Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

BACKGROUND

Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.

METHODS

We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5-19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school-aged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median).

FINDINGS

From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness.

INTERPRETATION

The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity.

FUNDING

UK Medical Research Council, UK Research and Innovation (Research England), UK Research and Innovation (Innovate UK), and European Union.

Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants

BACKGROUND

Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories.

METHODS

We used data from 1990 to 2019 on people aged 30-79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age.

FINDINGS

The number of people aged 30-79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306-359) million women and 317 (292-344) million men in 1990 to 626 (584-668) million women and 652 (604-698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55-62) of women and 49% (46-52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43-51) of women and 38% (35-41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20-27) for women and 18% (16-21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran.

INTERPRETATION

Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings.

FUNDING

WHO.

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions.

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

BACKGROUND

Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents.

METHODS

For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5-19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence.

FINDINGS

We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9-10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes-gaining too little height, too much weight for their height compared with children in other countries, or both-occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls.

INTERPRETATION

The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks.

FUNDING

Wellcome Trust, AstraZeneca Young Health Programme, EU.

Parental Education and Genetics of BMI from Infancy to Old Age: A Pooled Analysis of 29 Twin Cohorts

OBJECTIVE

The objective of this study was to analyze how parental education modifies the genetic and environmental variances of BMI from infancy to old age in three geographic-cultural regions.

METHODS

A pooled sample of 29 cohorts including 143,499 twin individuals with information on parental education and BMI from age 1 to 79 years (299,201 BMI measures) was analyzed by genetic twin modeling.

RESULTS

Until 4 years of age, parental education was not consistently associated with BMI. Thereafter, higher parental education level was associated with lower BMI in males and females. Total and additive genetic variances of BMI were smaller in the offspring of highly educated parents than in those whose parents had low education levels. Especially in North American and Australian children, environmental factors shared by co-twins also contributed to the higher BMI variation in the low education level category. In Europe and East Asia, the associations of parental education with mean BMI and BMI variance were weaker than in North America and Australia.

CONCLUSIONS

Lower parental education level is associated with higher mean BMI and larger genetic variance of BMI after early childhood, especially in the obesogenic macro-environment. The interplay among genetic predisposition, childhood social environment, and macro-social context is important for socioeconomic differences in BMI.

Childcare before age 6 and body mass index at age 7 years in a cohort of Danish children

BACKGROUND

Previous studies show inconsistent associations between childcare and obesity.

AIMS

Our prior work demonstrated that childcare in infancy was associated with higher weight in a cohort of Danish children. Here, we extend this work and examine childcare through 6 years and body mass index (BMI) at age 7 years.

MATERIALS AND METHODS

We examined 24 714 children in the Danish National Birth Cohort who were also in the Childcare Database. We conducted multivariable linear regressions examining children prior to age 6, overall and by type (daycare, crèche, age-integrated and kindergarten), and BMI z-score at 7 years, stratifying on maternal socio-occupational status.

RESULTS

A total of 19 760 (80.0%) children attended childcare before age 6. Childcare prior to age 6 was associated with BMI z-score at 7 years (0.004 units per each additional 6 months of care; 95% CI: 0.001, 0.008; p = 0.01). Childcare in a kindergarten was the only type of care associated with BMI (0.009 units; 95% CI: 0.003, 0.02; p = 0.01). For children of higher socio-occupational status mothers, childcare was associated with a 0.008 unit increase in BMI (95% CI: 0.004, 0.01; p > 0.001).

CONCLUSIONS

Childcare was weakly associated with later BMI. This relationship was more pronounced in children from higher socio-occupational status mothers and children in kindergarten care.

Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults

BACKGROUND

Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare trends with those of adults.

METHODS

We pooled 2416 population-based studies with measurements of height and weight on 128·9 million participants aged 5 years and older, including 31·5 million aged 5-19 years. We used a Bayesian hierarchical model to estimate trends from 1975 to 2016 in 200 countries for mean BMI and for prevalence of BMI in the following categories for children and adolescents aged 5-19 years: more than 2 SD below the median of the WHO growth reference for children and adolescents (referred to as moderate and severe underweight hereafter), 2 SD to more than 1 SD below the median (mild underweight), 1 SD below the median to 1 SD above the median (healthy weight), more than 1 SD to 2 SD above the median (overweight but not obese), and more than 2 SD above the median (obesity).

FINDINGS

Regional change in age-standardised mean BMI in girls from 1975 to 2016 ranged from virtually no change (-0·01 kg/m2 per decade; 95% credible interval -0·42 to 0·39, posterior probability [PP] of the observed decrease being a true decrease=0·5098) in eastern Europe to an increase of 1·00 kg/m2 per decade (0·69-1·35, PP>0·9999) in central Latin America and an increase of 0·95 kg/m2 per decade (0·64-1·25, PP>0·9999) in Polynesia and Micronesia. The range for boys was from a non-significant increase of 0·09 kg/m2 per decade (-0·33 to 0·49, PP=0·6926) in eastern Europe to an increase of 0·77 kg/m2 per decade (0·50-1·06, PP>0·9999) in Polynesia and Micronesia. Trends in mean BMI have recently flattened in northwestern Europe and the high-income English-speaking and Asia-Pacific regions for both sexes, southwestern Europe for boys, and central and Andean Latin America for girls. By contrast, the rise in BMI has accelerated in east and south Asia for both sexes, and southeast Asia for boys. Global age-standardised prevalence of obesity increased from 0·7% (0·4-1·2) in 1975 to 5·6% (4·8-6·5) in 2016 in girls, and from 0·9% (0·5-1·3) in 1975 to 7·8% (6·7-9·1) in 2016 in boys; the prevalence of moderate and severe underweight decreased from 9·2% (6·0-12·9) in 1975 to 8·4% (6·8-10·1) in 2016 in girls and from 14·8% (10·4-19·5) in 1975 to 12·4% (10·3-14·5) in 2016 in boys. Prevalence of moderate and severe underweight was highest in India, at 22·7% (16·7-29·6) among girls and 30·7% (23·5-38·0) among boys. Prevalence of obesity was more than 30% in girls in Nauru, the Cook Islands, and Palau; and boys in the Cook Islands, Nauru, Palau, Niue, and American Samoa in 2016. Prevalence of obesity was about 20% or more in several countries in Polynesia and Micronesia, the Middle East and north Africa, the Caribbean, and the USA. In 2016, 75 (44-117) million girls and 117 (70-178) million boys worldwide were moderately or severely underweight. In the same year, 50 (24-89) million girls and 74 (39-125) million boys worldwide were obese.

INTERPRETATION

The rising trends in children's and adolescents' BMI have plateaued in many high-income countries, albeit at high levels, but have accelerated in parts of Asia, with trends no longer correlated with those of adults.

FUNDING

Wellcome Trust, AstraZeneca Young Health Programme.

Association between birthweight and later body mass index: an individual-based pooled analysis of 27 twin cohorts participating in the CODATwins project

Background

There is evidence that birthweight is positively associated with body mass index (BMI) in later life, but it remains unclear whether this is explained by genetic factors or the intrauterine environment. We analysed the association between birthweight and BMI from infancy to adulthood within twin pairs, which provides insights into the role of genetic and environmental individual-specific factors.

Methods

This study is based on the data from 27 twin cohorts in 17 countries. The pooled data included 78 642 twin individuals (20 635 monozygotic and 18 686 same-sex dizygotic twin pairs) with information on birthweight and a total of 214 930 BMI measurements at ages ranging from 1 to 49 years. The association between birthweight and BMI was analysed at both the individual and within-pair levels using linear regression analyses.

