Birth cohort effects among US-born adults born in the 1980s: foreshadowing future trends in US obesity prevalence

Differences in cancer rates among adults born between 1920 and 1990 in the USA: an analysis of population-based cancer registry data

BACKGROUND

Trends in cancer incidence in recent birth cohorts largely reflect changes in exposures during early life and foreshadow the future disease burden. Herein, we examined cancer incidence and mortality trends, by birth cohort, for 34 types of cancer in the USA.

METHODS

In this analysis, we obtained incidence data for 34 types of cancer and mortality data for 25 types of cancer for individuals aged 25-84 years for the period Jan 1, 2000, to Dec 31, 2019 from the North American Association of Central Cancer Registries and the US National Center for Health Statistics, respectively. We calculated birth cohort-specific incidence rate ratios (IRRs) and mortality rate ratios (MRRs), adjusted for age and period effects, by nominal birth cohort, separated by 5 year intervals, from 1920 to 1990.

FINDINGS

We extracted data for 23 654 000 patients diagnosed with 34 types of cancer and 7 348 137 deaths from 25 cancers for the period Jan 1, 2000, to Dec 31, 2019. We found that IRRs increased with each successive birth cohort born since approximately 1920 for eight of 34 cancers (pcohort<0·050). Notably, the incidence rate was approximately two-to-three times higher in the 1990 birth cohort than in the 1955 birth cohort for small intestine (IRR 3·56 [95% CI 2·96-4·27]), kidney and renal pelvis (2·92 [2·50-3·42]), and pancreatic (2·61 [2·22-3·07]) cancers in both male and female individuals; and for liver and intrahepatic bile duct cancer in female individuals (2·05 [1·23-3·44]). Additionally, the IRRs increased in younger cohorts, after a decline in older birth cohorts, for nine of the remaining cancers (pcohort<0·050): oestrogen-receptor-positive breast cancer, uterine corpus cancer, colorectal cancer, non-cardia gastric cancer, gallbladder and other biliary cancer, ovarian cancer, testicular cancer, anal cancer in male individuals, and Kaposi sarcoma in male individuals. Across cancer types, the incidence rate in the 1990 birth cohort ranged from 12% (IRR1990 vs 1975 1·12 [95% CI 1·03-1·21] for ovarian cancer) to 169% (IRR1990 vs 1930 2·69 [2·34-3·08] for uterine corpus cancer) higher than the rate in the birth cohort with the lowest incidence rate. The MRRs increased in successively younger birth cohorts alongside IRRs for liver and intrahepatic bile duct cancer in female individuals, uterine corpus, gallbladder and other biliary, testicular, and colorectal cancers, while MRRs declined or stabilised in younger birth cohorts for most cancers types.

INTERPRETATION

17 of 34 cancers had an increasing incidence in younger birth cohorts, including nine that previously had declining incidence in older birth cohorts. These findings add to growing evidence of increased cancer risk in younger generations, highlighting the need to identify and tackle underlying risk factors.

FUNDING

American Cancer Society.

Gender Disparities in Blood Pressure and the Role of Body Mass Index: A Birth Cohort Analysis in China

BACKGROUND

The slow decline in cardiovascular disease (CVD) mortality and the stagnant or increasing hypertension prevalence in low- and middle-income countries necessitate investigation. Evolving gender disparities suggested that male cardiovascular health disadvantage may be preventable, offering potential for enhancing population cardiovascular health. Despite global body mass index (BMI) increases, its role in shaping the gender disparities remains underexplored.

OBJECTIVE

This study investigated the birth cohort dynamics of gender disparities in systolic/diastolic blood pressure (SBP/DBP) in China, one of the world's largest low- and middle-income countries, and explored the potential role of BMI in explaining the changing gender disparities.

METHODS

Data from the China Health and Nutrition Survey (1991-2015) were analyzed using multilevel growth-curve models to estimate gender- and cohort-specific SBP/DBP trajectories among individuals born between 1950 and 1975.

RESULTS

Men had higher SBP and DBP than women at the sample's mean age of 41.7 years. The gender disparities in SBP and DBP increased with each successive one-year cohort from 1950 to 1975 by 0.14 mm Hg and 0.09 mm Hg, respectively. Adjusting for BMI reduced the increasing gender disparities in SBP and DBP by 31.9% and 34.4%, respectively.

CONCLUSION

Chinese men experienced a greater increase in SBP/DBP across successive cohorts compared to women. The increasing gender disparities in SBP/DBP were partially attributable to a greater BMI increase across cohorts among men. Given these findings, prioritizing interventions that aim to reduce BMI, particularly among men, could potentially alleviate the burden of CVD in China through lowering SBP/DBP.

Weight gain is associated with shorter lifespan: a longitudinal study of New Zealand soldiers serving in both world wars

Obesity is an increasing public health concern with important mortality consequences. Weight gain or maximum adult BMI, not BMI at one point in time, has been shown to be an important risk factor in cohorts studied recently during an era of rapid increase in population levels of overweight and obesity. However, there is limited evidence on individual weight trajectories from cohorts born before the mid-twentieth century. Archival world war military personnel files from New Zealand are freely available online, and identify service in both wars. A pilot study of 316 soldiers confirmed the files contain sufficient information to examine health trajectories and lifespan. Because this cohort are now entirely deceased, nearly the entire sample can be found in death records to estimate the impact of weight increases on lifespan. Weight change over 20-30 years and its relationship with lifespan is examined using ordinary least squares regression. The study demonstrates that military records are a feasible source for collecting data on adult weight and health trajectories in the first half of the twentieth century. Although this sample is likely to be composed of men fitter than average, there is a clear pattern of increasing weight from early to mid-adulthood. Weight gain from early adulthood to middle-age was found to be more strongly associated with mortality than weight in early adulthood. A one unit increase in BMI over the inter-war period was found to be associated with an 8 month decline in lifespan. These results confirm that weight gain in adulthood has an important impact on mortality in an earlier birth cohort than previously studied, and that data exist to measure any changes more precisely over time.

