Asnawi Abdullah

The magnitude of association between overweight and obesity and the risk of diabetes: a meta-analysis of prospective cohort studies.

The objectives of this meta-analysis were to examine the magnitude of the relative risk (RR) of developing type 2 diabetes for overweight and obese populations, compared to those with normal weight, and to determine causes of the variation in RR between various cohort studies. The magnitude of the RR was analyzed by combining 18 prospective cohort studies that matched defined criteria. The variance in RR between studies was explored. The overall RR of diabetes for obese persons compared to those with normal weight was 7.19, 95% CI: 5.74, 9.00 and for overweight was 2.99, 95% CI: 2.42, 3.72. The variation in RR among studies was explored and it was found that the effect of heterogeneity was highly related with sample size, method of assessment of body mass index (BMI) and method of ascertainment of type 2 diabetes. By combining only cohort studies with more than 400 cases of incident diabetes (>median), adjusted by at least three main confounding variables (age, family history of type 2 diabetes, physical activity), measured BMI, and diabetes determined by clinical diagnosis, the RR was 7.28, 95% CI: 6.47, 8.28 for obesity and 2.92, 95% CI: 2.57, 3.32 for overweight.

The number of years lived with obesity and the risk of all-cause and cause-specific mortality

BACKGROUND The role of the duration of obesity as an independent risk factor for mortality has not been investigated. The aim of this study was to analyse the association between the duration of obesity and the risk of mortality. METHODS A total of 5036 participants (aged 28-62 years) of the Framingham Cohort Study were followed up every 2 years from 1948 for up to 48 years. The association between obesity duration and all-cause and cause-specific mortality was analysed using time-dependent Cox models adjusted for body mass index. The role of biological intermediates and chronic diseases was also explored. RESULTS The adjusted hazard ratio (HR) for mortality increased as the number of years lived with obesity increased. For those who were obese for 1-4.9, 5-14.9, 15-24.9 and ≥ 25 years of the study follow-up period, adjusted HRs for all-cause mortality were 1.51 [95% confidence interval (CI) 1.27-1.79], 1.94 (95% CI 1.71-2.20), 2.25 (95% CI 1.89-2.67) and 2.52 (95% CI 2.08-3.06), respectively, compared with those who were never obese. A dose-response relation between years of duration of obesity was also clear for all-cause, cardiovascular, cancer and other-cause mortality. For every additional 2 years of obesity, the HRs for all-cause, cardiovascular disease, cancer and other-cause mortality were 1.06 (95% CI 1.05-1.07), 1.07 (95% CI 1.05-1.08), 1.03 (95% CI 1.01-1.05) and 1.07 (95% CI 1.05-1.11), respectively. CONCLUSIONS The number of years lived with obesity is directly associated with the risk of mortality. This needs to be taken into account when estimating its burden on mortality.

The Duration of Obesity and the Risk of Type-2 Diabetes

OBJECTIVE The evidence for the association between obesity and the risk of type 2 diabetes has been derived mainly from the analysis of the degree of obesity. The role of the duration of obesity as an independent risk has not been fully explored. The objective of the present study was to investigate the association between the duration of obesity and the risk of type 2 diabetes. DESIGN Prospective cohort study. SETTING The Framingham Heart Study (FHS), follow-up from 1948 to 1998. SUBJECTS A total of 1256 FHS participants who were free from type 2 diabetes at baseline, but were obese on at least two consecutive of the studys twenty-four biennial examinations, were included. Type 2 diabetes status was collected throughout the 48 years of follow-up of the study. The relationship between duration of obesity and type 2 diabetes was analysed using time-dependent Cox models, adjusting for a number of covariates. RESULTS The unadjusted hazard ratio (HR) for the risk of type 2 diabetes for men was 1.13 (95 % CI 1.09, 1.17) and for women was 1.12 (95 % CI 1.08, 1.16) per additional 2-year increase in the duration of obesity. Adjustment for sociodemographic variables, family history of diabetes, health behaviour and physical activity made little difference to these HR. For women the evidence of a dose-response relationship was less clear than for men, particularly for women with an older age at obesity onset. CONCLUSIONS The duration of obesity is a relevant risk factor for type 2 diabetes, independent of the degree of BMI.