Results

At the individual level, a 1-kg increase in birthweight was linearly associated with up to 0.9 kg/m2 higher BMI (P < 0.001). Within twin pairs, regression coefficients were generally greater (up to 1.2 kg/m2 per kg birthweight, P < 0.001) than those from the individual-level analyses. Intra-pair associations between birthweight and later BMI were similar in both zygosity groups and sexes and were lower in adulthood.

Conclusions

These findings indicate that environmental factors unique to each individual have an important role in the positive association between birthweight and later BMI, at least until young adulthood.

Childhood body mass index and risk of adult pancreatic cancer

BACKGROUND

Excess weight in adulthood is one of the few modifiable risk factors for pancreatic cancer, and height has associations as well. This leads to question whether body weight and height in childhood are associated with adult pancreatic cancer.

OBJECTIVE

To examine if childhood body mass index (BMI; kg/m2) and height are associated with pancreatic cancer in adult life.

METHODS

We linked 293,208 children born from 1930-1982 in the Copenhagen School Health Records Register who had measured values of weights and heights at ages 7-13 years with the Danish Cancer Registry to identify incident pancreatic cancer cases from 1968-2012. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazard regressions.

RESULTS

During 8,207,015 person-years of follow-up, 1,268 pancreatic cancer cases were diagnosed. Childhood BMI z-scores at ages 7-13 years were positively and significantly associated with pancreatic cancer in men and women up to age 70 years; beyond age 70 the associations diminished. The HRs of pancreatic cancer were 1.13 (95% CI: 1.05-1.21) and 1.18 (95% CI: 1.09-1.27) per BMI z-score at ages 7 and 13 years, respectively. A BMI ≥1.5 z-score at ages 7, 10 and 13 years was positively and significantly associated with pancreatic cancer; however, the effect did not differ from having a BMI z-score ≥1.5 at only one of these ages. Positive, albeit non-statistically significant, associations were identified with height.

CONCLUSIONS

BMI at all ages from 7-13 years is positively and linearly associated with adult pancreatic cancer; the higher the BMI, the higher the risk. Excess childhood BMI may be indicative of processes initiated early in life that lead to this cancer. Prevention of childhood adiposity may decrease the burden of pancreatic cancer in adults.

Differences in genetic and environmental variation in adult BMI by sex, age, time period, and region: an individual-based pooled analysis of 40 twin cohorts

Background: Genes and the environment contribute to variation in adult body mass index [BMI (in kg/m²)], but factors modifying these variance components are poorly understood.Objective: We analyzed genetic and environmental variation in BMI between men and women from young adulthood to old age from the 1940s to the 2000s and between cultural-geographic regions representing high (North America and Australia), moderate (Europe), and low (East Asia) prevalence of obesity.Design: We used genetic structural equation modeling to analyze BMI in twins ≥20 y of age from 40 cohorts representing 20 countries (140,379 complete twin pairs).Results: The heritability of BMI decreased from 0.77 (95% CI: 0.77, 0.78) and 0.75 (95% CI: 0.74, 0.75) in men and women 20-29 y of age to 0.57 (95% CI: 0.54, 0.60) and 0.59 (95% CI: 0.53, 0.65) in men 70-79 y of age and women 80 y of age, respectively. The relative influence of unique environmental factors correspondingly increased. Differences in the sets of genes affecting BMI in men and women increased from 20-29 to 60-69 y of age. Mean BMI and variances in BMI increased from the 1940s to the 2000s and were greatest in North America and Australia, followed by Europe and East Asia. However, heritability estimates were largely similar over measurement years and between regions. There was no evidence of environmental factors shared by co-twins affecting BMI.Conclusions: The heritability of BMI decreased and differences in the sets of genes affecting BMI in men and women increased from young adulthood to old age. The heritability of BMI was largely similar between cultural-geographic regions and measurement years, despite large differences in mean BMI and variances in BMI. Our results show a strong influence of genetic factors on BMI, especially in early adulthood, regardless of the obesity level in the population.

Abstract LB-375: Childhood body size at age 13 years and associations with ovarian cancer in adult life

Background: Among women, body mass index (BMI; kg/m2) and attained height are positively associated with ovarian cancer. Few studies have, however, investigated associations with childhood body size. As such, it remains largely unknown if it is body size development in early life or adult life that contributes to these associations. Therefore, we examined if childhood BMI and height at age 13 years were associated with ovarian cancer in adult life.

Methods: Individuals were girls in the Copenhagen School Health Records Register who were born between 1930 and1989 and had available measures of height and weight at age 13 years. BMI and height z-scores were calculated from an internal age-specific reference. Via a personal identification number, individuals were followed up for ovarian cancer diagnosis by linkage to the Danish Cancer Registry. Cox proportional hazard regressions were performed and stratified by birth cohort.

Results: Among the included 137,416 girls, 1048 cases of ovarian cancer occurred during 5.2 million person-years of follow-up with a median age of diagnosis of 57 years (range: 19-83 years). BMI tended to be non-linearly associated with ovarian cancer such that only the heaviest girls had positive associations with ovarian cancer. Compared with a 13-year-old girl of average-size (BMI z-score = 0, corresponding to a weight of 45 kg and a height of 157 cm), an equally tall girl who was at least 9 kg heavier (corresponding to a BMI z-score &gt;1.28) had a hazard ratio (HR) for ovarian cancer of 1.33 (95% confidence interval [CI]: 1.08-1.63). In analyses adjusted for childhood height, the association was only marginally attenuated (HR = 1.30, 95% CI: 1.06-1.60). Childhood height was positively and statistically significantly associated with ovarian cancer. At age 13 years, per height z-score (corresponding to approximately 7 cm), the HR for ovarian cancer was 1.07 (95% CI: 1.01-1.14).

Conclusion: Body size in early life was associated with ovarian malignancies later in life suggesting that childhood height and BMI might impact if women are later diagnosed with ovarian cancer. As ovarian cancers vary widely in their etiologies, associations with childhood body size may differ depending on the tumor type, which will be investigated.

Citation Format: Julie Aarestrup, Michael Gamborg, Nicolas Wentzensen, Lian G. Ulrich, Thorkild IA Sørensen, Jennifer L. Baker. Childhood body size at age 13 years and associations with ovarian cancer in adult life. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-375.

Intake of Total and Subgroups of Fat Minimally Affect the Associations between Selected Single Nucleotide Polymorphisms in the PPARγ Pathway and Changes in Anthropometry among European Adults from Cohorts of the DiOGenes Study

BACKGROUND

Although the peroxisome proliferator-activated receptor γ (PPARγ) pathway is central in adipogenesis, it remains unknown whether it influences change in body weight (BW) and whether dietary fat has a modifying effect on the association.

OBJECTIVES

We examined whether 27 single nucleotide polymorphisms (SNPs) within 4 genes in the PPARγ pathway are associated with the OR of being a BW gainer or with annual changes in anthropometry and whether intake of total fat, monounsaturated fat, polyunsaturated fat, or saturated fat has a modifying effect on these associations.

METHODS

A case-noncase study included 11,048 men and women from cohorts in the European Diet, Obesity and Genes study; 5552 were cases, defined as individuals with the greatest BW gain during follow-up, and 6548 were randomly selected, including 5496 noncases. We selected 4 genes [CCAAT/enhancer binding protein β (CEBPB), phosphoenolpyruvate carboxykinase 2, PPARγ gene (PPARG), and sterol regulatory element binding transcription factor 1] according to evidence about biologic plausibility for interactions with dietary fat in weight regulation. Diet was assessed at baseline, and anthropometry was followed for 7 y.