Increasing Incidence of Gallbladder Cancer among Non-Hispanic Blacks in the United States: A Birth Cohort Phenomenon

BACKGROUND

Gallbladder cancer incidence varies among racial/ethnic subgroups in the United States (US). We investigated trends in gallbladder cancer incidence rates in 50 states from 2001 to 2018.

METHODS

Age-adjusted incidence rates and trends in adults were calculated using data from the US Cancer Statistics registry. We used joinpoint regression to compute annual percentage of changes (APC). We analyzed incidence trends by time periods, age groups, and birth cohorts through age-period-cohort modeling.

RESULTS

Overall, age standardized incidence rates for gallbladder cancer decreased by 0.3% annually between 2001 and 2018 [95% confidence interval (CI) -0.5% to -0.1%]. However, secular trends varied by race/ethnicity. Although gallbladder cancer rates declined in other racial/ethnic groups, rates increased by 1.4% annually among non-Hispanic Blacks (NHB) between 2001 and 2018 (APC = 1.4%; 95% CI, 0.9%-2.0%). We found evidence for period and birth cohort effects with increasing rates among successive birth cohorts of NHBs. Relative to NHB cohorts born circa 1946, gallbladder cancer rates were 85% higher in NHB cohorts born circa 1971 [incidence rate ratio (IRR), 1.85; 95% CI, 1.26-2.72). The rates among NHBs in South region were higher in cohorts born circa 1971 (IRR, 2.17; 95% CI, 1.27-3.73) relative to those born circa 1946.

CONCLUSIONS

The incidence of gallbladder cancer has consistently increased in the US among NHBs. A notable increase in incidence was observed among NHBs with evidence of birth cohort effects in South, Northeast, and Midwest regions.

IMPACT

The cohort effect observed among NHBs with increasing rates in different US regions suggests that gallbladder cancer rates will continue to rise in the US in the near future.

Forecasting future prevalence and gender differences in binge drinking among young adults through 2040

BACKGROUND

Binge drinking among adolescents and young adults has changed over time, but patterns differ by age and gender. Identifying high-risk groups to target future efforts at reducing drinking in this population remains a public health priority. Forecasting methods can provide a better understanding of variation and determinants of future binge drinking prevalence.

METHODS

We implemented regression-based forecasting models to estimate the prevalence and gender differences in binge drinking among cohort groups of U.S. young adults, ages 18, 23-24, and 29-30 through 2040. Forecasting models were adjusted for covariates accounting for changes in demographic, Big-5 social roles (e.g., residential independence), and drinking norms and related substance use, to understand the drivers of forecasted binge drinking estimates.

RESULTS

From the last observed cohort group (years varied by age) through 2040, unadjusted binge drinking prevalence was forecasted to decrease from 26% (95% CI: 20, 33%) (2011-15) to 11% (95% CI: 4, 27%) at age 18, decrease from 38% (95% CI: 30, 45%) (2006-2010) to 34% (95% CI: 18, 55%) at ages 23/24, and increase from 32% (95% CI: 25, 40%) (2001-2005) to 35% (95% CI: 16, 59%) at ages 29/30. Gender-stratified forecasts show a continuation in the narrowing of binge drinking prevalence between young men and women, though the magnitude of narrowing differs by age. Estimated trends were partially explained by changing norms regarding drinking and other substance use, though these indirect effects explained less of the total trend as age increased.

CONCLUSIONS

Understanding how covariates influence binge drinking trends can guide public health policies to leverage the most important determinants of future binge drinking to reduce the harm caused by binge drinking from adolescence to adulthood.

Body mass and the epidemic of chronic inflammation in early mid-adulthood

OBJECTIVES

Chronic inflammation is a potentially important mechanism through which social inequalities may contribute to health inequalities over the life course. Excess body fat contributes to chronic inflammation, and younger adults in the US have come of age during a pronounced secular increase in body mass index (BMI). We aim to document levels of chronic inflammation in a nationally representative sample of 33-to-44 year-old adults in the US, and to describe associations with BMI, race/ethnicity, and education.

METHODS

High sensitivity C-reactive protein (CRP) was measured in Wave V (2016-18) of the National Longitudinal Study of Adolescent to Adult Health, with complete data available for 4349 participants. Sex-stratified weighted regression models were implemented to investigate CRP in association with education, race/ethnicity, and BMI.

RESULTS

Geometric mean CRP was 1.9 mg/L, and 35.4% of the sample had CRP >3 mg/L. Females had significantly higher CRP than males. Body mass index was a strong positive predictor of CRP, and education level was negatively associated with CRP. Associations between education and CRP were substantially attenuated after adjusting for BMI. High risk CRP increased linearly with BMI even among the obese: 87.0 percent of females and 74.1 percent of males with class 3 obesity (BMI ≥40) were predicted to have high risk CRP > 3 mg/L.

CONCLUSIONS

The obesity epidemic is producing an epidemic of chronic inflammation in early mid-adulthood in the US. Strong associations between BMI and chronic inflammation portend high risk for future disease-and inequitable distribution of disease-as the cohort ages.

