Changes in BMI-distribution from 1966-69 to 1995-97 in adolescents. The Young-HUNT study, Norway

The sex-based disparity in BMI-for-age z-score trends among Xinjiang children and adolescents using four rounds of cross-sectional surveys from 1985 to 2014

BACKGROUND

This study aimed to evaluate trends in body mass index (BMI)-for-age z-scores among children and adolescents in Xinjiang.

METHODS

Data were obtained for children and adolescents aged 7-18 years in Xinjiang from the Chinese National Survey on Students' Constitution and Health (CNSSCH) in 1985 (n = 14 683), 1995 (n = 7198), 2005 (n = 10 253) and 2014 (n = 18 521).

RESULTS

The BMI-for-age z-score distribution of children and adolescents in Xinjiang showed an increased mean BMI-for-age z-score, dispersion and right-skewed of BMI-values, with a rapid increase in BMI with increasing BMI percentiles. The sex-based disparity in BMI-for-age z-scores became wider in the past 30 years.

CONCLUSIONS

Sex-based targeted public health measures and policies are urgently needed in Xinjiang. The rapid increases in the upper percentiles also implicated further efforts to prevent weight gain in those living already with overweight or obesity.

Sex-related change in BMI of 15- to 16-year-old Norwegian girls in cross-sectional studies in 2002 and 2017

Background

The prevalence of overweight and obesity (OWOB) has stabilized in some countries, but a portion of children with high body mass index (BMI) may have become heavier. This study aimed to describe the distributions of BMI and the point prevalence of OWOB in Norwegian adolescents in 2002 and 2017.

Methods

A cross-sectional study involving 15- to 16-year-old adolescents in Oppland, Norway, was undertaken in 2002 and 2017. We calculated their BMI, BMI z-scores (BMIz), and the prevalence of OWOB.

Results

The mean BMI increased from 20.7 to 21.4 (p < 0.001) for girls but remained unchanged at 21.5 vs 21.4 (p = 0.80) for boys. The prevalence of OWOB increased from 9 to 14% among girls (difference 5, 95% CI: 2, 8) and from 17 to 20% among boys (difference 3, 95% CI: − 1, 6%). The BMI density plots revealed similar shapes at both time points for both sexes, but the distribution for girls shifted to the right from 2002 to 2017.

Conclusion

Contrary to previous knowledge, we found that the increase in OWOB presented a uniform shift in the entire BMI distribution for 15–16-year-old Norwegian girls and was not due to a larger shift in a specific subpopulation in the upper percentiles.

Body Weight and Body Mass Index Influence Bone Mineral Density in Late Adolescence in a Two-Year Follow-Up Study. The Tromsø Study: Fit Futures

Determinants of bone acquisition in late adolescence and early adulthood are not well‐described. This 2‐year follow‐up study explored the associations of body weight (BW), body mass index (BMI), and changes in weight status with adolescent bone accretion in a sample of 651 adolescents (355 girls and 296 boys) between 15 and 19 years of age from The Tromsø Study: Fit Futures. This Norwegian population‐based cohort study was conducted from 2010 to 2011 and was repeated from 2012 to 2013. We measured femoral neck, total hip, and total body bone mineral content and areal bone mineral density (aBMD) by dual‐energy X‐ray absorptiometry. We measured height, BW, calculated BMI (kg/m ²), and collected information on lifestyle at both surveys. Mean BMI (SD) at baseline was 22.17 (3.76) and 22.18 (3.93) in girls and boys, respectively. Through multiple linear regression, baseline BW and BMI were positively associated with ∆aBMD over 2 years of follow‐up at all skeletal sites in boys ( p < 0.05), but not in girls. ∆BW and ∆BMI predicted ∆aBMD and ∆BMC in both sexes, but the strength of the associations was moderate. Individuals who lost weight during follow‐up demonstrated a slowed progression of aBMD accretion compared with those gaining weight, but loss of BW or reduction of BMI during 2 years was not associated with net loss of aBMD. In conclusion, our results confirm that adequate BW for height in late adolescence is important for bone health. Associations between change in weight status and bone accretion during follow‐up were moderate and unlikely to have any clinical implication on adolescents of normal weight. Underweight individuals, particularly boys, are at risk of not reaching optimal peak bone mass and could benefit from an increase in BMI. © 2019 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.

Adiposity Criteria in Assessing Increased Cardiometabolic Risk in Prepubertal Children

Objective: Adiposity induces the clustering of cardiometabolic risk factors, and pediatric adiposity is a better indicator for adulthood cardiometabolic diseases than pediatric metabolic syndrome. However, the observed prevalence of pediatric adiposity depends on the methods and cut-points used. Therefore, we aimed to define diagnostic criteria for adiposity which enable more valid identification of prepubertal children at increased cardiometabolic risk. Methods: The participants were 470 prepubertal children (249 boys) aged 6-8 years. The measures of adiposity included body mass index-standard deviation score (BMI-SDS), waist-to-height ratio (WHtR) and body fat percentage (BF%) assessed by bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA). Criteria for adiposity were determined by increased cardiometabolic risk. Cardiometabolic risk factors which correlated with BF% assessed by DXA in the upper but not lower half of BF% (serum insulin and plasma high-density lipoprotein cholesterol, triglycerides, gamma-glutamyl transferase, high-sensitivity C-reactive protein and uric acid) were included in the cardiometabolic risk score (CMS). We computed receiver operating characteristics curves for the measures of adiposity using the ≥90th percentile of CMS as a measure of increased cardiometabolic risk, and local regression curves were graphed to demonstrate the associations of the measures of adiposity with CMS. Results: In girls, WHtR of 0.445 (area under curve 0.778, its 95% confidence interval 0.65-0.91, sensitivity and specificity 0.73) and BF% of 19.5% assessed by BIA (0.801, 0.70-0.90, 0.73) were the best overall criteria for increased cardiometabolic risk. In boys, BMI-SDS of 0.48 (0.833, 0.75-0.92, 0.76) was the best overall criterion for increased cardiometabolic risk. While local regression curves in girls showed that WHtR of 0.445 corresponds well to a point where CMS began to increase, in boys local regression curves suggest that CMS began to increase even at a lower level of BMI-SDS than 0.48. Moreover, the diagnostic ability of the measures of adiposity to exclude increased cardiometabolic risk was poorer than the ability to detect it. Conclusions: In general, the measures of adiposity have sufficient diagnostic accuracy to be utilized as the screening tool for increased cardiometabolic risk. The observed cut-points for adiposity were lower than the traditional cut-points for adiposity.