RESULTS

The ORs for being a BW gainer for the 27 genetic variants ranged from 0.87 (95% CI: 0.79, 1.03) to 1.12 (95% CI: 0.96, 1.22) per additional minor allele. Uncorrected, CEBPB rs4253449 had a significant interaction with the intake of total fat and subgroups of fat. The OR for being a BW gainer for each additional rs4253449 minor allele per 100 kcal higher total fat intake was 1.07 (95% CI: 1.02, 1.12; P = 0.008), and similar associations were found for subgroups of fat.

CONCLUSIONS

Among European men and women, the influence of dietary fat on associations between SNPs in the PPARγ pathway and anthropometry is likely to be absent or marginal. The observed interaction between rs4253449 and dietary fat needs confirmation.

Road Traffic and Railway Noise Exposures and Adiposity in Adults: A Cross-Sectional Analysis of the Danish Diet, Cancer, and Health Cohort

BACKGROUND

Traffic noise has been associated with cardiovascular and metabolic disorders. Potential modes of action are through stress and sleep disturbance, which may lead to endocrine dysregulation and overweight.

OBJECTIVES

We aimed to investigate the relationship between residential traffic and railway noise and adiposity.

METHODS

In this cross-sectional study of 57,053 middle-aged people, height, weight, waist circumference, and bioelectrical impedance were measured at enrollment (1993-1997). Body mass index (BMI), body fat mass index (BFMI), and lean body mass index (LBMI) were calculated. Residential exposure to road and railway traffic noise exposure was calculated using the Nordic prediction method. Associations between traffic noise and anthropometric measures at enrollment were analyzed using general linear models and logistic regression adjusted for demographic and lifestyle factors.

RESULTS

Linear regression models adjusted for age, sex, and socioeconomic factors showed that 5-year mean road traffic noise exposure preceding enrollment was associated with a 0.35-cm wider waist circumference (95% CI: 0.21, 0.50) and a 0.18-point higher BMI (95% CI: 0.12, 0.23) per 10 dB. Small, significant increases were also found for BFMI and LBMI. All associations followed linear exposure-response relationships. Exposure to railway noise was not linearly associated with adiposity measures. However, exposure > 60 dB was associated with a 0.71-cm wider waist circumference (95% CI: 0.23, 1.19) and a 0.19-point higher BMI (95% CI: 0.0072, 0.37) compared with unexposed participants (0-20 dB).

CONCLUSIONS

The present study finds positive associations between residential exposure to road traffic and railway noise and adiposity.

Macro fat and micro fat: insulin sensitivity and gender dependent response of adipose tissue to isocaloric diet change

The adipose cell-size distribution is a quantitative characterization of adipose tissue morphology. At a population level, the adipose cell-size distribution is insulin-sensitivity dependent, and the observed correlation between obesity and insulin resistance is believed to play a key role in the metabolic syndrome. Changes in fat mass can be induced by altered energy intake or even diet composition. These macroscopic changes must manifest themselves as dynamic adipose cell-size distribution alterations at the microscopic level. The dynamic relationship between these 2 independent measurements of body fat is unknown. In this study, we investigate adipose tissue dynamics in response to various isocaloric diet compositions, comparing gender- and insulin sensitivity-dependent differences. A body composition model is used to predict fat mass changes in response to changes in diet composition for 28 individuals, separated into 4 subgroups according to gender and insulin sensitivity/resistance. Adipose cell-size distribution changes in each individual are simulated with a dynamic model and parameters corresponding to lipid turnover and cell growth rates are determined for each subgroup to match the relative change of fat mass for each diet composition, respectively. We find that adipose cell-size dynamics are associated with different modulations dependent on gender and insulin resistance. Larger turnover and growth/shrinkage rates in insulin resistant individuals suggest they may be more sensitive to changes in energy intake and diet composition than insulin sensitive subjects. The different cell-size distribution changes of adipose cells of various sizes in different subject groups further suggest distinct modulations of adipose cell dynamics.

Consumption of predefined 'Nordic' dietary items in ten European countries - an investigation in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

OBJECTIVE

Health-beneficial effects of adhering to a healthy Nordic diet index have been suggested. However, it has not been examined to what extent the included dietary components are exclusively related to the Nordic countries or if they are part of other European diets as well, suggesting a broader preventive potential. The present study describes the intake of seven a priori defined healthy food items (apples/pears, berries, cabbages, dark bread, shellfish, fish and root vegetables) across ten countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) and examines their consumption across Europe.

DESIGN

Cross-sectional study. A 24 h dietary recall was administered through a software program containing country-specific recipes. Sex-specific mean food intake was calculated for each centre/country, as well as percentage of overall food groups consumed as healthy Nordic food items. All analyses were weighted by day and season of data collection.

SETTING

Multi-centre, European study.

SUBJECTS

Persons (n 36 970) aged 35-74 years, constituting a random sample of 519 978 EPIC participants.

RESULTS

The highest intakes of the included diet components were: cabbages and berries in Central Europe; apples/pears in Southern Europe; dark bread in Norway, Denmark and Greece; fish in Southern and Northern countries; shellfish in Spain; and root vegetables in Northern and Central Europe. Large inter-centre variation, however, existed in some countries.

CONCLUSIONS

Dark bread, root vegetables and fish are strongly related to a Nordic dietary tradition. Apples/pears, berries, cabbages, fish, shellfish and root vegetables are broadly consumed in Europe, and may thus be included in regional public health campaigns.

Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche

Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition.

Genome wide association study identifies KCNMA1 contributing to human obesity

BACKGROUND

Recent genome-wide association (GWA) analyses have identified common single nucleotide polymorphisms (SNPs) that are associated with obesity. However, the reported genetic variation in obesity explains only a minor fraction of the total genetic variation expected to be present in the population. Thus many genetic variants controlling obesity remain to be identified. The aim of this study was to use GWA followed by multiple stepwise validations to identify additional genes associated with obesity.

METHODS

We performed a GWA analysis in 164 morbidly obese subjects (BMI:body mass index>40 kg/m2) and 163 Swedish subjects (>45 years) who had always been lean. The 700 SNPs displaying the strongest association with obesity in the GWA were analyzed in a second cohort comprising 460 morbidly obese subjects and 247 consistently lean Swedish adults. 23 SNPs remained significantly associated with obesity (nominal P<0.05) and were in a step-wise manner followed up in five additional cohorts from Sweden, France, and Germany together comprising 4214 obese and 5417 lean or population-based control individuals. Three samples, n=4133, were used to investigate the population-based associations with BMI. Gene expression in abdominal subcutaneous adipose tissue in relation to obesity was investigated for14 adults.

RESULTS

Potassium channel, calcium activated, large conductance, subfamily M, alpha member (KCNMA1) rs2116830*G and BDNF rs988712*G were associated with obesity in five of six investigated case-control cohorts. In meta-analysis of 4838 obese and 5827 control subjects we obtained genome-wide significant allelic association with obesity for KCNMA1 rs2116830*G with P=2.82×10(-10) and an odds ratio (OR) based on cases vs controls of 1.26 [95% C.I. 1.12-1.41] and for BDNF rs988712*G with P=5.2×10(-17) and an OR of 1.36 [95% C.I. 1.20-1.55]. KCNMA1 rs2116830*G was not associated with BMI in the population-based samples. Adipose tissue (P=0.0001) and fat cell (P=0.04) expression of KCNMA1 was increased in obesity.