Black American and Latinx Parent/Caregiver Participation in Digital Health Obesity Interventions for Children: A Systematic Review

Parents/caregivers are consistently described as integral targets given their influential role in supporting and managing behaviors such as diet and physical activity. Identifying effective obesity prevention interventions to enhance and sustain parent participation is needed. Digital obesity prevention interventions are a promising strategy to improve parent/caregiver participation. Digital health interventions demonstrate acceptable participation and retention among parents/caregivers. However, our understanding of digital obesity prevention interventions targeting Black American and Latinx parents/caregivers is limited. This systematic review aims to identify Black American and Latinx parents'/caregivers' level of participation in digital obesity prevention and treatment interventions and determine the relationship between parent/caregiver participation and behavioral and weight status outcomes. This review adheres to PRISMA guidelines and is registered in PROSPERO. Eligibility criteria include: intervention delivered by digital technology, targeted Black American and Latinx parents/caregivers of young children (2-12 years), reported parent/caregiver participation outcomes, targeted diet or physical activity behaviors, and randomized controlled trial study design. Searches were conducted in September 2020 in ERIC, PsychInfo, PubMed, and Web of Science. Initial searches returned 499 results. Four reviewers screened records against eligibility criteria and 12 studies met inclusion criteria. Across all studies, parent/caregiver participation ranged from low to high. Only half of the included studies reported significant improvements in behavioral or weight status outcomes for parents/caregivers and/or children. Of these studies, three reported high parental/caregiver participation rates, and three reported high satisfaction rates. These findings suggest that participation and satisfaction may impact behavior change and weight status. The small number of studies indicates that additional research is needed to determine whether engagement or other factors predict responsiveness to the digital health intervention. Our results lay the groundwork for developing and testing future digital health interventions with the explicit goal of parental/caregiver participation and considers the need to expand our digital health intervention research methodologies to address obesity inequities among diverse families better.

Excess weight and obesity prevalence in the RPS Brazilian Birth Cohort Consortium (Ribeirão Preto, Pelotas and São Luís)

Our objective was to estimate the prevalence of excess weight and obesity, according to sex and income in the RPS Brazilian Birth Cohort Consortium (Ribeirão Preto, Pelotas, and São Luís). Participants in the Ribeirão Preto (1978/1979 and 1994), Pelotas (1982, 1993 and 2004) and São Luís (1997/1998) birth cohorts were included in different follow-ups from 7 years old onwards. Excess weight (overweight and obesity) were assessed by body mass index. The highest prevalences were observed in Ribeirão Preto (excess weight: 27.7% at 9-11 and 47.1% at 22-23 years; obesity: 8.6% at 9-11 and 19.8% at 22-23 years) while the smallest was in São Luís (excess weight: 5.4 to 7-9 and 17.2% at 18-19 years; obesity: 1.8% at 7-9 and 3.6% at 18-19 years). The younger the cohort, the greater the prevalence of excess weight and obesity when comparing similar age groups. Increases in obesity prevalence were greater than in excess weight prevalence. Women had lower excess weight prevalence in older cohorts and higher obesity prevalence in younger cohorts. Higher excess weight and obesity prevalence were observed in higher income children and adolescents, and in poorer adults. Differences in the prevalence of excess weight and obesity evidenced that individuals from younger cohorts are more exposed to this morbidity, as well as those who were born in the most developed city, low-income adults as well as children and adolescents belonging to families of the highest income tertile. Therefore, the results of this study indicate the need to prioritize actions aimed at younger individuals.

An ecological evaluation of the increasing incidence of endometrial cancer and the obesity epidemic

BACKGROUND

The prevalence of obesity has increased significantly in recent decades, particularly among younger women, and is a known risk factor for endometrial cancer.

OBJECTIVE

This study aimed to evaluate the trend in the prevalence of obesity and the incidence of type I endometrial cancer over time in various age categories to determine whether an ecological relationship exists.

STUDY DESIGN

Data from the Surveillance, Epidemiology, and End Results Program and the National Health and Nutrition Examination Survey were used. The overall trend in the incidence of type 1 endometrial cancer and prevalence of obesity were observed over time from 1988 to 2016 and further categorized by age group (<45, 45-54, and ≥55 years).

RESULTS

The prevalence of obesity has increased for all women, but most significantly for women younger than 45 years with a 16.3% increase among women aged 20 to 34 years and a 17.9% increase for women aged 35 to 44 years. The incidence of endometrial cancer has also increased across all age categories, and although it has increased in patients younger than 45 years by more than 14-fold (from <0.1 per 100,000 in 1988 to 1.4 per 100,000 in 2016), a more pronounced increase of 63-fold and 50-fold was observed among women aged 45 to 54 years (0.2 per 100,000 in 1988 to 12.6 per 100,000 in 2016) and women aged 55 years and older (from 0.6 per 100,000 in 1988 to 30 per 100,000 in 2016), respectively. The mean age of women diagnosed as having endometrial cancer also decreased from 64.1 years from 1988 to 1990 to 61.0 years from 2014 to 2016.

CONCLUSION

The prevalence of obesity has increased significantly in women of all ages. This increase, particularly among women aged <45 years, occurred simultaneously with an increase in the incidence of endometrial cancer in young women, with an even more pronounced increase among women aged ≥45 years.

Trends in solitary plasmacytoma, extramedullary plasmacytoma, and plasma cell myeloma incidence and myeloma mortality by racial-ethnic group, United States 2003-2016

Plasma cell myeloma (also called multiple myeloma), solitary plasmacytoma, and extramedullary plasmacytoma are primarily diseases of the elderly. Evidence suggests an association between excess body weight and multiple myeloma. Few population-based studies have examined incidence and mortality of each site in one study. We analyzed incidence and death rates by site (solitary plasmacytoma, extramedullary plasmacytoma, and multiple myeloma) by gender, age, race/ethnicity, and rural-urban status among adult males and females (aged 20 years or older) in the United States during 2003-2016. Trends were characterized as average annual percentage change (AAPC) in rates. During 2003-2016, overall incidence rates among adults were 0.45 for solitary plasmacytoma, 0.09 for extramedullary plasmacytoma, and 8.47 for multiple myeloma per 100,000 persons. Incidence rates for multiple myeloma increased during 2003-2016 among non-Hispanic whites (AAPC = 1.78%) and non-Hispanic blacks (2.98%) 20-49 years of age; non-Hispanic whites (1.17%) and non-Hispanic blacks (1.24%) 50-59 years of age; and whites non-Hispanic (0.91%), and non-Hispanic blacks (0.96%). During 2003-2016 overall myeloma (extramedullary plasmacytoma and multiple myeloma) death rates among adults was 4.77 per 100,00 persons. Myeloma death rates decreased during 2003-2016 among non-Hispanic white (AAPC = -1.23%) and Hispanic (-1.34%) women; and non-Hispanic white (-0.74%), non-Hispanic American Indian/Alaska Native (-3.05%) men. The US population is projected to become older and will have a larger proportion of persons who have had an earlier and longer exposure to excess body weight. The potential impact of these population changes on myeloma incidence and mortality can be monitored with high-quality cancer surveillance data.