Socioeconomic inequalities in childhood-to-adulthood BMI tracking in three British birth cohorts

BACKGROUND

Body mass index (BMI) tracks from childhood-to-adulthood, but the extent to which this relationship varies across the distribution and according to socio-economic position (SEP) is unknown. We aimed to address this using data from three British cohort studies.

METHODS

We used data from: 1946 National Survey of Health and Development (NSHD, n = 2470); 1958 National Child Development Study (NCDS, n = 7747); 1970 British Cohort Study (BCS, n = 5323). BMI tracking between 11 and 42 years was estimated using quantile regression, with estimates reflecting correlation coefficients. SEP disparities in tracking were investigated using a derived SEP variable based on parental education reported in childhood. This SEP variable was then interacted with the 11-year BMI z-score.

RESULTS

In each cohort and sex, tracking was stronger at the upper end of the distribution of BMI at 42 years. For example, for men in the 1946 NSHD, the tracking estimate at the 10th quantile was 0.31 (0.20, 0.41), increasing to 0.71 (0.61, 0.82) at the 90th quantile. We observed no strong evidence of SEP inequalities in tracking in men in the 1946 and 1958 cohorts. In the 1970 cohort, however, we observed tentative evidence of stronger tracking in low SEP groups, particularly in women and at the higher end of the BMI distribution. For example, women in the 1970 cohort from low SEP backgrounds had tracking coefficients at the 50th, 70th, and 90th quantiles, which were 0.05 (-0.04; 0.15), 0.19 (0.06; 0.31), and 0.22 (0.02; 0.43) units higher, respectively, than children from high SEP groups.

CONCLUSION

Tracking was consistently stronger at the higher quantiles of the BMI distribution. We observed suggestive evidence for a pattern of greater BMI tracking in lower (compared to higher) SEP groups in the more recently born cohort, particularly in women and at the higher end of the BMI distribution.

Self-reported physical activity during leisure time was favourably associated with body composition in Norwegian adolescents

AIM

We studied the cross-sectional association between self-reported physical activity and body composition in adolescents.

METHODS

The Norwegian Fit Futures Cohort Study was conducted in the Tromsø and Balsfjord municipalities during 2010-2011. All 1,117 students in their first year of upper secondary high school were invited to attend an examination at the Clinical Research Unit at the University Hospital of Northern Norway and 93% agreed. After exclusions, we analysed 945 participants (51% boys) with a mean age of 16.1 years (range 15.5-17.5 years) with valid measurements. The associations between self-reported weekly hours of physical activity during leisure time and four measures of body composition were explored using linear regression.

RESULTS

Self-reported physical activity was significantly associated with the fat mass index (p < 0.03) and lean mass index (p < 0.001) in both genders. The lean mass index increased with higher levels of activity and the fat mass index decreased. Physical activity was not associated with body mass index for either gender, but there was an inverse association with waist circumference in girls (p = 0.04).

CONCLUSION

Physical activity was favourably associated with body composition in Norwegian adolescents and showed contrasting associations with the fat mass and lean mass indexes.

Change in BMI Distribution over a 24-Year Period and Associated Socioeconomic Gradients: A Quantile Regression Analysis

OBJECTIVE

This study assessed the change in body mass index (BMI) distribution among 18- or 19-year-olds over 24 years. It also investigated parallel changes in the distribution of birth weight and in the association between birth weight and later risk of overweight and/or obesity. Parental educational variations in the trends and associations were explored.

METHODS

The study used data on 606,832 male military conscripts enlisted between 1985 and 2008. Quantile regression was used to assess the temporal change in BMI and birth weight distribution. The association between birth weight and overweight and/or obesity at age 18 or 19 years was quantified by using logistic regression.

RESULTS

Increases in BMI over time were found namely in the 90th, 95th, 97th, and 99th percentiles. Socioeconomic differences in this increase were documented in the 75th to 97th percentiles. The distribution of birth weight and the association between birth weight and the risk of overweight and/or obesity at age 18 or 19 years remained stable over time.

CONCLUSIONS

The difference in the increase in BMI between low and high percentiles indicates the limited role of mean BMI in reflecting population changes. The results suggest a need to focus on those with low socioeconomic position in the upper ends of the BMI distribution to combat increasing disparities in obesity-related outcomes.

Intergenerational Transmission of Overweight and Obesity from Parents to Their Adolescent Offspring - The HUNT Study

Purpose

The main aim of this study was to examine weight associations between parents and offspring at two time points: 1995–97 and 2006–08, taking into account body mass index (BMI) and waist circumference.

Methods

The study included 8425 parent-offspring trios who participated in the population based Health Study of Nord Trøndelag (the HUNT Study), Norway, at either the HUNT2 (1995–97) or the HUNT3 (2006–08) survey. We used linear mixed effects models with siblings clustered within mothers to analyze the associations between 1) parental grouped BMI and offspring BMI z-scores and 2) parental grouped waist circumference and offspring waist circumference z-scores.

Results

Adolescent and adult overweight and obesity were higher in 2006–08 than in 1995–97, with the greatest increase observed in waist circumference. Both mother’s and father’s BMI and waist circumference were strongly associated with corresponding measures in offspring. Compared with both parents being normal weight (BMI <25 kg/m²), having two overweight or obese parents (BMI ≥25 kg/m²) was associated with a higher offspring BMI z-score of 0.76 (95% CI; 0.65, 0.87) and 0.64 (95% CI; 0.48, 0.80) in daughters, and 0.76 (95% CI; 0.65, 0.87) and 0.69 (95% CI; 0.53, 0.80) in sons, in 1995–97 and 2006–08 respectively. Offspring with one parent being overweight/obese had BMI z-scores of approximately half of offspring with two parents categorized as overweight/obese. The results of the waist circumference based analyses did not differ substantially from the BMI based analyses.