CONCLUSIONS

We have identified KCNMA1 as a new susceptibility locus for obesity, and confirmed the association of the BDNF locus at the genome-wide significant level.

Obesity in the Scandinavian countries: prevalence and developmental trends

In the population of Danish young men, whose height and weight have been measured at the draft boards since 1943, a sudden steep increase occurred after 1960 in the prevalence of severe obesity (body mass index (BMI) greater than or equal to 31 kg/m2). The increase appeared to be independent of height, homogeneous over the range of severe obesity, unaccompanied by any change in the psychosocial correlates, linked to the birth cohorts, and specific for the severely obese. The cause of the increase in prevalence must be of an environmental nature. Investigation of the developmental course through the school ages and distributional changes over time among school children suggests that the increase in prevalence of severe obesity among young men is due to an increased persistence of obesity through adolescence, which parallels the development of welfare conditions in this country.

Food intake patterns and body mass index in observational studies

OBJECTIVE

To review studies of patterns of food intake, as assessed by diet index, factor analysis or cluster analysis, and their associations with body mass index or obesity (BMI/Ob).

DESIGN

Systematic literature review MEDLINE search with crosscheck of references.

STUDIES

Thirty observational studies relating food intake patterns to anthropometric information were identified and reviewed. Food intake patterns were defined using a diet index, factor or cluster analysis in 12, nine and nine studies, respectively. Measures of body mass were made concurrently with the diet assessment in all studies, and only in a few cases were the primary outcomes related to BMI/Ob.

RESULTS

The food intake patterns identified could, in most factor or cluster analysis studies, be categorised as: (a) meat, fatty, sweet or energy dense foods; (b) vegetables, fruit, whole grain and low-fat foods; or (c) by high alcohol consumption. The diet indexes were designed to capture a high diversity and/or food combinations matching the recommendations. The relationships with BMI/Ob were inconsistent-ten studies found that intake patterns, which we categorised as fatty, sweet or energy dense were positively associated with BMI/Ob, while similar patterns in four other studies were negatively associated with BMI. The significant associations between diet index score and BMI/Ob were consistently negative, while the associations between factor scores or cluster membership and BMI/Ob were less clear in terms of food intake pattern. Men and women had similar food intake patterns, but food intake patterns were less often positively associated with BMI/Ob in women. In 11 studies, there were no significant associations between food intake pattern and BMI/Ob.

CONCLUSION

This review showed that no consistent associations could be identified between BMI or Ob and food intake patterns, derived from diet index, factor analysis or cluster analysis. However, the heterogeneity of food intake patterns identified by such analyses and the lack of gold standards for the application of these techniques hampers consistent analysis of a relation between food intake patterns and health.

The Danish National Birth Cohort--its background, structure and aim

BACKGROUND

It is well known that the time from conception to early childhood has importance for health conditions that reach into later stages of life. Recent research supports this view, and diseases such as cardiovascular morbidity, cancer, mental illnesses, asthma, and allergy may all have component causes that act early in life. Exposures in this period, which influence fetal growth, cell divisions, and organ functioning, may have long-lasting impact on health and disease susceptibility.

METHODS

To investigate these issues the Danish National Birth Cohort (Better health for mother and child) was established. A large cohort of pregnant women with long-term follow-up of the offspring was the obvious choice because many of the exposures of interest cannot be reconstructed with sufficient validity back in time. The study needs to be large, and it is aimed to recruit 100,000 women early in pregnancy, and to continue follow-up for decades. The Nordic countries are better suited for this kind of research than most other countries because of their population-based registers on diseases, demography and social conditions, linkable at the individual level by means of the unique ID-number given to all citizens. Exposure information is mainly collected by computer-assisted telephone interviews with the women twice during pregnancy and when their children are six and 18 months old. Participants are also asked to fill in a self-administered food frequency questionnaire in mid-pregnancy. Furthermore, a biological bank has been set up with blood taken from the mother twice during pregnancy and blood from the umbilical cord taken shortly after birth. Data collection started in 1996 and the project covered all regions in Denmark in 1999. By August 2000. a total of 60,000 pregnant women had been recruited to the study. It is expected that a large number of gene-environmental hypotheses need to be based on case-control analyses within a cohort like this.

Influence of genes and family environment on adult smoking behavior assessed in an adoption study

Twin studies suggest that genetic factors influence smoking behavior. However, in these studies, genetic and environmental influences may be confounded. We examined whether smoking behavior of adoptees is associated with smoking behavior in adoptive and biological relatives in a design in which this confounding is minimized. Data on smoking status were collected using a mailed questionnaire in a sample of 840 adoptive families from the Danish Adoption Register including all non-familial adoptions from 1924 through 1947. Smoking data were available for 706 adoptees, 451 biological fathers, 580 biological mothers, 641 adoptive fathers, 693 adoptive mothers, 199 biological full-siblings, 684 maternal half-siblings, and 576 paternal half-siblings. Adoptees' status as ever, current, heavy, or former (ex-)smokers was related to their relatives' smoking status. Adoptees ever smoking was associated with their full-siblings' status as ever smokers (OR = 3.6 [1.5-8.7]). Adoptees' current smoking was also associated with their full-siblings' ever (OR = 3.2 [1.5-7.7]) and current (OR = 2.6 [1.3-5.0]) smoking, whereas adoptees' heavy smoking was associated with their full-siblings ever (OR = 5.5 [2.1-14.3]), current (OR = 4.0[1.9-8.6]) and heavy (OR = 2.0[1.0-4.2]) smoking. Compared with current smokers, adoptee ex-smokers had full-siblings who were ex-smokers more often (OR = 3.5 [1.0-11.6]), current (OR = 0.4 [0.2-0.8]), and heavy (OR = 0.3 [0.1-0.9]) smokers less often. Adoptees' smoking behavior was not associated with adoptive or biological parents' status as current smokers. This study of smoking behavior in adult adoptees and their biological and adoptee family supports the finding in twin studies of a genetic influence on smoking within the same generation.

Pooling analysis of genetic data: the association of leptin receptor (LEPR) polymorphisms with variables related to human adiposity

Analysis of raw pooled data from distinct studies of a single question generates a single statistical conclusion with greater power and precision than conventional metaanalysis based on within-study estimates. However, conducting analyses with pooled genetic data, in particular, is a daunting task that raises important statistical issues. In the process of analyzing data pooled from nine studies on the human leptin receptor (LEPR) gene for the association of three alleles (K109R, Q223R, and K656N) of LEPR with body mass index (BMI; kilograms divided by the square of the height in meters) and waist circumference (WC), we encountered the following methodological challenges: data on relatives, missing data, multivariate analysis, multiallele analysis at multiple loci, heterogeneity, and epistasis. We propose herein statistical methods and procedures to deal with such issues. With a total of 3263 related and unrelated subjects from diverse ethnic backgrounds such as African-American, Caucasian, Danish, Finnish, French-Canadian, and Nigerian, we tested effects of individual alleles; joint effects of alleles at multiple loci; epistatic effects among alleles at different loci; effect modification by age, sex, diabetes, and ethnicity; and pleiotropic genotype effects on BMI and WC. The statistical methodologies were applied, before and after multiple imputation of missing observations, to pooled data as well as to individual data sets for estimates from each study, the latter leading to a metaanalysis. The results from the metaanalysis and the pooling analysis showed that none of the effects were significant at the 0.05 level of significance. Heterogeneity tests showed that the variations of the nonsignificant effects are within the range of sampling variation. Although certain genotypic effects could be population specific, there was no statistically compelling evidence that any of the three LEPR alleles is associated with BMI or waist circumference in the general population.

