Calcium and Dairy Intake and Measures of Obesity in Hyper‐ and Normocholesterolemic Children

Objective: Calcium intake has been inversely associated with body weight and body fatness in adults and, to a lesser extent, in children. Dairy intake has been inversely associated with metabolic syndrome in overweight but not normal‐weight adults. We assessed whether intakes of calcium and dairy foods were associated with measures of obesity in hypercholesterolemic (HC) and normocholesterolemic (non‐HC) children at baseline and over 1 year. Research Methods and Procedures: Non‐obese 4‐ to 10‐year‐old HC and non‐HC children (342) completed three 24‐hour dietary recalls and provided measures of relative weight (BMI and BMI z scores) and adiposity (sum of skinfolds, trunk skinfolds) at baseline, 3, 6, and 12 months. Cross‐sectional and longitudinal regression analyses, stratified by cholesterol risk status (HC vs. non‐HC) and age (4 to 6 years and 7 to 10 years) and adjusted for potential confounders, were conducted. Results: After adjusting for age, sex, energy intake, and percentage energy from fat, calcium intake was inversely associated with BMI, sum of skinfolds, and trunk skinfolds at baseline and over 1 year in the 7‐ to 10‐year‐old non‐HC children. Results from the regression models also indicated an inverse relation between intake of dairy foods and measures of obesity at baseline in these children. Calcium or dairy intake was not associated with measures of obesity in HC children or in the 4‐ to 6‐year‐old non‐HC children. Discussion: These results suggest a complex relation among intake of calcium and dairy foods, measures of obesity, age, and serum cholesterol in children. Older children without risk of metabolic syndrome may benefit most from increased calcium intake.     

Evaluation of the Influence of Cardiorespiratory Fitness on Diverse Health Risk Factors,Independent of Waist Circumference,in 40‐Year‐Old Flemish Males

Objective: To examine whether cardiorespiratory fitness is associated with health risk factors, independent of abdominal obesity (waist circumference). Research Methods and Procedures: Data from 141 40‐year‐old Flemish male subjects were used in a cross‐sectional design. The main outcome measure in this study was the health risk profile, composed of lipid parameters, blood pressure, and body composition parameters. Data were analyzed by regression analysis and by means of analysis of covariance with waist circumference (WC) as covariate and cardiorespiratory fitness as source of variance. Results: The data demonstrated that cardiorespiratory fitness was significantly associated with triglycerides, with the ratio of total cholesterol/serum high density lipoprotein cholesterol, and with percent body fat, independent of an association with WC. Discussion: Major findings of the present cross‐sectional study indicate that a high WC is associated with adverse health‐related lipid profile and body composition characteristics and that relatively high levels of aerobic fitness attenuate the health risk associated with a large WC.     

Adiposity, physical activity, and physical fitness among children from Aragón, Spain

Objective: The main purpose of this study was to determine the relationship between physical activity (PA) levels and adiposity. The secondary purpose was to assess the effect of physical fitness and living area on adiposity. Research Methods and Procedures: A cross‐sectional study was carried out in a regional representative sample of 1068 children 7 to 12 years of age. Anthropometric and physical fitness values (including BMI, aerobic capacity, strength levels, velocity assessment, and flexibility) were measured in all children. Results: The prevalence of being overweight and obese in the entire sample was 31% and 6%, respectively. No difference between urban and rural children was found. The proportion of boys who were classified as overweight and obese was similar in physically active and sedentary (non‐physically active) groups. However, physically active girls tended to show lower obesity prevalence compared with their sedentary counterparts (p = 0.06). In girls, the sum of the 6 skinfolds thickness (SSF) measurements was lower in the physically active group when compared with the non‐physically active group (p < 0.05); however, this effect was not observed in boys. Multiple regression analysis revealed that the level of physical activity (PA) had a significant effect on BMI and SSF in boys but not in girls, while maximal oxygen uptake (Vo _2max) was significantly related to adiposity in both sexes. Discussion: Regular participation in at least 2 hours per week of sports activities on top of the compulsory education program is associated with better physical fitness and lower whole body adiposity. In the children included in our study, among all physical fitness variables, Vo _2max showed the strongest relationship with BMI and fat mass assessed by means of skinfold measurements.     

