Childhood body-mass index and the risk of coronary heart disease in adulthood

Weight loss and the effect on stature in children during a residential intervention program

Weight loss is generally high in residential weight-loss programs but the effect of a large weight loss on linear growth is not known. We report the weight loss and the influence on linear growth in a large group of children during a residential weight-loss program focusing on nutrition and physical activity. In a longitudinal noncontrolled intervention study of 990 overweight children (540 girls) attending the weight reduction program from 1990 to 2001 for about 11 weeks (age: 10-14 years, mean BMI-standard deviation score (SDS) at enrollment: 2.83) weight and height were measured initially and after end of treatment. Weekly measurements of height and weight were performed on 138 children. The children lost on average 9.4 kg, reduced their BMI by 4.5 kg/m(2) and BMI-SDS by 0.98. In a multiple regression analysis (P < or = 0.001) weight loss was higher in boys than girls (1.7 kg), higher if the weight was higher at admission (-0.192 kg/kg at baseline) and was positively associated with duration of stay (-80 g/day). Initially the boys' BMI-SDS was higher than the girls' BMI-SDS (P < or = 0.05) but after 8 weeks of treatment the boys had lower BMI-SDS than the girls. There was no negative effect on linear growth during the treatment; on the contrary, linear growth accelerated during the stay as the average increase in height was 2.38 cm corresponding to 11.4 cm/year. In conclusion the children lost close to 1 kg/week during the stay without any negative effect on linear growth. The cause of the linear growth acceleration needs further investigation.

The influence of birth weight and body mass in early adulthood on early coronary heart disease risk among Danish men born in 1953

This study examines the joint and separate influence of birth weight and body mass in young adulthood on subsequent coronary heart disease (CHD) risk. A cohort of 9,143 men born in Copenhagen, Denmark, in 1953, for whom information on birth weight and body weight and height around age 19 years were retrieved from birth certificates and conscript records, respectively, were followed from 1978 until 2005 (between age 25 and 52 years) for incident fatal and non-fatal CHD. Data on CHD were obtained through record linkage to the Cause of Death Registry and the National Patient Registry. During follow-up, a total of 475 men had a CHD diagnosis. Men with low birth weight, high body mass index (BMI) at age 19, a father from the working class, and low educational level at age 19 had an increased risk for CHD. Birth weight was inversely associated with CHD only in men with BMI of 25 kg/m(2) or above. Adjustment for childhood social circumstances and educational status at age 19 had minor influence on the estimates. In conclusion, BMI in young adulthood seems to be strongly associated with the risk of CHD before age 52, and birth weight seem to modify the association. The risk estimates is highest for individuals with a combination of low birth weight and overweight in young adulthood.

Protein restriction during pregnancy induces hypertension and impairs endothelium-dependent vascular function in adult female offspring

Intrauterine undernutrition plays a role in the development of adult hypertension. Most studies are done in male offspring to delineate the mechanisms whereby blood pressure may be raised; however, the vascular mechanisms involved in female offspring are unclear. Female offspring of pregnant Sprague-Dawley rats fed either a control (C; 18%) or a low-protein (LP; 6%) diet during pregnancy were used. Birth weight and later growth were markedly lower in LP than in C offspring. LP offspring exhibited impaired estrous cyclicity with increased mean arterial pressure. Hypotensive response to acetylcholine (ACh) and the hypertensive response to phenylephrine (PE) were greater in LP than in C rats. N-nitro-L-arginine methyl ester (L-NAME) induced greater hypertensive responses in C than in LP rats. Endothelium-intact mesenteric arteries from LP offspring exhibited increased contractile responses to PE and reduced vasodilation in response to ACh. In endothelium-denuded arteries, relaxation responses to sodium nitroprusside were similar in both groups. Basal and ACh-induced increase in vascular nitrite/nitrate production was lower in LP than in C offspring. L-NAME or 1H-1,2,4-oxadiazolo-4,3-quinoxalin-1-one inhibited ACh relaxations and enhanced PE contractions in C offspring, but had minimal effect in LP rats. The decreased NO-mediated vascular response might explain the increased vascular contraction and arterial pressure in female offspring with low birth weight.

