BMI Trajectories Among the Severely Obese: Results From an Electronic Medical Record Population

Epidemiological studies have documented the growing prevalence of severe obesity during the past three decades. The primary goal of this study was to estimate the trajectory of BMI change over 5+ years in a cohort of subjects identified as severely obese (BMI ≥35). We conducted a retrospective cohort study among adults enrolled in Group Health (GH) in Washington State. We tracked 11,735 subjects with at least one BMI measure of 35 or greater in the calendar year 2005 through April 2010. Population averaged BMI trajectories were estimated as a quadratic function of time using a marginal regression model, adjusting for gender and baseline BMI and age. For the average male in GH, the estimated BMI trajectory exhibited a slightly inverted U-shaped pattern and a 0.17 increase in BMI over the sample period. For the average female, the BMI trajectory was slightly U-shaped with BMI decreasing 0.03 units over the sample period. We found a high degree of heterogeneity in the shape of estimated trajectories across baseline characteristics with larger 5-year BMI increases among younger subjects with a lower initial BMI. We conclude that BMI changes over 5 years among individuals classified as severely obese are generally small and consistent with studies documenting BMI changes for individuals in other lower BMI categories. Our results also suggest that once the 35 BMI threshold is reached, individuals will continue to remain severely obese, especially at younger ages.     

Familial Risk of Overweight and Obesity in the Canadian Population using the WHO/NIH Criteria

Objective: To determine the familial risk of overweight and obesity in Canada. Research Methods and Procedures: The sample was comprised of 15,245 participants from 6377 families of the Canada Fitness Survey. The risk of overweight and obesity among spouses and first‐degree relatives of individuals classified as underweight, normal weight, pre‐obese, or obese (Class I and II) according to the WHO/NIH guidelines for body mass index (BMI) was determined using standardized risk ratios. Results: Spouses and first‐degree relatives of underweight individuals have a lower risk of overweight and obesity than the general population. On the other hand, the risk of Class I and Class II obesity (BMI 35 to 39.9 kg/m²) in relatives of Class I obese (BMI 30 to 34.9 kg/m²) individuals was 1.84 (95% CI: 1.27, 2.37) and 1.97 (95% CI: 0.67, 3.25), respectively, in spouses, and 1.44 (95% CI:1.10, 1.78) and 2.05 (95% CI: 1.37, 2.73), respectively in first‐degree relatives. Further, the risk of Class II obesity in spouses and first‐degree relatives of Class II obese individuals was 2.59 (95% CI: ?0.91, 6.09) and 7.07 (95% CI: 1.48, 12.66) times the general population risk, respectively. Discussion: There is significant familial risk of overweight and obesity in the Canadian population using the BMI as an indicator. Comparison of risks among spouses and first‐degree relatives suggests that genetic factors may play a role in obesity at more extreme levels (Class II obese) more so than in moderate obesity.     

Developmental Trajectories of Girls' BMI Across Childhood and Adolescence

This study describes qualitatively distinct trajectories of BMI change among girls participating in a longitudinal study of non‐Hispanic, white girls (n = 182) and their parents, assessed at daughters' ages 5, 7, 9, 11, 13, and 15 years. Height, weight, body fat, fasting blood glucose and lipids, blood pressure, waist circumference, and pubertal status were measured, and participants self‐reported dietary, physical activity, and television (TV) viewing patterns. Growth mixture models were used to model heterogeneity in girls' BMI trajectories over 10 years. Statistical support was strongest for four distinct BMI trajectories: (i) upward percentile crossing (UPC; n = 25, 14%); (ii) delayed downward percentile crossing (DDPC; n = 37, 20%); (iii) 60th percentile tracking (60PT; n = 52, 29%); and (iv) 50th percentile tracking (50PT; n = 68, 37%). Girls in the UPC group had more metabolic risk factors at age 15 years, even after adjusting for concurrent weight status. Girls in the UPC group had mothers with the highest BMIs at study entry and were breast‐fed for a shorter duration. This novel approach for examining differences in growth trajectories revealed four distinct BMI trajectories that predicted adolescent metabolic health outcomes in girls. The present study provides support for BMI monitoring in girls and for the potential utility of combining data on BMI tracking with data on familial characteristics for the early identification of girls at elevated risk for obesity and metabolic syndrome.     

