Body size and risk of atrial fibrillation: a cohort study of 1.1 million young men.

BACKGROUND: Whilst tall stature has been related to lower risk of vascular disease, it has been proposed as a risk factor for atrial fibrillation. Little is known about other anthropometric measures and their joint effects on risk of atrial fibrillation. OBJECTIVES: We aim to investigate associations and potential joint effects of height, weight, body surface area (BSA) and body mass index (BMI) with risk of atrial fibrillation. METHODS: In a cohort covering 1 153 151 18-year-old men participating in the Swedish military conscription (1972-1995), Cox regression was used to investigate associations of height, weight, BSA and BMI with risk of atrial fibrillation. RESULTS: During a median of 26.3 years of follow-up, higher height was associated with higher risk of atrial fibrillation (hazard ratio [HR] 2.80; 95% CI 2.63-2.98; for 5th vs. 1st quintile) and so was larger BSA (HR 3.05; 95% CI 2.82-3.28; for 5th vs. 1st quintile). Higher weight and BMI were to a lesser extent associated with risk of atrial fibrillation (BMI: 1.42; 95% CI 1.33-1.52, for 5th vs. 1st quintile). We found a multiplicative joint effect of height and weight. Adjusting for muscle strength, exercise capacity and diseases related to atrial fibrillation attenuated these measures. CONCLUSIONS: Higher height and weight are strongly associated with higher risk of atrial fibrillation. These associations are multiplicative and independent of each other and are summarized in a strong association of body surface area with risk of atrial fibrillation. The mechanisms remain unknown but may involve increased atrial volume load with larger body size.

U-shaped association of body mass index in early adulthood with unintentional mortality from injuries: a cohort study of Swedish men with 35 years of follow-up.

OBJECTIVES: To investigate the dose-response association between body mass index (BMI) in young adulthood and the risk of mortality caused by unintentional injuries. METHODS: We performed a cohort study including 7 43 398 men identified by linkage of the Multigeneration Register and the Military Service Conscription Register. Cox regression models were used to examine crude and adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) of the relationships between BMI at age 18-20 years and the risk of death from all unintentional injuries as well as from specific unintentional injuries. We then estimated the population attributable fractions (PAFs)-the proportion of unintentional deaths that was attributable to underweight, overweight and obesity in this population-based cohort. RESULTS: During 35.9 years of follow-up, 6461 deaths occurred from unintentional injuries, including 3064 deaths from road injury, 978 from poisoning, 503 from falls, 243 from fire and 348 from drowning. Underweight subjects had a higher risk of mortality in all unintentional injuries (HR, 1.05; 95% CI, 1.03-1.10) and mortality in burns (HR, 1.65; 95% CI, 1.13-2.40) compared with BMI between 18.5 and 22.5 kg m(-2) (reference group). BMI >25 kg m(-2) was associated with increased risk of death from all unintentional injuries (HR, 1.36; 95% CI, 1.12-1.65) and road accidents (HR, 1.50; 95% CI, 1.14-1.97). Estimates of PAF suggested that 4.4% of the mortality in Swedish men caused by unintentional injuries could have been avoided if BMI values were kept between 18.5 and 22.5 kg m(-2). CONCLUSIONS: A U-shaped association was observed between BMI and risk of unintentional death. Both underweight and overweight were associated with increased mortality risk for all unintentional injuries and for subtype causes. Our study suggests that BMI might be a significant target for preventive interventions on deaths caused by unintentional injuries.

Alcohol and substance abuse, depression and suicide attempts after Roux-en-Y gastric bypass surgery.

