Resemblance for body mass index in families of obese African American and European American women

Assortative mating for human height: A meta-analysis

OBJECTIVES

The study of assortative mating for height has a rich history in human biology. Although the positive correlation between the stature of spouses has often been noted in western populations, recent papers suggest that mating patterns for stature are not universal. The objective of this paper was to review the published evidence to examine the strength of and universality in assortative mating for height.

METHODS

We conducted an extensive literature review and meta-analysis. We started with published reviews but also searched through secondary databases. Our search led to 154 correlations of height between partners. We classified the populations as western and non-western based on geography. These correlations were then analyzed via meta-analytic techniques.

RESULTS

148 of the correlations for partner heights were positive and the overall analysis indicates moderate positive assortative mating (r = .23). Although assortative mating was slightly stronger in countries that can be described as western compared to non-western, this difference was not statistically significant. We found no evidence for a change in assortative mating for height over time. There was substantial residual heterogeneity in effect sizes and this heterogeneity was most pronounced in western countries.

CONCLUSIONS

Positive assortative mating for height exists in human populations, but is modest in magnitude suggesting that height is not a major factor in mate choice. Future research is necessary to understand the underlying causes of the large amount of heterogeneity observed in the degree of assortative mating across human populations, which may stem from a combination of methodological and ecological differences.

Body Mass Index, Self-Esteem, and Suicide Risk in Clinically Depressed African American and White American Females

Self-esteem and depression, as well as depression and body mass index (BMI), have consistently been found to be significantly associated for African American and White American females. The results are dissimilar when BMI and self-esteem are studied. Historically, the relationship between BMI and self-esteem is weak or nonexistent for African American females; however, for White American females, the relationship is usually significant. The goal of this study was to determine whether clinically depressed, healthy-weight, overweight, and obese females would differ significantly on self-esteem and suicide risk measures. In a voluntary hospital-based inpatient psychiatric unit, 165 clinically depressed females completed the self-esteem rating scale and the suicide risk scale. Healthy-weight, overweight, and obese African American females did not differ significantly on measures of self-esteem and suicide risk. However, depressed, obese White American females had significantly lower self-esteem and increased suicide risk than depressed healthy-weight and overweight White American females. Implications of the current results are discussed.

Obesity among Black Adolescent Girls: Genetic, Psychosocial, and Cultural Influences

This article focuses on the causes, consequences, and prevention of obesity among a subgroup of the American population, Black adolescent girls. Using an ecological perspective on obesity among Black adolescent girls, including feminist-womanist perspectives and historical and medical sociological perspectives, the authors discuss genetic, psychosocial, and cultural factors that may influence the propensity of Black adolescent girls’ susceptibility to obesity and to diabetes, one of the major complications of obesity. Prevention strategies, including individual and structural interventions, are illuminated.

Prevalence, associated factors and heritabilities of metabolic syndrome and its individual components in African Americans: the Jackson Heart Study

OBJECTIVE

Both environmental and genetic factors play important roles in the development of metabolic syndrome (MetS). Studies about its associated factors and genetic contribution in African Americans (AA) are sparse. Our aim was to report the prevalence, associated factors and heritability estimates of MetS and its components in AA men and women.

PARTICIPANTS AND SETTING

Data of this cross-sectional study come from a large community-based Jackson Heart Study (JHS). We analysed a total of 5227 participants, of whom 1636 from 281 families were part of a family study subset of JHS.

METHODS

Participants were classified as having MetS according to the Adult Treatment Panel III criteria. Multiple logistic regression analysis was performed to isolate independently associated factors of MetS (n=5227). Heritability was estimated from the family study subset using variance component methods (n=1636).

RESULTS

About 27% of men and 40% of women had MetS. For men, associated factors with having MetS were older age, lower physical activity, higher body mass index, and higher homocysteine and adiponectin levels (p<0.05 for all). For women, in addition to all these, lower education, current smoking and higher stress were also significant (p<0.05 for all). After adjusting for covariates, the heritability of MetS was 32% (p<0.001). Heritability ranged from 14 to 45% among its individual components. Relatively higher heritability was estimated for waist circumference (45%), high density lipoprotein-cholesterol (43%) and triglycerides (42%). Heritability of systolic blood pressure (BP), diastolic BP and fasting blood glucose was 16%, 15% and 14%, respectively.