Adiposity,blood pressure,and carotid intima‐media thickness in greek adolescents

Objective:

In children and adolescents with cardiovascular risk factors, the assessment of subclinical target‐organ damage is of paramount importance. This study investigated factors associated with carotid intima‐media thickness (cIMT) in adolescents.

Design and Methods:

A cross‐sectional study was performed in 448 apparently healthy adolescents recruited from schools (mean age 14 ± 2.2 years, 211 boys), which involved cIMT measurements (common carotid artery) and assessment of lipid profile, glucose, and blood pressure (BP).

Results:

The prevalence of overweight/obesity was 28.1%/12.7% and of BP ≥95th percentile 19.6%. Left cIMT was correlated with age (r = 0.10), waist circumference (WC) (0.15), and BP (0.21/0.13, systolic/diastolic) (all P < 0.05). Right cIMT was correlated with waist to hip ratio (WHR) (0.10), whereas the mean of left and right cIMT was correlated with WC (0.12), WHR (0.12), and systolic BP (0.14) (all P < 0.05). After the age of 13 years, boys tended to have higher cIMT than girls, which was significant in the 13‐15 years subgroup (P < 0.05). In stepwise multivariate analysis (independent variables: age, gender, WC, WHR, body mass index z‐score, lipid parameters, glucose, BP), left cIMT was independently associated with systolic BP; right cIMT with WHR; mean left and right cIMT with WC. Adolescents with BP ≥90th percentile had higher left cIMT than those <90th percentile (0.63 ± 0.09 vs. 0.61 ± 0.09 mm respectively, P < 0.05).

Conclusion:

Central adiposity and systolic BP appear to be independently associated with increased cIMT values in apparently healthy adolescents. Left side cIMT appears to be superior to right side measurements in terms of association with cardiovascular risk factors.     

Independent Associations Between Cardiorespiratory Fitness and Abdominal Obesity With Metabolic Risk in Adolescents and Adults

Our objective was to examine the independent association between abdominal obesity (waist circumference (WC)) and cardiorespiratory fitness (CRF) with metabolic syndrome (MetS) in 2,197 adults (ages 20–49 years) and 3,223 adolescents (ages 12–19 years). Individuals were stratified by CRF and WC using sex‐ and age‐specific MetS criteria for adolescents and adults. Adolescents had a lower prevalence rate of MetS (5.4% vs. 12.8%) and high WC (15.5% vs. 35.7%), but a higher prevalence rate of low CRF (37.6% vs. 15.9%) than adults. As compared to adolescents and adults with low WC, those with a high WC (odds ratio (OR) = 5.5–16.5, P < 0.001) were more likely to have a clustering of MetS factors than those with low WC (OR = 1.2–3.8, P = 0.3 to <0.001), regardless of fitness level. Conversely, the beneficial effects of having moderate/high CRF on MetS were only observed in individuals with low WC, and not high WC. Thus, in conclusion, both high WC and low CRF are associated with increased odds of MetS in adolescents and adults. However, increased abdominal obesity is more strongly associated with MetS in adolescents and adults.     

Waist circumference and BMI cut-off based on 10-year cardiovascular risk: evidence for "central pre-obesity"