Elevated blood pressure in relation to overweight and obesity among children in a rural Canadian community

OBJECTIVE

Childhood overweight and obesity may result in premature onset of cardiovascular risk factors such as hypertension. Rural populations in North America may be at increased risk for overweight. We evaluated whether overweight and obesity were associated with prehypertension and hypertension in a well-characterized population of children in rural Canada.

METHODS

The study population for this cross-sectional study was composed of children (aged 4-17 years) who were participants of the Walkerton Health Study (Canada) in 2004. Prehypertension and hypertension were defined on the basis of percentiles from the average of 3 blood pressure measures taken on a single occasion. Percentiles for BMI and blood pressure were calculated by using the 2000 Centers for Disease Control and Prevention growth charts. Multinomial logistic regression was used to evaluate the odds for prehypertension and hypertension resulting from overweight and obesity.

RESULTS

Of 675 children (98.7% white), 122 (18.1%) were overweight and 77 (11.4%) were obese. Prehypertension and hypertension were detected in 51 (7.6%) and 50 (7.4%), respectively. After adjustment for family history of hypertension and kidney disease, obesity was associated with both prehypertension and hypertension. Overweight was associated with hypertension but not prehypertension. These associations were observed across the genders and children aged <13 and >or=13 years, except that overweight was not associated with hypertension among girls.

CONCLUSIONS

In this population of children who lived in a rural community in Canada, overweight and obesity were strongly associated with elevated blood pressure. Whether blood pressure normalizes with improvements in diet, physical activity, and environment is an area for additional study.

Thirty-year persistence of obesity after presentation to a pediatric obesity clinic

BACKGROUND

Few large, long-term studies are available on the relationship between childhood and adult obesity.

AIM

The present study examined the 30-year association between childhood and adult obesity in a large sample of girls with essential and uncomplicated obesity.

SUBJECTS AND METHODS

318 girls who had visited our Pediatric Obesity Clinic between January 1972 and December 1974 were re-contacted between January 2002 and December 2005. All had undergone an assessment of weight, height and pubertal status at the baseline visit. Anthropometry was performed again on those who agreed to take part in the follow-up visit. The women's general practitioners were also asked to compile a health questionnaire. Hypertension, hypercholesterolemia, hypertriglyceridemia and diabetes were defined according to current guidelines. Rates are expressed as number of cases per 1000 person-years (PY). Multivariable Poisson regression was used to identify predictors of persistent obesity.

RESULTS

224 (70%) of the 318 girls took part to the 30-year follow-up study. They had the same baseline anthropometry of those not available at follow-up. Sixteen per cent of them were still obese at the 30-year follow-up, giving a persistence rate of obesity of 5.2 x 1000 PY. Tanner stages > or = 1 [rate = ratios (RR) from 4.73 to 7.74 for different stages, p < or = 0.021] and Z-score of BMI (RR = 2.72 for one SDS, p = 0.019) were independent predictors of obesity persistence. Having a university degree vs. an elementary degree was instead protective (RR = 0.32, p = 0.009). The most prevalent complication was hypertriglyceridemia (8.8 x 1000 PY), followed by hypercholesterolemia (rate = 8.4 x 1000 PY), hypertension (rate = 5.2 x 1000 PY) and diabetes mellitus (rate = 1.0 x 1000 PY).

CONCLUSION

The study reinforces the notion that obesity should be prevented at an early age and shows that adolescents with severe obesity and low educational degree are at greater risk of becoming obese adults.

Contribuições das práticas alimentares e inatividade física para o excesso de peso infantil