BACKGROUND: Small studies suggest that subjects who have undergone bariatric surgery are at increased risk of suicide, alcohol and substance use disorders. This population-based cohort study aimed to assess the incidence of treatment for alcohol and substance use disorders, depression and attempted suicide after primary Roux-en-Y gastric bypass (RYGB). METHODS: All patients who underwent primary RYGB in Sweden between 2001 and 2010 were included. Incidence of hospital admission for alcohol and substance use disorders, depression and suicide attempt was measured, along with the number of drugs prescribed. This cohort was compared with a large age-matched, non-obese reference cohort based on the Swedish population. Inpatient care and prescribed drugs registers were used. RESULTS: Before RYGB surgery, women, but not men, were at higher risk of being diagnosed with alcohol and substance use disorder compared with the reference cohort. After surgery, this was the case for both sexes. The risk of being diagnosed and treated for depression remained raised after surgery. Suicide attempts were significantly increased after RYGB. The adjusted hazard ratio for attempted suicide in the RYGB cohort after surgery compared with the general non-obese population was 2·85 (95 per cent c.i. 2·40 to 3·39). CONCLUSION: Patients who have undergone RYGB are at an increased risk of being diagnosed with alcohol and substance use, with an increased rate of attempted suicide compared with a non-obese general population cohort.

The associations between overweight, weight change and health related quality of life: Longitudinal data from the Stockholm Public Health Cohort 2002-2010.

OBJECTIVE: Cross-sectional studies have shown that people with obesity and overweight report lower health related quality of life (HRQoL). With a lack of longitudinal studies, this study aims to assess the association between eight-year weight change and HRQoL measured by the EQ-5D instrument and to investigate whether the association differs with regard to baseline body mass index (BMI). METHOD: A population-based survey was conducted among a random sample of 31,182 individuals from Stockholm County aged 18-84years in 2002 and reassessed in 2010 and supplemented by record linkage with regional and national registers. Multivariate Poisson regression and linear regression were conducted with adjustments for socio-demographic and health-related variables and baseline BMI category as effect modifier for the association between weight change and HRQoL. RESULTS: Individuals with overweight and obesity respectively have 0.014 and 0.039 lower EQ-5D indexes compared to those being normal weight. Over the eight-year follow-up, 17.6% gained moderately (≥5% body weight) and 13.9% gained heavily (≥10% body weight) in weight. In the fully adjusted analysis, heavy weight gain was associated with a significantly lower overall EQ-5D index and an increased risk of reporting impairment in all but one EQ-5D dimensions irrespective of baseline BMI category. Weight reduction had no significant preventive effect. CONCLUSION: Next to obesity status itself, weight gain leads to impairment in HRQoL irrespective of BMI category at baseline while eight year weight loss seems not to have the reversed effect on HRQoL, emphasizing the importance of primary prevention of weight gain.

Is bipolar disorder more common in highly intelligent people? A cohort study of a million men.

Anecdotal and biographical reports have long suggested that bipolar disorder is more common in people with exceptional cognitive or creative ability. Epidemiological evidence for such a link is sparse. We investigated the relationship between intelligence and subsequent risk of hospitalisation for bipolar disorder in a prospective cohort study of 1,049,607 Swedish men. Intelligence was measured on conscription for military service at a mean age of 18.3 years and data on psychiatric hospital admissions over a mean follow-up period of 22.6 years was obtained from national records. Risk of hospitalisation with any form of bipolar disorder fell in a stepwise manner as intelligence increased (P for linear trend <0.0001). However, when we restricted analyses to men with no psychiatric comorbidity, there was a 'reversed-J' shaped association: men with the lowest intelligence had the greatest risk of being admitted with pure bipolar disorder, but risk was also elevated among men with the highest intelligence (P for quadratic trend=0.03), primarily in those with the highest verbal (P for quadratic trend=0.009) or technical ability (P for quadratic trend <0.0001). At least in men, high intelligence may indeed be a risk factor for bipolar disorder, but only in the minority of cases who have the disorder in a pure form with no psychiatric comorbidity.

Poor school performance is associated with a larger gain in body mass index during puberty.