Objective: The objective was to assess the waist circumference (WC) cut‐off point that best identifies a level of 10‐year cardiovascular disease (CVD) risk with optimal balance of sensitivity and specificity in Chinese subjects according to their predicted 10‐year CVD risk. Research Methods and Procedures: A community‐based cross‐sectional observational study involving 14,919 Hong Kong Chinese subjects. The 10‐year CVD risk based on various prediction models was calculated. The projected WC cut‐off points were then determined. Results: There were 4837 (32.4%) men and 10,082 (67.6%) women (mean age ± standard deviation, 47.3 ± 13.5 years; age range, 18 to 93 years; median age, 45.0 years). The mean optimal WC or BMI predicting a 15% to 30% 10‐year CVD risk were 83 to 88 cm and 25 kg/m² for men, and 76 cm and 23 kg/m² for women, respectively. With WC ≥90 cm in men and ≥80 cm in women, the likelihood ratio at various WC cut‐off points to develop a ≥20% 10‐year CVD risk is 1.5 to 2.0 in men and 3.0 in women. The likelihood ratio was 1.5 in men with WC at 84 cm and in women at 70 cm. Discussion: Our results agree with the present guidelines on the definition of general and central obesity in Asia‐Pacific regions. We propose the creation of an intermediate state of high WC, the “central pre‐obesity” for Chinese men with WC ≥84 to 90 cm (≥33 to 36 inches) and women with WC ≥74 to 80 cm (≥29 to 32 inches). People with central pre‐obesity, similar to those with overweight (BMI ≥23 to 25 kg/m²), already have an increased risk of co‐morbidities.     

Ethnic Differences in Subcutaneous Adiposity and Waist Girth in Children and Adolescents

The purpose of this study was to examine ethnic differences in adiposity as measured by sum of skinfolds (SKF) and waist circumference (WC) in children and adolescents, after statistical adjustment for the BMI and age. A cross sectional sample of 3,218 (55% white, 49% male) children and adolescents aged 5–18 years who participated in the Bogalusa Heart Study (1992–1994) were included in these analyses. Sex‐specific ANOVAs, adjusted for BMI and age, for each 2‐year age group compared measures of adiposity (SKF and WC) between ethnic groups. No significant differences in the proportions of children and adolescents who were overweight and obese by ethnicity or sex were found. Mean SKF in normal weight (P < 0.0001) and overweight (P < 0.0001) categories was higher for white than black children of both sexes. Across most age categories, white boys and girls had significantly higher SKF than black boys and girls, respectively (P ≤ 0.05). Across most age categories, white boys had significantly higher WC than black boys (P ≤ 0.05) with no difference in the girls, when adjusted for BMI and age. Measures of adiposity in childhood and adolescence were significantly higher in white children compared to black children, when adjusted for BMI and age. Throughout childhood and adolescence, white boys and girls had higher SKF and white boys had higher WC. Differences in adiposity between ethnic groups should be considered in disease risk assessment and stratification as they are observed even for a given BMI level.     

Interaction of FTO and physical activity level on adiposity in African-American and European-American adults: the ARIC study

Physical inactivity accentuates the association of variants in the FTO locus with obesity‐related traits but evidence is largely lacking in non‐European populations. Here we tested the hypothesis that physical activity (PA) modifies the association of the FTO single‐nucleotide polymorphism (SNP) rs9939609 with adiposity traits in 2,656 African Americans (AA) (1,626 women and 1,030 men) and 9,867 European Americans (EA) (5,286 women and 4,581 men) aged 45–66 years in the Atherosclerosis Risk in Communities (ARIC) study. Individuals in the lowest quintile of the sport activity index of the Baecke questionnaire were categorized as low PA. Baseline BMI, waist circumference (WC), and skinfold measures were dependent variables in regression models testing the additive effect of the SNP, low PA, and their interaction, adjusting for age, alcohol use, cigarette use, educational attainment, and percent European ancestry in AA adults, stratified by sex and race/ethnicity. rs9939609 was associated with adiposity in all groups other than AA women. The SNP × PA interaction was significant in AA men (P ≤ 0.002 for all traits) and EA men (P ≤ 0.04 for all traits). For each additional copy of the A (risk) allele, WC in AA men was higher in those with low PA (β_lowPA: 5.1 cm, 95% confidence interval (CI): 2.6–7.5) than high PA (β_highPA: 0.7 cm, 95% CI: ?0.4 to 1.9); P (interaction) = 0.002). The interaction effect was not observed in EA or AA women. FTO SNP × PA interactions on adiposity were observed for AA as well as EA men. Differences by sex require further examination.     

