Forecasting the obesity epidemic in the aging U.S. population

Projection scenarios of body mass index (2013-2030) for Public Health Planning in Quebec

Background

Projection analyses can provide estimates of the future health burden of increasing BMI and represent a relevant and useful tool for public health planning. Our study presents long-term (2013–2030) projections of the prevalence and numbers of individuals by BMI category for adult men and women in Quebec. Three applications of projections to estimate outcomes more directly pertinent to public health planning, as well as an in-depth discussion of limits, are provided with the aim of encouraging greater use of projection analyses by public health officers.

Methods

The weighted compositional regression method is applied to prevalence time series derived from sixteen cross-sectional survey cycles, for scenarios of linear change and deceleration. Estimation of the component of projected change potentially amenable to intervention, future health targets and the projected impact on type 2 diabetes, were done.

Results

Obesity prevalence in Quebec is projected to rise steadily from 2013 to 2030 in both men (from 18.0-19.4% to 22.2-30.4%) and women (from 15.5-16.3% to 18.2-22.4%). Corresponding projected numbers of obese individuals are (579,000-625,000 to 790,000-1,084,000) in men and (514,000-543,000 to 661,000-816,000) in women. These projected increases are found to be primarily an ‘epidemiologic’ rather than ‘demographic’ phenomenon and thus potentially amenable to public health intervention. Assessment of obesity targets for 2020 illustrates the necessity of using projected rather than current prevalence; for example a targeted 2% drop in obesity prevalence relative to 2013 translates into a 3.6-5.4% drop relative to 2020 projected levels. Type 2 diabetes is projected to increase from 6.9% to 9.2-10.1% in men and from 5.7% to 7.1-7.5% in women, from 2011–2012 to 2030. A substantial proportion of this change (25-44% for men, and 27-43% for women) is attributable to the changing BMI distribution.

Conclusions

Obesity in Quebec is projected to increase and should therefore continue to be a public health priority. Application of projections to estimate the proportion of change potentially amenable to intervention, feasible health targets, and future chronic disease prevalence are demonstrated. Projection analyses have limitations, but represent a pertinent tool for public health planning.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-996) contains supplementary material, which is available to authorized users.

More americans living longer with cardiovascular disease will increase costs while lowering quality of life

In the past several decades, some risk factors for cardiovascular disease have improved, while others have worsened. For example, smoking rates have dropped and treatment rates for cardiovascular disease have increased-factors that have made the disease less fatal. At the same time, Americans' average body mass index and incidence of diabetes have increased as the population continues to live longer-factors that have made cardiovascular disease more prevalent. To assess the aggregate impact of these opposing trends, we used the nine National Health and Nutrition Examination Survey waves from 1973 to 2010 to forecast total cardiovascular disease risk and prevalence from 2015 to 2030. We found that continued improvements in cardiovascular disease treatment and declining smoking rates will not outweigh the influence of increasing population age and obesity on cardiovascular disease risk. Given an aging population, an obesity epidemic, and declining mortality from the disease, the United States should expect to see a sharp rise in the health care costs, disability, and reductions in quality of life associated with increased prevalence of cardiovascular disease. Policies that target the treatment of high blood pressure and cholesterol and the reduction of obesity will be necessary to curb the imminent spike in cardiovascular disease prevalence.

Life course impact of school-based promotion of healthy eating and active living to prevent childhood obesity

Background

The Alberta Project Promoting active Living and healthy Eating in Schools (APPLE Schools) is a comprehensive school health program that is proven feasible and effective in preventing obesity among school aged children. To support decision making on expanding this program, evidence on its long-term health and economic impacts is particularly critical. In the present study we estimate the life course impact of the APPLE Schools programs in terms of future body weights and avoided health care costs.

Method

We modeled growth rates of body mass index (BMI) using longitudinal data from the National Population Health Survey collected between 1996–2008. These growth rate characteristics were used to project BMI trajectories for students that attended APPLE Schools and for students who attended control schools (141 randomly selected schools) in the Canadian province of Alberta.

Results

Throughout the life course, the prevalence of overweight (including obesity) was 1.2% to 2.8% (1.7 on average) less among students attending APPLE Schools relative to their peers attending control schools. The life course prevalence of obesity was 0.4% to 1.4% (0.8% on average) less among APPLE Schools students. If the APPLE Schools program were to be scaled up, the potential cost savings would be $33 to 82 million per year for the province of Alberta, or $150 to 330 million per year for Canada.

Conclusions

These projected health and economic benefits seem to support broader implementation of school-based health promotion programs.

