Flexible age-period-cohort modelling illustrated using obesity prevalence data

Twenty-year trend in comorbidity score among adults aged 50-85 years in Lombardy, Italy: Age-Cohort-Period analysis and future trends

OBJECTIVES

To assess the effects of age, birth cohort, and period on comorbidity rates as well as project their future trends over the next 25 years.

DESIGN

Population-based retrospective observational study.

SETTING

Record linkage from the population-based healthcare utilisation database of Lombardy, Italy, between 2004 and 2023.

PARTICIPANTS

All beneficiaries of the Italian National Health Service (NHS) aged 50-85 years residing in Lombardy. Data were separately analysed for each year from 2004 to 2023, with thus the availability of 20 study populations.

PRIMARY OUTCOME MEASURES

Comorbidities were traced via the medical services provided by the NHS, and the overall quantification was obtained by the Multisource Comorbidity Score, which was developed and validated for the Italian population. The temporal analysis of the 20 yearly temporal comorbidity rates was obtained by the Age-Cohort-Period models. The comorbidities prevalence trends were forecasted from 2025 to 2050.

RESULTS

From 2004 to 2023, the prevalence of comorbidities declined from 46% to 40% in men and from 47% to 42% in women. An increase in prevalence between the ages of 50 and 85 years was observed for both women (from 33% to 63%) and men (from 29% to 67%). A declining prevalence was observed among cohorts born from 1922 to 1970 for both women (by 33%) and men (by 50%). A continued decline in the absolute number and prevalence rate of comorbidities is expected for both women and men until 2050.

CONCLUSIONS

The decline in ageing-related comorbidity prevalence over time may persist up to 2050. Improved medical care and public health initiatives benefiting individuals born in more recent years may counterbalance the expected trend of increasing comorbidity prevalence due to population ageing.

Mortality rates for Parkinson's disease are increasing in Spain. An age-period-cohort and joinpoint analysis of mortality rates from 1981 to 2020

BACKGROUND

Mortality in Parkinson's disease is increasing worldwide, but Spanish data need further study.

OBJECTIVE

To analyse the mortality trends of Parkinson's disease in Spain between 1981 and 2020.

METHODS

This observational retrospective study assessed the Parkinson's disease mortality data from 1981 to 2020 collected from the National Statistics Institute of Spain. Age-standardised mortality rates were analysed by age and sex groups, detecting significant mortality trends through a joinpoint analysis. Age-period-cohort effect and potential years of life lost analyses were conducted. The European standard population of 2013 was considered for the analyses.

RESULTS

A total of 88 034 deaths were assessed. The overall age-standardised mortality rate rose throughout the period from 3.67 to 8.57 per 100 000 inhabitants. Mortality rates in men were higher than in women, 11.63 versus 6.57 deaths per 100 000 inhabitants. The sex ratio showed an increase in premature mortality in men during 2020. The overall joinpoint analysis recorded a rise in mortality, primarily since the 20th century, mainly in male and older groups, that matched with a period effect. The age effect was detected, confirming higher mortality at an older age. The analysis of potential years of life lost detected a growth in this rate, changing from 0.66 in 1981 to 1.06 in 2020.

CONCLUSIONS

Mortality data for Parkinson's disease in Spain rose significantly in forty years. Mortality rate was higher in the male and age group above 75 years of age. The sex ratio showed premature mortality in men in 2020, which will need further study.

Age, period and cohort analysis of suicide trends in Australia, 1907-2020

Background

Suicide rates have been increasing in Australia since the mid-2000s, especially for women aged ≤25 years. We conducted an age-period-cohort study to investigate these recent trends in the context of historical Australian suicide rates.

Methods

Data on annual suicides in Australia from 1907 to 2020 were extracted from the General Record of Incidence of Mortality. We modelled age-specific effects for a reference cohort, after adjustment for period effects.