Conclusions

Parental overweight was strongly positively associated with offspring weight both in 1995–97 and 2006–08 where both parents being overweight/obese gave the largest effect. This seemingly stable association, strongly address the importance of public health initiatives towards preventing obesity in parents of both sexes to decrease further obesity expansion in offspring.

Trends in Socioeconomic Inequalities in Body Mass Index, Underweight and Obesity among English Children, 2007-2008 to 2011-2012

Background

Socioeconomic inequalities in childhood obesity have been reported in most developed countries, with obesity more common in deprived groups. Whether inequalities are found in the prevalence of underweight, the rest of the body mass index (BMI) distribution, or have changed across time is not clear.

Methods and Findings

The sample comprised 5,027,128 children on entry (4 to 5 years old) and leaving (10 to 11 years) state primary (elementary) school who participated in the National Child Measurement Programme (England, United Kingdom). We used area-level deprivation (Indices of Multiple Deprivation at the lower super output area) as a measure of socioeconomic deprivation. From 2007–2008 to 2011–2012 inequalities in obesity between the most compared to least deprived group increased (from 7.21% to 8.30%; p<0.001), whereas inequalities in the prevalence of underweight (1.50% to 1.21%; p = 0.15) were stable during this period. There were no differences by age group or by sex, but a three-way interaction suggested inequalities in obesity had increased at a faster rate for 10 to 11 year old girls, than 4 to 5 year old boys, (2.03% vs 0.07%; p<0.001 for interaction). Investigating inequalities across the distribution of zBMI showed increases in mean zBMI (0.18 to 0.23, p<0.001) could be attributed to increases in inequalities between the 50^th and 75^th centiles of BMI. Using the 2011 to 2012 population attributable risk estimates, if inequalities were halved, 14.04% (95% CI 14.00% to 14.07%) of childhood obesity could be avoided.

Conclusions

Socioeconomic inequalities in childhood obesity and zBMI increased in England between 2007–2008 and 2011–2012. Inequalities in the prevalence of underweight did not change. Traditional methods of examining inequalities only at the clinical thresholds of overweight and obesity may have led the magnitude of inequalities in childhood BMI to be underestimated.

Parental misperceptions of children's underweight status: a meta-analysis

BACKGROUND

Accurate parental perceptions of their children's underweight status are needed to prevent overlooking potential disordered eating patterns or health conditions affecting growth.

PURPOSE

The aim of this study is to determine overall proportion of parents who misperceive children's underweight status and correlates of such misperceptions.

METHODS

Original studies published to January 2013 were chosen through a literature search in established databases. Studies included assessed parental perceptions of their children's underweight and then compared perceptions to recognized standards for defining underweight based on anthropometric measures. Random- and mixed-effects models were used.

RESULTS

Thirty-seven articles (representing 39 studies; N = 4,039) were included. Pooled effect sizes indicated that 46.58 % (95 % CI 40.90-52.35 %) of parents misperceive their children's underweight status, though the extent of misperceptions depended on a number of moderators.

CONCLUSIONS

Nearly half of parents perceive their underweight children as weighing more than they actually do. Health care professionals are well positioned to take steps to remedy misperceptions and encourage healthy behaviors.

How Has the Age-Related Process of Overweight or Obesity Development Changed over Time? Co-ordinated Analyses of Individual Participant Data from Five United Kingdom Birth Cohorts

BACKGROUND

There is a paucity of information on secular trends in the age-related process by which people develop overweight or obesity. Utilizing longitudinal data in the United Kingdom birth cohort studies, we investigated shifts over the past nearly 70 years in the distribution of body mass index (BMI) and development of overweight or obesity across childhood and adulthood.

METHODS AND FINDINGS

The sample comprised 56,632 participants with 273,843 BMI observations in the 1946 Medical Research Council National Survey of Health and Development (NSHD; ages 2-64 years), 1958 National Child Development Study (NCDS; 7-50), 1970 British Cohort Study (BCS; 10-42), 1991 Avon Longitudinal Study of Parents and Children (ALSPAC; 7-18), or 2001 Millennium Cohort Study (MCS; 3-11). Growth references showed a secular trend toward positive skewing of the BMI distribution at younger ages. During childhood, the 50th centiles for all studies lay in the middle of the International Obesity Task Force normal weight range, but during adulthood, the age when a 50th centile first entered the overweight range (i.e., 25-29.9 kg/m2) decreased across NSHD, NCDS, and BCS from 41 to 33 to 30 years in males and 48 to 44 to 41 years in females. Trajectories of overweight or obesity showed that more recently born cohorts developed greater probabilities of overweight or obesity at younger ages. Overweight or obesity became more probable in NCDS than NSHD in early adulthood, but more probable in BCS than NCDS and NSHD in adolescence, for example. By age 10 years, the estimated probabilities of overweight or obesity in cohorts born after the 1980s were 2-3 times greater than those born before the 1980s (e.g., 0.229 [95% CI 0.219-0.240] in MCS males; 0.071 [0.065-0.078] in NSHD males). It was not possible to (1) model separate trajectories for overweight and obesity, because there were few obesity cases at young ages in the earliest-born cohorts, or (2) consider ethnic minority groups. The end date for analyses was August 2014.

CONCLUSIONS

Our results demonstrate how younger generations are likely to accumulate greater exposure to overweight or obesity throughout their lives and, thus, increased risk for chronic health conditions such as coronary heart disease and type 2 diabetes mellitus. In the absence of effective intervention, overweight and obesity will have severe public health consequences in decades to come.

Trends in group inequalities and interindividual inequalities in BMI in the United States, 1993-2012

BACKGROUND

Marked increases in mean body mass index (BMI) and prevalence of obesity and overweight in the United States are well known. However, whether these average increases were accompanied by changing dispersion (or SD) remains understudied.

OBJECTIVE

We investigated population-level changes in the BMI distribution over time to understand how changes in dispersion reflect between-group compared with within-group inequalities in weight gain in the United States.