AIM: Social inequalities in type 2 diabetes and coronary heart disease may be established in formative school years. We investigated whether school performance is associated with adiposity and increase in body mass index (BMI) between 10 and 15 years of age. METHODS: A community sample of 2633 school children had height and weight measured in school at the ages of 10 and 15. Percentages of body fat and waist circumference were measured at the age of 15. Mean grades in several school subjects at the age of 15 (ninth school year) were divided into quartiles. A linear regression analysis with BMI as the main outcome took into account parental education and ethnicity, obtained from registers, and children's living habits, collected by questionnaires. RESULTS: In adjusted models, longitudinal changes in BMI between the ages of 10 and 15 were larger in the lowest quartiles of school grades compared with the highest: for girls, they were ß = 0.45 (p = 0.007) and for boys they were ß = 0.45 (p = 0.016). Cross-sectional regression analyses, with percentage of body fat and waist circumference as outcomes, showed similar results. CONCLUSION: Our results suggest that school performance is one pathway to social inequalities in obesity in school children.

Modifiable environmental influences on body mass index shared by young adult brothers.

OBJECTIVES: Twin and adoption studies suggest that family environment has little, if any, influence on body mass index (BMI) in adulthood. We investigated the hypothesis that the differences in the years of birth between siblings influence their similarity in BMI at comparable ages, which would give evidence for a possibly modifiable influence of the environment shared by family members. METHODS: Swedish full-brother pairs (N=261 712) born between 1951 and 1983 were measured for BMI in conscription examination at 16-26 years (median: 18.2 years) of age and were divided into quartiles by the difference between their birth-years (< 2.25 years, 2.25-3.33 years, 3.34-5.08 years and >5.08 years). Furthermore, 1961 dizygotic twin brother pairs from the same population representing brothers born at the same time were included. In addition, the log BMI of the younger brother was modeled as a linear function of the log BMI of the older brother. Subsequently, the significance of the interaction between birth-year difference and the BMI of the older brother was tested. RESULTS: Intraclass correlation for BMI in dizygotic twin pairs was higher (0.431, 95% confidence interval (CI) 0.394-0.466) than the correlation for full-brothers in the first quartile of birth-year difference (0.376, CI 0.342-0.408). Among full-brothers, the BMI correlation decreased from 0.376 (CI 0.342-0.408) [corrected] in the first quartile to 0.338 (CI 0.331-0.345) in the last quartile. The regression analysis showed a statistically significant decrease in correlation with increasing birth-year difference (P<0.001). CONCLUSION: The influence on BMI in young men of the environment shared by dizygotic twin brothers is greater than between non-twin full-brothers, indicating important influences of concomitant exposure to the same early life environment before and/or after birth. Among non-twin siblings there is a slight possibly modifiable influence as evidenced by declining correlations by increasing distance in years of birth.

Infrequent attention to dietary and physical activity behaviours in conversations in Swedish child health services.

AIM: To investigate conversations between nurses and parents in Swedish child health services and to assess to what extent attention is directed towards dietary and physical activity behaviours in children. METHODS: Twenty-three nurses audio-recorded one session each. Recordings were assessed and topics were classified according to predetermined categories. RESULTS: The three most frequent topics of conversation concerned physical examinations of the child (30% of session time), talking to the child to establish or maintain contact and interest (15%), and development of language skills (12%). Dietary habits came on fourth place (10%), and physical activity ranked 14 (4%). CONCLUSION: Attention to dietary and physical activity behaviours in children is infrequent in Swedish child health services. Concern is raised about the efficacy of prevention efforts against childhood obesity.

Impact of mental health problems on case fatality in male cancer patients.

BACKGROUND: Although mortality rates are elevated in psychiatric patients relative to their healthy counterparts, little is known about the impact of mental health on survival in people with cancer. METHODS AND RESULTS: Among 16 498 Swedish men with cancer, survival was worse in those with a history of psychiatric hospital admissions: multiply-adjusted hazard ratio (95% confidence interval) comparing cancer mortality in men with and without psychiatric admissions: 1.59 (1.39, 1.83). CONCLUSION: Survival in cancer patients is worse among those with a history of psychiatric disease. The mechanisms underlying this association should be further explored.

Morbidity and mortality before and after bariatric surgery for morbid obesity compared with the general population.

