Stability in the prevalence of Swedish children who were overweight or obese in 2003 and 2011.

AIM: We aimed to explore the prevalence and determinants of overweight including obesity among children in Sweden in 2003 and 2011. METHODS: Two population-based cross-sectional surveys included 7728 and 12 882 12-year-old children in Sweden, and 1198 and 2699 eight-year-old children in Stockholm County, in 2003 and 2011. Weighted prevalence of overweight including obesity and multivariate-adjusted relative risks (RRs) with 95% confidence intervals (CIs) was calculated. RESULTS: In 2011, the overweight prevalence was lower for 12-year-old girls than boys (RR=0.84, CI=0.77-0.92), lower for girls and boys with a higher rather than a lower educated mother (for example, RRgirls =0.76, CI=0.65-0.88), but higher for girls and boys in smaller rather than main cities (RRgirls =1.52, CI=1.28-1.82). There was no difference in overweight prevalence between 2003 and 2011 among the 12-year-old children. However, eight-year-old girls had a lower overweight prevalence in 2011 than in 2003 (RR=0.76, CI=0.59-0.97). The strongest decrease in overweight was among eight-year-old girls with mothers with lower levels of education (RR=0.63, CI=0.47-0.86). CONCLUSION: The prevalence of overweight including obesity was stable among Swedish children between 2003 and 2011. Gradients in the determinants of overweight persisted. There was some evidence of a less steep socio-economic gradient in overweight in eight-year-old girls over time.

Post-infection symptoms following two large waterborne outbreaks of Cryptosporidium hominis in Northern Sweden, 2010-2011.

BACKGROUND: In 2010-2011, two large waterborne outbreaks caused by Cryptosporidium hominis affected two cities in Sweden, Östersund and Skellefteå. We investigated potential post-infection health consequences in people who had reported symptoms compatible with cryptosporidiosis during the outbreaks using questionnaires. METHODS: We compared cases linked to these outbreaks with non-cases in terms of symptoms present up to eleven months after the initial infection. We examined if cases were more likely to report a list of symptoms at follow-up than non-cases, calculating odds ratios (OR) and 95 % confidence intervals (CI) obtained through logistic regression. RESULTS: A total of 872 (310 cases) and 743 (149 cases) individuals responded to the follow-up questionnaires in Östersund and Skellefteå respectively. Outbreak cases were more likely to report diarrhea (Östersund OR: 3.3, CI: 2.0-5.3. Skellefteå OR: 3.6, CI: 2.0-6.6), watery diarrhea (Östersund OR: 3.4, CI: 1.9-6.3. Skellefteå OR: 2.8, CI: 1.5-5.1) abdominal pain (Östersund OR: 2.1, CI: 1.4-3.3, Skellefteå OR: 2.7, CI: 1.5-4.6) and joint pain (Östersund OR: 2.0, CI: 1.2-3.3, Skellefteå OR: 2.0, CI: 1.1-3.6) at follow-up compared to non-cases. CONCLUSIONS: Our findings suggest that gastrointestinal- and joint symptoms can persist several months after the initial infection with Cryptosporidium and should be regarded as a potential cause of unexplained symptoms in people who have suffered from the infection.

Trends in self-reported BMI and prevalence of obesity 2002-10 in Stockholm County, Sweden.

BACKGROUND: Trends in obesity have been reported to level off in several Western countries. The aim of this study was to investigate trends in body mass index (BMI) and prevalence of obesity between 2002 and 2010 in Stockholm County, Sweden. METHODS: Three cross-sectional questionnaires from the Stockholm Health Surveys were used for this study. A total of 31 182, 34 707 and 30 767 men and women aged between 18 and 64 years completed the questionnaire regarding sociodemographic factors, health parameters, physical activity, smoking habits and anthropometry in 2002, 2006 and 2010, respectively (response rate: 62.5, 61.3 and 55.6%, respectively). Linear regression was used to investigate changes in mean BMI. Relative risk regression models were used to investigate changes in prevalence of obesity, defined as BMI ≥ 30 kg/m(2). All analyses were stratified on age and further adjusted for smoking, education and socioeconomic position. RESULTS: Between 2002 and 2006, a stabilization was found in BMI and prevalence of obesity in both men and women. But from 2006 to 2010, BMI and prevalence of obesity had increased, also among the young. In 2010, the prevalence of obesity was 12.2% among men and 10.3% among women. CONCLUSION: After a period of stabilization in 2002-06, BMI and prevalence of obesity are increasing in Stockholm County, Sweden.