Obesity Prevalence in the Long-Term Future in 18 European Countries and in the USA

INTRODUCTION

Obesity constitutes a major public health problem in Europe, but how the obesity epidemic in European countries will evolve remains unknown. Most previous obesity projections considered the short-term future only, focused on single non-European countries, and projected ongoing increases foremost. We comparatively project obesity prevalence into the long-term future for 18 European countries and the USA.

DATA

We used national age-specific (20-84 years) and sex-specific obesity prevalence estimates (1975-2016) from the NCD Risk Factor Collaboration (NCD-RisC) 2017 study, which are based on available measured height and weight data, supplemented with estimates from a Bayesian hierarchical model.

METHODS

We projected age- and sex-specific obesity prevalence up to the year 2100 by integrating the notion of a wave-shaped obesity epidemic into conventional age-period projections.

RESULTS

In 1990-2016, the increasing trends in obesity prevalence were decelerating. Obesity is expected to reach maximum levels between 2030 and 2052 among men, and between 2026 and 2054 among women. The maximum levels will likely be reached first in The Netherlands, USA, and UK, and last in Switzerland; and are expected to be highest in the USA and UK, and lowest in The Netherlands for men and Denmark for women. In 2060, obesity prevalence is expected to be lowest among Dutch men and highest among Swiss men. The projected age-specific obesity prevalence levels have an inverse U-shape, peaking at around the age of 60-69 years.

DISCUSSION

Applying our novel approach to the NCD-RisC 2017 data, obesity prevalence is expected to reach maximum levels between 2026 and 2054, with the USA and UK reaching the highest maximum levels first, followed by other European countries.

Exploring the role of social support and social media for lifestyle interventions to prevent weight gain with young adults: Focus group findings

BACKGROUND

Young adults gain more weight annually than other adults and may be destined for future obesity. Effective interventions are needed, and social support may be a key element for success. The present study explores how best to leverage social media to support young adults with their health goals in a healthy lifestyle programme.

METHOD

Young adults aged 18-25 years were recruited from the community to a series of four focus groups led by an experienced facilitator who used a discussion guide developed a priori. The discussion explored their opinions regarding which social media platforms were appropriate for providing social support, the types of support that were relevant (family and friends versus strangers) and factors that would encourage peer-to-peer communication in a healthy lifestyle intervention. Sessions were audio-taped, transcribed and analysed using the qualitative software, nvivo, version 11 (QSR International Pty Ltd., Melbourne, VIC, Australia). Themes were generated using an inductive approach informed by the Theory of Social Identity and Social Influence Model of Consumer Participation.

RESULTS

Thirty-three people (12 male) participated. Facebook was the most popular platform for facilitating social support as a result of its private group capabilities and already being embedded into their daily routines. The preference was to be grouped with strangers who shared similar goals in smaller groups of participants. The discussions highlighted the integral role of a credible and relatable health coach to serve as a mentor, mediator and role model.

CONCLUSIONS

The learnings from this research will be applied to optimise engagement within social media support groups in lifestyle interventions.

Emerging cancer trends among young adults in the USA: analysis of a population-based cancer registry

BACKGROUND

Cancer trends in young adults, often under 50 years, reflect recent changes in carcinogenic exposures, which could foreshadow the future overall disease burden. Previous studies reported an increase in early onset colorectal cancer, which could partly reflect the obesity epidemic. We examined age-specific contemporary incidence trends in the USA for 30 common cancers, including 12 obesity-related cancers.

METHODS

We obtained incidence data for invasive cancers among people aged 25-84 years diagnosed from Jan 1, 1995, to Dec 31, 2014, for 25 population-based state registries in the USA. All patients in the registry were included in the analyses. We considered the 20 most common cancer types and 12 obesity-related cancers (30 cancer types in total). We used age-period-cohort modelling to estimate average annual percentage change in incidence rates by 5-year age group (25-29 years to 80-84 years in 5-year increments) and incidence rate ratios (IRR) by birth cohort (10-year overlapping birth cohorts from 1910-19 to 1980-89 in 5-year increments). No exclusion criteria were applied after including all invasive cancer cases based on age group and diagnosis year.

FINDINGS

From 1995 to 2014 there were 14 672 409 incident cases for 30 types of cancer. Incidence significantly increased for six of 12 obesity-related cancers (multiple myeloma, colorectal, uterine corpus, gallbladder, kidney, and pancreatic cancer) in young adults (25-49 years) with steeper rises in successively younger generations. Annual increases ranged from 1·44% (95% CI -0·60 to 3·53) for multiple myeloma to 6·23% (5·32-7·14) for kidney cancer at age 25-29 years, and ranged from 0·37% (0·03-0·72) for uterine corpus cancer to 2·95% (2·74-3·16) for kidney cancer at age 45-49 years. Compared with people born around 1950, IRRs for those born around 1985 ranged from 1·59 (95% CI 1·14-2·21) for multiple myeloma to 4·91 (4·27-5·65) for kidney cancer. Conversely, incidence in young adults increased in successively younger generations for only two cancers (gastric non-cardia cancer and leukaemia), and decreased for eight of the 18 additional cancers, including smoking and HIV infection-associated cancers.