BACKGROUND: Bariatric surgery reduces morbidity and mortality in obese subjects, but it is unclear how rates compare with those in the population. The aim was to assess the risk of admission to hospital for obesity-related co-morbidities and overall mortality after bariatric surgery in relation to the general population. METHODS: A nationwide, population-based cohort study was conducted of all patients who underwent bariatric surgery in Sweden between 1980 and 2006. Each patient was compared with ten age- and sex-matched controls randomly selected from the Total Population Register. Hospital admission for co-morbidities was identified through the Patient Register. Cox proportional regression was used to calculate hazard ratios (HRs). RESULTS: A total of 13 273 patients underwent bariatric surgery between 1980 and 2006. After surgery, the overall adjusted HR remained increased for myocardial infarction (HR 1·56, 95 per cent confidence interval 1·35 to 1·81), angina pectoris (HR 2·05, 1·84 to 2·31), stroke (HR 2·13, 1·88 to 2·42), hypertension (HR 2·80, 2·61 to 3·01), diabetes (HR 2·44, 2·23 to 2·67) and death (HR 1·24, 1·15 to 1·34) in these patients compared with the general population. The 4161 patients who underwent gastric bypass surgery no longer had a higher risk of diabetes (HR 1·23, 0·88 to 1·72) or myocardial infarction (HR 0·78, 0·42 to 1·45), whereas morbidity remained increased after restrictive surgery in 7855 patients. The adjusted mortality remained higher after both gastric bypass and restrictive surgery. CONCLUSION: Gastric bypass, but not restrictive surgery, in patients with morbid obesity seems to reduce the risk of diabetes and myocardial infarction to population levels, but the risk of death remains increased.

Nationwide cohort study of post-gastric bypass hypoglycaemia including 5,040 patients undergoing surgery for obesity in 1986-2006 in Sweden.

AIMS/HYPOTHESIS: Symptomatic hypoglycaemia with related confusion, syncope, epilepsy or seizures is a newly recognised complication of gastric bypass surgery for obesity. The incidence of these conditions is not known. We therefore studied the incidence of post-gastric bypass hypoglycaemia and related symptoms in patients who have undergone gastric bypass and a reference cohort from the general population of Sweden. METHODS: This is a nationwide cohort study based on national registries with 5,040 persons who underwent gastric bypass, vertical banded gastroplasty or gastric banding for obesity in Sweden between 1 January 1986 and 31 December 2006 and a cohort of ten referents per patient matched for sex and age randomly sampled from the general population. The incidence rates of hospitalisation for hypoglycaemia, confusion, syncope, epilepsy or seizures before and after dates of surgery or inclusion in the reference cohort were studied. RESULTS: Preoperative incidences of hospitalisation for hypoglycaemia were similar in the surgical and referent cohorts. After gastric bypass surgery, the adjusted hazard ratios were significantly elevated for hypoglycaemia (2.7 [95% CI 1.2-6.3]), confusion (2.8 [1.3-6.0]), syncope (4.9 [3.4-7.0]), epilepsy (3.0 [2.1-4.3]) and seizures (7.3 [5.0-10.8]). The proportions of gastric bypass patients and reference participants affected by hypoglycaemia were very low (0.2% and 0.04%, respectively). There was no increased risk of hypoglycaemia after vertical banded gastroplasty or gastric banding compared with the referent population. CONCLUSIONS/INTERPRETATION: Obese persons who have undergone gastric bypass have an increased risk of hospitalisation for diagnoses associated with post-gastric bypass hypoglycaemia, although few patients are affected.

Obesity status and risk of disability pension due to psychiatric disorders.