Weight status at age 18 influences marriage prospects. A population-based study of Swedish men.

BACKGROUND: In a longitudinal population-based study of the relationship between body mass index (BMI) in early adulthood and marital status at 40 years of age, obese men were half as likely to be married compared with men of normal weight. Significant associations between obesity and marital status among men in a longitudinal setting are novel findings. METHODS: The study cohort comprised Swedish men born from 1951 to 1961. Height and weight at age 18 was gathered from the Military Service Conscription Register and information on marital status at 40 years of age was obtained from population registers by record-linkage using the unique personal identification number. The odds ratio (OR) for being married was calculated by polytomous logistic regression analysis adjusting for birth year, intellectual performance, education, country of birth, residential area, socioeconomic position in childhood and adulthood, parental education and muscle strength. RESULTS: Our study included 486 599 Swedish men. Young men who were obese (BMI ≥ 30.0) at 18 years of age had an OR of 0.49 (95% CI: 0.46-0.52) for being married at 40 years of age compared to normal weight men (BMI: 18.5-24.9). Underweight men (BMI ≤ 18.5) had an OR of 0.84 (0.82-0.86) and overweight men (BMI: 25.0-29.9) had an OR of 0.83 (0.80-0.85) for being married at 40 years of age. CONCLUSION: Underweight, overweight and obese men were less likely to be married than their normal weight counterparts. Obese men had the lowest likelihood of being married. Stigmatization and discrimination may partly explain these findings, but further research is needed before firm conclusions can be drawn.

Association between obesity status and sick-leave in Swedish men: nationwide cohort study.

BACKGROUND: Sick-leave is an important source of productivity losses to society. The objective of this study was to investigate the association between body mass index (BMI) status in young adulthood and future sick-leave. METHODS: A nation-wide cohort of 43,989 Swedish men (18.7 ± 0.5 years) performing military conscription tests in 1969-70 were followed between 1986 and 2005 regarding sick-leave. BMI was used to define underweight (<18.5), normal weight (18.5-24.9), overweight (25.0-29.9) and obesity (≥ 30.0). Relative risks of sick-leave were estimated with Cox proportional hazards models adjusted for smoking, socio-economic index and muscular strength, using normal weight as the reference. RESULTS: During 803,684 person-years of follow-up, 488,570 sick-leave episodes were recorded. On average, one short-term (≤ 7 days) episode occurred every eight person-months, one intermediate-term (8-30 days) every five person-years and one long-term (>30 days) episode every 15 person-years. Overweight was associated with 20% and obesity with >30% risk elevation for episodes ranging from 8 to 30 days [hazard ratio (HR) 1.20; 95% CI 1.15-1.24 and HR 1.35; 95% CI 1.24-1.47, respectively] as well as for episodes >30 days (HR 1.19; 95% CI 1.15-1.23 and HR 1.34; 95% CI 1.24-1.47, respectively) compared to normal weight. Obesity was also associated with an increased risk of sick-leave episodes ≤ 7 days (HR 1.13; 95% CI 1.09-1.16), but the corresponding risk increase for overweight was very small (HR 1.02; 95% CI 1.00-1.03). Underweight showed increased risk only for short-term episodes (HR 1.05; 95% CI 1.04-1.07). DISCUSSION: Overweight and obesity are associated with increased risk for sick-leave compared to normal weight, especially for sick-leave episodes of longer duration.

Validation of the new Swedish vaccination register - Accuracy and completeness of register data.

OBJECTIVE: The aims of this study are to validate infant vaccination data in the Swedish Vaccination Register (SVR) to the Swedish administrative coverage reports, and to assess differences in register-based vaccination coverage estimates between providers using different data reporting methods. METHODS: The study population included all infants born in Sweden with a Swedish Personal Identity Number during 2014 and 2015 (n = 230,220). Data on all National Immunisation Programme vaccinations administered before 24 months of age were collected from the SVR and from administrative coverage reports. Information regarding data registration methods in the SVR were collected from national and regional authorities. Coverage from health care providers using single registration methods, where vaccination data were transferred automatically from the electronic health care record to the SVR, was compared to that from providers using double registration methods where data had to be added into the SVR in a separate process. RESULTS: For 98,4% of the study population at least one vaccination was recorded in the SVR. The coverage of 3-dose DTP-containing (87,1%) and 1 dose MMR (91,1%) in the register did not reach administrative data coverage (97,4% for 3-dose DTP-containing and 97,0% for MMR). Single registration procedures yielded significantly higher coverage than double registration procedures (92,24% vs 87,10%, p < 0,0001). A regional switch from double to single registration increased coverage from 80,0 to 95,2%. CONCLUSIONS: The SVR is a valuable data source for vaccination coverage monitoring. For research purposes, the SVR provides valuable data, since every health care provider is obliged to register all vaccine doses given within the national immunisation program. The SVR shows a high completeness validated by comparison to a very well-functioning administrative data system. Single-registration procedures give more complete data and should be supported by health systems while creating health care registers.