Aging exacerbates obesity-induced cerebromicrovascular rarefaction, neurovascular uncoupling, and cognitive decline in mice

Epidemiological studies show that obesity has deleterious effects on the brain and cognitive function in the elderly population. However, the specific mechanisms through which aging and obesity interact to promote cognitive decline remain unclear. To test the hypothesis that aging exacerbates obesity-induced cerebromicrovascular impairment, we compared young (7 months) and aged (24 months) high-fat diet-fed obese C57BL/6 mice. We found that aging exacerbates the obesity-induced decline in microvascular density both in the hippocampus and in the cortex. The extent of hippocampal microvascular rarefaction and the extent of impairment of hippocampal-dependent cognitive function positively correlate. Aging exacerbates obesity-induced loss of pericyte coverage on cerebral microvessels and alters hippocampal angiogenic gene expression signature, which likely contributes to microvascular rarefaction. Aging also exacerbates obesity-induced oxidative stress and induction of NADPH oxidase and impairs cerebral blood flow responses to whisker stimulation. Collectively, obesity exerts deleterious cerebrovascular effects in aged mice, promoting cerebromicrovascular rarefaction and neurovascular uncoupling. The morphological and functional impairment of the cerebral microvasculature in association with increased blood-brain barrier disruption and neuroinflammation (Tucsek Z, Toth P, Sosnowsk D, et al. Obesity in aging exacerbates blood-brain barrier disruption, neuroinflammation and oxidative stress in the mouse hippocampus: effects on expression of genes involved in beta-amyloid generation and Alzheimer's disease. J Gerontol Biol Med Sci. 2013. In press, PMID: 24269929) likely contribute to obesity-induced cognitive decline in aging.

Obesity and cancer pathogenesis

Overweight and obesity have reached pandemic levels on a worldwide basis and are associated with increased risk and worse prognosis for many but not all malignancies. Pathophysiologic processes that affect this association are reviewed, with a focus on the relationship between type 2 diabetes mellitus and cancer, lessons learned from the use of murine models to study the association, the impact of obesity on pancreatic cancer, the effects of dietary fats and cholesterol on cancer promotion, and the mechanisms by which the intestinal microbiome affects obesity and cancer.

Outcomes of a specialist weight management programme in the UK National Health Service: prospective study of 1838 patients

OBJECTIVES

There is limited evidence on the effectiveness of weight management programmes provided within routine healthcare and inconsistent use of outcome measures. Our aim was to evaluate a large National Health Service (NHS) weight management service and report absolute and proportional weight losses over 12 months.

DESIGN

Prospective observational study.

SETTING

Glasgow and Clyde Weight Management Service (GCWMS), which provides care for residents of NHS Greater Glasgow and Clyde area (population 1.2 million).

PARTICIPANTS

All patients who began GCWMS between 1 October 2008 and 30 September 2009.

INTERVENTIONS

Structured educational lifestyle programme employing cognitive behavioural therapy, 600 kcal deficit diet, physical activity advice, lower calorie diet and pharmacotherapy.

PRIMARY AND SECONDARY OUTCOMES MEASURES

Baseline observation carried forward (BOCF), last observation carried forward (LOCF) and changes in programme completers reported using outcomes of absolute 5 kg and 5% weight losses and mean weight changes at a variety of time points.

RESULTS

6505 referrals were made to GCWMS, 5637 were eligible, 3460 opted in and 1916 (34%) attended a first session. 78 patients were excluded from our analysis on 1838 patients. 72.9% of patients were women, mean age of all patients at baseline was 49.1 years, 43.3% lived in highly socioeconomically deprived areas and mean weights and body mass indices at baseline were 118.1 kg and 43.3 kg/m(2), respectively. 26% lost ≥5 kg by the end of phase 1, 30% by the end of phase 2 and 28% by the end of phase 3 (all LOCF). Weight loss was more successful among men, particularly those ≤29 years old.

CONCLUSIONS

Routine NHS weight management services may achieve moderate weight losses through a comprehensive evidence-based dietary, activity and behavioural approach including psychological care. Weight losses should be reported using a range of outcome measures so that the effectiveness of different services can be compared.

Body mass index, waist circumference and employment: evidence from older Irish adults

Data from the first wave of the Irish Longitudinal Study on Ageing are used to examine the relationship between fatness and obesity and employment status among older Irish adults. Employment status is regressed on one of the following measures of fatness: BMI and waist circumference entered linearly as continuous variables and obesity as a categorical variable defined using both BMI and waist circumference. Controls for demographic and socioeconomic characteristics, socioeconomic characteristics in childhood and physical, mental and behavioural health are also included. The regression results for women indicate that all measures of fatness are negatively associated with the probability of being employed and that the employment elasticity associated with waist circumference is larger than the elasticity associated with BMI. The results for men indicate that employment is not significantly associated with BMI and waist circumference when these are entered linearly in the regression, but it is significantly and negatively associated with obesity defined either using BMI or waist circumference as categorical variables. The results also indicate that the negative association between obesity and employment status is larger among women. For example, the probability of being employed for the obese category defined using BMI is around 8 percentage points lower for women and 5 percentage points lower for men.