OBJECTIVE: The aim of this study was to investigate associations between underweight, overweight and obesity in young adult men and risk of disability pension (DP) due to psychiatric disorders. DESIGN AND SUBJECTS: In this nationwide study of 1 110 139 Swedish men (mean age 18.3+/-0.5 years), weight, height and muscular strength were measured at mandatory military conscription testing (1969-1994). Information on DP (1971-2006), residential area, parental socioeconomic position and education and preexisting psychiatric disorders was obtained by record linkage of national registers. RESULTS: During 26 million person-years of follow-up, 19 684 men received DP due to psychiatric disorders. After adjustment, hazard ratios (HRs) due to any psychiatric disorder were 1.20 (95% CI: 1.15-1.26) for underweight, 1.14 (95% CI: 1.08-1.21) for overweight and 1.43 (95% CI: 1.28-1.60) for obesity compared to normal weight. For affective disorders, HRs were elevated for underweight (1.24, 95% CI: 1.16-1.32), overweight (1.19, 95% CI: 1.10-1.28) and obesity (1.55, 95% CI: 1.33-1.81), whereas for substance abuse increased risks were seen only for underweight (1.41, 95% CI: 1.23-1.61) and obesity (1.50, 95% CI: 1.07-2.12). For nonaffective disorders (including schizophrenia) overweight (HR=0.87, 95% CI: 0.76-1.00) and obesity (HR=0.79, 95% CI: 0.57-1.10) seemed to be protective, although not statistically significant. HRs for personality disorders were increased for underweight (1.18, 95% CI: 1.04-1.34), overweight (1.16, 95% CI: 1.00-1.30) and obesity (1.40, 95% CI: 1.03-1.90). CONCLUSION: Underweight and overweight were associated with small risk increases, whereas higher risks for DP were generally found for obesity.

The combined effects of overweight and smoking in late adolescence on subsequent disability pension: a nationwide cohort study.

BACKGROUND: Smoking and obesity are two of the most important risk factors for chronic disease today. Their combined effect on the risk of disability pension is not known. METHODS: A nationwide cohort of 45 920 Swedish men (18.7 + or - 0.5 years) were followed for 38 years. The body mass index (BMI), based on measured height and weight, was used to define underweight (<18.5), normal weight (18.5-24.9), overweight (25.0-29.9) and obesity (> or = 30.0). The hazard ratios (HRs) associated with BMI and smoking status at baseline for receiving disability pension were adjusted for socio-economic index (SEI), muscular strength, geographic region and place of residence. RESULTS: During 1.6 million person-years, 4631 disability pensions and 2897 deaths occurred. After adjustment, overweight (HR 1.34, 95% CI 1.19-1.51) and obesity (HR 1.55, 1.18-2.05) were associated with an increased risk of disability pension, independent of smoking, whereas underweight (18.5; HR 1.07, 0.97-1.17) was not compared with normal weight. Similarly, smoking 1-10 (HR 1.37, 1.27-1.49) or >10 cigarettes per day (HR 2.01, 1.86-2.17) showed independent risk increases versus non-smoking. Although obese individuals smoking >10 daily cigarettes were at greatly increased risk (HR 2.98, 1.98-4.47), no evidence of interaction between the two risk factors could be detected. CONCLUSIONS: Both increased adiposity and smoking are strong and independent predictors of disability pension, but they do not act synergistically.

Bariatric surgery reduces mortality in Swedish men.

BACKGROUND: Mortality is lower in obese patients who have undergone surgery for obesity than in those who have not. The majority of patients in these studies have been women. Perioperative mortality is known to be higher among men, and this may counterbalance the survival advantage seen after surgery. This cohort study compared mortality among operated obese patients, non-operated obese patients and a general control cohort of men. METHODS: The study was based on record linkage between Swedish registries. An operated obese, a non-operated obese and a general control cohort were created. The two non-operated cohorts were assigned pseudosurgery dates. Data regarding preoperative and postoperative morbidity were collected, as well as mortality data. RESULTS: Hazard ratios were calculated for mortality between the cohorts adjusting for preoperative morbidity and age. Comparison of all-cause mortality for the obese surgical and non-surgical cohorts gave an adjusted mortality risk of 0.7 (95 per cent confidence interval (c.i.) 0.5 to 1.0) (P = 0.039); the adjusted mortality risk was 1.5 (95 per cent c.i. 1.1 to 2.0) (P = 0.011) when the obese surgical cohort was compared with the general control cohort. CONCLUSION: Bariatric surgery reduces overall mortality in obese men.

Paternal and maternal ages at conception and risk of bipolar affective disorder in their offspring.