Findings

We found evidence of age, cohort and period effects. For males, compared to the cohort born in 1946-1950, rates were higher for all cohorts born after this year. The period effect showed peaks in the risk of male suicide in the mid 1960s and the early 1990s, followed by a decline in risk until early 2010, after which the risk began to rise again. For females, compared to the cohort born in 1946-1950, the risk of suicide was higher for all cohorts born after this, with the highest risk for those born in 2006-2010. The period effect for females showed an elevated risk of suicide in the mid 1960s followed by a sharp decline, and an increase in risk after 2009.

Interpretation

Suicide rates in Australia have fluctuated substantially over time and appear to be related to age trends as well as period and cohort trends. Advocacy and policy making tends to focus on contemporaneous changes in suicide rates. However, this study shows that focusing only on year-on-year changes in suicide rates ignores underlying trends for specific population birth-cohorts.

Funding

None.

Trends in uterine cancer incidence in the United States: The contribution of age, period and cohort effects

OBJECTIVE

In the U.S., uterine cancer incidence is rising, with racial and ethnic minorities experiencing the largest increases. We performed age-period-cohort analyses using novel methods to examine the contribution of age at diagnosis (age), year of diagnosis (period), and birth cohort (cohort), to trends in uterine cancer incidence.

METHODS

We used uterine cancer incidence data from the Surveillance, Epidemiology, and End Result (SEER) 12 database (1992-2019), and performed hysterectomy-correction. We generated hexamaps to visualize age, period, and cohort effects, and used mutual information to estimate the percent contribution of age, period, and cohort effects, individually and combined, on uterine cancer incidence, overall and by race and ethnicity and histology.

RESULTS

Hexamaps showed an increase in uterine cancer in later time periods, and a cohort effect around 1933 showing a lower incidence compared with earlier and later cohorts. Age, period, and cohort effects combined contributed 86.6% (95% CI: 86.4%, 86.9%) to the incidence. Age effects had the greatest contribution (65.1%, 95% CI: 64.3%, 65.9), followed by cohort (20.7%, 95% CI: 20.1%, 21.3%) and period (14.2%, 95% CI: 13.7%, 14.8%) effects. Hexamaps showed higher incidence in recent years for non-Hispanic Blacks and non-endometrioid tumors.

CONCLUSIONS

Age effects had the largest contribution to uterine cancer incidence, followed by cohort and period effects overall and across racial and ethnic groups and histologies.

IMPACT

These findings can inform uterine cancer modeling studies on the effects of interventions that target risk factors which may vary across age, period, or cohort.

Gender differences in the prevalence of mental distress in East and West Germany over time: a hierarchical age-period-cohort analysis, 2006-2021

PURPOSE

Mental distress has become a major public health concern. Temporal trends in psychological distress are complex and depend on numerous factors. In this study, we examined age-period-cohort effects for mental distress including gender and German region over a 15 years' time span.

METHODS

Data on mental distress from ten cross-sectional surveys of the general German population, covering the years from 2006 to 2021, was used. Hierarchical age-period-cohort analyses including gender and German region as predictors were performed to disentangle age, period, and cohort effects. The Patient Health Questionnaire-4 was used as a brief screener for mental distress.

RESULTS

We found significant period and cohort effects, with peek values for mental distress in the years 2017 and 2020 and for the oldest birth cohort (born before 1946). Age did not affect mental distress when cohort- and period effects as well as gender and German region were considered. An interaction effect for gender and the German region was found. Women in West Germany reported significantly higher mental distress compared to women in East Germany. Compared to men, women reported the highest prevalence in both regions.

CONCLUSION

Important political events as well as major crises can lead to an increase of mental distress in societies. Furthermore, an association between birth cohort and mental distress could be linked to socialization effects of that certain time, causing traumatic experiences or a specific coping style within this cohort group. Prevention and intervention strategies could benefit from acknowledging structural differences linked to period and cohort effects.