DESIGN

Using data from the Behavioral Risk Factor Surveillance System survey (1993-2012), we analyzed associations between mean, SD, and median BMI and BMI at the 5th and 95th percentiles for 3,050,992 non-Hispanic white, non-Hispanic black, and Hispanic men and women aged 25-64 y.

RESULTS

Overall, an increase of 1.0 in mean BMI (in kg/m²) was associated with an increase of 0.70 (95% CI: 0.67, 0.73) in the SD of BMI. A change of 1.0 in median BMI was associated with a change of 0.18 (95% CI: 0.14, 0.21) in the BMI value at the 5th percentile compared with a change of 2.94 (95% CI: 2.81, 3.07) at the 95th percentile. Quantile-quantile plots showed unequal changes in the BMI distribution, with pronounced changes at higher percentiles. Similar patterns were observed in subgroups stratified by sex, race-ethnicity, and education with non-Hispanic black women and women with less than a high school education having highest mean BMI, SD of BMI, and BMI values at the 5th and 95th percentiles.

CONCLUSIONS

Mean BMI and the percentage of overweight and obese individuals do not fully describe population changes in BMI. Increases in within-group inequality in BMI represent an underrecognized characteristic of population-level weight gain. Crucially, similar increases in dispersion within groups suggest that growing inequalities in BMI at the population level are not driven by these socioeconomic and demographic factors. Future research should focus on understanding factors driving inequalities in weight gain between individuals.

Risk factors for suicidal thoughts in adolescence--a prospective cohort study: the Young-HUNT study

OBJECTIVES

Examining the associations between health and lifestyle factors recorded in the participants' early teens and development of suicidal thoughts recorded 4 years later.

DESIGN

Population-based prospective cohort study.

SETTINGS

All students in the two relevant year classes in Nord-Trøndelag County were invited, 80% attended both waves of data collection.

PARTICIPANTS

2399 secondary school students who participated in the Young-HUNT1 study in 1995-1997 (13-15 years old) were included in a follow-up study 4 years later (17-19 years old).

PRIMARY OUTCOME MEASURE

Suicidal thoughts reported at age 17-19 years.

RESULTS

408 (17%, 95% CI 15.5% to 18.5%) of the adolescents reported suicidal thoughts at follow-up, 158 (14.2%, CI 13.6% to 16.4%) boys and 250 (19.5%, CI 18.8% to 22.0%) girls. Baseline anxiety and depressive symptoms (adjusted OR (aOR) 1.9, CI 1.4 to 2.6), conduct problems (aOR 1.8, CI 1.3 to 2.6), overweight (aOR 1.9 CI 1.4 to 2.4), and muscular pain and tension (aOR 1.8, CI 1.4 to 2.4), were all associated with reporting suicidal thoughts at follow-up.

CONCLUSIONS

One in six young adults experienced suicidal thoughts, girls predominating. Suicidal thoughts were most strongly associated with symptoms of anxiety/depression, conduct problems, pain/tension and overweight reported when participants were 13-15 years old. Specific preventive efforts in these groups might be indicated. Future research should investigate whether similar associations are seen with suicide/suicidal attempts as endpoints.

Women's health in India: the role of body mass index

We examined the health status of women in relation to their body mass indices and waist-to-hip ratio (WHR) by analyzing data from a follow-up study of 325 women, selected from the Indian National Family Health Survey (NFHS-2/1998-99) Delhi samples, reinterviewed after 4 years (2003). Obese women were five times more likely (OR = 4.87; p <.0001) and women with a higher WHR (> 0.90) were two times more likely (OR = 1.70; p =.050) to perceive their health condition as worse than others. Arthritis, hypertension, and shortness of breath were found to be higher among obese women and women with a high WHR. Healthy lifestyle choices must be promoted to contain the growing burden of obesity-related health problems among Indian women.

[Diabetes in general practice--were treatment goals reached?]

BACKGROUND

In Norway, most people with diabetes are treated by general practitioners. At our own general practice, we wanted to find out whether we were succeeding in following the Directorate of Health's 2009 clinical guidelines on treatment and management of diabetes.

MATERIAL AND METHOD

All patients with the diagnosis diabetes mellitus in our electronic archive between November 2009 and October 2010 were registered. Those patients on our general practice lists in October 2010 were identified. The patient records were manually reviewed and relevant data recorded.

RESULTS

In all, 271 patients with diabetes attended our surgery for check-ups in October 2010. 11% had type 1 diabetes and 88% had type 2 diabetes. HbA1c was measured in 99% of the diabetes patients, blood pressure in 98% and lipids in 93%. The measurements were taken at our surgery during the past year for 96% of the patients. The treatment goals for HbA1c, systolic blood pressure and LDL cholesterol were reached in, respectively, 55%, 55% and 49% of the patients. 13% reached all three treatment goals. 82% had a check-up with an ophthalmologist. Weight and smoking habits were documented in 85% and 90% respectively. 19% of the patients for whom we had documented data, smoked. Examinations of height, feet and microalbumin were documented in 57%, 35% and 28% of the patients respectively.

INTERPRETATION

The guidelines are being followed on most points to a high degree, and the proportion of patients reaching the stricter treatment goals is consistent with the results of earlier Norwegian surveys. There is the potential for further improvement of these results.

Social Inequalities in Obesity Persist in the Nordic Region Despite Its Relative Affluence and Equity

Social inequalities in overweight and obesity (OWOB) have persisted in the affluent and reputedly egalitarian Nordic countries. In this review we examine associations between socioeconomic position (SEP) and OWOB, and secular trends in such associations. Determinants and possible causes of the relations are discussed together with opportunities to cope with OWOB as a public health problem. The findings show a persisting inverse social gradient. An interaction between SEP and gender is noted for adults in Denmark, Finland and Iceland and for children in Sweden. There are overall tendencies for increased inequality, however no consistent trend for an increased social gradient in OWOB. Reasons that increased inequality does not unequivocally mirror in a steepened social gradient in obesity may include methodological questions as well as societal efforts to counteract obesity. Multi-level efforts are needed to prevent OWOB.