CONCLUSIONS

Stress and low education were associated with having MetS in AA women, but not in men. Higher heritability estimates for lipids and waist circumference support the hypothesis of lipid metabolism playing a central role in the development of MetS and encourage additional efforts to identify the underlying susceptibility genes for this syndrome in AA.

Treating rural paediatric obesity through telemedicine vs. telephone: Outcomes from a cluster randomized controlled trial

OBJECTIVE

The objective of the current study was to examine the feasibility of telemedicine vs. telephone for the delivery of a multidisciplinary weekly family-based behavioural group intervention to treat paediatric obesity delivered to families living in rural areas using a randomized controlled trial methodology.

METHODS

103 rural children and their families were recruited. Feasibility measures included participant satisfaction, session attendance and retention. Treatment outcome measures included child Body Mass Index z-score (BMIz), parent BMI, 24-hour dietary recalls, accelerometer data, the child behavior checklist and the behavioral pediatrics feeding assessment scale.

RESULTS

Participants were highly satisfied with the intervention both via telemedicine and via telephone. Completion rates were much higher than for other paediatric obesity intervention programmes, and both methodologies were highly feasible. There were no differences in telemedicine and telephone groups on primary outcomes.

CONCLUSION

Both telemedicine and telephone intervention appear to be feasible and acceptable methods of delivering paediatric obesity treatment to rural children.

Parent-child resemblance in weight status and its correlates in the United States

Background

Few studies have examined parent-child resemblance in body weight status using nationally representative data for the US.

Design

We analyzed Body Mass Index (BMI), weight status, and related correlates for 4,846 boys, 4,725 girls, and their parents based on US nationally representative data from the 2006 and 2007 Medical Expenditure Panel Survey (MEPS). Pearson partial correlation coefficients, percent agreement, weighted kappa coefficients, and binary and multinomial logistic regression were used to examine parent-child resemblance, adjusted for complex sampling design.

Results

Pearson partial correlation coefficients between parent and child’s BMI measures were 0.15 for father-son pairs, 0.17 for father-daughter pairs, 0.20 for mother-son pairs, and 0.23 for mother-daughter pairs. The weighted kappa coefficients between BMI quintiles of parent and child ranged from −0.02 to 0.25. Odds ratio analyses found children were 2.1 (95% confidence interval (CI): 1.6, 2.8) times more likely to be obese if only their father was obese, 1.9 (95% CI: 1.5, 2.4) times more likely if only their mother was obese, and 3.2 (95% CI: 2.5, 4.2) times more likely if both parents were obese.

Conclusions

Parent-child resemblance in BMI appears weak and may vary across parent-child dyad types in the US population. However, parental obesity status is associated with children’s obesity status. Use of different measures of parent-child resemblance in body weight status can lead to different conclusions.

Sex-specific genetic architecture of human fatness in Chinese: the SAPPHIRe Study

To dissect the genetic architecture of sexual dimorphism in obesity-related traits, we evaluated the sex-genotype interaction, sex-specific heritability and genome-wide linkages for seven measurements related to obesity. A total of 1,365 non-diabetic Chinese subjects from the family study of the Stanford Asia-Pacific Program of Hypertension and Insulin Resistance were used to search for quantitative trait loci (QTLs) responsible for the obesity-related traits. Pleiotropy and co-incidence effects from the QTLs were also examined using the bivariate linkage approach. We found that sex-specific differences in heritability and the genotype-sex interaction effects were substantially significant for most of these traits. Several QTLs with strong linkage evidence were identified after incorporating genotype by sex (G × S) interactions into the linkage mapping, including one QTL for hip circumference [maximum LOD score (MLS) = 4.22, empirical p = 0.000033] and two QTLs: for BMI on chromosome 12q with MLS 3.37 (empirical p = 0.0043) and 3.10 (empirical p = 0.0054). Sex-specific analyses demonstrated that these linkage signals all resulted from females rather than males. Most of these QTLs for obesity-related traits replicated the findings in other ethnic groups. Bivariate linkage analyses showed several obesity traits were influenced by a common set of QTLs. All regions with linkage signals were observed in one gender, but not in the whole sample, suggesting the genetic architecture of obesity-related traits does differ by gender. These findings are useful for further identification of the liability genes for these phenotypes through candidate genes or genome-wide association analysis.