OBJETIVO: Revisar estudos que abordam as práticas alimentares atuais e o padrão de atividade física como contribuintes do excesso de peso na infância. FONTES DE DADOS: Ovid Journals, Highwire e SciELO, com seleção de artigos originais e de revisão nos últimos dez anos (1997 a 2007), na língua portuguesa e inglesa. SÍNTESE DE DADOS: O acompanhamento do estado nutricional de crianças permite diagnosticar seu estado de saúde atual, bem como predizer parcialmente seu prognóstico na vida adulta. A prevalência de obesidade infantil, no Brasil, apresenta aumento progressivo em todas as classes sociais e sua freqüência varia entre cinco a 18%, dependendo da região estudada. A associação da transição epidemiológica, demográfica e comportamental e a alteração do hábito alimentar são apontadas como fatores causais do aumento progressivo da obesidade infantil. Práticas alimentares caracterizadas por elevado teor de lipídios, sacarose e sódio e por reduzido consumo de cereais integrais, frutas e hortaliças associadas à inatividade física decorrente do uso de computadores, jogos eletrônicos e televisores influenciam parte considerável de crianças. Este estilo de vida reflete os hábitos familiares e pode ser influenciado pelo ambiente escolar no qual a criança está inserida. CONCLUSÕES: Os dados sugerem influência considerável dos fatores ambientais, principalmente hábitos alimentares e inatividade física, no crescente aumento da prevalência de excesso de peso na população pediátrica.

Early undernutrition leads to long-lasting reductions in body weight and adiposity whereas increased intake increases cardiac fibrosis in male rats

Previous studies suggest that both overfeeding and undernutrition during development increase the risk of obesity and hypertension in adulthood. In this study, we examined both short- (24 d) and long- (16 wk) term effects of early postnatal over- and underfeeding in rats on body weight, body composition, plasma hormones, adiposity markers, and hypothalamic neuropeptide Y content. Cardiovascular changes were also examined by measuring blood pressure and cardiac fibrosis. Rats raised in litters of 3, 12, or 18 pups per mother were used to model early onset overfeeding, control, and underfeeding, respectively. At 24 d of age, pups raised in small litters (SL) were 10% heavier than pups from normal litters, accompanied by increased organ mass and fat mass, elevated plasma leptin, corticosterone, and uncoupling protein-1 mRNA in brown adipose tissue. On the other hand, pups raised in large litters were 17% lighter with no significant changes in plasma leptin. Overfeeding during the first 3 wk of life led to increased plasma leptin concentration in adulthood, whereas underfed rats remained significantly lighter throughout the study, with no evidence of catch-up growth. Rats raised in SL were more susceptible to developing cardiac fibrosis with a 22% increase in collagen deposition compared with control rats at 16 wk of age (P < 0.05). This was independent of any changes in blood pressure. This study demonstrates that nutritional changes early in postnatal development can have long-lasting effects on body weight, adiposity, and some mediators involved in energy homeostasis and can also lead to structural changes in the heart in adulthood. This highlights the importance of identifying potential early life risk factors involved in the modulation of childhood nutrition.

Adipose macrophage infiltration is associated with insulin resistance and vascular endothelial dysfunction in obese subjects

OBJECTIVE

Experimental studies suggest that adipose inflammation is etiologically linked to obesity-induced systemic disease. Our goal was to characterize the state of inflammation in human fat in relation to vascular function and metabolic parameters in obese individuals.

METHODS AND RESULTS

We collected subcutaneous abdominal fat in 77 obese subjects (BMI >or=30 kg/m(2)) and quantified adipose macrophage population using targeted immunohistochemistry. Brachial artery vasodilator function was examined using high-resolution vascular ultrasound. In 50 subjects, an inflamed adipose phenotype characterized by tissue macrophage accumulation in crown-like structures was associated with systemic hyperinsulinemia and insulin resistance (HOMA-IR 5.5+/-4.5 versus 2.6+/-1.9, P=0.002) and impaired endothelium-dependent flow-mediated vasodilation (8.5+/-4.4% versus 10.8+/-3.8%, P<0.05), as compared to subjects with quiescent noninflamed adipose architecture (n=27). Macrophage retention in fat was linked to upregulated tissue CD68 and tumor necrosis factor (TNF)-alpha mRNA expression in addition to increased plasma hs-CRP.

CONCLUSIONS

In a cohort of obese subjects, we demonstrate that proinflammatory changes in adipose tissue are associated with systemic arterial dysfunction and insulin resistance. These findings suggest that adipose inflammation may be linked to vascular injury and increased cardiovascular risk in obese subjects.

FTO gene associated fatness in relation to body fat distribution and metabolic traits throughout a broad range of fatness

BACKGROUND

A common single nucleotide polymorphism (SNP) of FTO (rs9939609, T/A) is associated with total body fatness. We investigated the association of this SNP with abdominal and peripheral fatness and obesity-related metabolic traits in middle-aged men through a broad range of fatness present already in adolescence.