The Role of Cdc42 in the Insulin and Leptin Pathways Contributing to the Development of Age-Related Obesity

Age-related obesity significantly increases the risk of chronic diseases such as type 2 diabetes, cardiovascular diseases, hypertension, and certain cancers. The insulin-leptin axis is crucial in understanding metabolic disturbances associated with age-related obesity. Rho GTPase Cdc42 is a member of the Rho family of GTPases that participates in many cellular processes including, but not limited to, regulation of actin cytoskeleton, vesicle trafficking, cell polarity, morphology, proliferation, motility, and migration. Cdc42 functions as an integral part of regulating insulin secretion and aging. Some novel roles for Cdc42 have also been recently identified in maintaining glucose metabolism, where Cdc42 is involved in controlling blood glucose levels in metabolically active tissues, including skeletal muscle, adipose tissue, pancreas, etc., which puts this protein in line with other critical regulators of glucose metabolism. Importantly, Cdc42 plays a vital role in cellular processes associated with the insulin and leptin signaling pathways, which are integral elements involved in obesity development if misregulated. Additionally, a change in Cdc42 activity may affect senescence, thus contributing to disorders associated with aging. This review explores the complex relationships among age-associated obesity, the insulin-leptin axis, and the Cdc42 signaling pathway. This article sheds light on the vast molecular web that supports metabolic dysregulation in aging people. In addition, it also discusses the potential therapeutic implications of the Cdc42 pathway to mitigate obesity since some new data suggest that inhibition of Cdc42 using antidiabetic drugs or antioxidants may promote weight loss in overweight or obese patients.

Trends in alcohol-related liver disease mortality in Australia: An age-period-cohort perspective

BACKGROUND AND AIMS

There have been few systematic attempts to examine how alcohol-related mortality has changed in Australia, and no studies that have explored cohort effects in alcohol-related mortality. This study uses more than 50 years of data to measure age, period and cohort trends in alcohol-related liver disease (ALD) mortality.

DESIGN, SETTING AND CASES

This was a retrospective age-period-cohort analysis of total Australian ALD mortality data from 1968 to 2020 in Australia. There was a total of 35 822 deaths-27 208 men (76%) and 8614 women (24%).

MEASUREMENTS

Deaths from ALD were grouped into 5-year age groups and periods (e.g. deaths for 20-24-year-olds between 1968 and 1972 were combined).

FINDINGS

ALD mortality peaked in the late 1970s and early 1980s for both men and women. In age-period-cohort models, mortality was highest for cohorts born 1915-30. For example, men born between 1923 and 1927 had a relative risk of 1.58 [95% confidence interval (CI) = 1.52, 1.64] compared with men born between 1948 and 1952. For women, there was an increase in risk for cohorts born in the 1960s [e.g. the 1963-67 cohort had a relative risk (RR) of 1.16 (95% CI = 1.07, 1.25) compared with women born in 1948-52]. For men, there was a broad decline in mortality over time [e.g. in 2020, the RR was 0.87 (95% CI = 0.82, 0.92) compared with the reference year of 2000]. For women, mortality declined until 2000 and has been stable since.

CONCLUSIONS

Alcohol-related liver disease mortality has declined across the Australian population since the 1970s and 1980s partly due to cohort-specific shifts as the highest-risk birth cohorts age. For women, this decline had stalled by the year 2000, and cohorts of women born during the 1960s were at higher risk than earlier cohorts, suggesting the need for thoughtful interventions as this population enters its highest-risk years for ALD mortality.

Age, period and cohort effects on alcohol-related risky behaviours in Australia from 2001 to 2016

AIMS

The aim of this study is to examine age, period and birth cohort trends in the prevalence of any alcohol-related risky behaviour and to compare these trends between men and women.

DESIGN AND SETTING

We used an age-period-cohort analysis of repeated cross-sectional survey data from the Australian National Drug Strategy Household Survey from 2001 to 2016.

PARTICIPANTS

Participants were 121 281 people aged 14-80 years who reported consuming alcohol in the past 12 months.