Transferability and fine-mapping of genome-wide associated loci for adult height across human populations

Human height is the prototypical polygenic quantitative trait. Recently, several genetic variants influencing adult height were identified, primarily in individuals of East Asian (Chinese Han or Korean) or European ancestry. Here, we examined 152 genetic variants representing 107 independent loci previously associated with adult height for transferability in a well-powered sample of 1,016 unrelated African Americans. When we tested just the reported variants originally identified as associated with adult height in individuals of East Asian or European ancestry, only 8.3% of these loci transferred (p-values≤0.05 under an additive genetic model with directionally consistent effects) to our African American sample. However, when we comprehensively evaluated all HapMap variants in linkage disequilibrium (r²≥0.3) with the reported variants, the transferability rate increased to 54.1%. The transferability rate was 70.8% for associations originally reported as genome-wide significant and 38.0% for associations originally reported as suggestive. An additional 23 loci were significantly associated but failed to transfer because of directionally inconsistent effects. Six loci were associated with adult height in all three groups. Using differences in linkage disequilibrium patterns between HapMap CEU or CHB reference data and our African American sample, we fine-mapped these six loci, improving both the localization and the annotation of these transferable associations.

The prevalence and factors associated with obesity among adult women in Selangor, Malaysia

INTRODUCTION

The prevalence of obesity in developing countries especially among women is on the rise. This matter should be taken seriously because it can burden the health care systems and lower the quality of life.

AIM

The purpose of this study was to determine the prevalence of obesity among adult women in Selangor and to determine factors associated with obesity among these women.

METHODS

This community based cross sectional study was conducted in Selangor in January 2004. Multi stage stratified proportionate to size sampling method was used. Women aged 20-59 years old were included in this study. Data was collected using a questionnaire-guided interview method. The questionnaire consisted of questions on socio-demographic (age, ethnicity, religion, education level, occupation, monthly income, marital status), Obstetric & Gynaecology history, body mass index (BMI), and the Patient Health Questionnaire (PHQ-9).

RESULTS

Out of 1032 women, 972 agreed to participate in this study, giving a response rate of 94.2%. The mean age was 37.91 +/- 10.91. The prevalence of obesity among the respondents was 16.7% (mean = 1.83 +/- 0.373). Obesity was found to be significantly associated with age (p = 0.013), ethnicity (p = 0.001), religion (p = 0.002), schooling (p = 0.020), educational level (p = 0.016), marital status (p = 0.001) and the history of suffering a miscarriage within the past 6 months (p = 0.023).

CONCLUSION

The prevalence of obesity among adult women in this study was high. This problem needs to be emphasized as the prevalence of obesity keeps increasing, and will continue to worsen unless appropriate preventive measures are taken.

Weight loss and health outcomes in African Americans and whites after gastric bypass surgery

OBJECTIVE

The objective was to describe differences in weight loss, dietary intake, and cardiovascular risk factors between white and African-American patients after gastric bypass (GBP).

RESEARCH METHODS AND PROCEDURES

This was a retrospective database review of a sample of 84 adult patients (24 African-American and 60 white women and men) between the ages of 33 and 53 years. All subjects had GBP surgery in 2001 at the Bariatric Surgery Program at Boston Medical Center in Boston, MA, and were followed for one year postoperatively. Patients were excluded if weight data were missing at baseline, 3 months, or 1 year after GBP. A total of 9 African Americans and 41 whites provided data at all 3 time-points and were included in the study. Differences in weight loss, diet, and cardiovascular risk factors were analyzed.

RESULTS

There were no differences in baseline characteristics between African Americans and whites. Mean weight loss for the entire sample was 36 +/- 9%, with a range of 8% to 54% relative to initial body weight. Whites lost more weight (39 +/- 8%) than African Americans (26 +/- 10%) (p < 0.05). Dietary parameters, as well as improvements in blood pressure and lipid profiles, were similar in the two racial groups.

DISCUSSION

Differences in weight loss between severely obese African Americans and whites undergoing open GBP are unlikely to be related to postoperative dietary practices. Our data are consistent with previous reports implicating metabolic differences between the two racial groups.

A comparison of weight histories in women with class III vs. class I-II obesity

OBJECTIVE

To describe the weight histories of women with extreme or class III obesity (BMI >or= 40 kg/m(2)) in comparison with a sample of women with class I-II obesity (BMI < 40 kg/m(2)) and to provide reliability data for a clinical instrument that assesses weight history.