METHODOLOGY/PRINCIPAL FINDINGS

Obese young Danish men (n = 753, BMI > or = 31.0 kg/m(2)) and a randomly selected group (n = 879) from the same population were examined in three surveys (mean age 35, 46 and 49 years, respectively). The traits included anthropometrics, body composition, oral glucose tolerance test, blood lipids, blood pressure, fibrinogen and aspartate aminotransferase. Logistic regression analysis was used to assess the age-adjusted association between the phenotypes and the odds ratios for the FTO rs9939609 (TT and TA genotype versus the AA genotype), for anthropometrics and body composition estimated per unit z-score. BMI was strongly associated with the AA genotype in all three surveys: OR = 1.17, p = 1.1*10(-6), OR = 1.20, p = 1.7*10(-7), OR = 1.17, p = 3.4*10(-3), respectively. Fat body mass index was also associated with the AA genotype (OR = 1.21, p = 4.6*10(-7) and OR = 1.21, p = 1.0*10(-3)). Increased abdominal fatness was associated with the AA genotype when measured as waist circumference (OR = 1.21, p = 2.2*10(-6) and OR = 1.19, p = 5.9*10(-3)), sagittal abdominal diameter (OR = 1.17, p = 1.3*10(-4) and OR = 1.18, p = 0.011) and intra-abdominal adipose tissue (OR = 1.21, p = 0.005). Increased peripheral fatness measured as hip circumference (OR = 1.19, p = 1.3*10(-5) and OR = 1.18, p = 0.004) and lower body fat mass (OR = 1.26, p = 0.002) was associated with the AA genotype. The AA genotype was significantly associated with decreased Stumvoll insulin sensitivity index (OR = 0.93, p = 0.02) and with decreased non-fasting plasma HDL-cholesterol (OR = 0.57, p = 0.037), but not with any other of the metabolic traits. However, all significant results for both body fat distribution and metabolic traits were explained by a mediating effect of total fat mass.

CONCLUSION

The association of the examined FTO SNP to general fatness throughout the range of fatness was confirmed, and this association explains the relation between the SNP and body fat distribution and decreased insulin sensitivity and HDL-cholesterol. The SNP was not significantly associated with other metabolic traits suggesting that they are not derived from the general accumulation of body fat.

Assessment of adiponectin and leptin as biomarkers of positive metabolic outcomes after lifestyle intervention in overweight and obese children

BACKGROUND

A number of metabolic changes are caused by childhood obesity, including insulin resistance, diabetes, and dyslipidemia. To counteract them, lifestyle modification with changes in dietary habits and physical activity is the primary intervention. Anthropometric parameters may not identify all positive changes associated with lifestyle modifications, whereas circulating adipokines may represent an alternative as biomarkers. The aim of this study was to evaluate adiponectin and leptin levels as markers of positive metabolic outcomes in childhood obesity.

METHODS

Changes in clinical, anthropometric, and metabolic parameters, including adiponectin and leptin, were assessed in 104 overweight and obese children before and after 1 yr of lifestyle intervention. Obesity and overweight were defined according to the Italian body mass index reference tables for age and sex. Fifty-four normal-weight children were evaluated as controls. Forty-eight of the children (47.5%) returned for follow-up at 1 yr.

RESULTS

Compared with normal-weight children, overweight and obese subjects differed significantly at baseline for glycemia, insulinemia, homeostasis model assessment for insulin resistance, adiponectinemia (5.8 vs. 18.2 microg/ml in controls), low-density lipoprotein-cholesterol, and triglycerides. These parameters were all higher in the overweight/obese children. At follow-up, most parameters improved in overweight/obese children. The most significant changes were observed in adiponectin concentration, which increased by 245% (P < 0.0001), reaching the levels observed in normal-weight children. Leptin levels showed changes unrelated to positive metabolic outcomes, remaining high at 1 yr of follow-up in overweight/obese children. Regardless of changes in weight status, children with lifestyle intervention reported changes in homeostasis model assessment for insulin resistance and in adiponectin that were associated with loss of fat mass.