Obesity and physical activity among Aboriginal Canadians

Objective: To investigate ethnic differences in obesity and physical activity among Aboriginal and non‐Aboriginal Canadians. Methods and Procedures: The sample included 24,279 Canadians (1,176 Aboriginals, 23,103 non‐Aboriginals) aged 2–64 years from the 2004 Canadian Community Health Survey (CCHS). Adult participants were classified as underweight/normal weight, overweight (BMI 25–29.9 kg/m²) or obese (BMI ≥ 30 kg/m²). Children and youth 2–17 years of age were classified as normal weight, overweight or obese based on the International Obesity Task Force criteria. Leisure‐time physical activity levels over the previous 3 months were obtained by questionnaire in those aged 12–64 years. Results: The prevalence of obesity in adults was 22.9% (men: 22.9%; women: 22.9%), and the prevalence was higher among Aboriginals (37.8%) compared to non‐Aboriginals (22.6%). The prevalence of obesity in children and youth was 8.2% (boys: 9.2%; girls: 7.2%), and the prevalence was higher among Aboriginals (15.8%) compared to non‐Aboriginals (8.0%). In both youth and adults, the odds for obesity were higher among Aboriginals (youth: OR = 2.3 (95% CI: 1.4–3.8); adults: OR = 2.4 (95% CI: 1.6–3.6)) after adjustment for a number of covariates. There were no ethnic differences in the prevalence of physical inactivity; however, physical inactivity was a predictor of obesity in both the Aboriginal and non‐Aboriginal samples. Discussion: The prevalence of obesity is higher among Canadian Aboriginals compared to the rest of the population. Further research is required to better delineate the determinants of obesity and the associated health consequences in this population.     

Accelerated Growth in Early Life and Obesity in Preschool Chilean Children

In Chile, childhood obesity rates are high. The purpose of this article is to compare BMI growth characteristics of normal (N), overweight (OW), and obese (OB) 5‐year olds from 0 to 5 years and explore the influence of some prenatal factors on these patterns of growth. The study was done on a retrospective cohort of 1,089 5‐year olds with birth weight >2,500 g. Weight and height were obtained from records at nine occasions (0–36 months); at 52 and 60 months, we measured them. At 60 months, children were classified as N, OW, and OB. At each age, BMI and z‐score of BMI (BMI Z) differences were compared among groups. The influence of birth weight, pre‐pregnancy BMI, and prenatal variables (weight gain, smoking, and presence of diabetes and preeclampsia) on BMI Z differences between N and OB was also explored. Adiposity rebound (AR) was not observed for the N, although for the OW, it occurred ～52 months and for the OB at ～24 months. BMI Z differences between N and OB were significant from birth, but were greatest between 6–12 and 36–52 months. Additional adjustment by birth weight, pre‐pregnancy BMI, and prenatal variables decreased the BMI Z differences for the first 24 months with virtually no effect after this age. Accelerated growth in OB children from post‐transition countries occurs immediately after birth, much earlier than the AR. The influence of prenatal factors on adiposity acquisition may extend at most until 2 years of life, although BMI gains thereafter are more related to postnatal variables.     

Weight Loss Expectations in Obese Patients and Treatment Attrition: An Observational Multicenter Study

Objective: To investigate the influence of weight loss expectations (expected 1‐year BMI loss, dream and maximum acceptable BMI) on attrition in obese patients seeking treatment. Research Methods and Procedures: Obese subjects (1785; 1393 women; median age, 46 years; median BMI, 36.7 kg/m²) seeking treatment in 23 medical Italian centers were evaluated. Baseline diet and weight history, weight loss expectations, and primary motivation for seeking treatment (health or improving appearance) were systematically recorded. Psychiatric distress, binge eating, and body image dissatisfaction were tested at baseline by self‐administered questionnaires (Symptom Check List‐90, Binge Eating Scale, and Body Uneasiness Test). Attrition and BMI change at 12 months were prospectively recorded. Results: At 12 months, 923 of 1785 patients (51.7%) had discontinued treatment. Compared with continuers, drop‐outs had a significantly lower age, a lower age at first dieting, lower dream BMI, a higher expected 1‐year BMI loss, and a higher weight phobia. At logistic regression analysis, the strongest predictors of attrition at 12 months were lower age and higher expected 1‐year BMI loss. The risk of drop‐out increased systematically for unit increase in expected BMI loss at 12 months (hazard ratio, 1.12; 95% confidence interval, 1.04 to 1.20; p = 0.0018). The risk was particularly elevated in the first 6 months. Discussion: Baseline weight loss expectations are independent cognitive predictors of attrition in obese patients entering a weight‐losing program; the higher the expectations, the higher attrition at 12 months. Unrealistic weight goals should be tackled at the very beginning of treatment.     