RESEARCH METHODS AND PROCEDURES

Female patients (N = 149) with extreme obesity seeking bariatric surgery and 90 class I-II obese women seeking behavioral treatment completed the Weight and Lifestyle Inventory (WALI), a self-report instrument that assesses age of onset of obesity, maximum weight at different ages, family weight history, and weight changes related to pregnancy. Test-retest reliability data were obtained by administering the WALI to a subsample (n = 58) of class I-II obese participants at their initial visit and at another pretreatment visit 1 to 2 weeks later.

RESULTS

Patients with extreme obesity had a significantly younger age of onset of obesity, were significantly heavier at all age ranges, reported significantly more weight gain with their first pregnancy, and had significantly heavier parents and siblings as compared with less obese patients. There were no significant differences between groups with respect to weight gain during second pregnancies or postpartum weight retention. Robust test-retest correlations were obtained for the weight history items on the WALI.

DISCUSSION

Patients with extreme obesity report more indicators of a genetic predisposition to obesity as compared with less obese patients. The WALI appears to be a reliable instrument for the assessment of weight history in obese patients.

Loci contributing to adult height and body mass index in African American families ascertained for type 2 diabetes

Height and body mass index (BMI) have high heritability in most studies. High BMI and reduced height are well-recognized as important risk factors for a number of cardiovascular diseases. We investigated these phenotypes in African American families originally ascertained for studies of linkage with type 2 diabetes using self-reported height and weight. We conducted a genome wide scan in 221 families containing 580 individuals and 672 relative pairs of African American descent. Estimates of heritability and support for linkage were assessed by genetic variance component analyses using SOLAR software. The estimated heritabilities for height and BMI were 0.43 and 0.64, respectively. We have identified major loci contributing to variation in height on chromosomes 15 (LOD = 2.61 at 35 cM, p = 0.0004), 3 (LOD = 1.82 at 84 cM, p = 0.0029), 8 (LOD = 1.92 at 135 cM, p = 0.0024) and 17 (LOD = 1.70 at 110 cM, p = 0.0044). A broad region on chromosome 4 supported evidence of linkage to variation in BMI, with the highest LOD = 2.66 at 168 cM (p = 0.0005). Two height loci and two BMI loci appear to confirm the existence of quantitative trait loci previously identified by other studies, providing important replicative data to allow further resolution of linkage regions suitable for positional cloning of these cardiovascular disease risk loci.

Gender differences in associations of eating pathology between mothers and their adolescent offspring

OBJECTIVE

To study the association of eating pathology between mothers and their adolescent offspring in a population sample.

RESEARCH METHODS AND PROCEDURES

The participants were 481 women (mean age, 47+/-SD 5 years; BMI, 25+/-4 kg/m2) and their 481 adolescent children 16 to 17 years old (BMI, 21+/-3 kg/m2) of the Stockholm Weight Development Study. Assessment methods were the Three-Factor Eating Questionnaire Revised 18 and the Eating Disorder Inventory 2.

RESULTS

A higher body weight was most related to cognitive restraint for adolescents and to emotional eating for adult women. A mother-daughter link could be identified for eating pathology, with the strongest link found for emotional eating. No mother-son link could be identified. Age subgroup analyses revealed a stronger mother-daughter link for body attitudes in younger mothers and for cognitive restraint in older mothers.

DISCUSSION

Gender differences revealed that eating pathology was shared by mothers and daughters but not by mothers and sons. A psychological strategy such as eating as a response to negative emotions was most interrelated between mothers and daughters. Younger mothers shared more attitudes toward the body with their daughters, whereas older mothers shared more restrictive eating behaviors with their daughters. The mother-daughter links found may be due to gender-specific genetic and psychological family transmission and gender-specific environmental influences. The sons' eating behaviors seem to be more independent and would be formed by other factors than for the girls.