High systolic blood pressure increases the risk of obtaining a disability pension because of cardiovascular disease: a cohort study of 903 174 Swedish men.

BACKGROUND: Hypertension puts a heavy economic burden on society through large medical care expenditures and productivity losses resulting from disability and premature death. The risk of obtaining a disability pension (DP) because of cardiovascular disease (CVD) has not been explored in previous research. The aim of this study was to investigate the extent to which high systolic blood pressure (BP) among 18-year-old men increases the risk of obtaining a DP in later life, for any reason or specifically because of CVD, compared with men with normal systolic BP. DESIGN/METHODS: A record linkage was performed involving several nation-wide Swedish registers. The study cohort consisted of men born between 1951 and 1970 who underwent military conscription during 1969-1994, when they were 17-20 years of age. Data on BP, weight, height and muscle strength were obtained from conscription examinations, and information on DP and the underlying International Classification of Diseases diagnosis were retrieved from the Social Insurance Office 1971-2006. Analyses were conducted by Cox proportional hazards regression models with adjustment for several confounding factors. RESULTS: Among 903 174 men with complete data, mean follow-up time was 26.8 years and 54 524 men (6.0%) attained DP. The risk of obtaining a DP because of CVD among men with moderate/severe hypertension (systolic BP> or =160 mmHg) was moderately increased, fully adjusted hazard ratio = 1.52 (95% confidence interval=1.04-2.22) compared with men with normal systolic BP. CONCLUSION: This large population-based cohort study showed that moderate/severe hypertension in young adulthood conveyed an increased risk of obtaining a DP caused by CVD. Primary prevention of hypertension and optimal early treatment of hypertension may reduce productivity losses because of DP caused by CVD.

Associations between birthweight and weight change during infancy and later childhood, and systolic blood pressure at age 15 years: the COMPASS study.

Inconsistent findings have been reported on associations between postnatal weight change with later blood pressure. This study analysed the impact of weight change during fetal life, infancy and later childhood on systolic blood pressure (SBP) in adolescence. A longitudinal population-based study was conducted in Stockholm, Sweden. Weight, length at birth and gestational age were extracted from the Medical Birth Register, weight and height in childhood was collected from child health records, and body size and SBP were measured during a health examination at 15 years of age. Complete data on 2438 individuals were analysed using linear regression. In fully adjusted models SBP increased 0.99 mmHg [95% confidence interval (CI), 0.27, 1.71] in girls and 1.02 mmHg [0.31, 1.73] in boys per 1 SD increase in weight during the first year of life. The effect on SBP of weight change from 10 to 15 years among boys was 3.70 mmHg [2.67, 4.73] and among girls 1.30 mmHg [0.38, 2.22] per 1 SD increase in weight. Weight gain in infancy and later childhood was positively associated with SBP at age 15 years, while birthweight showed a weaker inverse association with SBP. No apparent effect of weight gain from 1 to 10 years of age was seen. Degree of weight change in infancy was equally important for SBP in both boys and girls, while growth during puberty showed a stronger association with SBP among boys than among girls.

The Swedish Young Male Twins Study: a resource for longitudinal research on risk factors for obesity and cardiovascular diseases.

