Short-term predictors of overweight in early adolescence

Childhood cardiovascular risk factors, a predictor of late adolescent overweight

Background:

We conducted a prospective study to elucidate the effects of increased cardiovascular risk factors on future weight gain and also the relation between body mass index (BMI) and other cardiovascular risk factors in children and adolescents.

Materials and Methods:

This study was conducted on 1525 nonobese children and adolescents with an age range of 3-16 years old, participating in the 1^st phase and follow-up phases of Tehran Lipid and Glucose Study. The subjects were evaluated 4 times with a 3-year time interval regarding lipid profile status and BMI, and other cardiovascular disease (CVD) risk factors. All the cases had a BMI <85% and had been appraised in at least two evaluation points.

Results:

Cardiovascular risk factors, high-density lipoprotein (HDL) (P = 0.019), low-density lipoprotein (P = 0.016), triglyceride (TG) (P < 0.001), and blood pressure (BP) (P = 0.001); had significant effects on weight gain. There was also no difference between boys and girls and no age trend for increasing weight in both groups. The associations between BMI with cardiovascular risk factors were assessed cross-sectionally. For both sexes, BMI was significantly correlated to systolic and diastolic BP and TG (P = 0.05). For girls, BMI was significantly related to HDL (P = 0.05) regardless to age, but in boys, the relation of BMI with HDL only increased with age (P = 0.05).

Conclusion:

Increased CVD risk factors are predictors of future overweight in childhood and adolescent and increased weight is linked significantly with dyslipidemia and hypertension in this age group.

High cardiorespiratory fitness is inversely associated with incidence of overweight in adolescence: a longitudinal study

To assess the association of baseline cardiorespiratory fitness (CRF) with incidence of overweight over a 4.6-year period in adolescence. In a cohort of 4878 adolescents, we assessed body mass index in years 2001-2003 and 2007. CRF was assessed at baseline as maximal oxygen consumption (VO2max , mL/kg/min) using the 20-m shuttle run test and was examined against incidence of overweight at follow-up. Estimated VO2max at baseline was higher in males than in females, P < 0.001, and was lower in overweight and obese than in non-overweight subjects. The incidence of overweight at follow-up among non-overweight participants at baseline was 15.5% [95% confidence interval (CI) 13.7% to 17.3%] in males and 5.6% (95% CI 4.9% to 7.0%) in females, P < 0.001. Adjusted odds ratio for incidence of overweight in participants in the fourth quartile of VO2max was 0.40 (95%CI 0.26 to 0.61) in males and 0.57 (95% CI 0.33 to 0.99) in females in comparison with participants in the first quartiles of VO2max . Incidence of overweight was three times more frequent in males than in females. Among non-overweight at baseline, high fitness levels were inversely associated with incidence of overweight at follow-up, suggesting that interventions aiming to increase CRF in early childhood might help reverse increasing trends in obesity.

Are you what your mother weighs? Evaluating the impact of maternal weight trajectories on youth overweight

In this study, we investigate how three alternative measures of maternal body mass index (BMI) relate to youth overweight. We contrast the typical cross-sectional measure of maternal BMI with a longitudinal mean and a standard deviation in maternal BMI. Using National Longitudinal Survey of Youth data, we estimate logistic regressions that relate maternal BMI to the risk of a youth being overweight while controlling for other familial characteristics. Participants in this study are 918 males and 841 females who were age 16-21 and either healthy weight or overweight in 2006. To be eligible for inclusion, teens were 15 years old by December 2006. After comparing several measures of maternal weight, we find that higher mean maternal BMI measured over the life of the adolescent has the strongest relationship with the odds of youth overweight for both male and female adolescents. For boys, a one unit increase in mother's mean BMI increases the odds of being overweight by 16% (OR = 1.16, 95% CI 1.11-1.20) while for girls the increase in the odds of being overweight is 13% (OR = 1.13, 95% CI 1.09-1.18). Our findings suggest that researchers should move beyond static measures of maternal weight when examining the correlates of youth BMI. Maternal weight histories offer additional insights about the youth's home environment that are associated with the risk of a youth being overweight.