[Tobacco smoking and risk of hip fracture in men and women. Results from the Hovedstadens Center for Prospective Population Studies]

INTRODUCTION

In the present population-based cohort study, we prospectively determined the influence of current, previous, and cumulative smoking history on the risk of hip fracture in men and women and addressed the issue of possible gender difference in susceptibility to tobacco smoking.

MATERIAL

A total of 13,393 women and 17,379 men, initially examined between 1964 and 1992, were followed up until 1997 for their first admission because of hip fracture.

RESULTS

During follow-up, a total of 1169 hip fractures were identified. After adjustment for potential confounders, female current smokers had a relative risk of hip fracture of 1.36 (1.12-1.65) and male smoked 1.59 (1.04-2.43) relative to those who have never smoked. In both sexes, the relative risk of hip fracture gradually increased with current and accumulated tobacco consumption. A test for interaction between gender and smoking habits was insignificant. Men who stopped smoking for more than five years had a lower risk of hip fracture than men who currently smoked, whereas no such risk reduction was seen in female ex-smokers.

CONCLUSION

Tobacco smoking is an independent risk factor for hip fracture in men and women, and there appears to be no gender differences in the smoking-related risk. Men who stopped smoking for more than five years had lower risk of hip fracture than men who currently smoked, whereas no such risk reduction was seen in female ex-smokers.

The Asn363Ser variant of the glucocorticoid receptor gene is not associated with obesity or weight gain in Danish men

OBJECTIVE

Testing association of the Asn363Ser variant of the glucocorticoid gene with measures of obesity and weight gain.

SUBJECTS

741 obese subjects (BMI > or = 31 kg/m(2) at selection) and 854 random control subjects from the same population, examined at draft board examination and after on average 27.4+/- y. A lean control group (n=351) was further selected as the fraction from the cohort group having a BMI below 25.0 kg/m(2) at the latest examination.

METHODS

Using PCR-RFLP subjects were genotyped for the Asn363Ser variant and grouped according to genotype.

RESULTS

The prevalence of the Ser363 allele was 4.7% (95% Cl: 3.3-6.2%) among the obese, 4.1% (2.7-5.5%) among the random cohort subjects and 4.3% (2.1-6.5%) among lean control subjects, respectively, showing no significant differences between the groups (P > 0.1). Furthermore, no differences in BMI, waist-hip ratio or weight gain were seen within any of the groups when defined according to the glucocorticoid receptor genotype.

CONCLUSION

In the examined population this marker is not a relevant predictor of obesity.

[Tobacco and alcohol are risk factors of complicated peptic ulcers. A prospective cohort study]

Both the incidence of and mortality from bleeding and perforated peptic ulcers are growing. We assessed the association between smoking, ingestion of alcohol (including the type of alcoholic beverage), and risk of a complicated peptic ulcer in a population-based study of 26,518 Danish subjects followed up for an average of 13.4 years. There were 214 cases of incident bleeding and 107 cases with perforated ulcers. We estimated the relative risks (RRs) of incident bleeding and perforated peptic ulcers with the Poisson regression analysis. Smoking more than 15 cigarettes a day compared with never smoking increased the risk of a perforated ulcer more than threefold (RR = 3.5; 95% confidence interval [CI] = 1.7-7.1). Ingestion of more than 42 drinks a week increased the risk of a bleeding ulcer fourfold (RR = 4.4; 95% CI = 2.3-8.3) compared with ingestion of less than one drink a week. Comparison of the same group, showed that subjects who ingested more than 21 drinks a week, but no wine, were at a higher risk of a bleeding ulcer (RR = 8.8; 95% CI = 2.2-35) than drinkers of the same amount of alcohol, but with more than 25% of their intake as wine (RR = 2.4; 95% CI = 1.0-6.0).

Leisure-time physical activity levels and changes in relation to risk of hip fracture in men and women

The authors prospectively studied the effect of leisure-time physical activity level on hip fracture risk along with the influence of within-subject changes in activity levels, while taking possible confounding by other health behaviors and poor health into account. Analyses were based on pooled data from three population studies conducted in Copenhagen, Denmark. Among 13,183 women and 17,045 men, 1,121 first hip fractures were identified during follow-up. In comparison with being sedentary, the relative risk (RR) of hip fracture associated with being moderately physically active 2-4 hours per week was 0.72 (95% confidence interval (CI): 0.59, 0.89) in women and 0.75 (95% CI: 0.55, 1.03) in men after adjustment for confounders. Being in the most active leisure activity category did not decrease the risk of hip fracture further. Adjustment for poor health affected the risk estimates only modestly. Subjects who, during follow-up, reduced their physical activity level from the highest or the intermediate activity level to a sedentary level had a higher risk of hip fracture than did those who remained moderately physically active at the intermediate level (multivariate adjusted RR = 2.19, 95% CI: 1.00, 4.84 and RR = 1.89, 95% CI: 1.21, 2.95, for reduction from the highest and intermediate levels, respectively). There was no evidence of a fracture-protective effect from increasing physical activity. In conclusion, moderate levels of physical activity appear to provide protection against later hip fracture. Decline in the physical activity level over time is an important risk factor for hip fracture.

[Beer, wine, spirits and mortality]

A population based cohort study investigates the association between alcohol intake and mortality from all causes, coronary heart disease and cancer. The design is prospective with baseline assessment of intake of beer, wine and spirits, smoking habits, educational level, physical activity, and body mass index and a total of 257,859 person-years follow-up on mortality. A total of 4,833 participants died, of these 1,075 from coronary heart disease and 1,552 of cancer. Compared with non-drinkers, light drinkers who avoided wine, had a relative risk of death from all causes of 0.90 (0.82-0.99) and those who drank wine had a relative risk of 0.66 (0.55-0.77). Heavy drinkers who avoided wine were at higher risk of death from all causes than were heavy drinkers who included wine in their alcohol intake. Wine drinkers had significantly lower mortality from both coronary heart disease and cancer than did non-wine drinkers (p = 0.007 and p = 0.004, respectively). In conclusion, wine intake may have a beneficial effect on all cause mortality that is additive to that of alcohol. This effect may be attributable to a reduction in death from both coronary heart disease and cancer.

[Beer, wine, spirits and mortality. Results from a prospective population study]

INTRODUCTION

The aim of the present population-based cohort study was to examine the association between alcohol intake and mortality from all causes, coronary heart disease, and cancer.

METHODS

A prospective population study with baseline assessment of beer, wine and spirit consumption, smoking habits, educational level, physical activity, and body mass index in a total of 257,859 person-years follow-up on mortality.

RESULTS

A total of 4833 participants died, 1075 of these from coronary heart disease and 1552 of cancer. Compared with non-drinkers, light drinkers, who avoided wine, had a relative risk of death from all causes of 0.90 (0.82-0.99) and those who drank wine had a relative risk of 0.66 (0.55-0.77). Heavy drinkers, who avoided wine, were at higher risk of death from all causes than were heavy drinkers, who included wine in their alcohol consumption. Wine drinkers had a significantly lower mortality from both coronary heart disease and cancer than had non-wine drinkers (p = 0.007 and p = 0.004, respectively).

CONCLUSION

A moderate consumption of wine may have a beneficial effect on all causes of mortality, which is additive to that of alcohol. This effect may be attributable to a reduction in death from both coronary heart disease and cancer.