BACKGROUND: A consistent association between paternal age and their offspring's risk of schizophrenia has been observed, with no independent association with maternal age. The relationship of paternal and maternal ages with risk of bipolar affective disorders (BPAD) in the offspring is less clear. The present study aimed at testing the hypothesis that paternal age is associated with their offspring's risk of BPAD, whereas maternal age is not. METHOD: This population-based cohort study was conducted with individuals born in Sweden during 1973-1980 and still resident there at age 16 years. Outcome was first hospital admission with a diagnosis of BPAD. Hazard ratios (HRs) were calculated using Cox's proportional hazard regression. RESULTS: After adjustment for all potential confounding variables except maternal age, the HR for risk of BPAD for each 10-year increase in paternal age was 1.28 [95% confidence interval (CI) 1.11-1.48], but this fell to 1.20 (95% CI 0.97-1.48) after adjusting for maternal age. A similar result was found for maternal age and risk of BPAD [HR 1.30 (95% CI 1.08-1.56) before adjustment for paternal age, HR 1.12 (95% CI 0.86-1.45) after adjustment]. The HR associated with having either parent aged 30 years or over was 1.26 (95% CI 1.01-1.57) and it was 1.45 (95% CI 1.16-1.81) if both parents were >30 years. CONCLUSIONS: Unlike schizophrenia, the risk of BPAD seems to be associated with both paternal and maternal ages.

High-sensitive C-reactive protein is associated with reduced lung function in young adults.

Systemic inflammation has been associated with reduced lung function. However, data on the interrelationships between lung function and inflammation are sparse, and it is not clear if low-grade inflammation leads to reduced lung function. Associations between high-sensitive C-reactive protein (CRP) and spirometric lung function were assessed in a population-based cohort of approximately 1,000 Danes aged 20 yrs. In males, the average decline in forced expiratory volume in one second (FEV(1)) in the highest CRP quintile was 23 mL.yr(-1) versus 1.6 mL.yr(-1) in the lowest quintile. In females, the average decline was 6.2 mL.yr(-1) in the highest CRP quintile versus an increase of 1.8 mL.yr(-1) in the lowest CRP quintile. In a multiple regression analysis adjusted for sex, body mass index, cardiorespiratory fitness, smoking, asthma, airway hyperresponsiveness and serum eosinophil cationic protein, higher levels of CRP at age 20 yrs were associated with a greater reduction in both FEV(1) and forced vital capacity between ages 20 and 29 yrs. The findings show that higher levels of C-reactive protein in young adults are associated with subsequent decline in lung function, suggesting that low-grade systemic inflammation in young adulthood may lead to impaired lung function independently of the effects of smoking, obesity, cardiorespiratory fitness, asthma and eosinophilic inflammation.

Association between obesity status in young adulthood and disability pension.

OBJECTIVE: Obesity and underweight in young adulthood are associated with greater risk of future disability pension. Neither underlying causes of disability pension nor whether overweight confers excess risk is established in this age group. The aim of this study was to investigate risk of future disability pension according to body mass index (BMI) in young adulthood. DESIGN: BMI was measured at military conscription (1969-1994; n=1 191 027; mean age 18.3+/-0.5 years). Date and cause of disability pension, death and emigration dates were collected from national registers (1971-2006). Muscular strength, age, municipality, socioeconomic position, testing center and year were adjusted for in Cox regressions. RESULTS: During 28.4 million person-years, 60 024 subjects were granted disability pension. The hazard ratios (HRs) for underweight (1.14, CI 95% 1.11-1.17), overweight (1.36, 1.32-1.40), moderate (BMI 30-34.9; 1.87, 1.76 to 1.99) and morbid obesity (BMI>or=35; 3.04, 2.72-3.40) were elevated compared to normal weight. Not adjusting for muscular strength led to overestimation of the risk in underweight (1.27, 1.24-1.31), but underestimation in overweight (1.29, 1.25-1.33), moderately (1.72, 1.62-1.82) and morbidly obese subjects (2.77, 2.48-3.09). For circulatory and musculoskeletal causes, respectively, HRs were elevated only for overweight (2.06; 1.82-2.34; 1.47; 1.39-1.55) and obesity (3.51; 2.79-4.40; 2.15; 1.94-2.38). The same applied for tumors and nervous system, but not psychiatric causes, for which underweight (1.20; 1.16-1.24) displayed similar HR as overweight (1.21; 1.16-1.27), whereas the risk in obese subjects was higher (1.60; 1.46-1.75). CONCLUSION: The risks in overweight and obese, but not underweight, subjects were significantly elevated for each cause investigated. Although causality cannot be inferred, productivity losses associated with adverse BMI in young adulthood appear to be large.