Normative data of BMI and physical fitness in a Norwegian sample of early adolescents

Aim: The purpose of the present study was to 1) provide normative data quantifying the physical fitness level and body mass index of 13–15-year-old Norwegian adolescents using a multi-component fitness assessment, and 2) compare the physical fitness of Norwegian teenagers with available European and International fitness data. Methods: 1059 adolescents (529 males, 530 females) from 12 public schools in Kristiansand were invited to testing at age 13, 14, and 15 years (Grades 8–10). Test participation was 75%–80%. The participants performed objectively anthropometrical measures (height and weight) and six field-based physical fitness tests. Results and Conclusions: As expected, sex differences in physical fitness expanded from age 13 to 15. Strength and power increased more in males than females. Aerobic capacity increased slightly in males while remaining stable or tending to decline in females. Balance and gross motor coordination improved identically in males and females from age 13 to 15. Compared to European and International reference data, the sample performed superior in endurance and balance, slightly above median in lower-body strength, but inferior in flexibility.

Growth references for 0-19 year-old Norwegian children for length/height, weight, body mass index and head circumference

BACKGROUND

Previous growth references for Norwegian children were based on measurements from the 1970s and 1980s. New reference data, collected through the Bergen Growth Study and the Medical Birth Registry of Norway, are presented as LMS values.

MATERIALS AND METHODS

A cross-sectional sample of children aged 0-19 years in stratified randomized design measured in 2003-2006 as a part of the Bergen Growth Study (n = 7291) and birth data of children born in 1999-2003 from the Medical Birth Registry of Norway (n = 12 576) was used to estimate the new references by the means of the LMS method. Measurement reliability was assessed by test-rest studies.

RESULTS

New references were constructed for length/height, weight, body mass index (BMI) and head circumference. Length/height and weight for children aged 0-4 years were similar to previous Norwegian references, but mean height increased up to a maximum of 3.4 cm in boys and 2.5 cm in girls during the pubertal years. Mean height was similar to (or slightly higher) in comparison with other recent European references. Reliability of the measurements compared well with published estimates.

CONCLUSION

Because of the observed secular trends in growth, it is advised to use the new references, which have been endorsed by the Norwegian Department of Health.

Cohort profile of the Young-HUNT Study, Norway: a population-based study of adolescents

The Young-HUNT Study is the adolescent part (13-19 years) of HUNT, the Nord-Trøndelag Health Study, Norway. Three cross-sectional surveys have been conducted: Young-HUNT1 (1995-97), Young-HUNT2 (2000-01) and Young-HUNT3 (2006-08). Major public health issues, including somatic and mental health, quality of life and health behaviours are covered. Young-HUNT was performed in schools visited by trained nurses. Data collection included self-reported questionnaires, structured interviews, clinical measurements and, in Young-HUNT3, buccal smears. The total response rates varied from 90% to 83% and the Young-HUNT database includes 17 820 teenagers. Some Young-HUNT1 participants constitute the baseline for two follow-up studies: a 4-year follow-up through adolescence to Young-HUNT2 and an 11-year follow-up into young adulthood to the adult HUNT3. Longitudinal data are also obtained by linkage of data from Young-HUNT to different national health registers. Linkage to family registers allows the possibility of studying genetic and environmental interactions through generations. Presently 20 PhD students are working with the data, 11 Young-HUNT based PhD theses have been completed and more than 50 scientific papers published.

Changes in adiposity indicators of Ho Chi Minh City adolescents in a 5-year prospective cohort study

OBJECTIVE

The aim of this study was to examine changes over 5 years in body mass index (BMI) and waist circumference (WC) of adolescents from Ho Chi Minh City by age, gender and household economic status.

METHODS

Anthropometry including height, weight and WC measurements of 759 secondary high school students were collected 1-year apart in a prospective cohort study, between 2004 and 2009. BMI was calculated and overweight/obesity was defined using International Obesity Task Force (IOTF) BMI cutoffs. Abdominal 'overweight' and 'obesity' were defined as WC >91st-97th and 98th centile, respectively. BMI z-scores were also created.

RESULTS

Over the 5-year period, the absolute changes in mean BMI and WC were statistically significant (P<0.001). Boys had higher BMI and WC values than girls (P<0.001). The prevalence of overweight and obesity defined by IOTF BMI cutoff values increased gradually from 12.5% and 1.7% in the first year to 16.7% and 5.1% in the last year. Using WC cutoff values, the prevalence of abdominal overweight and obesity increased from 12.9% and 1.8% to 18.5% and 6.6%, respectively. BMI z-score curves shifted towards the right-hand side of the distribution (that is, towards overweight and obesity).

CONCLUSION

Overweight and obesity, as measured by BMI or WC, continued to increase among adolescents of Ho Chi Minh City over the 5-year period.

Effects of sedentary lifestyle and dietary habits on body mass index change among adult women in India: findings from a follow-up study

We examined the effects of sedentary lifestyle and dietary habits on body mass index (BMI) change in a follow-up study of 325 women (aged 15-49 years) in Delhi, systematically selected from the 1998-1999 National Family Health Survey samples who were re-interviewed after 4 years in 2003. Information was collected on height, weight, dietary habits, and sedentary lifestyle through face-to-face interviews. Overall, a 2.0-point increase in mean BMI was found among women in just 4 years. Every second normal-BMI woman, two in five overweight women, and every fourth obese woman experienced a > 2.0-point increase in her mean BMI. High sedentary lifestyle (OR: 2.63; 95% CI: 1.29-5.35) emerged as the main predictor of a > 2.0-point increase in mean BMI in adjusted analysis, but there was weak evidence of association with the dietary covariates. Our findings suggest that a high sedentary lifestyle is a determinant of weight gain among adult women in urban India.

Change in the body mass index distribution for women: analysis of surveys from 37 low- and middle-income countries

BACKGROUND

There are well-documented global increases in mean body mass index (BMI) and prevalence of overweight (BMI ≥ 25.0 kg/m(2)) and obese (BMI ≥ 30.0 kg/m(2)). Previous analyses, however, have failed to report whether this weight gain is shared equally across the population. We examined the change in BMI across all segments of the BMI distribution in a wide range of countries, and assessed whether the BMI distribution is changing between cross-sectional surveys conducted at different time points.