A prevalent polymorphism in the promoter of the UCP3 gene and its relationship to body mass index and long term body weight change in the Danish population

Variability of the uncoupling protein 3 (UCP3) promoter has been associated with increased body mass index (BMI) and altered lipid profiles. Here we tested the hypothesis that variation of the UCP3 promoter is associated with either juvenile or maturity-onset obesity or body weight change over a 26-yr follow-up among Danish subjects. Mutation screening of approximately 1 kb 5' upstream of the UCP3 gene revealed one previously described -55 C-->T variant. The frequency of the polymorphism was evaluated by restriction fragment length polymorphism analysis in four groups of subjects: 1) a group of 744 obese Danish men who at the draft board examinations had a body mass index (BMI) of at least 31 kg/m(2), 2) a randomly selected control group consisting of 857 draftees, 3) 258 middle-aged subjects, and 4) 409 60-yr-old subjects. The frequency of the T allele was 26.0% (95% confidence interval, 23.8-28.2%) among the obese draftees and 26.9% (24.8-29.0%) in the control group (P = 0.6). The variant was not associated with BMI at a young age or with weight gain after a 26-yr follow-up. The frequency of the T allele was 29.5% (25.6-33.4%) in the middle-aged group and 25.8% (22.8-28.8%) among the 60-yr-old subjects. The polymorphism was not associated with increased BMI or percent body fat in these 2 groups. It is concluded that this variant does not play a major role in the development of common obesity among Danish subjects.

Third-party rights and risks: a forum on informed consent of persons affected by the study of human subjects--conditions, experiences, and concerns in a Nordic country

In Denmark, health research using personal information can be conducted only with permission from a regional scientific ethical committee and the national Data Protection Office. There are no rules applying to the rights and risks of third parties. In this article, the implications for third-party rights and risks of the type and level of involvement of the subjects are discussed from a Danish point of view. Particular emphasis is put on the current conditions, experiences, and concerns with regard to use of already registered personal information, which in the Nordic countries offers unique opportunities for large-scale, longitudinal, population-based studies also involving third parties. These opportunities have recently been challenged by a European Community Directive, with which all member states must comply, requiring informed consent on every transaction of personal data, but through a political process, it was possible to obtain a series of amendments allowing the special register-based research to continue. Crucial arguments favoring the amendments were that no damage has been observed so far and that such research has no interest in the individual data, only in the statistical distributions and associations. Finally, the article suggests that the rights and risks of third parties might be considered on the basis of use: third-party information provided by the subject only as a source of such information distinct from use of the information as an integral part of the subjects' information about themselves and their lives.

Concordance of inflammatory bowel disease among Danish twins. Results of a nationwide study

BACKGROUND

Previous studies have shown an increased risk of inflammatory bowel disease (IBD) among relatives of patients with Crohn disease and ulcerative colitis. In the present study the probandwise concordance rates for ulcerative colitis and Crohn disease among mono- and dizygotic twins were estimated. Further we aimed to evaluate whether smoking habits might influence the concordance, and to look for clinical characteristics of concordant versus discordant twin pairs.

METHODS

Among the 38,507 identified twins born in Denmark from 1953 to 1982, a questionnaire was sent to the 34,076 who previously had accepted to participate in studies. For twins reporting IBD, the diagnosis was verified by applying standard criteria to records requested from hospitals or practitioners.

RESULTS

Among the 29,421 (86.3%) twins answering the questionnaire, 103 pairs had at least one twin who suffered from IBD. In the Crohn disease group five of 10 monozygotic pairs, but none of 27 dizygotic pairs were concordant. In the ulcerative colitis group three of 21 monozygotic, and two of 44 dizygotic pairs were concordant. The probandwise concordance rate among monozygotic pairs was 58.3% for Crohn disease and 18.2% for ulcerative colitis; among the dizygotic pairs the rates were 0 and 4.5%, respectively. The frequency of smokers was higher among twins with Crohn disease and lower among twins with ulcerative colitis compared to the frequency in the twin register. Furthermore, smoking habits were found to be of significance for discordance for disease. Regarding the clinical characteristics no homogenous pattern was observed within the concordant pairs and the differences between concordant and discordant pairs were not significant.

CONCLUSION

The observation of a significantly higher concordance rate among monozygotic than among dizygotic twin pairs strongly points to a genetic influence on occurrence of IBD, which seems to be more pronounced with regard to Crohn disease than to ulcerative colitis. Differences in smoking habits among the members of the discordant twin pairs may influence the discordance.

Type of alcohol consumed and mortality from all causes, coronary heart disease, and cancer

BACKGROUND

Although the J-shaped relation between alcohol intake and mortality has been reproduced in many large cohort studies, the question of whether the effects of beer, wine, and spirits differ remains controversial.

OBJECTIVE

To examine the relation between intake of different types of alcohol and death from all causes, coronary heart disease, and cancer.

DESIGN

Pooled cohort studies in which intake of beer, wine, and spirits; smoking status; educational level; physical activity; and body mass index were assessed at baseline.

SETTING

Copenhagen, Denmark.

PARTICIPANTS

13 064 men and 11 459 women 20 to 98 years of age.

MEASUREMENTS

Number of deaths and time to death from all causes, coronary heart disease, and cancer during follow-up.

RESULTS

During 257 859 person-years of follow-up, 4833 participants died. J-shaped relations were found between total alcohol intake and mortality at various levels of wine intake. Compared with nondrinkers, light drinkers who avoided wine had a relative risk for death from all causes of 0.90 (95% CI, 0.82 to 0.99) and those who drank wine had a relative risk of 0.66 (CI, 0. 55 to 0.77). Heavy drinkers who avoided wine were at higher risk for death from all causes than were heavy drinkers who included wine in their alcohol intake. Wine drinkers had significantly lower mortality from both coronary heart disease and cancer than did non-wine drinkers (P = 0.007 and P = 0.004, respectively).

CONCLUSION

Wine intake may have a beneficial effect on all-cause mortality that is additive to that of alcohol. This effect may be attributable to a reduction in death from both coronary heart disease and cancer.

Smoking and alcohol intake as risk factors for bleeding and perforated peptic ulcers: a population-based cohort study

Both the incidence of and mortality from bleeding and perforated peptic ulcers are increasing. We assessed the association between smoking, intake of alcohol (including type of alcoholic beverage), and risk of a complicated peptic ulcer in a population-based study of 26,518 Danish subjects followed up for an average of 13.4 years. There were 214 cases of incident bleeding and 107 cases with perforated ulcers. We estimated relative risks (RRs) for incident bleeding and perforated peptic ulcers using Poisson regression analysis. Smoking more than 15 cigarettes per day compared with never smoking increased the risk of a perforated ulcer more than threefold [RR = 3.5; 95% confidence interval (CI) = 1.7-7.1)]. Drinking more than 42 drinks per week increased the risk of a bleeding ulcer fourfold (RR = 4.4; 95% CI = 2.3-8.3) compared with drinking less than one drink per week. Using the same comparison group, subjects who drank more than 21 drinks per week but no wine were at a higher risk of a bleeding ulcer (RR = 8.8; 95% CI = 2.2-35) than drinkers of the same amount of alcohol, but with more than 25% of their intake as wine (RR = 2.4; 95% CI = 1.0-6.0).