Ethnicity,Insurance Type,and Follow‐up in a Pediatric Weight Management Program

Objective: To assess the characteristics of children and adolescents who drop out of a clinical weight management program. Research Methods and Procedures: A retrospective survey of children and adolescents attending a pediatric weight management program [n = 518; mean ± SEM: age 10.4 ± 0.2 years, BMI z‐score 4.9 ± 0.1, 62% female, 41% African American and 57% white] was undertaken. Characteristics of children (age, relative weight, gender, and ethnicity) who dropped out of the program were compared with characteristics of those who continued beyond the initial assessment as a function of type of insurance. Results: The children who dropped out of the program after the initial assessment differed by ethnicity from those who continued in the program: 63% of white children returned for more than one visit, whereas only 35% of the African‐American children continued in the program. Indemnity insurance coverage was associated with more clinic visits, as compared with managed care insurance. The association between insurance type and clinic visit number was of borderline significance (p = 0.06), when ethnic group was added to this analysis. Discussion: Ethnicity is associated with attendance in a Pediatric Weight Management Program. Given the epidemic of obesity in children and adolescents, issues related to program compliance must be assessed to improve overall outcome. This is especially important given the high rate of obesity among African Americans and the low rate of ongoing attendance observed among African Americans in the Weight Management Program.     

The growth of children in relation to the timing of obesity development

Objective: To examine whether there is an association between the timing of the development of obesity and children's growth. Research Methods and Procedures: This study investigated 141 prepubertal obese children (76 girls) and 72 healthy non‐obese children (39 girls). The target height standard deviation score (SDS), the percentage weight for height, and the height SDS (H‐SDS) at presentation and at the age of 2 years were calculated. Patients were classified, according to whether obesity developed before or after the age of 3 years, as presenting with early‐onset or late‐onset obesity, respectively. Results: Mean age (±SD) at presentation was 9.4 (2.1) years. At the age of 2 years, the H‐SDS of the children with early‐onset obesity was 1.3 (1.0) vs. 0.9 (1.3) for the late‐onset obese (p > 0.5) and 0.4 (1.0) for controls (p < 0.001), and the children with late‐onset obesity were also significantly taller than controls (p < 0.005). At presentation, children with early‐onset obesity were significantly taller than children with late‐onset obesity [1.1 (0.8) vs. 0.6 (1.0); p < 0.001] and controls [0.2 (0.8); p < 0.001]. There was no increase in H‐SDS after the age of 2 years in the late‐onset obese children (p > 0.05). H‐SDS values were below average in 21% of the children with late‐onset obesity and in only 4% of the children with early‐onset obesity. Discussion: These findings indicate that late development of obesity is not associated with increased stature in prepubertal children; however, it may be preceded by growth acceleration in the early years of life. Growth acceleration in early life may be a predictor for future obesity.     

Serum 25‐Hydroxyvitamin D Concentration,Life Factors and Obesity in Mexican Children

Although current evidence emphasizes a high prevalence of vitamin D deficiency and an inverse association between serum 25‐hydroxyvitamin D (25‐OHD) concentration and obesity, no studies have been conducted in Mexican children. The objective was to determine the prevalence of vitamin D deficiency and its association with obesity and lifestyle factors in a sample of school‐aged Mexican children. A cross‐sectional study of 99 obese and 99 nonobese 6–12 year‐old children, skin phototypes III–V, from six public schools was conducted during summer at latitude 25°40′, in northeastern Mexico. Anthropometric measurements were determined. Serum 25‐OHD was measured by immunoluminometric direct assay. Consumption of foods rich in vitamin D, sunscreen use and vitamin consumption were assessed through applied questionnaires. 62.1% of the subjects had insufficiency of 25‐OHD (21–29 ng/ml) and 20.2% had deficiency (<20 ng/ml). Obese subjects (BMI ≥95th percentile for age and gender) had significantly lower concentration of 25‐OHD than nonobese. Predictors of 25‐OHD concentration were, in order of significance: percentage of body fat, BMI, triceps skin fold, and waist circumference (WC). A significantly higher rate of 25‐OHD deficiency was observed in children with inadequate milk/yoghurt consumption, but no difference was found for other foods, physical activity (PA) or screen‐time. In a multivariate model, being obese was significantly associated with the risk of 25‐OHD deficiency, after adjustment for PA, screen‐time, skin phototype, ingestion of milk/yoghurt, fish, cheese, and carbonated beverages. A high prevalence of vitamin D deficiency and an inverse association between serum 25‐OHD concentration and obesity was found.     