Comparing trends in BMI and waist circumference

The nature of excess body weight may be changing over time to one of greater central adiposity. The aim of this study is to determine whether BMI and waist circumference (WC) are increasing proportionately among population subgroups and the range of bodyweight, and to examine the public health implications of the findings. Our data are from two cross‐sectional surveys (the US National Health and Nutrition Examination Studies (NHANES) in 1988–1994 (NHANES III) and 2005–2006), from which we have used samples of 15,349 and 4,176 participants aged ≥20 years. Between 1988–1994 and 2005–2006 BMI increased by an average of 1.8 kg/m2 and WC by 4.7 cm (adjusted for sex, age, race‐ethnicity, and education). The increase in WC was more than could be attributed simply to increases in BMI. This independent increase in WC (of on average, 0.9 cm) was consistent across the different BMI categories, sexes, education levels, and race‐ethnicity groups. It occurred in younger but not older age groups. Overall in each BMI category, the prevalence of low‐risk WC decreased and the prevalence of increased‐risk or substantially increased‐risk WC increased. These results suggest that the adverse health consequences associated with obesity may be increasingly underestimated by trends in BMI alone. Since WC is closely linked to adverse cardiovascular outcomes, it is important to know the prevailing trends in both of these parameters.

Epidemiologic Merit of Obese-Years, the Combination of Degree and Duration of Obesity

This study aims to test the effect of combining the degree and the duration of obesity into a single variable-obese-years-and to examine whether obese-years is a better predictor of the risk of diabetes than simply body mass index (BMI) or duration of obesity. Of the original cohort of the Framingham Heart Study, 5,036 participants were followed up every 2 years for up to 48 years (from 1948). The variable, obese-years, was defined by multiplying for each participant the number of BMI units above 30 kg/m(2) by the number of years lived at that BMI. Associations with diabetes were analyzed by using time-dependent Cox proportional hazards regression models adjusted for potential confounders. The incidence of type-2 diabetes increased as the number of obese-years increased, with adjusted hazard ratios of 1.07 (95% confidence interval: 1.06, 1.09) per additional 10 obese-years. The dose-response relation between diabetes incidence and obese-years varied by sex and smoking status. The Akaike Information Criterion was lowest in the model containing obese-years compared with models containing either the degree or duration of obesity alone. A construct of obese-years is strongly associated with risk of diabetes and could be a better indicator of the health risks associated with increasing body weight than BMI or duration of obesity alone.

Estimating the risk of cardiovascular disease using an obese-years metric

Objective To examine the association between obese-years and the risk of cardiovascular disease (CVD). Study design Prospective cohort study. Setting Boston, USA. Participants 5036 participants of the Framingham Heart Study were examined. Methods Obese-years was calculated by multiplying for each participant the number of body mass index (BMI) units above 29 kg/m2 by the number of years lived at that BMI during approximately 50 years of follow-up. The association between obese-years and CVD was analysed using time-dependent Cox regression adjusted for potential confounders and compared with other models using the Akaike information criterion (AIC). The lowest AIC indicated better fit. Primary outcome CVD. Results The median cumulative obese-years was 24 (range 2–556 obese-years). During 138 918 person-years of follow-up, 2753 (55%) participants were diagnosed with CVD. The incidence rates and adjusted HR (AHR) for CVD increased with an increase in the number of obese-years. AHR for the categories 1–24.9, 25–49.9, 50–74.9 and ≥75 obese-years were, respectively, 1.31 (95% CI 1.15 to 1.48), 1.37 (95% CI 1.14 to 1.65), 1.62 (95% CI 1.32 to 1.99) and 1.80 (95% CI 1.54 to 2.10) compared with those who were never obese (ie, had zero obese-years). The effect of obese-years was stronger in males than females. For every 10 unit increase in obese-years, the AHR of CVD increased by 6% (95% CI 4% to 8%) for males and 3% (95% CI 2% to 4%) for females. The AIC was lowest for the model containing obese-years compared with models containing either the level of BMI or the duration of obesity alone. Conclusions This study demonstrates that obese-years metric conceptually captures the cumulative damage of obesity on body systems, and is found to provide slightly more precise estimation of the risk of CVD than the level or duration of obesity alone.