METHODS AND FINDINGS

We used nationally representative surveys of women between 1991-2008, in 37 low- and middle-income countries from the Demographic Health Surveys ([DHS] n = 732,784). There were a total of 96 country-survey cycles, and the number of survey cycles per country varied between two (21/37) and five (1/37). Using multilevel regression models, between countries and within countries over survey cycles, the change in mean BMI was used to predict the standard deviation of BMI, the prevalence of underweight, overweight, and obese. Changes in median BMI were used to predict the 5th and 95th percentile of the BMI distribution. Quantile-quantile plots were used to examine the change in the BMI distribution between surveys conducted at different times within countries. At the population level, increasing mean BMI is related to increasing standard deviation of BMI, with the BMI at the 95th percentile rising at approximately 2.5 times the rate of the 5th percentile. Similarly, there is an approximately 60% excess increase in prevalence of overweight and 40% excess in obese, relative to the decline in prevalence of underweight. Quantile-quantile plots demonstrate a consistent pattern of unequal weight gain across percentiles of the BMI distribution as mean BMI increases, with increased weight gain at high percentiles of the BMI distribution and little change at low percentiles. Major limitations of these results are that repeated population surveys cannot examine weight gain within an individual over time, most of the countries only had data from two surveys and the study sample only contains women in low- and middle-income countries, potentially limiting generalizability of findings.

CONCLUSIONS

Mean changes in BMI, or in single parameters such as percent overweight, do not capture the divergence in the degree of weight gain occurring between BMI at low and high percentiles. Population weight gain is occurring disproportionately among groups with already high baseline BMI levels. Studies that characterize population change should examine patterns of change across the entire distribution and not just average trends or single parameters.

Is physical activity maintenance from adolescence to young adulthood associated with reduced CVD risk factors, improved mental health and satisfaction with life: the HUNT Study, Norway

BACKGROUND

Little is known about the effect maintaining physical activity throughout adolescence has on cardiovascular risk factors and health status in early adulthood. This ten-year prospective longitudinal study investigated whether differences in physical activity patterns from adolescence to young-adulthood showed different associations with subsequent cardio-metabolic risk factors and mental health in young-adulthood.

METHODS

Based on the second and third Norwegian Nord-Trøndelag Health Surveys (HUNT2 and 3), we included 1869 individuals (838 males) participating in Young-HUNT (1995-97), aged 13-19 years and followed-up at HUNT3 (2006-08), aged 23-31. Self-reported physical activity (PA), mental health and perceived health were recorded, along with measurements of body mass index (BMI), waist circumference (WC), total cholesterol (TC), HDL cholesterol, glucose, triglycerides, resting heart rate (HR) and blood pressure. We used separate linear regressions models to investigate associations between physical activity and each CVD risk factor, and logistic regression analysis to examine PA patterns and subsequent mental health. Physically active maintainers were compared to inactive maintainers. Adopters (inactive as adolescents and physically active as young adults) were compared to inactive maintainers and to those who discontinued activity (relapsers).

RESULTS

Active maintainers had significantly lower HR, compared to all other PA patterns. Active maintaining men had significantly lower WC than relapsers and inactive maintainers. When adjusted for age and gender, WC, BMI, HR, diastolic blood pressure and HDL-C showed significant differences comparing active maintaining to other PA patterns. Comparing inactive maintainers against adopters, only HR was significantly lower. Male adopters did not differ significantly in CVD risk compared to inactive maintainers and relapsers. Among females adopting was associated with lower HR and TC compared to inactive maintainers. Active maintainers showed better mental health than inactive maintainers. Active maintaining males had an increased likelihood of good mental health compared to adopters. Active maintaining females reported greater satisfaction with life compared to adopters.

CONCLUSIONS

Those who maintained their physical activity from adolescence to young adulthood demonstrated a significantly lower CVD risk and better mental health, compared to inactive maintainers. Compared to inactivity maintainers and relapsers, adopting physical activity was not significantly associated with lowered CVD risk. Adopting physical activity between adolescence and young adulthood may not necessarily protect against mental distress.

Morbidity patterns among the underweight, overweight and obese between 2 and 18 years: population-based cross-sectional analyses

CONTEXT

No study has documented how symptomatic morbidity varies across the body mass index (BMI) spectrum (underweight, normal weight, overweight and obese) or across the entire child and adolescent age range.

OBJECTIVE

To (1) quantify physical and psychosocial morbidities experienced by 2-18-year-olds according to BMI status and (2) explore morbidity patterns by age.

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional data from two Australian population studies (the Longitudinal Study of Australian Children and the Health of Young Victorians Study) were collected during 2000-2006. Participants were grouped into five age bands: 2-3 (n=4606), 4-5 (n=4983), 6-7 (n=4464), 8-12 (n=1541) and 13-18 (n=928) years.

MAIN MEASURES

Outcomes-Parent- and self-reported global health; physical, psychosocial and mental health; special health-care needs; wheeze; asthma and sleep problems. Exposure-measured BMI (kg m(-2)) categorised using standard international cutpoints.

ANALYSES

The variation in comorbidities across BMI categories within and between age bands was examined using linear and logistic regression models.

RESULTS

Comorbidities varied with BMI category for all except sleep problems, generally showing the highest levels for the obese category. However, patterns differed markedly between age groups. In particular, poorer global health and special health-care needs were associated with underweight in young children, but obesity in older children. Prevalence of poorer physical health varied little by BMI in 2-5-year-olds, but from 6 to 7 years was increasingly associated with obesity. Normal-weight children tended to experience the best psychosocial and mental health, with little evidence that the U-shaped associations of these variables with BMI status varied by age. Wheeze and asthma increased slightly with BMI at all ages.

CONCLUSIONS

Deviation from normal weight is associated with health differences in children and adolescents that vary by morbidity and age. As well as lowering risks for later disease, promoting normal body weight appears central to improving the health and well-being of the young.

Factors predicting changes in physical activity through adolescence: the Young-HUNT Study, Norway

PURPOSE

The purpose of this prospective population-based study was to analyze predictors of changes in physical activity (PA) levels from early to late adolescence.