Waist Circumference,BMI, and Visceral Adipose Tissue in White Women and Women of African Descent

Although waist circumference (WC) is a marker of visceral adipose tissue (VAT), WC cut‐points are based on BMI category. We compared WC‐BMI and WC‐VAT relationships in blacks and whites. Combining data from five studies, BMI and WC were measured in 1,409 premenopausal women (148 white South Africans, 607 African‐Americans, 186 black South Africans, 445 West Africans, 23 black Africans living in United States). In three of five studies, participants had VAT measured by computerized tomography (n = 456). Compared to whites, blacks had higher BMI (29.6 ± 7.6 (mean ± s.d.) vs. 27.6 ± 6.6 kg/m², P = 0.001), similar WC (92 ± 16 vs. 90 ± 15 cm, P = 0.27) and lower VAT (64 ± 42 vs. 101 ± 59 cm², P < 0.001). The WC‐BMI relationship did not differ by race (blacks: β (s.e.) WC = 0.42 (.01), whites: β (s.e.) WC = 0.40 (0.01), P = 0.73). The WC‐VAT relationship was different in blacks and whites (blacks: β (s.e.) WC = 1.38 (0.11), whites: β (s.e.) WC = 3.18 (0.21), P < 0.001). Whites had a greater increase in VAT per unit increase in WC. WC‐BMI and WC‐VAT relationships did not differ among black populations. As WC‐BMI relationship did not differ by race, the same BMI‐based WC guidelines may be appropriate for black and white women. However, if WC is defined by VAT, race‐specific WC thresholds are required.     

Common PCSK1 Haplotypes Are Associated With Obesity in the Chinese Population

Prohormone convertase subtilisin/kexin type 1 (PCSK1) genetic polymorphisms have recently been associated with obesity in European populations. This study aimed to examine whether common PCSK1 genetic variation is associated with obesity and related metabolic phenotypes in the Chinese population. We genotyped nine common tag single‐nucleotide polymorphisms (tagSNP) of the PCSK1 gene in 1,094 subjects of Chinese origin from the Stanford Asia‐Pacific Program for Hypertension and Insulin Resistance (SAPPHIRe) family study. One SNP in the PCSK1 gene (rs155971) were nominally associated with risk of obesity in the SAPPHIRe cohort (P = 0.01). A common protective haplotype was associated with reduced risk of obesity (23.79% vs. 32.89%, P = 0.01) and smaller waist circumference (81.71 ± 10.22 vs. 84.75 ± 10.48 cm, P = 0.02). Another common haplotype was significantly associated with increased risk of obesity (37.07% vs. 23.84%, P = 0.005). The global P value for haplotype association with obesity was 0.02. We also identified a suggestive association of another PCSK1 SNP (rs3811951) with fasting glucose, fasting insulin, homeostasis model assessment of insulin resistance (HOMA_IR), triglycerides, and high‐density lipoprotein cholesterol (P = 0.05, 0.003, 0.001, 0.04, and 0.04, respectively). These data indicate common PCSK1 genetic variants are associated with obesity in the Chinese population.     