Fatores socioeconômicos, demográficos, ambientais e comportamentais associados ao excesso de peso em adolescentes: uma revisão sistemática da literatura

OBJETIVO: Identificar fatores socioeconômicos, ambientais e comportamentais associados ao excesso de peso (EP) em adolescentes por meio de uma revisão sistemática da literatura. MÉTODOS: Foram consultadas seis bases de dados (Lilacs, Adolec, SciELO, Medline via Pubmed, ISI Web of Knowlwdge e Cochrane Library) entre os dias 3 e 13 de janeiro de 2008. Os descritores e respectivos termos MeSH utilizados foram: "sobrepeso", "obesidade", "adolescência", "adolescentes", "fatores de risco", "fatores associados". Foram avaliados artigos em inglês, espanhol e português publicados entre 1997 e 2007, e incluídos estudos observacionais que estudaram adolescentes com idades entre 10 e 19 anos, cujo desfecho era o EP diagnosticado por critérios internacionalmente utilizados. Foram excluídos estudos com base em amostras de conveniência ou que não investigavam fatores sociais, ambientais e psicocomportamentais entre as variáveis independentes. RESULTADOS: Da leitura dos títulos e resumos, e da aplicação inicial dos critérios de elegibilidade, resultaram 202 artigos. A revisão das publicações completas permitiu a inclusão e análise de 56 artigos. Observou-se que o nível socioeconômico associou-se inversamente com o EP em países desenvolvidos e de forma direta em países em desenvolvimento. Dieta para emagrecer, número de horas alocadas em TV/vídeo por dia, mãe e/ou pais obesos e ocorrência de EP na infância associaram-se diretamente com o EP. Foram identificados como fatores protetores o hábito de consumir desjejum e a prática de atividade física. CONCLUSÃO: Variáveis socioeconômicas, comportamentais, familiares e do início da vida associaram-se com EP e estas devem ser consideradas nas intervenções dirigidas para este agravo entre adolescentes.

Cardiovascular risk in 26,008 European overweight children as established by a multicenter database

OBJECTIVE

Although the obesity epidemic is progressing in European children too, there is no consensus on the population-specific prevalence of comorbidities or efficient diagnostic strategies. Therefore, weight-related risk factors, their interrelationship, and association with biological parameters were assessed in a large group of overweight (OW) children, documented by an electronic database.

METHODS AND PROCEDURES

Data of 26,008 children (age 12.6+/-2.9 years, 56% females) presented for OW (BMI >90th percentile) or obesity (>97th percentile) in 98 specialized centers were evaluated using a simple software (Adipositas Patienten Verlaufsbeobachtung (APV)) for standardized longitudinal documentation. After local anonymization, data were transmitted for central analysis including multiple logistic regression.

RESULTS

A total of 5.9% of the children were normal weight, 41% obese (OB), and 37% extremely OB (>99.5th percentile, XXL; 41% of the girls). In 50%, at least one risk factor and in 11% a cluster of two were found, comprising increased blood pressure (BP): 35.4%, dyslipidemia: 32% (total cholesterol: 14.1%, low-density lipoprotein (LDL)-cholesterol: 15.8%, high-density lipoprotein (HDL)-cholesterol: 11.1%, triglycerides: 14.3%), impaired glucose tolerance (IGtT): 6.5% and suspicion of diabetes: 0.7%. The degree of OW was inversely associated with HDL-cholesterol and directly with clustered risk factors, impaired glucose metabolism, increased BP and triglycerides (odds ratios (ORs) XXL vs. normal=6.15, >10, 4.3, 3.0 and 2.5, respectively), but not with LDL-cholesterol.

DISCUSSION

In a very large cohort of young Europeans risk factors for cardiovascular (CV) diseases are frequently found, related to the degree of OW and tend to cluster, thus a comprehensive screening is justified in all OW or OB children. Electronic patient documentation is feasible in a large obesity care network.

Anthropometric predictors of serum fasting insulin in 9- and 15-year-old children and adolescents

BACKGROUND AND AIM

As the prevalence of overweight and obesity increases, the risk of insulin resistance rises. The aim was to study the association between anthropometric measurements and fasting insulin concentration in a population-based sample of 9- and 15-year-old children and adolescents.

METHODS AND RESULTS

Subjects were randomly selected 9- and 15-year-old pupils (n=262) in a cross-sectional, population-based study. Weight and height, waist, hip and mid-arm-circumference and subcutaneous skinfolds were measured using standard procedures. Fasting insulin was measured. In general the mean anthropometric measurements increased across insulin quartiles. Higher fasting insulin concentration was seen in overweight children and adolescents than in those of normal weight (8.3+/-4.4 vs. 4.9+/-3.6 mmol/L and 11.0+/-4.4 vs. 9.0+/-4.2 mmol/L in 9- and 15 year-olds, respectively). The odds ratio for having insulin in the highest quartile (age and gender-specific) was, when compared with the lowest quartile, 7.2 (95% CI 3.0-17.2) for body mass index and 6.9 (2.8-16.7) for waist circumference. Other measurements of body fatness were less predictive. About 14-20% of children defined as being of normal weight had high fasting insulin values, i.e., were in the highest quartile of fasting insulin.