The Swedish Young Male Twins Study is a population-based longitudinal twin study founded in 1997 through record-linkages of several national registers. Details on pregnancy and birth were obtained from the Swedish Medical Birth Register and used to identify 3566 male twins (1783 pairs) born in Sweden between 1973 and 1979 and resident in Sweden in 1997. A record-linkage was made between the Medical Birth Register and the Military Service Conscription Register for the years 1991 to 1999, providing information on body weight, height, blood pressure, muscle strength, cognitive ability of these twins at age 18 and 19 years. In 1998, 2002 and 2005 to 2006, the twins were surveyed on their zygosity, socioeconomic status, lifestyle factors (such as eating habits, physical activity, smoking habits, use of alcohol etc), height and weight. In 2002, additional information was collected on perceived body shape and size, and eating behavior, according to the Three-Factor Eating Questionnaire. In 2003, DNA via buccal mucosa was collected from a subset of the twins. Recent research using the Swedish Young Male Twins datasets has explored the relationships between fetal growth, body size and blood pressure in young adulthood, genetic and environmental contributions to eating behavior and physical activity, and relationships between diet and physical activity patterns with longitudinal changes in body mass index and attained waist circumference.

Obesity in young adulthood and later disability pension: a population-based cohort study of 366,929 Swedish men.

BACKGROUND: The prevalence of obesity has increased threefold among Swedish men during recent decades. Knowledge from Sweden on how obese men manage in working life and become disability pensioners is sparse. The aim of this nationwide and population-based cohort study was to investigate to what extent body mass index (BMI) in young adulthood predicts later disability pension. METHOD: All Swedish men born 1952-59, who had their weight and height measured at age 18 years in the compulsory military conscription examinations, were followed up longitudinally from 1990 to 2001 with regard to receiving disability pension. Data on own socioeconomic position (1985), education and marital status (1990), parental socioeconomic position (1960), and education (1970) were obtained from censuses. For 366,929 men (81% of the eligible men) the hazard ratio for receiving disability pension was calculated with Cox regression controlling for own education, parental education, childhood and adult socioeconomic position, marital status, morbidity, and type of municipality. RESULTS: Obesity in young adulthood increased the risk for disability pension later in life (1.35, 95% CI 1.19, 1.52) compared with men of normal weight. The relationship between BMI and disability pension was J-shaped with higher risks for underweight (1.14, 95% CI 1.09, 1.20) and obese men. CONCLUSIONS: Obese men in Sweden are at higher risk of receiving disability pension. The relationship between BMI and disability pension is J-shaped. An important future task is to estimate the societal costs due to disability pension of obese people.

Blood pressure in young adulthood and later disability pension. A population-based study on 867 672 men from Sweden.

Hypertension is a common chronic condition and can lead to an economic burden for society because of the costs of treatment for high blood pressure and most likely also because of disabilities related to hypertension and its co-morbidities. The aim of this study was to investigate to what extent moderate/severe hypertension in young adulthood increases the risk of becoming a disability pensioner later in life. All Swedish men born 1951 to 1970, who had their systolic blood pressure measured at age 18-19 years in the compulsory military conscription examination were followed from 1990 to 2001 with respect to receiving disability pension. Among 867 672 men (84.3% of the target population), the hazard ratio was 1.33 (95% CI 1.15-1.52) for being granted disability pension because of moderate/severe hypertension compared with men with normal systolic blood pressure after adjustment for conscription centre, body mass index and socio-economic conditions in childhood and adulthood. Men with mild hypertension had also an increased hazard ratio (1.09, 95% CI 1.05-1.13) compared with men with normal systolic blood pressure. This study showed that hypertension in young adulthood increased the risk of disability pension in later life.

Growing social inequalities in the occurrence of overweight and obesity among young men in Sweden.

AIMS: The aims of the present study are to investigate time trends and social inequalities in mean body mass index (BMI), overweight, and obesity among 18-year-old men in Sweden from 1970 to 2000 and to explore whether social inequalities in these conditions have increased. METHODS: A record linkage was made between the Military Service Conscription Register, Population and Housing Censuses, the Register of Education and the Register of the Total Population. All 1,748,800 males born in 1952-82 who were living in Sweden at the age of 17 years in 1969-99 were eligible for this nationwide study. The study population comprises 1,500,499 18-year-old men with information on BMI (86% of eligible subjects). RESULTS: During the study period from 1970 to 2000, mean BMI increased from 20.89 kg/m2 to 22.49 kg/m2, the prevalence of overweight increased from 6.6% to 13.6% and the prevalence of obesity increased from 1.0% to 3.8%. Mean BMI and the prevalence of overweight and obesity were higher among young men with low-educated mothers than among those with high-educated mothers. A noteworthy finding was that the socioeconomic gap increased over time. CONCLUSIONS: Between 1970 and 2000, the prevalence of overweight increased twofold and the prevalence of obesity increased fourfold in this study population. The social inequalities in overweight and obesity have steadily increased among young men in Sweden during the past three decades.