MEASUREMENTS

Any risky behaviour undertaken while under the influence of alcohol in the past 12 months (e.g. operating a motor vehicle) was measured: male or female.

FINDINGS

Controlling for age and cohort, cubic spline models showed that any alcohol-related risky behaviour declined with time among participants who consumed alcohol [2016 versus 2007 rate ratio (RR) = 0.80, 95% confidence interval (CI) = 0.76-0.84]. Risky behaviour peaked in the 1954 birth cohort (1954 versus 1971 RR = 1.42, 95% CI = 1.30-1.55) and then steadily declined with more recent birth cohorts (2002 versus 1971 RR = 0.32, 95% CI = 0.27-0.39). Risky behaviour peaked at age 21 years, followed by steady decline and stabilization at approximately age 70 years. Males were overall twice as likely as females to report alcohol-related risky behaviour (RR = 2.10, 95% CI = 1.84-2.39), but this effect was smaller in cohorts born after 1980 [1980 prevalence rate ratios (PRR) = 2.09, 95% CI = 1.81-2.43; 2002 PRR = 1.31, 95% CI = 1.03-1.68].

CONCLUSIONS

Alcohol-related risky behaviour in Australia has declined generally since 2001, with rates for recent cohorts having the sharpest decline. Risky behaviour remains most prevalent in young adults, and the male-female gap in risky behaviour is closing for more recent birth cohorts. These trends are consistent with alcohol consumption trends observed in Australia and world-wide.

Most degenerative cervical myelopathy remains undiagnosed, particularly amongst the elderly: modelling the prevalence of degenerative cervical myelopathy in the United Kingdom

BACKGROUND

Degenerative cervical myelopathy (DCM) is a poorly recognised form of spinal cord injury which arises when degenerative changes in the cervical spine injure the spinal cord. Timely surgical intervention is critical to preventing disability. Despite this, DCM is frequently undiagnosed, and may be misconstrued as normal ageing. For a disease associated with age, we hypothesised that the elderly may represent an underdiagnosed population. This study aimed to evaluate this hypothesis by comparing age-stratified estimates of DCM prevalence based on spinal cord compression (SCC) data with hospital-diagnosed prevalence in the UK.

METHODS

We queried the UK Hospital Episode Statistics database for admissions with a primary diagnosis of DCM. Age-stratified incidence rates were calculated and extrapolated to prevalence by adjusting population-level life expectancy to the standardised mortality ratio of DCM. We compared these figures to estimates of DCM prevalence based on the published conversion rate of asymptomatic SCC to DCM.

RESULTS

The mean prevalence of DCM across all age groups was 0.19% (0.17, 0.21), with a peak prevalence of 0.42% at age 50-54 years. This contrasts with estimates from SCC data which suggest a mean prevalence of 2.22% (0.436, 2.68) and a peak prevalence of 4.16% at age > 79 years.

CONCLUSIONS

To our knowledge, this is the first study to estimate the age-stratified prevalence of DCM and estimate underdiagnosis. There is a substantial difference between estimates of DCM prevalence derived from SCC data and UK hospital activity data. This is greatest amongst elderly populations, indicating a potential health inequality.

Past, present, and future trends of overweight and obesity in Belgium using Bayesian age-period-cohort models

Background

Overweight and obesity are one of the most significant risk factors of the twenty-first century related to an increased risk in the occurrence of non-communicable diseases and associated increased healthcare costs. To estimate the future impact of overweight, the current study aimed to project the prevalence of overweight and obesity to the year 2030 in Belgium using a Bayesian age-period-cohort (APC) model, supporting policy planning.

Methods

Height and weight of 58,369 adults aged 18+ years, collected in six consecutive cross-sectional health interview surveys between 1997 and 2018, were evaluated. Criteria used for overweight and obesity were defined as body mass index (BMI) ≥ 25, and BMI ≥ 30. Past trends and projections were estimated with a Bayesian hierarchical APC model.