[Proper advice on nutrition. Recommendations concerning the conduct of the nutritional news]

The Committee on Proper Conduct in Public Advice on Nutrition, set up by the Danish Nutrition Council, has produced recommendations to persons involved in communicating results of nutrition research. The guidelines are targeted on scientists, industry, journalists and publishers as well as consumers to facilitate proper conduct in communication of own or other scientists' research results, which might influence consumers' choice and intake of food. The results are presented as recommendations and checklists providing the necessary requirements to bring people in a position to make the best possible evaluation of the new scientific results and to put the results into their proper perspective. The aim of this report is to improve the process so that the communicator focuses on the background information necessary for the reader/listener/viewer in the current situation to achieve a balanced view and benefit from the new scientific result.

The changing lifestyle in the world. Body weight and what else?

Body weight and the prevalence of obesity are rising so rapidly in many countries that the World Health Organization has recognized that there is a "global epidemic of obesity." The prevalence of type 2 diabetes is rising in parallel. In view of its associated cardiovascular complications, we are facing a severe public health problem. Both obesity and type 2 diabetes have a combined genetic and environmental background, but the epidemic must be due to major changes in the environment. By definition, obesity is a result of a positive energy balance, which usually amounts to a tiny proportion of the total energy turnover. Energy intake, energy expenditure, and energy accumulation (as fat) may all be primarily disturbed. There is a great, and still insufficiently understood, variation in prevalence of obesity and in the rate of change of the prevalence. The prevailing contention is that the epidemic is due to the changes in the society--the so-called modernization--leading to overnutrition and a sedentary life. These factors are likely contributors, but it has been difficult to provide consistent evidence for their effects. In Denmark, a steep rise has taken place in the prevalence of obesity among schoolboys and young men in two phases linked to the birth cohorts of the 1940s and of the mid-1960s and later. This rise suggests that environmental influences operating early in life are involved. In conclusion, a global obesity epidemic is developing, but the causes of the epidemic are not yet clear and more research is needed to establish the grounds for prevention.

Tobacco smoking and risk of hip fracture in men and women

BACKGROUND

Previous findings suggest that tobacco smoking increases the risk of hip fracture in women. A similar adverse effect of smoking is suspected to be present in men, but bone mineral density studies have raised the concern that men may be more sensitive to the deleterious effect of smoking on bone than women. In this study we prospectively determined the influence of current, previous, and cumulative smoking history on risk of hip fracture in men and women and addressed the issue of possible gender difference in the susceptibility to tobacco smoking.

METHODS

Pooled data from three population studies conducted in Copenhagen with detailed information on smoking habit. A total of 13,393 women and 17,379 men, initially examined between 1964 and 1992, were followed until 1997 for first admission due to hip fracture. The relative risks (RR) of hip fracture associated with smoking were estimated by means of multiplicative Poisson regression models.

RESULTS

During follow-up, 722 hip fractures were identified in women, and 447 in men. After adjustment for potential confounders, including body mass index, female current smokers had an RR of hip fracture of 1.36 (95% CI: 1.12-1.65) and male smokers 1.59 (95% CI: 1.04-2.43) relative to never smokers. In both sexes, the RR of hip fracture gradually increased by current and accumulated tobacco consumption. The RR were consistently higher in men than in women, but the test for interaction between sex and tobacco smoking was insignificant. After 5 years, male ex-smokers had an adjusted RR of 0.73 (95% CI: 0.55-0.98) relative to current smokers, while no significant decrease in risk was observed in female ex-smokers (RR = 0.91; 95% CI: 0.72-1.17)). Approximately 19% of all hip fractures in the present study population were attributable to tobacco smoking.

CONCLUSION

Tobacco smoking is an independent risk factor for hip fracture in men and women, and there appears to be no gender differences in smoking related risk. Smoking cessation reduces the risk of hip fracture in men after 5 years, while the deleterious effect of smoking seems to be more long-lasting in female ex-smokers.

An untranslated insertion variant in the uncoupling protein 2 gene is not related to body mass index and changes in body weight during a 26-year follow-up in Danish Caucasian men

AIMS

Associations between a 45 bp 3'untranslated insertion polymorphism in the uncoupling protein 2 (UCP2) gene and both body mass index (BMI) and sleeping metabolic rate have previously been reported. We investigated the impact of this polymorphism on BMI and long-term body weight changes.

METHODS

The allelic frequency of the UCP2 insertion variant was determined in a cohort of 744 obese Danish Caucasian men who had a BMI of at least 31 kg/m2 at the draft-board examinations and a randomly selected control cohort consisting of 872 draftees. Follow-up measurements of BMI were done on average 26 years after the draft-board examinations.

RESULTS

The prevalence of the insertion allele was 30.4% (95% confidence interval: 28.0-32.8%) among the obese and 29.6% (27.4-31.8%) in the control group (p = 0.6). In a lean group selected as the 354 subjects with a BMI less than 25 kg/m2 at 46 years of age from the control group, the frequency of insertion allele was 29.0% (27.2-30.8%) (p = 0.5 compared with the obese cohort). The BMI at the ages of 20 and 46 years did not differ between genotypes either in the obese or the control group. Similarly, the changes in BMI/year between examinations at 20 and 46 years of age did not differ between genotypes in either group.

CONCLUSION/INTERPRETATION

In a large group of Danish Caucasian men we found no association between a 3'untranslated insertion polymorphism in the UCP2 gene and obesity. Neither did we identify a relation between this variant and BMI changes during adult age.

Sequence variants in the human cocaine and amphetamine-regulated transcript (CART) gene in subjects with early onset obesity

OBJECTIVE

The cocaine and amphetamine-regulated transcript (CART) is expressed in the brain of rodents and humans, and intracerebroventricular injection of the peptide in rats reduces food intake. The objective of the present study was to chromosomally map the CART gene and to examine the coding region of the gene for variability in obese subjects.

METHODS

The coding region of the CART gene was analyzed by single-strand conformation polymorphism analysis in 84 subjects with early onset obesity. The prevalence of identified mutations was estimated in a cohort of 757 subjects with juvenile onset obesity [body mass index (BMI) = 35.7+/-5.7 kg/m2+/-standard deviation (S)] and in 890 random control subjects (BMI = 26.1+/-3.6 kg/m2+/-S). Furthermore, using radiation hybrid mapping we mapped the chromosomal localization of the human CART gene.

RESULTS

Radiation hybrid mapping co-localized the CART gene with a recently published human obesity locus at chromosome 5q13-14 corresponding also to an obesity locus at the similar syntenic region in mice. We identified two silent polymorphisms in the 3'UTR region of the gene (position 1457 deletion of A and position 1475 A-->G substitution) and the prevalence of these was determined among obese and control subjects. However, none of the variants were associated with either obesity or weight gain during an average follow-up period of 27.4+/-8.4 years (S).

CONCLUSION

Mutations in the coding region of the CART gene are unlikely to be involved in body weight control in Danish Caucasians with early onset obesity.

Beer, wine, spirits and subjective health

STUDY OBJECTIVE

To examine the association between intake of different types of alcoholic beverages and self reported subjective health.

DESIGN

Cross sectional health survey with assessment of intake of beer, wine and spirits (at last non-weekend day), smoking habits, social networks, physical activity, body mass index, educational level, presence of chronic disease, and self reported health.

SETTING

WHO Copenhagen Healthy City Survey, Denmark.

PARTICIPANTS

4113 men and 7926 women aged 18 to 100 years.