Asthma Trajectories in Early Childhood: Identifying Modifiable Factors

Background

There are conflicting views as to whether childhood wheezing represents several discreet entities or a single but variable disease. Classification has centered on phenotypes often derived using subjective criteria, small samples, and/or with little data for young children. This is particularly problematic as asthmatic features appear to be entrenched by age 6/7. In this paper we aim to: identify longitudinal trajectories of wheeze and other atopic symptoms in early childhood; characterize the resulting trajectories by the socio-economic background of children; and identify potentially modifiable processes in infancy correlated with these trajectories.

Data and Methods

The Millennium Cohort Study is a large, representative birth cohort of British children born in 2000–2002. Our analytical sample includes 11,632 children with data on key variables (wheeze in the last year; ever hay-fever and/or eczema) reported by the main carers at age 3, 5 and 7 using a validated tool, the International Study of Asthma and Allergies in Childhood module. We employ longitudinal Latent Class Analysis, a clustering methodology which identifies classes underlying the observed population heterogeneity.

Results

Our model distinguished four latent trajectories: a trajectory with both low levels of wheeze and other atopic symptoms (54% of the sample); a trajectory with low levels of wheeze but high prevalence of other atopic symptoms (29%); a trajectory with high prevalence of both wheeze and other atopic symptoms (9%); and a trajectory with high levels of wheeze but low levels of other atopic symptoms (8%). These groups differed in terms of socio-economic markers and potential intervenable factors, including household damp and breastfeeding initiation.

Conclusion

Using data-driven techniques, we derived four trajectories of asthmatic symptoms in early childhood in a large, population based sample. These groups differ in terms of their socio-economic profiles. We identified correlated intervenable pathways in infancy, including household damp and breastfeeding initiation.     

Associations between early-life growth pattern and body size and follicular lymphoma risk and survival: a family-based case-control study

BackgroundThe influence of early-life growth pattern and body size on follicular lymphoma (FL) risk and survival is unclear. In this study, we aimed to investigate the association between gestational age, growth during childhood, body size, changes in body shape over time, and FL risk and survival.MethodsWe conducted a population-based family case-control study and included 706 cases and 490 controls. We ascertained gestational age, growth during childhood, body size and body shape using questionnaires and followed-up cases (median=83 months) using record linkage with national death records. We used a group-based trajectory modeling approach to identify body shape trajectories from ages 5–70. We examined associations with FL risk using unconditional logistic regression and used Cox regression to assess the association between body mass index (BMI) and all-cause and FL-specific mortality among cases.ResultsWe found no association between gestational age, childhood height and FL risk. We observed a modest increase in FL risk with being obese 5 years prior to enrolment (OR=1.43, 95 %CI=0.99–2.06; BMI ≥30 kg/m²) and per 5-kg/m² increase in BMI 5 years prior to enrolment (OR=1.14, 95 %CI=0.99–1.31). The excess risk for obesity 5 years prior to enrolment was higher for ever-smokers (OR=2.00, 95 %CI=1.08–3.69) than never-smokers (OR=1.14, 95 %CI=0.71–1.84). We found no association between FL risk and BMI at enrolment, BMI for heaviest lifetime weight, the highest categories of adult weight or height, trouser size, body shape at different ages or body shape trajectory. We also observed no association between all-cause or FL-specific mortality and excess adiposity at or prior to enrolment.ConclusionWe observed a weak association between elevated BMI and FL risk, and no association with all-cause or FL-specific mortality, consistent with previous studies. Future studies incorporating biomarkers are needed to elucidate possible mechanisms underlying the role of body composition in FL etiology.     