CONCLUSIONS

After lifestyle intervention, adiponectin increased regardless of changes in weight, whereas no consistent changes was observed in serum leptin. Therefore, circulating adiponectin may represent a good biomarker to evaluate the efficacy of lifestyle intervention in overweight/obese children.

Update in female reproduction: a life-cycle approach

CONTEXT

Female reproduction spans a developmental life arc from fetal life and childhood, through puberty to the reproductive years, and, finally, ovarian follicle depletion and the onset of menopause.

OBJECTIVE

This invited review highlights a selection of reports from leading journals over the past 2 yr that have significantly advanced our understanding of female reproduction from conception to menopause.

SYNTHESIS

During fetal life, in utero exposures may be important determinants of later pubertal and adult endocrine physiology. Epigenetic mechanisms are likely involved in the fetal programming of adult endocrine function. With regards to the polycystic ovary syndrome, recent clinical trials have confirmed the central role of clomiphene for ovulation induction in women with this disease. In addition, an expert panel has recommended that all women with polycystic ovary syndrome have a glucose tolerance test because of the high prevalence of impaired glucose tolerance in this population. In menopausal women the precise impact of estrogen therapy on cardiovascular biology remains to be delineated fully. Evolving data indicate that when initiated near the onset of menopause, estrogen therapy has fewer cardiovascular risks than when it is administered decades after the menopause.

CONCLUSIONS

The essence of reproduction is the successful transmission of germ-line DNA to a succeeding generation. Advances in genetics and endocrinology are converging to advance significantly our understanding of the biology of reproduction and our ability to influence reproductive processes. These advances will translate into new treatments for the prevalent medical problems of reproduction.

Body mass index in adolescence in relation to cause-specific mortality: a follow-up of 230,000 Norwegian adolescents

The prevalence of obesity in childhood and adolescence has increased worldwide. Long-term effects of adolescent obesity on cause-specific mortality are not well specified. The authors studied 227,000 adolescents (aged 14-19 years) measured (height and weight) in Norwegian health surveys in 1963-1975. During follow-up (8 million person-years), 9,650 deaths were observed. Cox proportional hazards regression was used to compare cause-specific mortality among individuals whose baseline body mass index (BMI) was below the 25th percentile, between the 75th and 84th percentiles, and above the 85th percentile in a US reference population with that of individuals whose BMI was between the 25th and 75th percentiles. Risk of death from endocrine, nutritional, and metabolic diseases and from circulatory system diseases was increased in the two highest BMI categories for both sexes. Relative risks of ischemic heart disease death were 2.9 (95% confidence interval (CI): 2.3, 3.6) for males and 3.7 (95% CI: 2.3, 5.7) for females in the highest BMI category compared with the reference. There was also an increased risk of death from colon cancer (males: 2.1, 95% CI: 1.1, 4.1; females: 2.0, 95% CI: 1.2, 3.5), respiratory system diseases (males: 2.7, 95% CI: 1.4, 5.2; females: 2.5, 95% CI: 1.4, 4.8), and sudden death (males: 2.2, 95% CI: 1.2, 4.3; females: 2.7, 95% CI: 1.1, 6.6). Adolescent obesity was related to increased mortality in middle age from several important causes.

Measuring blood pressure in children

In theory should be routine, but in practice is rare

Children and adolescents with obesity-associated high blood pressure

Hypertension and obesity are both common health problems in children and adolescents. More than 17% of children are obese and even more children are overweight. Hypertension, although defined differently in children than in adults, can be detected in 3% to 4% of children, and approximately 30% of obese adolescents have high blood pressure (BP) associated with obesity. Children with high BP and obesity frequently have other risk factors that are components of the metabolic syndrome. Evidence of target organ damage, including left ventricular hypertrophy, is detectable in many children with hypertension and is more commonly found in children with high BP and obesity. Both obesity and hypertension are considered inflammatory conditions. There are some emerging data in the young that show an association of insulin resistance, obesity, and high BP with inflammatory markers. Children and adolescents with hypertension and especially obesity-associated hypertension can be identified and should be evaluated for additional metabolic risk factors. Considering the heightened risk for premature cardiovascular (CV) disease, therapeutic interventions, including lifestyle changes and medications, when indicated, are important for all children and adolescents with obesity-associated hypertension.

