic resonance (MR) measurements of liver fat are required to validate the method as a useful clinical tool.

Adherence challenges encountered in an intervention programme to combat chronic non-communicable diseases in an urban black community, Cape Town

BackgroundChronic non-communicable diseases (CNCD) have become the greatest contributor to the mortality rate worldwide. Despite attempts by Governments and various non-governmental organisations to prevent and control the epidemic with various intervention strategies, the number of people suffering from CNCD is increasing at an alarming rate in South Africa and worldwide. ObjectivesStudy's objectives were to explore perceived challenges with implementation of, and adherence to health messages disseminated as part of a CNCD intervention programme; to gain an understanding of participants' expectations of CNCD intervention programmes;, and to explore the acceptability and preference of health message dissemination methods. In addition, participants' awareness of, and willingness to participate in CNCDs intervention programmes in their community was explored. MethodsParticipants were recruited from the existing urban Prospective Urban Rural Epidemiology study site in Langa, Cape Town. Focus group discussions were conducted with 47 participants using a question guide. Summative content analysis was used to analyse the data. ResultsFour themes emerged from the data analysis: practical aspects of implementation and adherence to intervention programmes; participants' expectations of intervention programmes; aspects influencing participants' acceptance of interventions; and their preferences for health message dissemination. The results of this study will be used to inform CNCDs intervention programmes. ConclusionsOur findings revealed that although participants found current methods of health message dissemination in CNCDs intervention acceptable, they faced real challenges with implementing and adhering to CNCDs to these messages.

Population Muscle Strength Predicts Olympic Medal Tallies: Evidence from 20 Countries in the PURE Prospective Cohort Study.

BackgroundNational sporting achievement at the Olympic Games is important for national pride and prestige, and to promote participation in sport. Summer Olympic Games medal tallies have been associated with national wealth, and also social development and healthcare expenditure. It is uncertain however, how these socioeconomic factors translate into Olympic success. The objective of this study was therefore to examine the relationship between population muscle strength and Olympic medal tallies.Methods and ResultsThis study of handgrip strength represents a cross-sectional analysis of the Prospective Urban Rural Epidemiology (PURE) study, which is an ongoing population cohort study of individuals from high-, middle-, and low-income countries. Within participating countries, households from both urban and rural communities were invited to participate using a sampling strategy intended to yield a sample that was representative of the community. Households were eligible if at least one member was aged 35–70 years and if they intended living at the same address for a further four years. A total of 152,610 participants from these households, located in 21 countries, were included in this analysis. Handgrip strength was measured using a Jamar dynanometer. Olympic medal tallies were made over the five most recent Summer Games.There was a significant positive association between national population grip strength (GS) and medal tally that persisted after adjustment for sex, age, height, average daily caloric intake and GDP (total and per capita). For every 1kg increase in population GS, the medal tally increased by 36% (95% CI 13–65%, p = 0.001) after adjustment. Among countries that won at least one medal over the four most recent Summer Olympic Games, there was a close linear relationship between adjusted GS and the natural logarithm of the per capita medal tally (adjusted r = 0.74, p = 0.002).ConclusionsPopulation muscle strength may be an important determinant of Summer Olympic Games medal success. Further research is needed to understand whether population muscle strength is modifiable, and whether this can improve Olympic medal success. Extreme outcomes may reflect the average attributes of the population from which the individual experiencing the extreme outcome is drawn.

Effects of bidi smoking on all-cause mortality and cardiorespiratory outcomes in men from south Asia: an observational community-based substudy of the Prospective Urban Rural Epidemiology Study (PURE).