Controlled study of critical parent and family factors in the obesigenic environment

Objective: Critical gaps remain in our understanding of the obesigenic family environment. This study examines parent and family characteristics among obese youth presenting for treatment in a clinic setting. Research Methods and Procedures: Families of 78 obese youth (BMI z‐score = 2.4; age, 8 to 16 years; 59% girls; 49% African‐American) were compared with 71 non‐overweight (BMI z‐score = ?0.02) demographically matched comparisons. Parents completed measures assessing family demographics, psychological distress (Symptom Checklist 90‐Revised), and family functioning both broadly (Family Environment Scale: Conflicted, Support, Control) and at mealtimes (About Your Child's Eating‐Revised: Mealtime Challenges, Positive Mealtime Interaction). Height and weight were obtained from all participants. Results: Compared with mothers and fathers of non‐overweight youth, parents of obese youth had significantly higher BMIs (p < 0.001). Mothers of obese youth reported significantly greater psychological distress (p < 0.01), higher family conflict (p < 0.05), and more mealtime challenges (p < 0.01). Less positive family mealtime interactions were reported by both mothers (p < 0.01) and fathers (p < 0.05) of obese youth. These group differences did not vary by child sex or race. Logistic regression analyses indicated that maternal distress and mealtime challenges discriminated between obese and non‐overweight youth after controlling for maternal BMI. Family conflict was explained, in part, by maternal distress. Discussion: Obese youth who present for treatment in a clinic setting are characterized by psychosocial factors at the parent and family level that differ from non‐overweight youth. These data are critical because they identify factors that may be serving as barriers to a family's or youth's ability to implement healthy lifestyle behaviors but that are potentially modifiable.     

BMI and headache among women: results from 11 epidemiologic datasets

Objective: To evaluate the association between BMI (kg/m²) and headaches among women. Methods and Procedures: Cross‐sectional analysis of 11 datasets identified after searching for all large publicly available epidemiologic cohort study datasets containing relevant variables. Datasets included National Health Interview Survey (NHIS): 1997–2003, the first National Health Examination and Nutrition Survey, Alameda County Health Study (ACHS), Tecumseh Community Health Study (TCHS), and Women's Health Initiative (WHI). The women (220,370 in total) were aged 18 years or older and had reported their headache or migraine status. Results: Using nonlinear regression techniques and models adjusted for age, race, and smoking, we found that increased BMI was generally associated with increased likelihood of headache or severe headache among women. A BMI of ～20 was associated with the lowest risk of headache. Relative to a BMI of 20, mild obesity (BMI of 30) was associated with roughly a 35% increase in the odds for experiencing headache whereas severe obesity (BMI of 40) was associated with roughly an 80% increase in odds. Results were essentially unchanged when models were further adjusted for socioeconomic variables, alcohol consumption, and hypertension. Being diagnosed with migraine showed no association with BMI. Discussion: Among US women, a BMI of ～20 (about the 5th percentile) was associated with the lowest likelihood of headache. Consistently across studies, obese women had significantly increased risk for headache. By contrast, the risk for diagnosed migraine headache per se was not obviously related to BMI. The direction of causation and mechanisms of action remain to be determined.     

The effect of obesity on overall,circulatory disease- and diabetes-specific mortality

This paper explores the relationship between body mass and risk of death among US adults. The National Health Interview Survey-Multiple Cause of Death linked data set is used for the years 1987-1997, and Cox proportional hazard models are employed to estimate the association between obesity, as measured by the body mass index (BMI), and overall, circulatory disease-specific and diabetes-specific mortality. A U-shaped relationship is found between BMI and overall mortality. Compared with normal weight individuals, mortality during the follow-up period is 34% higher among obese class II individuals and 77% higher among obese class III individuals, controlling for age and sex. A J-shaped relationship exists between circulatory disease mortality and obesity, with a slightly higher risk of death for all categories of BMI. The relationship between BMI and diabetes mortality is striking. Compared with normal weight individuals, obese class I individuals are 2.8 times as likely to die, obese class II individuals are 4.7 times as likely to die, and obese class III individuals are 9.0 times as likely to die of diabetes during the follow-up period, controlling for age and sex. These results demonstrate that obesity heightens the risk of overall and circulatory disease mortality, and even more substantially increases the risk of diabetes mortality. These mortality findings, together with the substantial recent increases in obesity, lend urgency to public health programmes aimed at reducing the prevalence and consequences of obesity.     