CONCLUSIONS

Body fatness is positively related to fasting insulin concentration in 9- and 15-year-old children. A large number of normal-weight individuals with high fasting insulin concentration was observed, and these children could be at increased risk of weight gain, compared with normal-weight individuals with normal fasting insulin concentration.

Changing relationships of obesity and dyslipidemia in Greek children: 1982-2002

BACKGROUND

The prevalence of childhood overweight and obesity has been increasing rapidly during the past decades in many parts of the world. Less is known with respect to the effects of increasing adiposity on blood lipid profile. The present study was designed to examine the influence of adiposity on secular trends in anthropometric characteristics and plasma lipids of Greek children.

METHODS

A total of 419 and 374 boys with normal body weight and 109 and 246 boys with abnormal body weight (overweight and obese) were randomly recruited in 1982 and 2002, respectively (aged 12.1 +/- 0.1 years). Height, weight, body mass index (BMI, kg/m(2)), Rohrer index (kg/m(3)), plasma total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), triglyceride (TG), TC/HDL-C ratio, and LDL-C/HDL-C ratio were determined.

RESULTS

Temporal changes in weight (positive), BMI (positive), HDL-C (negative), and cholesterol ratios (positive) were greater among overweight and obese vs. normal-weight boys (P < 0.05), while those for height (positive), LDL-C (positive), TG (positive), and TC (no change) were of similar magnitude. The increase in Rohrer index since 1982 failed to reach significance for children with normal body weight (P = 0.077) but did so for overweight and obese subjects (P = 0.027).

CONCLUSIONS

These results indicate that secular increases in measures of fatness and adverse changes in plasma lipids were more pronounced among overweight and obese children than among normal-weight individuals, although qualitatively similar shifts were observed across the entire population.

Short-term predictors of abdominal obesity in children

BACKGROUND

The aim of this study was to examine the short-term tracking of abdominal adiposity in children.

METHODS

A total of 918 children (477 boys) aged 6-12 years at baseline were followed-up for 2 years. Central obesity was assessed by waist circumference (WaistC), whereas body fat distribution by waist-to-hip ratio. Maturity was assessed by the Khamis-Roche method. Parental fatness and children's cardiorespiratory fitness (CRF) were also evaluated. Multiple and logistic regressions were employed to identify the predictors of BMI and WaistC.

RESULTS

Tracking of body fatness and body fat distribution was high (r = 0.69-0.86, P < 0.01). More boys remained obese than girls (P < 0.05), whereas a greater percentage of boys moved to a higher quartile of WaistC after the 2-year follow-up (22.0 vs 14.1%, P < 0.01). Sex, child's maturity and WaistC at baseline, CRF, and maternal BMI explained 76% of the variability in BMI and WaistC at the follow-up (n = 290). Children with high WaistC at baseline and low CRF presented 1.9- and 4.3-fold increased risk of remaining in the upper quartile of WaistC at the follow-up (P < 0.01; n = 552).

CONCLUSION

Youth with increased WaistC at baseline and low CRF presented an increased chance of maintaining central obesity at the follow-up. More boys than girls moved into a higher quartile of abdominal obesity during the 2-year follow-up period and this should be taken into account in designing programmes for childhood obesity.

Incidence and remission rates of overweight among children aged 5 to 13 years in a district-wide school surveillance system

OBJECTIVES

To monitor annual changes in weight status, we determined incidence and remission rates of overweight among school-aged children with longitudinal school-based surveillance.

METHODS

We estimated 1-year changes in weight status among students enrolled in public schools in Cambridge, Mass. Physical education teachers measured height and weight annually. Adjusted odds ratios (ORs) were estimated via multivariate logistic regression, accounting for repeated observations of individual children across years.

RESULTS

The 1-year incidence of overweight was 4%, and the remission rate was 15%. Among overweight children, 85% remained overweight at a 1-year follow-up, while 18% of children at risk for overweight became overweight. Overweight incidence rates were higher among children aged 7 and 8 years than among those aged 11 to 13 years (boys: OR=1.68; 95% confidence interval [CI]=1.14, 2.47; girls: OR=1.86; 95% CI=1.25, 2.77).

CONCLUSIONS

Both incidence and remission rates were higher among younger children. Children who were at risk for overweight were more likely to change their weight status than those who were already overweight. Our results support targeting overweight prevention efforts toward younger children and children at risk for overweight.