Shift in the composition of obesity in young adult men in Sweden over a third of a century.

OBJECTIVE: To assess whether the composition of the obese category (body mass index (BMI)> or =30) has changed during the last one-third of a century in young adult men. DESIGN: Retrospective study of 1,580,913 men (18.3+/-0.4 years) representing 82% of the Swedish male population at military conscription age between 1969 and 2005. Measured height and weight were used to define moderate and morbid obesity as BMI 30-34.9 and > or =35, respectively. Data on socio-economic position (SEP), place of residence (urban, semi-urban and rural), age and test center were also collected. RESULTS: From the period 1969-1974 to 2000-2005, the prevalence of moderate obesity almost quintupled (0.8-3.8%; P<0.0001), while morbid obesity increased 10-fold (0.1-1.3%; P<0.0001). The composition of the obese category changed from 12.9 to 25.1% morbidly obese during the same time, corresponding to an annual growth in the odds of 2.8% (CI(95%) 2.5-3.1%) per year within the obese category. Compared to 1969-1974, the odds ratios of obesity and morbid obesity, respectively, were 1.6 (1.6-1.7) and 1.9 (1.7-2.2) in 1980-1984, 2.8 (2.7-2.9) and 4.0 (3.5-4.5) in 1990-1994, and 6.0 (5.7-6.3) and 11.4 (10.1-12.9) in 2000-2005, after adjustment for SEP, urban/rural place of residence, age and test center. Extrapolation of the growth rate during the observation period resulted in an estimated 4% morbidly obese in 2020. CONCLUSION: Morbid obesity increased faster than moderate obesity during the last 35 years. As the health risks and costs of obesity-related morbidity increase disproportionately in the morbidly obese, it is important to assess morbid obesity in prevalence studies, and distinguish the morbidly from the moderately obese in cost analyses.

Childhood overweight and obesity prevalences levelling off in Stockholm but socioeconomic differences persist.

BACKGROUND: Time trends in overweight, obesity and underweight among 10-year-old children were investigated between 1999 and 2003 with attention to gender and areas with different socioeconomic status (SES). MATERIAL: The study was performed in Stockholm County, where schools within eight different SES areas were randomly sampled. In selected schools, data on height and weight were abstracted from school health records of 2416 ten-year-old boys and girls examined by school nurses in 1999 and 2183 examined in 2003. RESULTS: Among boys, the prevalence of overweight was 21.6% in 1999 and 20.5% in 2003 (difference -1.1% (95% confidence interval (CI), -4.6; 2.4)) and for obesity 3.2 and 3.8% (difference 0.6% (95% CI, -0.9; 2.2)). Among girls overweight decreased from 22.1 to 19.2% (difference -2.9% (95% CI, -6.3; 0.6)) and obesity from 4.4 to 2.8% (difference -1.6% (95% CI, -3.1; 0.0)). There was a marginally significant difference in obesity trends in girls versus boys (P=0.051). The prevalence of underweight decreased nonsignificantly both in boys and in girls. Strong gradients, with more obesity and overweight in socioeconomically disadvantaged areas, were observed in both genders in 2003. Differences between SES areas were also seen in 1999 but were more pronounced in 2003. Among boys divergent trends in obesity were observed between 1999 and 2003, with evidence for increases in less affluent areas only. CONCLUSION: This population-based study of 10-year-olds indicates that rates of obesity, overweight and underweight are stable in Stockholm County. However, obesity is more prevalent in relatively less advantaged SES.