An obesity-related locus in chromosome region 12q23-24

Obesity is a growing health problem in the U.S. As a complex trait, obesity involves multiple genes and gene-gene and gene-environment interactions that contribute to its pathogenesis. Here we report significant linkage from a scan of a large sample segregating extreme obesity and normal weight. We have used 382 microsatellite markers in 1,297 individuals from 260 European-American families. We conducted nonparametric linkage (NPL) analyses for dichotomous BMI (using BMI >/=27, >/=30, >/=35, and >/=40 kg/m(2)) using Genehunter. We also analyzed quantitative traits (BMI, percentage of fat, and waist circumference) by the family regression method using Merlin_regress. We found evidence for linkage on chromosome 12 (125 cM, D12S2070, logarithm of odds [LOD] 3.79, P = 0.00001 for percentage of fat; LOD 2.98, P = 0.0001 for BMI; and LOD 2.86, P = 0.00014 for waist circumference) by family regression analyses. Adding three additional markers to the intervals flanking the chromosome 12 peak yielded an LOD score of 4.08 (P = 0.00001) for percentage of fat at 116 cM and LOD scores of 3.57 (P = 0.00003) and 3.05 (P = 0.00009) for BMI and waist circumference, respectively, at 125 cM. We also obtained other suggestive linkages on chromosomes 2, 3, 7, 8, 9, 12, 13, and 21. Our results suggest multiple loci that could influence obesity, particularly a locus in chromosome region 12q23-24.

Interacting genetic loci on chromosomes 20 and 10 influence extreme human obesity

Obesity is a multigenic trait that has a substantial genetic component. Animal models confirm a role for gene-gene interactions, and human studies suggest that as much as one-third of the heritable variance may be due to nonadditive gene effects. To evaluate potential epistatic interactions among five regions, on chromosomes 7, 10, and 20, that have previously been linked to obesity phenotypes, we conducted pairwise correlation analyses based on alleles shared identical by descent (IBD) for independent obese affected sibling pairs (ASPs), and we determined family-specific nonparametric linkage (NPL) scores in 244 families. The correlation analyses were also conducted separately, by race, through use of race-specific allele frequencies. Conditional analyses for a qualitative trait (body mass index [BMI] >/=27) and hierarchical models for quantitative traits were used to further refine evidence of gene interaction. Both the ASP-specific IBD-sharing probability and the family-specific NPL score revealed that there were strong positive correlations between 10q (88-97 cM) and 20q (65-83 cM), through single-point and multipoint analyses with three obesity thresholds (BMI >/=27, >/=30, and >/=35) across African American and European American samples. Conditional analyses for BMI >/=27 found that the LOD score at 20q rises from 1.53 in the baseline analysis to 2.80 (empirical P=.012) when families were weighted by evidence for linkage at 10q (D10S1646) through use of zero-one weights (weight(0-1)) and to 3.32 (empirical P<.001) when proportional weights (weight(prop)) were used. For percentage fat mass, variance-component analysis based on a two-locus epistatic model yielded significant evidence for interaction between 20q (75 cM) and the chromosome 10 centromere (LOD = 1.74; P=.024), compared with a two-locus additive model (LOD = 0.90). The results from multiple methods and correlated phenotypes are consistent in suggesting that epistatic interactions between loci in these regions play a role in extreme human obesity.

Genetic and environmental influences on body-fat measures among African-American twins

OBJECTIVE

To investigate the genetic and environmental influences on body-fat measures including waist circumference (WC), waist-to-hip ratio (WHR), and body mass index (BMI) among African-American men and women.

RESEARCH METHODS AND PROCEDURES

Measurements were taken as part of the Carolina African American Twin Study of Aging. This sample currently comprises 146 same-sex African-American twins with an average age of 50 years (range, 22 to 88 years). This analysis included 26 monozygotic and 29 dizygotic men and 45 monozygotic and 46 dizygotic women. Maximum likelihood quantitative genetic analysis was used.

RESULTS

In men, additive genetic effects accounted for 77% of the variance in WC, 59% in WHR, and 89% in BMI. In women, additive genetic effects accounted for 76% of the variance in WC, 56% in WHR, and 73% in BMI. The remaining variance in both men and women was attributed to unique environmental effects (WC, 21%; WHR, 36%; BMI, 11% in men and WC, 22%; WHR, 38%; BMI, 27% in women) and age (WC, 2%; WHR, 5% in men and WC, 2%; WHR, 6% in women). When BMI was controlled in the analysis of WC and WHR, it accounted for a portion of the genetic and environmental variance in WHR and over one-half of the genetic and environmental variance in WC.

DISCUSSION

There are both genetic and environmental influences on WC, WHR, and BMI, and independent of BMI, there are genetic and environmental effects on WC and WHR among both genders. The results from this African-American twin sample are similar to findings among white twin samples.