METHODS

Data presented are from 2,348 adolescents and their parents who participated in the Nord-Trøndelag Health study (HUNT 2, 1995-1997) and at follow-up in Young-HUNT 2, 2000-2001 Participants completed a self-reported questionnaire and participated in a clinical examination that included measurements of height and weight.

RESULTS

Four patterns of PA emerged in the study: active or inactive at both time points (active maintainers, 13%; inactive maintainers, 59%), inactive and became active (adopters, 12%), active and became inactive (relapsers, 16%). Being overweight, dissatisfied with life, and not actively participating in sports at baseline were significant predictors of change regarding PA among boys at follow-up. For girls, smoking, drinking, low maternal education, and physical inactivity predicted relapsers and inactive maintainers. Higher levels of education and more physically active parents at baseline seemed to protect against decreased PA during follow-up for both genders.

CONCLUSION

Predictors of change in, or maintaining PA status during adolescence differed by gender. These results suggest that PA-promoting interventions should be tailored by gender and focus on encouraging activity for inactive adolescents and maintenance of PA in those already active.

Psychological factors and weight problems in adolescents. The role of eating problems, emotional problems, and personality traits: the Young-HUNT study

BACKGROUND

The associations between psychological factors and weight problems in adolescents are not conclusive. We studied associations between psychological factors, including personality and weight problems, in an adolescent population. In addition, we examined the same psychological factors as predictors for change in weight categories during adolescence.

METHOD

From 1995 to 1997, 8,090 adolescents, aged 13-18 years, participated in the Young-HUNT-I study; of those, 1,619 also participated in a follow-up study in 2000-2001. They completed a questionnaire monitoring eating problems, self-esteem, personality, anxiety, and depression, and had their height and weight measured. Weight problems were defined using the international age-and sex-specific BMI-cut-offs defining underweight, overweight, and obesity. Psychological factors at baseline were studied both in relation to weight categories at baseline, and as predictors for weight change between baseline and the follow-up.

RESULTS

Significant sex differences in mean values were found in all psychological factors, with higher scores in girls compared with boys. In the cross-sectional design, eating problems were associated with weight problems, and the two factors of oral control (EAT-A) and food preoccupation (EAT-B) showed an inverse association. Oral control was associated with underweight, while food preoccupation was associated with overweight and obesity in both sexes. Low self-esteem was associated with overweight and obesity in both sexes, but no association was found between emotional problems or personality traits, and weight problems. During the follow-up, oral control was a clear predictor of weight change during adolescence in both sexes. Oral control protected against unhealthy weight gain but also predicted unhealthy weight reduction in both sexes.

CONCLUSIONS

Girls scored higher on all psychological factors compared with boys, but no sex differences were found with regard to the association between psychological factors and weight problems. Eating problems showed the strongest association with weight problems at baseline and were also the strongest predictor of weight change during adolescence.

Secular trends in aerobic fitness performance in a cohort of Norwegian adolescents

The purpose of the present study was to compare 3000 m running test results between 1969 and 2009 in a cohort of Norwegian high school pupils. Between 1969 and 2009, a total of 4981 (2827 boys) 3000 m running tests were collected from two Norwegian senior high schools. One-way ANOVA with Tukey's post hoc test was used to analyze the differences in the running times between the different decades. The running times have increased by 10% and 6% from the 1980s to the 2000s for boys and girls, respectively. The distribution showed a decline in aerobic fitness performance for all deciles. The largest negative change in difference was found for pupils with the poorest aerobic fitness level in both boys and girls. The cohort of 16- to 18-year-old boys and girls in the decade 2000-2009 had a poorer aerobic fitness performance in the 3000 m running test compared with earlier decades. The decline in running performance was greater for boys than girls, and the gap between the most and the least fit is becoming considerably larger.

Parental perception of overweight and underweight in children and adolescents

AIMS

To compare the parental perception of overweight and underweight in their children to objective criteria, based on body mass index (BMI), waist circumference and triceps skinfold thickness, and to explore the effects of potential determinants.

METHODS

Logistic regression of anthropometric measurements, socio-demographic characteristics and self-reported parental height and weight on the parental perception of their child's weight status in 3770 children aged 2-19.

RESULTS

Seventy per cent of overweight/obese children and 40.8% of underweight children were perceived having normal weight by parents. In 2- to 5-year-old overweight children, 91.2% were considered to have normal weight. For a given BMI, primary school age children, adolescents and girls had a higher probability to be assigned as overweight, whereas adolescents and girls had a lower probability to be assigned as underweight. Overweight parents more readily assigned their children as underweight, but there was no effect of parental educational level or parental underweight.

CONCLUSION

Parental ability to recognize overweight or underweight in their offspring was generally poor. The findings emphasize the need for objective criteria based on physical measurements in the routine follow up of children, as parental ability to recognize weight problems in their children is nonreliable.

Availability of data assessing the prevalence and trends of overweight and obesity among European adolescents

OBJECTIVE

To review recent data on objectively measured overweight/obesity in national representative samples of European adolescents (aged 10-18 years), as well as availability of studies assessing trends in overweight/obesity in this target group. Attention was paid to the ability of the data to describe the obesity epidemic, especially in sociodemographic subgroups.

DESIGN/SETTING/SUBJECTS

Data on prevalence and trends in overweight/obesity among adolescents in the twenty-seven European Community member states, Iceland, Norway and Switzerland, available as scientific publications as well as reports or unpublished data by the end of 2009, were retrieved. Reports on the most recent objectively measured data from national representative samples were selected and described with regard to the years of data collection, sample sizes, response rates, age ranges included, trends by age, type of measures of overweight/obesity, sociodemographic variables and the sources of information.

RESULTS

Objectively measured data on national representative samples were identified for only half of the countries, and the trend studies were mainly conducted applying subnational samples. Most studies used the criteria from the International Obesity Task Force (IOTF) to define overweight/obesity, but the age ranges studied and the years of data collection varied, and information on sample sizes and response rates were often not presented. Data on trends of overweight/obesity over time are increasing, and the most recent studies indicate that the prevalence rate of overweight/obesity has stabilized. Few studies reported data by sociodemographic subgroups other than gender and age.