Obesity history as a predictor of walking limitation at old age

Objective: To study whether walking limitation at old age is determined by obesity history. Research Methods and Procedures: In a retrospective longitudinal study based on a representative sample of the Finnish population of 55 years and older (2055 women and 1337 men), maximal walking speed, body mass, and body height were measured in a health examination. Walking limitation was defined as walking speed <1.2 m/s or difficulty in walking 0.5 km. Recalled height at 20 years of age and recalled weight at 20, 30, 40, and 50 years of age were recorded. Results: Subjects who had been obese at the age of 30, 40, or 50 years had almost a 4‐fold higher risk of walking limitation compared to non‐obese. Obesity duration increased the age‐ and gender‐adjusted risk of walking limitation among those who had been obese since the age of 50 (odds ratio, 4.33; 95% confidence interval, 2.59 to 7.23, n = 114), among the obese since the age of 40 [6.01 (2.55 to 14.14), n = 39], and among the obese since the age of 30 [8.97 (3.06 to 26.29), n = 14]. The risk remained elevated even among those who had previously been obese but lost weight during their midlife or late adulthood [3.15 (1.63 to 6.11), n = 71]. Discussion: Early onset of obesity and obesity duration increased the risk of walking limitation, and the effect was only partially mediated through current BMI and higher risk of obesity‐related diseases. Preventing excess weight gain throughout one's life course is an important goal in order to promote good health and functioning in older age.     

Genetic risk score for adult body mass index associations with childhood and adolescent weight gain in an African population

Background

Ninety-seven independent single nucleotide polymorphisms (SNPs) are robustly associated with adult body mass index (BMI kg/m²) in Caucasian populations. The relevance of such variants in African populations at different stages of the life course (such as childhood) is unclear. We tested whether a genetic risk score composed of the aforementioned SNPs was associated with BMI from infancy to early adulthood. We further tested whether this genetic effect was mediated by conditional weight gain at different growth periods. We used data from the Birth to Twenty Plus Cohort (Bt20+), for 971 urban South African black children from birth to 18 years. DNA was collected at 13 years old and was genotyped using the Metabochip (Illumina) array. The weighted genetic risk score (wGRS) for BMI was constructed based on 71 of the 97 previously reported SNPs.

Results

The cross-sectional association between the wGRS and BMI strengthened with age from 5 to 18 years. The significant associations were observed from 11 to 18 years, and peak effect sizes were observed at 13 and 14 years of age. Results from the linear mixed effects models showed significant interactions between the wGRS and age on longitudinal BMI but no such interactions were observed in sex and the wGRS. A higher wGRS was associated with an increased relative risk of belonging to the early onset obese longitudinal BMI trajectory (relative risk?=?1.88; 95%CI 1.28 to 2.76) compared to belonging to a normal longitudinal BMI trajectory. Adolescent conditional relative weight gain had a suggestive mediation effect of 56% on the association between wGRS and obesity risk at 18 years.

Conclusions

The results suggest that genetic susceptibility to higher adult BMI can be tracked from childhood in this African population. This supports the notion that prevention of adult obesity should begin early in life. The genetic risk score combined with other non-genetic risk factors, such as BMI trajectory membership in our case, has the potential to be used to screen for early identification of individuals at increased risk of obesity and other related NCD risk factors in order to reduce the adverse health risk outcomes later.

     

Negative peer perceptions of obese children in the classroom environment

Objective: It is asserted that the more immediate and observable consequences of pediatric obesity are psychosocial in nature. This study examines the peer relations of clinically referred obese youth compared to demographically comparable nonoverweight peers within the classroom environment. Methods and Procedures: Peer‐, teacher‐, and self‐reports of behavioral reputation (Revised Class Play (RCP)), and peer reports of social acceptance, nonsocial attributes (attractiveness, athleticism, academic competence), and health interference (school absence, illness, fatigue) were obtained regarding 90 obese youth (BMI > 95th percentile; 8–16 years, 57% girls, 50% African American) and 76 nonoverweight demographically similar comparison classmates. Results: Relative to comparison peers, obese children were nominated significantly less often as a best friend and rated lower in peer acceptance, although the two groups did not differ in the number of reciprocated friendships. Obese youth were described by peer, teacher, and self‐report as more socially withdrawn and by peers as displaying less leadership and greater aggressive‐disruptive behavior. Peers also described obese youth as less physically attractive, less athletic, more sick, tired, and absent from school. Being seen as less attractive and less athletic by peers helped to explain differences in obese and nonoverweight youth's levels of peer acceptance. Discussion: Clinically referred obese youth are characterized by peer relations that differ from those of nonoverweight youth. The peer environment provides a rich context to understand the social consequences of pediatric obesity as well as factors that could be targeted in intervention to promote more positive health and psychosocial outcomes.     