Update on obesity

Endocrinologists have unique skills in evaluating and caring for patients with metabolic diseases. As such, they have a special role to play within the organizations in which they work as leaders in the approach to managing obese patients. Recent epidemiological data demonstrate that the prevalence of obesity is beginning to plateau. However, the rate of severe obesity in adults and the prevalence of overweight among children continue to grow, suggesting that in the future there will be an increasing burden of obesity-related illnesses. A number of recent studies have identified a number of novel mechanisms that predispose to obesity including several newly identified genes, the role of intestinal microflora, and even social networks. The selection of treatment for obese patients remains a complex issue. Recent studies demonstrate that a range of dietary approaches including the Atkins diet can provide modest weight loss, although the key feature appears to be adherence in the dietary strategy. High levels of physical activity appear to be necessary to maintain a reduced state, although modest increases in activity improve fitness. Although the new understanding of biology of weight regulation has provided a wide range of potential drug targets, available pharmacotherapy options remain limited although a number of potential targets show promise. Recent data provides the most enthusiasm for surgical treatment of obesity. Several recent studies demonstrate a reduction in mortality and dramatic benefits in diabetes in obese patients treated surgically. Questions remain as to the best surgical approach and the cost effectiveness. Research advances in obesity continue to move at a rapid pace and raise hopes for more effective management strategies in the future.

Determining origins and causes of childhood obesity via Mendelian randomization analysis

The authors discuss a new study that investigated the developmental overnutrition hypothesis in a large cohort of British pregnant mothers.

No evidence for association between BMI and 10 candidate genes at ages 4, 7 and 10 in a large UK sample of twins

BACKGROUND

Over the last decade, associations between Body Mass Index (BMI) and a variety of candidate genes have been reported, but samples have almost all been limited to adults. The purpose of the present study was to test the developmental origins of some of these associations in a large longitudinal sample of children.

METHODS

For 10 single-nucleotide polymorphisms (SNPs) in candidate genes reported to be associated with BMI in adults, we examined associations with BMI in a sample of 5000 children (2500 twin pairs) with BMI data at 4, 7 and 10 years. Association analyses were performed using the Quantitative Transmission Disequilibrium Test and we corrected for multiple testing using the False Discovery Rate.

RESULTS

Despite having 80% power to detect associations that account for as little as 0.2% of the variance of BMI, none of the 10 SNPs were significantly associated with BMI at any age, although two SNPs showed trends in the expected direction.

CONCLUSION

The lack of association for these ten previously reported associations, despite our large sample size, is typical of associations between candidate genes and complex traits. However, some of the reported SNP associations with BMI might emerge as we continue to follow the sample into adolescence and adulthood. This report highlights the importance of developmentally appropriate candidate genes.

Fiber intake, not dietary energy density, is associated with subsequent change in BMI z-score among sub-groups of children

OBJECTIVE

Results from short-term studies demonstrate that energy density influences energy intake, but in children and adolescents the long-term effects of energy density and obesity development are sparse. We examined the longitudinal relationship between dietary energy density, fiber intake, and body weight change over 3 years among Danish children.

METHODS

Multiple regression analyses were performed using anthropometric and dietary data of 398 boys and girls (8-10 years) who were enrolled in 1997/1998 and followed up in 2000/2001. Validated 24-hour recall interviews were conducted in order to collect dietary energy intake. Overweight was defined as 1.05 SD, equivalent to the 85th percentile, of age- and sex-specific BMI z-score reference values.

RESULTS

An inverse association between fiber intake and subsequent excess weight gain was observed among the normal weight boys. In overweight boys, there was a direct association with excess weight gain. A high energy intake was associated with a higher weight gain among overweight than among normal-weight boys. No significant association between dietary energy density and subsequent excess weight change was seen. The prevalence of overweight increased from 27.1 to 29.9%. Mean Deltaz-score was +0.1 and +0.4 for boys and girls, respectively.

CONCLUSION

Dietary energy density was not associated with 3-year weight gain in boys and girls. Only energy and fiber intakes were related to weight gain, but in different ways for subgroups of normal-weight and overweight boys.