Results

The prevalence of overweight and obesity has increased between 1997 and 2018 in both men and women, whereby the highest prevalence was observed in the middle-aged group. It is likely that a further increase in the prevalence of obesity will be seen by 2030 with a probability of 84.1% for an increase in cases among men and 56.0% for an increase in cases among women. For overweight, it is likely to see an increase in cases in women (57.4%), while a steady state in cases among men is likely. A prevalence of 52.3% [21.2%; 83.2%] for overweight, and 27.6% [9.9%; 57.4%] for obesity will likely be achieved in 2030 among men. Among women, a prevalence of 49,1% [7,3%; 90,9%] for overweight, and 17,2% [2,5%; 61,8%] for obesity is most likely.

Conclusions

Our projections show that the WHO target to halt obesity by 2025 will most likely not be achieved. There is an urgent necessity for policy makers to implement effective prevent policies and other strategies in people who are at risk for developing overweight and/or obesity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13685-w.

Obesity Incidence in U.S. Children and Young Adults: A Pooled Analysis

INTRODUCTION

Obesity prevalence among children and adolescents has risen sharply, yet there is a limited understanding of the age-specific dynamics of obesity as there is no single nationally representative cohort following children into young adulthood. Investigators constructed a pooled data set of 5 nationally representative panels and modeled age-specific obesity incidence from childhood into young adulthood.

METHODS

This longitudinal prospective follow-up used 718,560 person-years of observation in a pooled data set of 5 high-quality nationally representative panels-National Longitudinal Survey of Youth 1979 and 1997, National Longitudinal Study of Adolescent Health, and Early Childhood Longitudinal Study-Kindergarten cohorts of 1998 and 2011-constructed by the authors, covering 1980-2016. Differences in obesity incidence across birth cohorts and disparities in obesity incidence by sex and race/ethnicity (non-Hispanic Black, Hispanic, and non-Hispanic White) were tested in multivariate models. Data were analyzed from September 2018 to October 2021.

RESULTS

Obesity incidence increased by approximately 6% for each 1 year of age (hazard ratio=1.06, 95% CI=1.05, 1.07); however, incidence was nonlinear, exhibiting an inverted "U"-shaped pattern before 15 years of age and then rising from adolescence through 30 years. Obesity incidence more than doubled between the cohorts born in 1957-1965 and those born in 1974-1985 during adolescence. There was no significant change among those born in 1991-1994 and 2003-2006 up to age 15 years. Compared with non-Hispanic White children, non-Hispanic Black and Hispanic children had higher obesity incidence in all study cohorts. The magnitude of these disparities on the relative scale remained stable throughout the study period.

CONCLUSIONS

Although many children become obese before the age of 10, obesity incidence rises from about 15 years into early adulthood, suggesting that interventions are required at multiple developmental stages.

Body mass index and the diagnosis of endometriosis: Findings from a national data linkage cohort study

BACKGROUND

Women with lower body mass index (BMI) have a higher risk of surgically confirmed endometriosis but this finding runs counterintuitive to the oestrogen-dependent theory for the disease. Increasingly, endometriosis is diagnosed via non-surgical methods. We examined BMI at age 18-23 years, and changes in BMI, and the risk of endometriosis according to the diagnostic method.

METHODS

We analysed data from 11 794 young women, born in 1989-95, who completed six surveys as part of an Australian, longitudinal cohort study between 2013 and 2018. Women's survey responses were linked to administrative health records to identify endometriosis. Cox proportional hazards models modelled associations between BMI at age 18-23 years, and changes in BMI, and endometriosis. Analyses were stratified by the diagnostic method of endometriosis: clinically confirmed endometriosis (based on hospital discharge diagnosis) versus clinically suspected endometriosis (women's reports of physician-diagnosed endometriosis).

RESULTS

There were 223 cases of clinically confirmed endometriosis and 396 cases of clinically suspected endometriosis. Women who gained weight after age 18-23 had lower risk of clinically confirmed endometriosis than women without endometriosis whose weight remained stable (HR = 0.64, 95% CI = 0.47-0.88). Women who were overweight (HR = 1.29, 95% CI = 1.01-1.66) at age 18-23 had higher risk of clinically suspected endometriosis than women of normal weight without endometriosis.