MAIN RESULTS

Of the 12,039 subjects, 8680 reported their health as optimal, and 3359 reported a suboptimal health. After controlling for the covariates, the relation between total alcohol intake and the proportion reporting suboptimal health was J shaped. Heavy drinkers of any of the three types of alcoholic beverages had a higher prevalence of suboptimal health than non-drinkers. However, only light (1-2 glasses of wine yesterday) and moderate (3-5) wine drinkers had significantly lower odds ratios for suboptimal health--0.72 (95% confidence limits; 0.56 to 0.92) and 0.65 (0.49 to 0.87), respectively--when compared with non-wine drinkers. Moderate beer or spirits drinkers did not differ significantly from non-drinkers of these beverages with regard to prevalence of suboptimal health. Consistently, beer preference drinkers had an odds ratio of 1.50 (1.25 to 1.80) for suboptimal health compared with wine preference drinkers.

CONCLUSIONS

A light to moderate wine intake is related to good self perceived health, whereas this is not the case for beer and spirits. The causal relations creating this association are unknown and should be considered when interpreting the relation between different types of alcoholic beverages and subsequent morbidity and mortality.

Independent effects of stable and changing body weight on total mortality

Most studies find that associations between mortality and either body mass index or weight change are U-shaped. Previous studies, however, have not considered independent effects of weight level and weight change while also controlling for confounding by diseases leading to weight change. We used follow-up data on average 10-year total mortality from a Danish population of 15,113 men and women, who had their weight measured at about 5-year intervals. We obtained information on preexisting disease at surveys and by linkage to hospital discharge registers. We defined subclinical disease as incident disease or death during the first 4 years of follow-up. We decomposed the mortality risk associated with weight change into a static effect, corresponding to the difference in mortality at stable weight at the initial and attained weight, and a dynamic effect, estimated as the difference between mortality after weight change and mortality at stable weight at the attained weight. Both weight level and weight change had independent effects on total mortality, with both these associations being U-shaped. Adjustment for smoking and the exclusion of subjects with preexisting and subclinical disease did not alter the associations.

Homozygosity of the Pro12Ala variant of the peroxisome proliferation-activated receptor-gamma2 (PPAR-gamma2): divergent modulating effects on body mass index in obese and lean Caucasian men

AIMS/HYPOTHESIS

The objectives of the present investigation were to examine: 1) whether a Pro115Gln variant in the peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) is associated with juvenile-onset obesity among Danish Caucasianmen and 2) whether the relation of a Pro12Ala polymorphism in PPAR-gamma2 with BMI and long-term weight regulation differ between lean and obese subjects within the same cohort.

METHODS

The Pro115Gln and Pro112Ala variants were examined using PCR and RFLP in a group of 752 subjects with a Body Mass Index (BMI) of 31.0 kg/m2 or more and in 869 non-obese control subjects.

RESULTS

We did not find Pro115Gln in any of the 1621 male subjects we examined. Among the males with juvenile-onset obesity, the allelic frequency of the Pro12Ala polymorphism was 14% (95% confidence interval: 12-16%) compared with 16% (14-17%) among the non-obese control subjects (NS). Heterozygosity of the codon 12 variant was not associated with differences in BMI or changes in body weight regulation during follow up in lean or obese subjects. In the group of obese subjects, 21 homozygous Ala12Ala carriers had, however, a higher BMI (38.9 +/- 5.4 kg/m2 (means +/- SD) vs 35.5 +/- 5.5 kg/ m2, p = 0.008) and a higher weight gain (0.27 +/- 0.24 kg x m(-2) x year(-1) vs 0.10 +/- 0.24 kg x m(-2) x year(-1), p = 0.004), compared with wild-type carriers. Moreover, within the control group of 869 men the 14 homozygous carriers of the variant had a lower BMI (24.4 +/- 2.7 kg/m2 vs 26.2 +/- 3.7 kg/m2, p = 0.005) and a slower increase in BMI (0.11 +/- 0.11 kg x m(-2) x year(-1) vs 0.17 +/- 0.11 kg x m(-2) x year(-1), p = 0.002) compared with wild-type carriers.

CONCLUSION/INTERPRETATION

The codon 12 variant of PPAR-gamma2 is not intrinsically associated with juvenile obesity. The variant may in its homozygous form interact, however, with various combinations of genetic and environmental factors in lean and obese subjects to cause divergent modulating effects on BMI and long-term body weight control.

Development of the obesity epidemic in Denmark: cohort, time and age effects among boys born 1930-1975

OBJECTIVE

A global epidemic of obesity is developing, but its causes are still unclear. In Denmark, two periods of steep increases in prevalence of obesity have occurred among young men born in the 1940s and 1960-70s. This study investigated the preceding changes in prevalence of obesity and in the entire body mass index (BMI = weight/height2) distribution by birth cohort, calendar time and age among Danish school boys.

METHODS

Children attending Copenhagen schools 1937-1983 had annual health examinations, from which we computerized 1,037,468 measurements of height (m) and weight (kg) of 161,314 boys aged 7-13 y. Obesity was defined as age-specific BMI exceeding the 95.0, the 99.0 and the 99.9 percentile among those born 1930-1934, the latter corresponding to the prevalence of obesity among the young men in these cohorts. The median, standard deviation, skewness, and the 5th, 25th, 75th and 95th percentiles of the age-specific BMI were estimated for each birth cohort.

RESULTS

The prevalence of obesity, defined by the 99.9 percentile, increased at all ages during the same birth years as among the young men, and, accordingly, at earlier calendar years. The prevalence of obesity, defined by the 95.0 percentile, showed a distinctly different pattern: a sharp increase, irrespective of age, during the calendar years 1947-1949, and thereafter a stable level until the 1970s, where a further modest increase began. The prevalence defined by the 99.0 percentile showed a mixture of the trends in those defined by the 99.9 and 95.0 percentiles. The median BMI showed small fluctuations, parallel at all ages. The standard deviation and right-sided skewness increased until birth year 1950, but were almost stable thereafter. The pattern of changes in the quartiles mostly reflected those in the median.

CONCLUSIONS

The prevalence of obesity defined by the 99.9 or 99.0 percentile has increased in Danish boys born in the 1940s and since the mid 1960s, without corresponding changes in the central part of the BMI distribution. When defining obesity by the 95.0 percentile, there was a sharp distinct age-independent increase in the late 1940s. The development of the obesity epidemic is a heterogeneous phenomenon that has involved changes in environmental influences starting at preschool ages and affecting different subsets of the population, either because of selective exposure or particular susceptibility.

The effect of recurrent events on register-based estimates of level and trends in incidence of acute myocardial infarction

Although changes in incidence of first acute myocardial infarctions (AMI) are of primary interest in the evaluation of preventive efforts, only few studies have used this measure. In the present study, the risk of recurrence over time in subjects with first AMI is analyzed, and the effect of inclusion of recurrent cases on the estimation of level and trend in the incidence of AMI is evaluated. The National Patient Register of Hospital Discharges and the Causes-of-Death Register were linked, and all cases of admission for AMI and fatal manifestation of the disease since 1977 and until 1992 in the Danish population were identified. New events occurred during the following 12 years in 46% of men and 42% of women with their first AMI in 1980. Ninety percent of the recurrent events occurred during the first 5 years. Using absence of events during only 1 preceding year as the inclusion criteria, the incidence rate would be overestimated by about 20%-30%. However, if the preceding event-free period was of the same duration throughout the study period, the trends in AMI rates were not altered by expanding the event-free period up to 14 years before the index event. Although rates of AMI based on the total number of affected persons without AMI in the previous year overestimate the true incidence by 20%-30%, trends in these rates reflect trends in rates of first events with reasonable accuracy.