Health Systems and Noncommunicable Diseases in the Asia-Pacific Region: A Review of the Published Literature

Addressing the growing burden of noncommunicable diseases (NCDs) in countries of the Asia-Pacific region requires well-functioning health systems. In low- and middle-income countries (LMICs), however, health systems are generally characterized by inadequate financial and human resources, unsuitable service delivery models, and weak information systems. The aims of this review were to identify (a) health systems interventions being implemented to deliver NCD programs and services and their outcomes and (b) the health systems bottlenecks impeding access to or delivery of these programs and services in LMICs of the Asia-Pacific region. A search of 4 databases for literature published between 1990 and 2010 retrieved 36 relevant studies. For each study, information on basic characteristics, type of health systems bottleneck/intervention, and outcome was extracted, and methodological quality appraised. Health systems interventions and bottlenecks were classified as per the World Health Organization health systems building blocks framework. The review identified interventions and bottlenecks in the building blocks of service delivery, health workforce, financing, health information systems, and medical products, vaccines, and technologies. Studies, however, were heterogeneous in methodologies used, and the overall quality was generally low. There are several gaps in the evidence base around NCDs in the Asia-Pacific region that require further investigation.

The Double Burden of Undernutrition and Overnutrition in Developing Countries: an Update

Many developing countries have achieved a remarkable improvement in nutrition status in the past decades. However, the prevalence of undernutrition remains a serious problem. At the same time, the prevalence of obesity is increasing substantially, and in some countries, it has approached that of developed countries. This article provides an update on this double burden of malnutrition (DBMN) in developing nations. One hundred countries (lower, middle-lower, and upper-middle income countries) were selected and analysed, and to support the analysis, a systematic review of current published studies was performed. The results show that DBMN already exists in almost all developing countries and that the DBMN ratio (i.e., overweight/underweight) has increased as income per capita has increased. DBMN may manifest within the community, household, or individual. In addition to common factors, poor nutrition in early childhood is suggested as another important driving factor behind the rising obesity rate in most developing countries. A life-course approach has been proposed to prevent undernutrition and overnutrition and should be integrated into the development of health systems to control double burden in developing countries.

Duration of obesity and incident hypertension in adults from the Framingham Heart Study

Background: Previous studies exploring the association between obesity and hypertension generally used a single baseline measurement of obesity. The effect of accumulating excess adiposity over time on the risk of hypertension is uncertain. This study aimed to examine the relationship between duration of obesity and incident hypertension using the Framingham Heart Study. Methods: Two thousand, nine hundred and fifty-three participants aged 30–62 years without baseline hypertension were included. Blood pressure, height and weight were measured biennially. Duration of obesity was calculated. Time to incident hypertension was analysed using time-varying Cox proportional hazards regression with age as the time scale and censoring at time of death or end of follow-up. Results: Eighty percent of participants developed hypertension (median follow-up 15.9 years). A positive association between obesity duration and incident hypertension was observed in women. There was no longer an association when time-varying BMI was adjusted for (hazard ratio 0.95; (95% confidence interval 0.85–1.05)). Conclusion: These findings suggest that the mechanism by which excess adiposity may increase blood pressure is primarily immediate and that long-term exposure to obesity does not further increase the risk of developing hypertension beyond the level of BMI attained.

How much does it cost to achieve coverage targets for primary healthcare services? A costing model from Aceh, Indonesia.

Despite significant investment in improving service infrastructure and training of staff, public primary healthcare services in low-income and middle-income countries tend to perform poorly in reaching coverage targets. One of the factors identified in Aceh, Indonesia was the lack of operational funds for service provision. The objective of this study was to develop a simple and transparent costing tool that enables health planners to calculate the unit costs of providing basic health services to estimate additional budgets required to deliver services in accordance with national targets. The tool was developed using a standard economic approach that linked the input activities to achieving six national priority programs at primary healthcare level: health promotion, sanitation and environment health, maternal and child health and family planning, nutrition, immunization and communicable diseases control, and treatment of common illness. Costing was focused on costs of delivery of the programs that need to be funded by local government budgets. The costing tool consisting of 16 linked Microsoft Excel worksheets was developed and tested in several districts enabled the calculation of the unit costs of delivering of the six national priority programs per coverage target of each program (such as unit costs of delivering of maternal and child health program per pregnant mother). This costing tool can be used by health planners to estimate additional money required to achieve a certain level of coverage of programs, and it can be adjusted for different costs and program delivery parameters in different settings.