Race, childhood insulin, childhood caloric intake, and class 3 obesity at age 24: 14-year prospective study of schoolgirls

The prevalence of Class 3 obesity (BMI ≥40 kg/m²) has more than doubled in the past 25 years. In a 14‐year prospective study from age 10 to 24 of a biracial schoolgirl cohort (293 black, 256 white), we assessed childhood correlates of Class 3 BMI at age 24. Of 42 girls with Class 3 BMI at age 24, 36 (86%) were black. By logistic regression, significant explanatory variables of Class 3 BMI at age 24 included top decile waist circumference at age 11 (odds ratio (OR) 5.7, 95% confidence interval (CI) 2.3–13.9, P = 0.0002), age 10 BMI ≥ the Center for Disease Control (CDC) 2000 top 15% (OR 7.0, 95% CI 2.5–19.3, P = 0.0002), and a three‐way interaction between race, childhood insulin, and average caloric intake from age 10 to age 19 (for each unit increase, OR 1.7 95% CI 1.3–2.2, P = 0.0003). Age 10 BMI, age 11 waist circumference, and interaction of race, childhood insulin, and childhood caloric intake predict Class 3 obesity in young adulthood, facilitating childhood identification of girls at high risk for developing Class 3 obesity.     

BMI and All‐cause Mortality Among Japanese Older Adults: Findings From the Japan Collaborative Cohort Study

The association between BMI and all‐cause mortality may vary with gender, age, and ethnic groups. However, few prospective cohort studies have reported the relationship in older Asian populations. We evaluated the association between BMI and all‐cause mortality in a cohort comprised 26,747 Japanese subjects aged 65–79 years at baseline (1988–1990). The study participants were followed for an average of 11.2 years. Proportional‐hazards regression models were used to estimate mortality hazard ratios (HRs) and 95% confidence intervals. Until 2003, 9,256 deaths occurred. The underweight group was associated with a statistically higher risk of all‐cause mortality compared with the mid‐normal‐range group (BMI: 20.0–22.9); resulting in a 1.78‐fold (95% confidence interval: 1.45–2.20) and 2.55‐fold (2.13–3.05) increase in mortality risk among severest thin men and women (BMI: <16.0), respectively. Even within the normal‐range group, the lower normal‐range group (BMI: 18.5–19.9) showed a statistically elevated risk. In contrast, being neither overweight (BMI: 25.0–29.9) nor obese (BMI: ≥30.0) elevated the risk among men; however among women, HR was slightly elevated in the obese group but not in the overweight group compared with the mid‐normal‐range group. Among Japanese older adults, a low BMI was associated with increased risk of all‐cause mortality, even among those with a lower normal BMI range. The wide range of BMI between 20.0 and 29.9 in both older men and women showed the lowest all‐cause mortality risk.     

Lipid and insulin levels in obese children: changes with age and puberty

Objective: The goal was to describe the lipid profile and insulin changes seen in obese children and adolescents at different stages of puberty. Research Methods and Procedures: A cross‐sectional study was conducted by chart review of 181 obese (BMI > 95th) children and adolescents 5 to 17 years of age, who were referred to the Center for Atherosclerosis Prevention for cardiovascular risk reduction from January 2003 through December 2003. Results: Eighty (44.2%) subjects were <12 years of age, and 101 (55.8%) were ≥12 years. Severity of obesity as expressed by BMI standard deviation score did not differ between these age groups. A significant difference with lower serum levels of total cholesterol, non‐high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol was seen with older age and with advancing sexual maturity rating. Triglycerides, very‐low‐density lipoprotein cholesterol, and lipoprotein(a) levels remained elevated across age and pubertal stages. Insulin levels and insulin resistance as expressed by homeostasis model assessment were significantly higher with older age. Similar trends were observed both in obese boys and obese girls during puberty. Discussion: The most striking findings of this study are that in the 5‐ to 17‐year‐old obese population, the combination of elevated triglycerides and very‐low‐density lipoprotein cholesterol and low high‐density lipoprotein cholesterol levels place them at greater cardiovascular risk than their non‐obese peers, even when the changing patterns of lipids and lipoproteins seen during pubertal maturation are accounted for.     