CONCLUSIONS

Objectively measured data on national representative samples of adolescents appear scattered, and there is a large heterogeneity with respect to the quality and comparability of available data. Increasing use of the IOTF criteria for overweight/obesity contributes to improved comparability across studies. Data by sociodemographic subgroups, and in particular by socio-economic status, are scarce.

Overweight and obesity in Norwegian children: prevalence and socio-demographic risk factors

AIM

The aim of this study was to estimate the prevalence of childhood overweight and obesity and to identify socio-demographic risk factors in Norwegian children.

METHODS

The body mass index of 6386 children aged 2-19 years was compared with the International Obesity Task Force (IOTF) cut-off values to estimate the prevalence of overweight including obesity (OWOB) and obesity (OB). The effect of socio-demographic factors on this prevalence was analysed using multiple ordinal logistic regression analysis in a subsample of 3793 children.

RESULTS

The overall prevalence of OWOB was 13.8% (13.2% in boys and 14.5% in girls, p = 0.146), but the prevalence was higher in primary school children aged 6-11 years (17%, p < 0.001). The risk of being OWOB or OB increased in children with fever siblings (p = 0.003) and with lower parental educational level (p = 0.001). There was no association with parental employment status, single-parent families or origin.

CONCLUSION

The prevalence of OWOB and OB in Norwegian primary school children is of concern. Socio-demographic factors have pronounced effects on the current prevalence of overweight and obesity in a cohort of Norwegian children. This knowledge could help to work out strategies to reduce the burden of overweight and obesity in children.

Secular trends in adiposity in Norwegian 9-year-olds from 1999-2000 to 2005

Background

Due to the negative health consequences of childhood obesity monitoring trends in body mass and adiposity is essential. The purpose of this study was to describe secular trends in the prevalence of overweight and obesity among 9-year-old children, and to study changes in adiposity and fat distribution by investigating changes in waist circumference (WC) and skinfold thicknesses.

Methods

A total of 859 9-year-olds were included in two cross-sectional studies conducted in 1999-2000 and 2005. Measurements of body mass index (BMI; in kg/m²), WC and skinfold thicknesses were taken by trained investigators. The International Obesity Task Force cut-offs were used to define overweight and obese subjects.

Results

The overall prevalence of overweight (including obesity) did not change over the five year period. However, a shift may have occurred as the prevalence of overweight (including obesity) increased by 6.4% in girls and 5.5% in boys over the five year period. In both study periods, logistic regression analyses revealed that children of non-Western origin had 2 times higher odds of being overweight/obese than those of Western origin. However, neither the children of Western origin nor the children of non-Western origin showed a significant increase in the prevalence of overweight over the five-year period. No changes were observed for mean BMI, while a significant increase in WC was reported for both girls and boys, and an increase in all skinfold measurements was observed in girls only. Shifts in percentile distribution were observed for BMI, WC and sum of 4 skinfold thickness, however, the shift appeared to be faster in the upper end of the population distribution (p < 0.001 for interactions).

Conclusion

From 1999-2000 to 2005, there have been increases in 9-year-olds measures of adiposity even though the BMI did not change. The results indicate the need of a large-scale monitoring of adiposity, in addition to BMI, in children.

Sex differences in time trends for overweight and obesity in adolescents: the Young-HUNT study

AIMS

To investigate sex differences in the prevalence and extent of overweight and obesity in adolescents aged 14-18 years.

METHODS

Standardized measurements of height and weight were collected from surveys of adolescents in the same geographical area in 1966-69 (n = 8378) and in 1995-97 (n = 6673). The prevalence rates of overweight and obesity were calculated using criteria approved by the International Obesity Task Force. The extents of overweight and obesity were assessed by computing age- and sex-specific body mass index (BMI) percentiles.

RESULTS

In 1995-97, 17.2% met the criteria for either overweight or obesity, as compared with 10.7% in 1966-69. The prevalence of overweight and obesity combined was higher in girls (13.0%) than in boys (8.5%) in 1966-69 (difference 4.5%, 95% confidence interval (CI) 3.1-5.9), while no sex difference was found in 1995-97 (girls 16.9%, boys 17.5%, difference -0.6, 95% CI -2.3-1.1). The increase in overweight was greater in boys (6.2PP, 95% CI 4.7-7.6) than in girls (1.9PP, 95% CI 0.4-3.5), while the sex difference in increased obesity was smaller (boys 2.8PP, 95% CI 2.1-3.4, girls 2.0PP, 95% CI 1.3-2.6). The increase in extent of overweight and obesity was highest in boys. The values of the 85th percentile and the 95th percentile in boys increased by 1.3 and 3.0 BMI units, respectively. The corresponding increases in girls were 0.7 and 1.7 BMI units.

CONCLUSIONS

A marked sex difference in time trends for both the prevalence and extent of overweight and obesity, with a more pronounced increase in boys than in girls, was demonstrated. This might have implications for preventive strategies.

Overweight and obesity among adolescents in Norway: cultural and socio-economic differences

BACKGROUND

The aim of this study was to investigate overweight and obesity among a representative population of 15,966 Norwegian 15-16 year olds and the associations with different socio-economic and cultural risk factors.

METHODS

Self-reported data were obtained from school-based surveys in six counties during 2000-04. Overweight and obesity were calculated using Cole's index.

RESULTS

The prevalence of overweight and obesity were 11.8% and 2.4%, respectively, higher among boys. Logistic regression analyses revealed that adolescents in Nordland, Troms and Finnmark (the northernmost counties) were 70-90% more likely to be overweight and obese compared with adolescents in Oslo (the capital and southernmost county) (OR for overweight in Finnmark = 1.7, CI = 1.3, 2.3). Lower educational plans and poor family economy were both significantly associated with overweight and obesity. So was physical inactivity (OR = 1.2, CI = 1.1, 1.3 and OR = 1.6, CI = 1.2, 2.1, respectively). Eating breakfast was positively associated with not being overweight/obese.

CONCLUSION

Overweight and obesity is associated with socio-economic factors and with factors related to food habits and nutrition, suggesting important areas for prevention.