Ten months of exercise improves general and visceral adiposity, bone, and fitness in black girls

Objective: The goal of this study was to evaluate the impact of a 10‐month after‐school physical activity (PA) program on body composition and cardiovascular (CV) fitness in young black girls. Research Methods and Procedures: Subjects were 8‐ to 12‐year‐olds recruited from elementary schools. Body composition was measured using anthropometrics {waist circumference and BMI, DXA [percentage body fat (%BF)] and bone mineral density (BMD)}, and magnetic resonance imaging [visceral adipose tissue (VAT)]. CV fitness was measured using a graded treadmill test. The intervention consisted of 30 minutes homework/healthy snack time and 80 minutes PA (i.e., 25 minutes skills instruction, 35 minutes aerobic PA, and 20 minutes strengthening/stretching). Analyses were adjusted for age, baseline value of the dependent variable, and sexual maturation (pediatrician observation). Results: Mean attendance was 54%. Compared with the control group, the intervention group had a relative decrease in %BF (p < 0.0001), BMI (p < 0.01), and VAT (p < 0.01) and a relative increase in BMD (p < 0.0001) and CV fitness (p < 0.05). Higher attendance was associated with greater increases in BMD (p < 0.05) and greater decreases in %BF (p < 0.01) and BMI (p < 0.05). Higher heart rate during PA was associated with greater increases in BMD (p < 0.05) and greater decreases in %BF (p < 0.005). Discussion: An after‐school PA program can lead to beneficial changes in body composition and CV fitness in young black girls. It is noteworthy that the control and intervention groups differed in change in VAT but not waist circumference. This suggests that changes in central adiposity can occur in response to PA, even in young children, but that waist circumference may not be a good indicator of central adiposity.     

Prostaglandin Endoperoxide H Synthase-2 (PGHS-2) Variants and Risk of Obesity and Microvascular Dysfunction Among Tunisians: Relevance of rs5277 (306G/C) and rs5275 (8473T/C) Genetic Markers

The purpose of this study was to determine the impact of six PGHS-2 genetic variants on obesity development and microvascular dysfunction. The study included 305 Tunisian subjects (186 normal weights, 35 overweights and 84 obeses). PCR analyses were used for allelic discrimination between polymorphisms. Prostaglandin (PGE2, PGI2), leptin, and matrix metalloproteinase (MMP1, 2, 3, 9) levels were evaluated by ELISA. Fatty acid composition was performed by gas chromatography–mass spectrometry. Our results revealed that subjects carrying the PGHS-2 306CC (rs5277) and 8473CC (rs5275) genotypes present higher anthropometric values compared to wild-type genotypes (306GG, BMI (Kg/m²): 27.11?±?0.58; WC (cm): 93.09?±?1.58; 306CC, BMI: 33.83?±?2.46; WC: 109.93?±?5.41; 8473TT, BMI: 27.75?±?0.68; WC: 93.96?±?1.75; 8473CC, BMI: 33.72?±?2.2; WC: 117.89?±?2.94). A reduced microvascular reactivity and a higher PGE2 level were also found in individuals with the 306CC and 8473CC genotypes in comparison to 306GG and 8473TT carriers (306GG, Peak Ach-CVC (PU/mmHg): 0.46?±?0.03; PGE2 (pg/ml): 7933.1?±?702; 306CC, Peak Ach-CVC: 0.24?±?0.01; PGE2: 13,380.3?±?966.2; 8473TT, Peak Ach-CVC: 0.48?±?0.05; PGE2: 7086.41?±?700.31; 8473CC, Peak Ach-CVC: 0.23?±?0.01; PGE2: 13,175.7?±?1165.8). Fatty acid analysis showed a significant increase of palmitic acid (PA) (34.2?±?2.09 vs. 16.82%?±?1.76, P?<?0.001), stearic acid (SA) (25.76?±?3.29 vs. 9.05%?±?2.53, P?<?0.001), and linoleic acid (LA) (5.25?±?1.18 vs. 0.5%?±?0.09, P?<?0.001) levels in individuals carrying the PGHS-2 306CC genotype when compared to GG genotype individuals. Subjects with the 8473CC genotype showed also a significant increase of PA, SA ,and LA levels when compared to TT genotype carriers (PA: 38.02?±?1.51 vs. 12.65%?±?1.54, P?<?0.001; SA: 32.96?±?1.87 vs. 1.38%?±?0.56, P?<?0.001; LA: 26.84?±?2.09 vs. 3.7%?±?1.54, P?<?0.001). Logistic regression analysis revealed that PGHS-2 306CC and 8473CC variants are significantly associated with obesity status (OR 6.25, CI (1.8–21.6), P?=?0.004; OR 3.01, CI (1.13–8.52), P?=?0.03, respectively). Haplotypes containing the C₃₀₆:T₈₄₇₃ (OR 2.91; P?=?0.01) and G_306:C₈₄₇₃ (OR 5.25; P?=?0.002) combinations were associated with an enhanced risk for obesity development in the studied population. In conclusion, our results highlight that PGHS-2 306G/C and 8473T/C variants could be useful indicators of obesity development, inflammation, and microvascular dysfunction among Tunisians.