Obesity in aging exacerbates blood-brain barrier disruption, neuroinflammation, and oxidative stress in the mouse hippocampus: effects on expression of genes involved in beta-amyloid generation and Alzheimer's disease

There is growing evidence that obesity has deleterious effects on the brain and cognitive function in the elderly population. However, the specific mechanisms through which aging and obesity interact to promote cognitive decline remain unclear. To test the hypothesis that aging exacerbates obesity-induced cerebromicrovascular damage and neuroinflammation, we compared young (7 months) and aged (24 months) high fat diet-fed obese C57BL/6 mice. Aging exacerbated obesity-induced systemic inflammation and blood-brain barrier disruption, as indicated by the increased circulating levels of proinflammatory cytokines and increased presence of extravasated immunoglobulin G in the hippocampus, respectively. Obesity-induced blood-brain barrier damage was associated with microglia activation, upregulation of activating Fc-gamma receptors and proinflammatory cytokines, and increased oxidative stress. Treatment of cultured primary microglia with sera derived from aged obese mice resulted in significantly more pronounced microglia activation and oxidative stress, as compared with treatment with young sera. Serum-induced activation and oxidative stress were also exacerbated in primary microglia derived from aged animals. Hippocampal expression of genes involved in regulation of the cellular amyloid precursor protein-dependent signaling pathways, beta-amyloid generation, and the pathogenesis of tauopathy were largely unaffected by obesity in aged mice. Collectively, obesity in aging is associated with a heightened state of systemic inflammation, which exacerbates blood-brain barrier disruption. The resulting neuroinflammation and oxidative stress in the mouse hippocampus likely contribute to the significant cognitive decline observed in aged obese animals.

Excess weight and abdominal obesity in postmenopausal Brazilian women: a population-based study

Background

The menopause is associated with a tendency to gain weight. Several alterations in fat deposits occur, leading to changes in the distribution of body fat. There are strong indications that, in middle age, obesity is associated with increased mortality. This study set out to determine the factors associated with the prevalence of overweight and abdominal obesity in postmenopausal women in a population-based study in Brazil.

Methods

The sample included 456 women, aged 45–69 years, residing in the urban area of Maringa, Parana. Systematic sampling, with a probability proportional to the size of the census sector, was performed. Behavioral, economic, and sociodemographic data were collected, and body mass index (BMI) and waist circumference (WC) were determined.

Results

According to BMI criteria (≥25.0 kg/m²), 72.6% of the women were overweight, and according to WC (≥88 cm), 63.6% had abdominal obesity. Based on logistic regression analysis, the factors that were most closely associated with overweight were: having three or more children (odds ratio (OR): 1.78; 95% confidence interval (CI): 1.06–3.00); and not taking hormone replacement therapy (OR: 1.69; 95% CI: 1.06–2.63). The prevalence of abdominal obesity was positively associated with greater parity (OR: 1.34, 95% CI: 1.05–1.72) and age older than 65 years (OR: 1.50; 95% CI: 1.03–2.19).

Conclusions

This study found that the prevalences of overweight and abdominal obesity were higher for postmenopausal women who had three or more children. Age over 65 years was also a risk factor for abdominal obesity and no use of hormonal replacement therapy was a risk factor for overweight.

Quantitative proteomic and functional analysis of liver mitochondria from high fat diet (HFD) diabetic mice

Insulin resistance plays a major role in the development of type 2 diabetes and obesity and affects a number of biological processes such as mitochondrial biogenesis. Though mitochondrial dysfunction has been linked to the development of insulin resistance and pathogenesis of type 2 diabetes, the precise mechanism linking the two is not well understood. We used high fat diet (HFD)-induced obesity dependent diabetes mouse models to gain insight into the potential pathways altered with metabolic disease, and carried out quantitative proteomic analysis of liver mitochondria. As previously reported, proteins involved in fatty acid oxidation, branched chain amino acid degradation, tricarboxylic acid cycle, and oxidative phosphorylation were uniformly up-regulated in the liver of HFD fed mice compared with that of normal diet. Further, our studies revealed that retinol metabolism is distinctly down-regulated and the mitochondrial structural proteins-components of mitochondrial inter-membrane space bridging (MIB) complex (Mitofilin, Sam50, and ChChd3), and Tim proteins-essential for protein import, are significantly up-regulated in HFD fed mice. Structural and functional studies on HFD and normal diet liver mitochondria revealed remodeling of HFD mitochondria to a more condensed form with increased respiratory capacity and higher ATP levels compared with normal diet mitochondria. Thus, it is likely that the structural remodeling is essential to accommodate the increased protein content in presence of HFD: the mechanism could be through the MIB complex promoting contact site and crista junction formation and in turn facilitating the lipid and protein uptake.