CONCLUSIONS

The risk of clinically confirmed endometriosis was lower among women who gained weight compared to women with stable weight. The risk of clinically suspected endometriosis was higher among women who were overweight compared to normal weight.

An Age-Period-Cohort Approach to Analyse Late-Life Depression Prevalence in Six European Countries, 2004-2016

Late-life depression is a condition that affects an ever-growing share of the population in ageing societies. While depression prevalence varies across countries for a myriad of reasons, generational factors, expressed in the shared experience of birth cohorts, may also play a part in such differentials. This paper describes the presence of age, period, and cohort (APC) effects in late-life depression prevalence trends (for adults aged 50 and above) for selected countries in Europe, using the Survey of Health and Ageing and Retirement of Europe (SHARE). We analysed six countries during the 2004-2016 period: Denmark, Sweden, and Germany, with a lower baseline prevalence, and Italy, Spain, and France, with a higher baseline prevalence. By applying a set of APC statistical models to visualise linear and nonlinear effects, we found that all countries followed a J-shaped curve when describing the transversal and longitudinal age trajectories of late-life depression. We also found a combination of nonlinear effects present in Germany, France and Sweden in males, indicating that younger male cohorts had a higher relative risk of depression. In females, we found nonlinear cohort effects, indicating that younger and older cohorts presented a higher risk of depression in Sweden and Germany and a lower risk in Spain. The presence of an increased risk for younger male cohorts may be indicative of a new trend in some countries, which may reduce the sex gap in prevalence. Future analysis should focus on the causes and mechanisms that lead to differential risks across cohorts.

Pre-pregnancy lifestyle characteristics and risk of miscarriage: the Australian Longitudinal Study on Women's Health

Background

Previous studies of lifestyle characteristics and risk of miscarriage have mostly been retrospective and failed to account for induced abortions. We examine whether pre-pregnancy body-mass index, alcohol intake and smoking influence the risk of miscarriage after accounting for induced abortions.

Methods

We conducted a prospective cohort study of 9213 women with 26,594 pregnancies participating in the Australian Longitudinal Study on Women’s Health. We examined whether body-mass index, smoking and alcohol intake prior to pregnancy was associated with miscarriage. We estimated adjusted relative risks (RR) using generalized estimating equations with an exchangeable correlation matrix. We explored the impact of accounting for induced abortion by first excluding all induced abortions, and secondly including 50% of induced abortions in the comparison group.

Results

Of the 26,592 pregnancies which occurred during the follow-up period, 19% ended in a miscarriage. We observed an increased risk of miscarriage according to pre-pregnancy obesity compared to normal weight (adjusted RR 1.13; 95% CI 1.05, 1.21), smoking between 10 and 19 cigarettes per day compared to not smoking (adjusted RR 1.13; 95% CI 1.02, 1.25), but not smoking 20 or more cigarettes per day (adjusted RR 1.07; 95% CI 0.94, 1.21) and risky drinking (≥2 units per day; adjusted RR 1.15; 95% CI 1.03, 1.28) compared to low risk drinking (< 2 units per day). The results for smoking (adjusted RR 1.09 for 10–19 cigarettes per day; 95% CI 0.98, 1.21) was attenuated after including 50% of induced abortions in the comparison group.

Conclusions

We observed a modest increased risk of miscarriage according to obesity and risky alcohol intake prior to pregnancy. There was no evidence of a dose-response relationship with smoking, and the association between smoking and risk of miscarriage was attenuated after accounting for induced abortions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04482-9.

The impact of pertussis vaccine programme changes on pertussis disease burden in Manitoba, 1992-2017-an age-period-cohort analysis

BACKGROUND

Changes to pertussis vaccination programmes can have impacts on disease burden that should be estimated independently from factors such as age- and period-related trends. We used age-period-cohort (APC) models to explore pertussis incidence in Manitoba over a 25-year period (1992-2017).