     

Paradoxical protective effect of central obesity in patients with suspected stable coronary artery disease

Objective:

Increased body mass index (BMI) has been paradoxically inversely associated with the presence of angiographic coronary artery disease (CAD). Central obesity measures, considered to be more appropriate for assessing obesity‐related cardiovascular risk, have been little studied in relation to the presence of CAD. The aim was to investigate the association of central obesity with the presence of angiographic CAD as well as the prognostic significance of obesity measures in CAD prediction when added to other cardiovascular risk factors.

Design and Methods:

Patients with suspected stable CAD (n = 403, age 61 ± 10 years, 302 males) referred for diagnostic coronary angiography with documented anthropometric data were enrolled.

Results:

Significant angiographic CAD was found in 51% of patients. Both BMI (OR = 0.64 per 1 SD increase, P = 0.001) and waist circumference (WC) (OR = 0.54 per 1 SD increase, P < 0.001) were inversely associated with the presence of CAD even after adjustment for cardiovascular risk factors. In subgroup analysis, BMI and WC were significantly inversely associated with the presence of CAD in males, non diabetics, patients >60 years old and patients with Framingham risk score (FRS) >20% (P < 0.01 for all). The addition of BMI or WC in FRS‐based regression models improved prediction of CAD (P = 0.03 and P < 0.001 for BMI and WC respectively) without a significant difference between the two models (P = 0.08).

Conclusions:

Central and overall obesity were independently associated with a reduced prevalence of angiographic CAD, lending further credence to the existence of the ‘obesity paradox’. Obesity measures may further improve risk discrimination for the presence of CAD when added in an established risk score such as FRS.     

Diurnal salivary cortisol is associated with body mass index and waist circumference: The multiethnic study of atherosclerosis

Objective:

Neuroendocrine abnormalities, such as activation of the hypothalamic‐pituitary‐adrenal (HPA) axis, are associated with obesity; however, few large‐scale population‐based studies have examined HPA axis and markers of obesity. We examined the cross‐sectional association of the cortisol awakening response (CAR) and diurnal salivary cortisol curve with obesity.

Design and Methods:

The Multiethnic Study of Atherosclerosis Stress Study includes 1,002 White, Hispanic, and Black men and women (mean age 65 ± 9.8 years) who collected up to 18 salivary cortisol samples over 3 days. Cortisol profiles were modeled using regression spline models that incorporated random parameters for subject‐specific effects. Cortisol curve measures included awakening cortisol, CAR (awakening to 30‐min postawakening), early decline (30 min to 2‐h postawakening), late decline (2‐h postawakening to bedtime), and the corresponding areas under the curve (AUC). Body mass index (BMI) and waist circumference (WC) were used to estimate adiposity.

Results:

For the entire cohort, both BMI and WC were negatively correlated with awakening cortisol (P < 0.05), AUC during awakening rise, and early decline and positively correlated to the early decline slope (P < 0.05) after adjustments for age, race/ethnicity, gender, diabetes status, socioeconomic status, β‐blockers, steroids, hormone replacement therapy, and smoking status. No heterogeneities of effects were observed by gender, age, and race/ethnicity.