Young adult weight trajectories through midlife by body mass category

Objective : To estimate the expected weight gain through midlife for those in a given BMI category in young adulthood. Design and Methods : Group‐based trajectory modeling and National Longitudinal Survey of Youth 1979 data from 1990 to 2008 were used to quantify weight trajectories through midlife for 10,038 young adult men and women stratified by BMI category. Logistic regression was used to assess the association of trajectory membership with obesity‐related conditions (hypertension, diabetes, arthritis) in middle age. Results : Annual weight gain averaged 0.53 kg (1.17 lb) across the entire sample. However, there was considerable variation by and within BMI categories. More than 98% of men and 92% of women were on upward‐sloping trajectories, generally moving into a higher BMI category by middle age. Those who experienced early and rapid weight gain during young adulthood were most likely to be on a steeper trajectory and had greater risks for obesity‐related conditions. Conclusion : This study points to the health and weight benefits of entering young adulthood with a normal BMI, but further reveals that this is no guarantee of maintaining a healthy weight through midlife. For those who are young adults today, weight maintenance is unlikely to occur without significant environmental or technical innovation.     

BMI and seatbelt use

Objective: Seatbelt use among obese persons may be reduced because seatbelts are uncomfortable. We investigated the association between obesity and seatbelt use with data from the 2002 Behavioral Risk Factor Surveillance System Survey. Research Methods and Procedures: Multivariable logistic regression was used to calculate odds ratios and 95% confidence intervals (CIs) for seatbelt use among overweight (BMI, 25.0 to 29.9), obese (BMI, 30.0 to 39.9), and extremely obese (BMI ≥ 40.0) persons, relative to a non‐overweight/non‐obese reference group (BMI ≤ 24.9), adjusted for age, race, gender, education, and state seatbelt law. Results: Adjusted odds ratios for seatbelt use were 0.89 (95% CI, 0.85 to 0.93) for overweight, 0.69 (0.66 to 0.73) for obese, and 0.45 (95% CI, 0.40 to 0.50) for extremely obese persons. Interaction effects were evident for all covariates, with stronger associations between increasing BMI and decreasing seatbelt use for women, increasing age, higher education, and residence in states with a secondary seatbelt law. There was a linear decrease in seatbelt use with increasing BMI for all subgroups except persons 18 to 24 years old. Discussion: Lack of seatbelt can be added to the list of risk factors associated with obesity. Effective preventive interventions are needed to promote seatbelt use among overweight and obese persons.     

Obesity and body fat classification in the metabolic syndrome: Impact on cardiometabolic risk metabotype

Objective:

Obesity is a key factor in the development of the metabolic syndrome (MetS), which is associated with increased cardiometabolic risk. We investigated whether obesity classification by BMI and body fat percentage (BF%) influences cardiometabolic profile and dietary responsiveness in 486 MetS subjects (LIPGENE dietary intervention study).

Design and Methods:

Anthropometric measures, markers of inflammation and glucose metabolism, lipid profiles, adhesion molecules, and hemostatic factors were determined at baseline and after 12 weeks of four dietary interventions (high saturated fat (SFA), high monounsaturated fat (MUFA), and two low fat high complex carbohydrate (LFHCC) diets, one supplemented with long chain n‐3 polyunsaturated fatty acids (LC n‐3 PUFAs)).

Results:

About 39 and 87% of subjects classified as normal and overweight by BMI were obese according to their BF%. Individuals classified as obese by BMI (≥30 kg/m²) and BF% (≥25% (men) and ≥35% (women)) (OO, n = 284) had larger waist and hip measurements, higher BMI and were heavier (P < 0.001) than those classified as nonobese by BMI but obese by BF% (NOO, n = 92). OO individuals displayed a more proinflammatory (higher C reactive protein (CRP) and leptin), prothrombotic (higher plasminogen activator inhibitor‐1 (PAI‐1)), proatherogenic (higher leptin/adiponectin ratio) and more insulin resistant (higher HOMA‐IR) metabolic profile relative to the NOO group (P < 0.001). Interestingly, tumor necrosis factor‐α (TNF‐α) concentrations were lower post‐intervention in NOO individuals compared with OO subjects (P < 0.001).

Conclusions:

In conclusion, assessing BF% and BMI as part of a metabotype may help to identify individuals at greater cardiometabolic risk than BMI alone.