INTERPRETATION

The risk of developing an obesity-related cancer seems to be increasing in a stepwise manner in successively younger birth cohorts in the USA. Further studies are needed to elucidate exposures responsible for these emerging trends, including excess bodyweight and other risk factors.

FUNDING

Intramural Research Department of the American Cancer Society and the Intramural Research Program of the National Cancer Institute.

Epidemiology of Obesity in Adults: Latest Trends

PURPOSE OF REVIEW

An increasing trend in obesity prevalence since the early 1980s has posed a significant population health burden across the globe. We conducted a systematic review for studies using measured anthropometry to examine trends in obesity in the USA published from 2012 to 2018 and for systematic reviews to document trends in obesity across the globe published from 2014 to 2018.

RECENT FINDINGS

For the USA, the only nationally representative data source capturing trends in obesity in this period was the National Health and Nutrition Examination Survey, which uses repeated cross-sectional data to document national trends in obesity in the USA. For global trends, the only systematic reviews of obesity across the globe were the Global Burden of Disease Obesity study and the Non-communicable Disease Risk Factor Collaboration study. In general, the population distribution of body mass index (BMI) in the USA has shifted towards the upper end of its distribution over the past three decades. The global distribution has similarly increased, albeit with large regional differences. US and global studies suggest an increasing trend in obesity since the 1980s, and there is a dearth of nationally representative longitudinal studies using measured anthropometry to capture trends in adult obesity in the USA for the same individuals over time. Greater efforts are needed to identify factors contributing to the continued increases in obesity.

Social Determinants and Poor Diet Quality of Energy-Dense Diets of Australian Young Adults

This research aimed to determine the diet quality and socio-demographic determinants by level of energy-density of diets of Australian young adults. Secondary analysis of the Australian National Nutrition and Physical Activity Survey-2011/2012 for adults aged 18–34 years (n = 2397) was conducted. Diet was assessed by 24-h recalls. Dietary energy-density was calculated as dietary energy/grams of food (kJ/g) and the Healthy-Eating-Index-for-Australians (HEIFA-2013) was used to assess diet quality (highest score = 100). Dietary energy-density was examined with respect to diet quality and sociodemographic determinants including gender, highest tertiary-education attainment, country-of-birth, age, income, and socio-economic-index-for-area (SEIFA). Higher dietary energy-density was associated with lower diet quality scores (β = −3.71, t (2394) = −29.29, p < 0.0001) and included fewer fruits and vegetables, and more discretionary foods. The mean dietary energy-density was 7.7 kJ/g and 7.2 kJ/g for men and women, respectively. Subpopulations most at risk of consuming high energy-dense diets included those with lower education, Australian and English-speaking countries of birth, and men with low income and women from areas of lower socio-economic status. Young adults reporting low energy-dense diets had higher quality diets. Intensive efforts are needed to reduce the high energy-density of young adults’ diets, and should ensure they include populations of lower socio-economic status.

Disparities in Diabetes by Education and Race/Ethnicity in the U.S., 1973-2012

INTRODUCTION

Diabetes mellitus incidence has more than doubled in the U.S. over the past 2 decades. Not all sectors of the population have experienced the increase proportionally. The goal of this study was to determine if disparities in diabetes by education and race/ethnicity have increased over time, and if there are differences by gender and birth cohort.

METHODS

Repeated cross-sectional data were used from the 1973-2012 National Health Interview Survey of adults aged 25-84 years. Logistic regression models were run and predicted probabilities were calculated to determine if disparities in self-reported diabetes by education and race/ethnicity changed over time, by gender and birth cohort (birth before 1946, 1946-1970, 1971 or after). Analyses were conducted in 2014-2015.

RESULTS

Relationships between education or race/ethnicity and diabetes were modified by time for people born before 1971, with stronger effect modification for women than men. Inequalities in diabetes prevalence grew over time, although the magnitude of disparities was smaller for the 1946-1970 cohort. For example, in 2005-2012, the gap in diabetes prevalence for women with the highest and lowest levels of education was 12.7% for pre-1946 versus 7.9% for 1946-1970. Similar trends were seen for differences between non-Hispanic whites and non-Hispanic blacks or Hispanics. Results were inconclusive for the youngest cohort.

CONCLUSIONS

Diabetes disparities are evident. Smaller differences in later cohorts may indicate that large structural changes in society (e.g., Civil Rights movement, increased educational and economic opportunities) have benefited later generations.

Do baby boomers use more healthcare services than other generations? Longitudinal trajectories of physician service use across five birth cohorts

OBJECTIVE

In light of concerns for meeting the provision of healthcare services given the large numbers of ageing baby boomers, we compared the trajectories of primary care and specialist services use across the lifecourse of 5 birth cohorts and examined factors associated with birth cohort differences.

DESIGN

Longitudinal panel.

SETTING

Canadian National Population Health Survey (1994-2011).

POPULATION

Sample of 10 186 individuals aged 20-69 years in 1994-1995 and who were from 5 birth cohorts: Generation X (Gen X; born: 1965-1974), Younger Baby Boomers (born: 1955-1964), Older Baby Boomers (born: 1945-1954), World War II (born: 1935-1944) and pre-World War II (born: 1925-1934).

MAIN OUTCOMES

Use of primary care and specialist services.

RESULTS

Although the overall pattern suggested less use of physician services by each successive recent cohort, this blinded differences in primary and specialist care use by cohort. Multilevel analyses comparing cohorts showed that Gen Xers and younger boomers, particularly those with multimorbidity, were less likely to use primary care than earlier cohorts. In contrast, specialist use was higher in recent cohorts, with Gen Xers having the highest specialist use. These increases were explained by the increasing levels of multimorbidity. Education, income, having a regular source of care, sedentary lifestyle and obesity were significantly associated with physician services use, but only partially contributed to cohort differences.