Bidis are minimally regulated, inexpensive, hand-rolled tobacco products smoked in south Asia. We examined the effects of bidi smoking on baseline respiratory impairment, and prospectively collected data for all-cause mortality and cardiorespiratory events in men from this region. This substudy of the international, community-based Prospective Urban Rural Epidemiology (PURE) study was done in seven centres in India, Pakistan, and Bangladesh. Men aged 35-70 years completed spirometry testing and standardised questionnaires at baseline and were followed up yearly. We used multilevel regression to compare cross-sectional baseline cardiorespiratory symptoms, spirometry measurements, and follow-up events (all-cause mortality, cardiovascular events, respiratory events) adjusted for socioeconomic status and baseline risk factors between non-smokers, light smokers of bidis or cigarettes (≤10 pack-years), heavy smokers of cigarettes only (>10 pack-years), and heavy smokers of bidis (>10 pack-years). 14 919 men from 158 communities were included in this substudy (8438 non-smokers, 3321 light smokers, 959 heavy cigarette smokers, and 2201 heavy bidi smokers). Mean duration of follow-up was 5·6 years (range 1-13). The adjusted prevalence of self-reported chronic wheeze, cough or sputum, dyspnoea, and chest pain at baseline increased across the categories of non-smokers, light smokers, heavy cigarette smokers, and heavy bidi smokers (p<0·0001 for association). Adjusted cross-sectional age-related changes in forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC) ratio were larger for heavy bidi smokers than for the other smoking categories. Hazard ratios (relative to non-smokers) showed increasing hazards for all-cause mortality (light smokers 1·28 [95% CI 1·02-1·62], heavy cigarette smokers 1·59 [1·13-2·24], heavy bidi smokers 1·56 [1·22-1·98]), cardiovascular events (1·45 [1·13-1·84], 1·47 [1·05-2·06], 1·55 [1·17-2·06], respectively) and respiratory events (1·30 [0·91-1·85], 1·21 [0·70-2·07], 1·73 [1·23-2·45], respectively) across the smoking categories. Bidi smoking is associated with severe baseline respiratory impairment, all-cause mortality, and cardiorespiratory outcomes. Stricter controls and regulation of bidis are needed to reduce the tobacco-related disease burden in south Asia. Population Health Research Institute, Canadian Institutes of Health Research, and Heart and Stroke Foundation of Ontario.

Are saturated fats in the diet bad for the heart? – A summary of the prospective urban rural epidemiology study

Are saturated fats in the diet bad for the heart? – A summary of the prospective urban rural epidemiology study

Prevalence and socio-demographic correlates of physical activity levels among South African adults in Cape Town and Mount Frere communities in 2008-2009.

BackgroundPhysical activity has been linked to reduced risk of various cardiometabolic disease, cancer, and premature mortality. We investigated the prevalence and socio-demographic correlates of physical activity among adults in urban and rural communities in South Africa. Methods: This was a cross-sectional survey comprising 1733 adults aged ≥35 years from the Cape Town (urban) and Mount Frere (rural) sites of the Prospective Urban Rural Epidemiology study. Physical activity was assessed using the validated International Physical Activity Questionnaire. Multinomial logistic regressions were used to relate physical activity with socio-demographic characteristics.ResultsOverall, 74% of participants engaged in moderate-to-vigorous physical activity. In the adjusted regression models, women were 34% less likely to engage in vigorous physical activity (OR =0.66, 95%-CI = 0.47-0.93). Physical activity decreased with age, varied with marital status, education and occupation, always in differential ways between urban and rural participants (all interactions p ≤ 0.047). For instance, in urban settings, those with secondary education were more likely to engage in moderate physical activity (OR = 2.06, 95%-CI = 1.08-3.92) than those with tertiary education. Single people were more likely to engage in high physical activity (OR = 2.10, 95%-CI = 1.03-4.28) than divorced. Overall, skilled participants were more likely to engage in vigorous physical activity (OR = 2.07, 95%-CI = 1.41-3.05) driven by significant effect in rural area (OR = 2.70, 95%-CI = 1.51-4.83). Urban participants were more likely to engage in moderate physical activity (OR = 1.67, 95%-CI = 1.31-2.13) than rural participants.ConclusionsTo prevent chronic diseases among South Africans, attention should be paid to specific policies and interventions aimed at promoting PA among young adults in rural and urban setting, and across the social-economic diversity.

Social disparities explain differences in hypertension prevalence, detection and control in Colombia.

Hypertension is the principal risk factor for cardiovascular diseases. The global Prospective Urban Rural Epidemiology study showed that the levels of awareness, treatment and control of this condition are very low worldwide and show large regional variations related to a country's income index. The aim of the present analysis was to identify associations between sociodemographic, geographic, anthropometric, behavioral and clinical factors and the awareness, treatment and control of hypertension within Colombia - a high-middle income country which participated in the global Prospective Urban Rural Epidemiology study. The sample comprised 7485 individuals aged 35-70 years (mean age 50.8 years, 64% women). Mean SBP and DBP were 129.12 ± 21.23 and 80.39 ± 11.81 mmHg, respectively. The overall prevalence of hypertension was 37.5% and was substantially higher amongst participants with the lowest educational level, who had a 25% higher prevalence (<0.001). Hypertension awareness, treatment amongst those aware, and control amongst those treated were 51.9, 77.5 and 37.1%, respectively. The prevalence of hypertension was higher amongst those with a higher BMI (<0.001) or larger waist-hip ratio (<0.001). Being male, younger, a rural resident and having a low level of education was associated with significantly lower hypertension awareness, treatment and control. The use of combination therapy was very low (27.5%) and was significantly lower in rural areas and amongst those with a low income. Overall Colombia has a high prevalence of hypertension in combination with very low levels of awareness, treatment and control; however, we found large variations within the country that appear to be associated with sociodemographic disparities.