Importance of smoking habits for longitudinal and age-matched changes in body mass index: a cohort study of Swedish men and women.

BACKGROUND: Previous longitudinal studies of smoking and BMI have focused on smoking cessation. The aim of the present study was to disentangle the effects of long-term smoking on longitudinal changes and age-matched BMI differences (time period effects) in a nation-wide Swedish cohort. METHODS: Men and women (n = 4349) ages 18-73 years reported height, weight, and smoking status for a baseline survey in 1980-1981. Eight and 16 years after baseline, follow-up surveys were conducted for 3244 (75%) of the 4349 subjects. Long-term smokers and long-term nonsmokers were compared with respect to longitudinal changes and age-matched BMI differences. RESULTS: For middle-age adults, the longitudinal increases in BMI were smaller among long-term smokers than long-term nonsmokers regardless of gender. Among the elderly, the longitudinal decrease in BMI was greatest among long-term smokers. Among men, age-matched BMI differences between surveys were smaller for long-term smokers than for nonsmokers. Among women, however, age-matched BMI differences were greater for long-term smokers than for nonsmokers. CONCLUSIONS: In middle-age subjects, longitudinal BMI increases are smaller among smokers than nonsmokers. During old age, the BMI of smokers decreases more than that of nonsmokers. Unknown factors related to gender contribute to larger time period effects of smoking in women than in men.

The Swedish Young Male Twins Register: a resource for studying risk factors for cardiovascular disease and insulin resistance.

A new Swedish twin register was created in 1998. All male twins born in Sweden 1973-1979 were identified in the Swedish Medical Birth Register. 3566 twins (1783 pairs) who were alive and residents of Sweden in 1997 were included in the new register. Data on birthweight, birthlength, gestational age, and so forth, were obtained from the Medical Birth Register. Record linkage was effected with the Military Service Conscription Register for the years 1991-1999. Anthropometrical data and information on blood pressure were obtained from this latter source. In 1998 a questionnaire was mailed to all twins in the register. Questions were posed about zygosity, socioeconomic conditions, lifestyle factors (physical activity, smoking habits, etc.), body shape and body size. Complete responses were obtained from 2654 twins (1327 pairs). In 2002 the cohort is being followed-up by a more extensive mailed questionnaire. Data will be collected about socioeconomic conditions, lifestyle, eating behaviour (TFEQ), body size and body shape. In the next few years genomic DNA will also be collected from buccal mucosa (using brush techniques).

Fetal growth and systolic blood pressure in young adulthood: the Swedish Young Male Twins Study.

The objective was to test the fetal origins hypothesis by examining the association between fetal growth and systolic blood pressure in a large cohort of adult male twins of known zygosity. This cohort study is based on a record linkage of routinely collected data from the Swedish Medical Birth Registry, the Swedish Military Conscription Registry and a mailed questionnaire. It comprises 886 pairs of same-sex male twins born in Sweden in 1973-79 for whom data were available on size at birth and systolic blood pressure, height and weight at age 17-19 years. Based on self-reported similarity of appearance in childhood, 384 twin pairs were classified as monozygotic (MZ), 269 as dizygotic (DZ) and 233 as of uncertain zygosity (XZ). Differences in systolic blood pressure within and between twin pairs were analysed in relation to birthweight and birthweight-for-gestational-age z-score using random effects linear models. Within twin pairs, a 1 kg difference in birthweight was associated with a difference of -1.30 mmHg in systolic blood pressure [95% confidence interval -4.15, +1.54] for MZ twins and +0.14 [-3.49, +3.76] for DZ twins; for all twins combined it was -0.21 [-2.13, +1.71]. Between twin pairs, a 1 kg difference in birthweight was associated with a difference of -2.68 mmHg in systolic blood pressure [-4.95, -0.42] for MZ twins and +0.28 [-2.35, +2.91] for DZ twins; for all twins combined -1.68 [-3.15, -0.22]. All these estimates included adjustment for age, year and conscription centre of examination, gestational age and height and weight at conscription. These results provide little support for the fetal origins hypothesis. The estimates of the within-pair effect in MZ twins and their wide confidence intervals (including zero) cannot exclude the existence of common genetic mechanisms, but are also not inconsistent with an in utero programming effect. This study highlights some methodological problems with twin studies.