CONCLUSIONS

The findings suggest a shift from primary care to specialist care among recent cohorts, particularly for those with multimorbidity. This is of concern given policies to promote primary care services to prevent and manage chronic conditions. There is a need for policies to address important generational differences in healthcare preferences and the balance between primary and specialty care to ensure integration and coordination of healthcare delivery.

What Does Self-rated Health Mean? Changes and Variations in the Association of Obesity with Objective and Subjective Components Of Self-rated Health

There are concerns about the meaning of self-rated health (SRH) and the factors individuals consider. To illustrate how SRH is contextualized, we examine how the obesity-SRH association varies across age, periods, and cohorts. We decompose SRH into subjective and objective components and use a mechanism-based age-period-cohort model approach with four decades (1970s to 2000s) and five birth cohorts of National Health and Nutrition Examination Survey data (N = 26,184). Obese adults rate their health more negatively than non-obese when using overall SRH with little variation by age, period, or cohort. However, when we decomposed SRH into objective and subjective components, the obesity gap widened with increasing age in objective SRH but narrowed in subjective SRH. Additionally, the gap narrowed for more recently born cohorts for objective SRH but widened for subjective SRH. The results provide indirect evidence that the relationship between obesity and SRH is socially patterned according to exposure to information about obesity and the availability of resources to manage it.

Contributions of increasing obesity and diabetes to slowing decline in subclinical coronary artery disease

Background

Our previous study of nonelderly adult decedents with nonnatural (accident, suicide, or homicide) cause of death (96% autopsy rate) between 1981 and 2004 revealed that the decline in subclinical coronary artery disease (CAD) ended in the mid‐1990s. The present study investigated the contributions of trends in obesity and diabetes mellitus to patterns of subclinical CAD and explored whether the end of the decline in CAD persisted.

Methods and Results

We reviewed provider‐linked medical records for all residents of Olmsted County, Minnesota, who died from nonnatural causes within the age range of 16 to 64 years between 1981 and 2009 and who had CAD graded at autopsy. We estimated trends in CAD risk factors including age, sex, systolic blood pressure, diabetes (qualifying fasting glucose or medication), body mass index, smoking, and diagnosed hyperlipidemia. Using multiple regression, we tested for significant associations between trends in CAD risk factors and CAD grade and assessed the contribution of trends in diabetes and obesity to CAD trends. The 545 autopsied decedents with recorded CAD grade exhibited significant declines between 1981 and 2009 in systolic blood pressure and smoking and significant increases in blood pressure medication, diabetes, and body mass index ≥30 kg/m². An overall decline in CAD grade between 1981 and 2009 was nonlinear and ended in 1994. Trends in obesity and diabetes contributed to the end of CAD decline.

Conclusions

Despite continued reductions in smoking and blood pressure values, the previously observed end to the decline in subclinical CAD among nonelderly adult decedents was apparent through 2009, corresponding with increasing obesity and diabetes in that population.

Exercise in pregnancies complicated by obesity: achieving benefits and overcoming barriers

An increasing number of women are entering pregnancy in an overweight or obese state. Obese women and their offspring are at increased risk of adverse perinatal outcomes, which may be improved by regular moderate-intensity antenatal exercise. Current guidelines recommend that all pregnant women without contraindications engage in ≥30 minutes of moderate-intensity exercise on a daily basis. However, obese women are usually less physically active and tend to further reduce activity levels during pregnancy. This commentary summarizes the potential short- and long-term benefits of antenatal exercise in obese pregnant women, highlights the challenges they face, and discusses means of improving their exercise levels. In addition, we make recommendations on exercise prescription for pregnancies complicated by obesity.

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.

Gender and reinforcing associations between socioeconomic disadvantage and body mass over the life course

Using the 1957-1993 data from the Wisconsin Longitudinal Study, we explore reciprocal associations between socioeconomic status (SES) and body mass in the 1939 birth cohort of non-Hispanic white men and women. We integrate the fundamental cause theory, the gender relations theory, and the life course perspective to analyze gender differences in (a) the ways that early socioeconomic disadvantage launches bidirectional associations of body mass and SES and (b) the extent to which these mutually reinforcing effects generate socioeconomic disparities in midlife body mass. Using structural equation modeling, we find that socioeconomic disadvantage at age 18 is related to higher body mass index and a greater risk of obesity at age 54, and that this relationship is significantly stronger for women than men. Moreover, women are more adversely affected by two mechanisms underlying the focal association: the obesogenic effect of socioeconomic disadvantage and the SES-impeding effect of obesity. These patterns were also replicated in propensity score-matching models. We conclude that gender and SES act synergistically over the life course to shape reciprocal chains of two disadvantaged statuses: heavier body mass and lower SES.

Are Baby Boomers healthier than Generation X? A profile of Australia's working generations using National Health Survey data

Background

To determine differences in sociodemographic and health related characteristics of Australian Baby Boomers and Generation X at the same relative age.

Methods

The 1989/90 National Health Survey (NHS) for Boomers (1946–1965) and the 2007/08 NHS for Generation Xers (1966–1980) was used to compare the cohorts at the same age of 25–44 years. Generational differences for males and females in education, employment, smoking, physical activity, Body Mass Index (BMI), self-rated health, and diabetes were determined using Z tests. Prevalence estimates and p-values are reported. Logistic regression models examining overweight/obesity (BMI≥25) and diabetes prevalence as the dependent variables, with generation as the independent variable were adjusted for sex, age, education, physical activity, smoking and BMI(diabetes model only). Adjusted odds ratios (OR) and 95% confidence intervals are reported.