Health-seeking behaviours of older black women living with non-communicable diseases in an urban township in South Africa.

BackgroundVarious studies have shown that non-communicable diseases (NCDs) especially diabetes and hypertension are prevalent among older women living in South African urban areas, placing a heavy burden on the healthcare system. This study aimed to understand the health-seeking behaviour, healthcare practices and prevalence of traditional herbal medicine (THM) use among older women self-reporting NCDs from the Prospective Urban Rural Epidemiology study (PURE).MethodA homogenous purposive sampling of PURE participants was used to recruit women who were 50 years or older (n = 250). Descriptive statistics were used to examine the number of NCDs reported by the study sample, health seeking behaviour and practices as well as THM use. Logistic regression was also employed to investigate possible associations between reported conditions and THM use or medical pluralism.ResultsWithin the study sample, 72 % self-reported an NCD. Of those with self-reported NCDs, 46 % had one, and 54 % had two or more NCDs. Those with NCDs usually visited public clinics (80 %), relied on doctors (90 %) and nurses (85 %) for health information, and mostly used conventional medicine (CM) to manage high blood pressure (81 %). About 30 % of those with NCDs indicated using THM, of whom 29 (53 %) reported practicing medical pluralism. Participants with dental problems (OR: 3.24, 95 % CI: 1.30–8.20), headaches (OR: 2.42, 95 % CI: 1.24–4.94), heart burn (OR: 2.30, 95 % CI: 1.18–4.48) and severe tiredness (OR: 2.05, 95 % CI: 1.08–3.99) were more likely to use THM. Anxiety and allergies increased the likelihood to practise medical pluralism by five and 20 times, respectively.ConclusionSelf-reported NCD with co-morbidities was prevalent among the participants in the study. Most of the study participants utilized state-owned clinics and hospitals for the management of their chronic conditions. THM use was not very common. However, among those who used THM, medical pluralism was prevalent. Family history was the most common reason for THM use, with many THM patrons utilizing these for treatment of a health condition. Older black women with anxiety and allergies were more likely to practise medical pluralism.

MPS 06-03 THE EXPLORATORY AND APPLICATION STUDY OF ESTIMATION METHOD OF 24-HOUR URINARY SODIUM EXCRETION BY USING SPOT URINE FOR CHINESE POPULATION

Objective: To develop and validation of the new estimation methods for 24-h urinary sodium excretion by using spot urine for Chinese urban and rural residents. Design and Method: Three populations were involved in this study. 100 healthy participants were enrolled in this study (Xishan population) and they all collected each spot urine sample and mixed finally as the 24-hour urine samples according to the study design and protocol. Data from previous researches were also used in this study, including Prospective Urban Rural Epidemiology study – China urine validation trial population (PURE-China urine trial population) and Application of prevention and treatment technique in community for noncommunicable diseases (Dexing population), for which these two researches were both collected the morning urine and 24-hour urine samples. The validation analysis conducted through correlation, bias distribution, residual analysis and Bland-Altman plots to assess the accuracy and the applicability of New methods in Chinese residents. Compared with the estimation by Kawasaki, INTERSALT, and Tanaka formula. Results: Second morning urine New method: Male: PrCRE24h = 9.39 × weight (kg)-3.567 × height (cm)-4.683 × age +1498.014 Female: PrCRE24h = 8.09 × weight (kg)+4.417 × height (cm)-1.906 × age -159.528 e-24-h USE = 2.41 × PrUCr24h × (NaSMU / CrSMU)0.461 New method underestimated the mean value of 24-h USE about 273 mg/day, which was better for population level estimation. Furthermore, the accuracy of estimation at individual level also was not improved through bias distribution analysis. With the similar effect of K method, New method showed a dispersed randomly Bland-Altman plot and indicated a relative accuracy. Although the gap between estimation values and real measured values was the least by using New method (Estimated – Measured), the bias of individual estimated values were all big no matter which methods used. Conclusions: The estimation for 24-h USE by using spot urine through New methods did not showed a good accuracy at individual level and could be an alternative for 24-h USE estimation at population level to evaluate the salt intake in given population.