Conclusions:

Higher BMI and WC are associated with neuroendocrine dysregulation, which is present in a large population sample, and only partially explained by other covariates.     

Autonomic Nervous System Activity and the State and Development of Obesity in Japanese School Children

Objective: The autonomic nervous system (ANS) plays an important role in regulating energy expenditure and body fat content; however, the extent to which the ANS contributes to pediatric obesity remains inconclusive. The aim of this study was to evaluate whether sympathetic and/or the parasympathetic nerve activities were altered in an obese pediatric population. We further examined a physiological association between the duration of obesity and the sympatho‐vagal activities to scrutinize the nature of ANS alteration as a possible etiologic factor of childhood obesity. Research Methods and Procedures: Forty‐two obese and 42 non‐obese healthy sedentary school children were carefully selected from 1080 participants initially recruited to this study. The two groups were matched in age, gender, and height. The clinical records of physical characteristics and development of the obese children were retrospectively reviewed to investigate the onset and progression of obesity. The ANS activities were assessed during a resting condition by means of heart rate variability power spectral analysis, which enables us to identify separate frequency components, i.e., total power (TP), low‐frequency (LF) power, and high‐frequency (HF) power. The spectral powers were then logarithmically transformed for statistical testing. Results: The obese children demonstrated a significantly lower TP (6.77 ± 0.12 vs. 7.11 ± 0.04 ln ms², p < 0.05), LF power (6.16 ± 0.12 vs. 6.42 ± 0.05 ln ms², p < 0.05), and HF power (5.84 ± 0.15 vs. 6.34 ± 0.07 ln ms², p < 0.01) compared with the non‐obese children. A partial correlation analysis revealed that the LF and HF powers among 42 obese children were negatively associated with the duration of obesity independent of age (LF: partial r = ?0.55, p < 0.001; HF: partial r = ?0.40, p < 0.01). The obese children were further subdivided into two groups based on the length of their obesity. All three spectral powers were significantly reduced in the obese group with obesity of >3 years (n = 18) compared to the group with obesity of <3 years. Discussion: Our data indicate that obese children possess reduced sympathetic as well as parasympathetic nerve activities. Such autonomic depression, which is associated with the duration of obesity, could be a physiological factor promoting the state and development of obesity. These findings further imply that preventing and treating obesity beginning in the childhood years could be an urgent and crucial pediatric public health issue.     

First nationwide survey of prevalence of overweight, underweight, and abdominal obesity in Iranian adults

Objective: The goal was to estimate the prevalence of overweight, obesity, underweight, and abdominal obesity among the adult population of Iran. Research Methods and Procedures: A nationwide cross‐sectional survey was conducted from December 2004 to February 2005. The selection was conducted by stratified probability cluster sampling through household family members in Iran. Weight, height, and waist circumference (WC) of 89,404 men and women 15 to 65 years of age (mean, 39.2 years) were measured. The criteria for underweight, normal‐weight, overweight, and Class I, II, and III obesity were BMI <18.5, 18.5 to 24.9, 25 to 29.9, 30 to 34.9, 35 to 39.9, and ≥40 (kg/m²), respectively. Abdominal obesity was defined as WC ≥102 cm in men and ≥88 cm in women. Results: The age‐adjusted means for BMI and WC were 24.6 kg/m² in men and 26.5 kg/m² in women and 86.6 cm in men and 89.6 cm in women, respectively. The age‐adjusted prevalence of overweight or obesity (BMI ≥25) was 42.8% in men and 57.0% in women; 11.1% of men and 25.2% of women were obese (BMI ≥30), while 6.3% of men and 5.2% of women were underweight. Age, low physical activity, low educational attainment, marriage, and residence in urban areas were strongly associated with obesity. Abdominal obesity was more common among women than men (54.5% vs. 12.9%) and greater with older age. Discussion: Excess body weight appears to be common in Iran. More women than men present with overweight and abdominal obesity. Prevention and treatment strategies are urgently needed to address the health burden of obesity.