Results

At the same age, tertiary educational attainment was higher among Generation X males (27.6% vs. 15.2% p<0.001) and females (30.0% vs. 10.6% p<0.001). Boomer females had a higher rate of unemployment (5.6% vs. 2.5% p<0.001). Boomer males and females had a higher prevalence of “excellent” self-reported health (35.9% vs. 21.8% p<0.001; 36.3% vs. 25.1% p<0.001) and smoking (36.3% vs. 30.4% p<0.001; 28.3% vs. 22.3% p<0.001). Generation X males (18.3% vs. 9.4% p<0.001) and females (12.7% vs. 10.4% p = 0.015) demonstrated a higher prevalence of obesity (BMI>30). There were no differences in physical activity. Modelling indicated that Generation X were more likely than Boomers to be overweight/obese (OR:2.09, 1.77–2.46) and have diabetes (OR:1.79, 1.47–2.18).

Conclusion

Self-rated health has deteriorated while obesity and diabetes prevalence has increased. This may impact workforce participation and health care utilization in the future.

Intakes of folate, methionine, vitamin B6, and vitamin B12 with risk of esophageal and gastric cancer in a large cohort study

BACKGROUND

Nutrients in the one-carbon metabolism pathway may be involved in carcinogenesis. Few cohort studies have investigated the intakes of folate and related nutrients in relation to gastric and esophageal cancer.

METHODS

We prospectively examined the association between self-reported intakes of folate, methionine, vitamin B6, and vitamin B12 and gastric and esophageal cancer in 492,293 men and women.

RESULTS

We observed an elevated risk of esophageal squamous cell carcinoma with low intake of folate (relative risk (95% confidence interval): Q1 vs Q3, 1.91 (1.17, 3.10)), but no association with high intake. Folate intake was not associated with esophageal adenocarcinoma, gastric cardia adenocarcinoma, or non-cardia gastric adenocarcinoma. The intakes of methionine, vitamin B6, and vitamin B12 were not associated with esophageal and gastric cancer.

CONCLUSION

Low intake of folate was associated with increased risk of esophageal squamous cell carcinoma.

Body mass index and mortality among blacks and whites adults in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial

OBJECTIVE

In a large prospective cohort, we examined the relationship of body mass index (BMI) with mortality among blacks and compared the results to those among whites in this population.

DESIGN AND METHODS

The study population consisted of 7,446 non-Hispanic black and 130,598 white participants, ages 49-78 at enrollment, in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. BMI at baseline, BMI at age 20, and BMI change were calculated using self-reported and recalled height and weight. Relative risks were stratified by race and sex and adjusted for age, education, marital status, and smoking.

RESULTS

During follow-up, 1,495 black and 18,236 white participants died (mean = 13 years). Clear J-shaped associations between BMI and mortality were observed among white men and women. Among black men and women, the bottoms of these curves were flatter, and increasing risks of death with greater BMI were observed only at higher BMI levels (≥35.0). Associations for BMI at age 20 and BMI change also appeared to be stronger in magnitude in whites versus blacks, and these racial differences appeared to be more pronounced among women.

CONCLUSION

Our results suggest that BMI may be more weakly associated with mortality in blacks, particularly black women, than in whites.

Pancreatic cancer death rates by race among US men and women, 1970-2009

BACKGROUND

Few studies have examined trends in pancreatic cancer death rates in the United States, and there have been no studies examining recent trends using age-period-cohort analysis.

METHODS

Annual percentage change in pancreatic cancer death rates was calculated for 1970 to 2009 by sex and race among adults aged 35 to 84 years using US mortality data provided by the National Center for Health Statistics and Joinpoint Regression. Age-period-cohort modeling was performed to evaluate the changes in cohort and period effects. All statistical tests were two-sided.

RESULTS

In white men, pancreatic cancer death rates decreased by 0.7% per year from 1970 to 1995 and then increased by 0.4% per year through 2009. Among white women, rates increased slightly from 1970 to 1984, stabilized until the late 1990s, then increased by 0.5% per year through 2009. In contrast, the rates among blacks increased between 1970 and the late 1980s (women) or early 1990s (men) and then decreased thereafter. Age-period-cohort analysis showed that pancreatic cancer death risk was highest for the 1900 to 1910 birth cohort in men and the 1920 to 1930 birth cohort in women and there was a statistically significant increase in period effects since the late 1990s in both white men and white women (two-sided Wald test, P < .001).

CONCLUSIONS

In the United States, whites and blacks experienced opposite trends in pancreatic cancer death rates between 1970 and 2009 that are largely unexplainable by known risk factors. This study underscores the needs for urgent action to curb the increasing trends of pancreatic cancer in whites and for better understanding of the etiology of this disease.

Pre-eclampsia rates in the United States, 1980-2010: age-period-cohort analysis

OBJECTIVE

To estimate the contributions of biological aging, historical trends, and birth cohort effects on trends in pre-eclampsia in the United States.

DESIGN

Population based retrospective study.

SETTING

National hospital discharge survey datasets, 1980-2010, United States.

PARTICIPANTS

120 million women admitted to hospital for delivery.

MAIN OUTCOME MEASURES

Temporal changes in rates of mild and severe pre-eclampsia in relation to maternal age, year of delivery, and birth cohorts. Poisson regression as well as multilevel age-period-cohort models with adjustment for obesity and smoking were incorporated.

RESULTS

The rate of pre-eclampsia was 3.4%. The age-period-cohort analysis showed a strong age effect, with women at the extremes of maternal age having the greatest risk of pre-eclampsia. In comparison with women delivering in 1980, those delivering in 2003 were at 6.7-fold (95% confidence interval 5.6-fold to 8.0-fold) increased risk of severe pre-eclampsia. Period effects declined after 2003. Trends for severe pre-eclampsia also showed a modest birth cohort effect, with women born in the 1970s at increased risk. Compared with women born in 1955, the risk ratio for women born in 1970 was 1.2 (95% confidence interval 1.1 to 1.3). Similar patterns were also evident for mild pre-eclampsia, although attenuated. Changes in the population prevalence of obesity and smoking were associated with period and cohort trends in pre-eclampsia but did not explain the trends.