METHODS

We identified all laboratory-confirmed cases of pertussis from Manitoba's Communicable Diseases Database and calculated age-standardized incidence rates. We used APC models to investigate trends in pertussis incidence.

RESULTS

During the study period, 2479 cases were reported. Age-standardized rates were highest during a large outbreak in 1994 (55 cases/100 000 person-years), with much lower peaks in 1998, 2012 and 2016. We saw strong age and cohort effects in the APC models, with a steady decrease in incidence with increasing age and increased risk in the cohort born between 1980 and 1995.

CONCLUSIONS

The highest risk for pertussis was consistently in young children, regardless of birth cohort or time period. The 1981 programme change to an adsorbed whole-cell pertussis vaccine with low effectiveness resulted in reduced protection in the 1981-95 birth cohort and contributed to the largest outbreak of disease during the 25-year study period.

Adverse generational changes in obesity development converge at midlife without increased cardiometabolic risk

OBJECTIVE

Obesity is becoming a global public health problem, but it is unclear how it impacts different generations over the life course. Here, a descriptive analysis of the age-related changes in anthropometric measures and related cardiometabolic risk factors across different generations was performed.

METHODS

The development of anthropometric measures and related cardiometabolic risk factors was studied during 26 years of follow-up in the Doetinchem Cohort Study (N = 6,314 at baseline). All analyses were stratified by sex and generation, i.e., 10-year age groups (20-29, 30-39, 40-49, and 50-59 years) at baseline. Generalized estimating equations were used to test for generational differences.

RESULTS

Weight, BMI, waist circumference, and prevalence of overweight and obesity were higher, in general, in the younger generations during the first 10 to 15 years of follow-up. From age 50 to 59 years onward, these measures converged in all generations of men and women. Among cardiometabolic risk factors, only type 2 diabetes showed an unfavorable shift between the two oldest generations of men.

CONCLUSIONS

It was observed that, compared with the older generations, the younger generations had obesity at an earlier age but did not reach higher levels at midlife and beyond. This increased exposure to obesity was not (yet) associated with increased prevalence of cardiometabolic risk factors.

Physical activity in the management of obesity in adults: A position statement from Exercise and Sport Science Australia

This Position Statement examines the evidence for physical activity in weight and adiposity loss, prevention of weight and adiposity gain, and in weight regain in adults, and provides guidance on implications for exercise practitioners. Research evidence indicates that >150 min but preferably 300 min per week of aerobic activity of at least moderate intensity is required to prevent weight and adiposity gain, and at least the upper end of this range of activity to prevent weight regain after weight loss. For meaningful weight and total adiposity loss, a minimum of 300-420 min per week of aerobic activity of at least moderate intensity is required. The evidence around the volume of aerobic physical activity required to reduce central adiposity is emerging, and research suggests that it may be substantially less than that required for weight loss. The impact of high-intensity physical activity and resistance exercise for weight management is uncertain. During consultations for weight management, exercise practitioners should advise that metabolic and cardiovascular health benefits can be achieved with physical activity at any weight, and irrespective of weight change.

Assessing Health Consequences of Vitamin D Fortification Utilizing a Societal Experiment Design: Methodological Lessons Learned from the D-Tect Project

By utilizing historical changes in Danish legislation related to mandatory vitamin D fortification of margarine, which was implemented in the mid 1930s and abruptly abandoned in June 1985, the studies in the D-tect project investigated the effects of vitamin D on health outcomes in individuals, who during gestation were exposed or unexposed to extra vitamin D from fortified margarine. This paper reviews and narratively summarizes the analytic approaches alongside the results of the societal fortification experiment studies from the D-tect project and addresses the challenges in designing societal experiment studies and evaluating their results. The latter are discussed as lessons learned that may be useful for designers of similar studies, expected to be extensively utilized while researching the health consequences of the COVID-19 pandemic by comparing individuals born before and after the epidemic. In the D-tect project, 16 articles based on the societal fortification experiment were published analyzing 10 different outcomes and using different statistical approaches. Lessons learned included the detail of the analysis of the historical information on the exposure, availability and validity of the outcome data, variety of analytical approaches, and specifics concerning vitamin D effect evaluation, such as consideration of the influence of sunshine or season. In conclusion, the D-tect project clearly demonstrated the cost-effectiveness and research potential of natural- or societal-experiment-based studies.