The Hispanic paradox and predictors of mortality in an aging biethnic cohort of Mexican Americans and European Americans: the san antonio longitudinal study of aging

OBJECTIVES

To examine predictors of mortality in aging Mexican Americans (MAs) and European Americans (EAs).

DESIGN

Longitudinal, observational cohort study.

SETTING

Socioeconomically diverse neighborhoods in San Antonio, Texas.

PARTICIPANTS

Community-dwelling adults aged 65 and older (394 MA; 355 EA) who completed the baseline examination (1992-96) of the San Antonio Longitudinal Study of Aging (SALSA) and for whom vital status was ascertained over an average 8.2 years of follow-up.

MEASUREMENTS

Ethnic group was classified using a validated algorithm. Hazard ratios (HRs) for mortality were estimated using Cox proportional hazards models with age, sex, ethnic group, education, income, frailty, diabetes mellitus with and without complications, comorbidity, cognition, depressive symptoms, and body mass index included as predictors in sequential models.

RESULTS

At baseline, MAs had a higher prevalence of diabetes mellitus and frailty and lower socioeconomic status (SES) than EAs. The age- and sex-adjusted ethnic HR (MA vs EA) for mortality was 1.54 (95% confidence interval (CI) = 1.17-2.03). After adjusting for SES, the ethnic HR was no longer significant (HR = 1.16, 95% CI = 0.83-1.61). In the final model, comorbidity, diabetes mellitus with complications, depressive symptoms, and cognitive impairment were significant independent risk factors for mortality.

CONCLUSION

Contrary to the Hispanic paradox, MAs were at greater risk of mortality than EAs. SES differences largely explained this ethnic disparity. Significant independent predictors of mortality, regardless of ethnic group, were diabetes mellitus with complications, comorbidity, depressive symptoms, and cognitive impairment. Mortality reduction in older MAs requires attention to socioeconomic disparities and disease factors.

Measurement of food volume based on single 2-D image without conventional camera calibration

Food portion size measurement combined with a database of calories and nutrients is important in the study of metabolic disorders such as obesity and diabetes. In this work, we present a convenient and accurate approach to the calculation of food volume by measuring several dimensions using a single 2-D image as the input. This approach does not require the conventional checkerboard based camera calibration since it is burdensome in practice. The only prior requirements of our approach are: 1) a circular container with a known size, such as a plate, a bowl or a cup, is present in the image, and 2) the picture is taken under a reasonable assumption that the camera is always held level with respect to its left and right sides and its lens is tilted down towards foods on the dining table. We show that, under these conditions, our approach provides a closed form solution to camera calibration, allowing convenient measurement of food portion size using digital pictures.

Immigrant assimilation and BMI and waist size: a longitudinal examination among Hispanic and Chinese participants in the multi-ethnic study of atherosclerosis

OBJECTIVE

US birth and longer length of US residence among the foreign-born have been linked to higher anthropometric measures. However, previous studies have been cross sectional and few have examined heterogeneity by ethnic group. Cross-sectional findings that show immigrant weight converging to US-born levels with longer time in the United States imply that immigrants' weight is increasing at a faster rate relative to US-born individuals. Prospective studies are necessary to confirm this pattern.

DESIGN AND METHODS

Using longitudinal data from 1,486 Hispanic and 802 Chinese adults aged 45-84 years in the Multi-ethnic Study of Atherosclerosis, we examined whether foreign-born participants experienced greater increases in BMI and waist circumference (WC) than the US-born over a median follow-up of 5 years. We also investigated heterogeneity in these associations by Hispanic subgroup.

RESULTS

Among Hispanics and Chinese, the foreign-born had a lower adjusted mean BMI and WC at baseline than the US-born, but there were no significant differences in BMI or WC change over time. There was heterogeneity by Hispanic subgroup: despite small baseline nativity differences in WC, foreign-born Mexican Hispanics had a greater annual mean increase in WC over time compared to US-born Mexican Hispanics (mean difference in annual change = 0.28 cm, P = 0.03). There were no nativity differences in the rate of WC increase over time among non-Mexican Hispanics. Foreign-born Mexican Hispanics also experienced a faster rate of WC increase compared to foreign-born non-Mexican Hispanics (mean difference in annual change = 0.24 cm, P = 0.01).

CONCLUSIONS

Longer time in the United States, examined prospectively, may only be linked to adverse anthropometric changes in some immigrant groups.