CONCLUSIONS

Rates of severe pre-eclampsia have been increasing in the United States and age-period-cohort effects all contribute to these trends. Although smoking and obesity have driven these trends, changes in the diagnostic criteria may have also contributed to the age-period-cohort effects. Health consequences of rising obesity rates in the United States underscore that efforts to reduce obesity may be beneficial to maternal and perinatal health.

Association between state physical education (PE) requirements and PE participation, physical activity, and body mass index change

OBJECTIVE

To determine if state physical education (PE) laws are associated with student physical education attendance and physical activity (PA), and whether physical education and competitive food laws, in conjunction, are associated with lower BMI change.

METHOD

State laws regarding physical education time requirements and competitive foods in 2003 and 2006 were classified as strong, weak, or none, based on codified law ratings obtained from the Classification of Laws Associated with School Students. Laws were linked to student data on PE attendance and physical activity (8th grade, Spring 2007) and BMI change (5th-8th grade, 2004-2007), obtained from the Early Childhood Longitudinal Study (n=5510 students in 40 states).

RESULTS

Girls reported 0.31 more days of activity (95% CI: 0.02, 0.61) and were more likely to attend physical education ≥ 3 days/week (74.1% versus 52.1%, difference=22.0, 95% CI: 2.1, 42.0) if they resided in states with strong physical education laws compared to no physical education laws. Weak physical education laws had modest associations with PE and activity, and there was no evidence that weak laws reduce BMI gain regardless of competitive food laws.

CONCLUSION

Strong physical education laws with specific time requirements may increase physical education attendance and activity in girls. There is insufficient evidence that physical education laws reduce student weight gain.

Birth cohort effects on abdominal obesity in the United States: the Silent Generation, Baby Boomers and Generation X

BACKGROUND

Abdominal obesity predicts a wide range of adverse health outcomes. Over the past several decades, prevalence of abdominal obesity has increased markedly in industrialized countries like the United States No previous analyses, however, have evaluated whether there are birth cohort effects for abdominal obesity. Estimating cohort effects is necessary to forecast future health trends and understand the past population-level trends.

METHODS

This analysis evaluated whether there were birth cohort effects for abdominal obesity for the Silent Generation (born 1925-1945), children of the Great Depression; Baby Boomers (born 1946-1964); or Generation X (born 1965-1980). Cohort effects for prevalence of abdominal obesity were estimated using the median polish method with data collected from the National Health and Nutrition Examination Survey (NHANES) between 1988 and 2008. Respondents were aged 20-74 years.

RESULTS

After taking into account age effects and ubiquitous secular changes, the Silent Generation and Generation X had higher cohort-specific prevalence of abdominal obesity than the Baby Boomers. Effects were more pronounced in women than men.

CONCLUSIONS

This work presents a novel finding: evidence that the birth cohorts of the post-World War II Baby Boom appeared to have uniquely low cohort effects on abdominal obesity. The growing prosperity of the post-World War II US may have exposed the baby-boom generation to lower levels of psychosocial and socioeconomic stress than the previous or subsequent generations. By identifying factors associated with the Baby Boomers' low cohort-specific sensitivity to the obesogenic environment, the obesity prevention community can identify early-life factors that can protect future generations from excess weight gain.

Age, period and cohort effects on adult body mass index and overweight from 1991 to 2009 in China: the China Health and Nutrition Survey

BACKGROUND

Contributions of age-period-cohort effects to increases in BMI and overweight among Chinese adults must be resolved in order to design appropriate interventions. The objectives were to (i) describe the period effect on BMI and overweight among Chinese adults from 1991 to 2009 and assess modification of this effect by age (e.g. cohort effect) and gender, and (ii) quantify the influence of household income and community urbanicity on these effects.

METHODS

Data are from the China Health and Nutrition Survey, a prospective sample across nine provinces in China; 53,298 observations from 18,059 participants were collected over a 19-year period. A series of mixed effects models was used to explicitly assess differences in BMI within individuals over time (age effect) and population-wide differences in BMI over time (period effect), and implicitly assess differences in the experienced period effect across individuals of varying ages (cohort effect).

RESULTS

Stronger period effects on BMI and overweight were observed among males compared with females; and younger cohorts had higher BMIs compared with older cohorts. Simulations predicted that increases in income and urbanicity in the order of magnitude of that observed from 1991 to 2009 would correspond to shifts in the BMIs of average individuals of 0.07 and 0.23 kg/m(2), respectively.

CONCLUSIONS

Although period effects had a stronger influence on the BMI of males, interventions should not overlook younger female cohorts who are at increased risk compared with their older counterparts.

Teaching Goal-Setting for Weight-Gain Prevention in a College Population: Insights from the CHOICES Study

PURPOSE

This article describes the effectiveness of goal setting instruction in the CHOICES (Choosing Healthy Options in College Environments and Settings) study, an intervention evaluating the effectiveness of weight gain prevention strategies for 2-year college students.

METHODS

Four hundred and forty-one participants from three community colleges were recruited. Participants randomized into the intervention (n=224) enrolled in a course that taught strategies to help maintain or achieve a healthy weight. Participants were instructed in SMART (Specific, Measurable, Attainable, Realistic, Time-based) and behavioral goal-setting practices. Throughout the course, participants set goals related to improving their sleep, stress-management, exercise, and nutrition."

RESULTS

Intervention participants set four hundred eighteen goals. Each goal was carefully evaluated. The efforts to teach behavioral goal-setting strategies were largely successful; however efforts to convey the intricacies of SMART goal-setting were not as successful.

CONCLUSIONS

Implications for effective teaching of skills in setting SMART behavioral goals were realized in this study. The insights gained from the goal-setting activities of this study could be used to guide educators who utilize goals to achieve health behavior change.

RECOMMENDATIONS

Based on the results of this study, it is recommended that very clear and directed instruction be provided in addition to multiple opportunities for goal-setting practice. Implications for future interventions involving education about goal-setting activities are discussed.