Age period cohort analysis of chewing ability in Korea from 2007 to 2018

There have been marked improvements in oral health in Korea during the past 10 years, including chewing ability. We sought to disentangle age, period, and cohort effects in chewing ability between 2007 and 2018. We analyzed data from the Korea National Health and Nutrition Examination Survey. The main variable was chewing difficulty, which was assessed among participants aged 20 years and older. APC analysis revealed three trends in chewing difficulty: (1) there was an increase in chewing difficulty starting at around 60 years of age (age effect), (2) there was a steady decrease in chewing difficulty during the observation period (period effect), and (3) chewing ability improved with each successive generation born after 1951 (cohort effect). Regarding recent improvements in chewing ability, cohort effects were somewhat more important than period effects.

Trends in mortality from lupus in Spain from 1980 to 2018

BACKGROUND

Recent studies suggest that Systemic lupus erythematosus (SLE) mortality rates in Spain are decreasing. However, SLE mortality in Spain has been poorly studied. The purpose of study is to assess the temporal trends of mortality rates in the Spanish population with SLE from 1980 to 2018.

METHODS

Death records and mid-year population data were collected from the National Statistics Institute. Age-standardized mortality rates were calculated for overall population and for each sex and age group. Significant changes in mortality trends were identified by Joinpoint regressions. Also, an Age-period-cohort (APC) and Potential Years of Life Lost (PYLL) analysis was carried out to know the burden of SLE disease.

RESULTS

The overall SLE mortality rates in Spain has experimented an increased through the last 39 years. Mortality rates from the period 1980-1984 was 0.83 per 1.000.000 inhabitants, reaching the value to 1.77 cases per 1.000.000 from the period 2014-2018. A decreasing trend has been observed since 1999.

CONCLUSIONS

SLE mortality rate has increased in Spain between 1980 and 1999, with a sustained decrease up to our days.

Dynamics of Anthropometric Indices in a Large Paired Cohort With 10 Years of Follow-Up: Paving the Way to Sarcopenic Obesity

Introduction: Paired cohort investigations assessing the evolution of anthropometric indices are scarce. Here we assessed the 10-year evolution of BMI, total body fat, and lean body mass in 50,019 participants aged 18-90 years at the time of first assessment. Material and Methods: A retrospective cohort study using an electronic database that contains anonymized, longitudinal data from Primary Care medical records covering the 2007-2008 and 2017-2018 periods. Total body fat was estimated using the Clínica Universidad de Navarra-Body Adiposity Estimator formula, and the Hume formula was applied to estimate lean body mass. Results: The mean BMI of participants <60 years old in the 2007-2008 period increased significantly, from 27.5 to 28.3 kg/m² (p < 0.001). However, the BMI of older subjects decreased during the next decade, from 28.9 to 28.3 kg/m² (p < 0.001). The estimated total body fat showed a continuous progressive increase over all ages. Finally, lean body mass showed a progressive increase until the 40s, with a plateau between 40-45 years old and an uninterrupted decrease until older ages. Also, subjects who increased their BMI by 2 kg/m² during the 10-year period were mainly women and younger at baseline, with a lower initial BMI and total body fat in comparison with those who experienced a BMI decrease of ≥2.0 kg/m². Conclusion: The evolutions of BMI and the estimated body compositions reported here confirm that the adverse decrease in lean body mass begins in middle age. The proportion of older subjects is important when evaluating overweight and obesity prevalence in cross-sectional studies.