RESUMO
The association between polymorphisms in the beta1, beta2 and alpha2B adrenergic receptor (ADR) genes (ADRB1, ADRB2 and ADRA2B) and resting heart rate was examined in white and African-American participants of the HyperGEN Study. All analyses were adjusted for age, sex, body mass index, alcohol use, smoking status and daily exercise within strata of race, hypertension status and beta-blocker use. The Ser49Gly polymorphism of the beta1 ADR was associated with resting heart rate in hypertensive African-Americans and hypertensive whites taking beta-blockers, with carriers of the Gly allele having a higher mean resting heart rate by 2.7 and 4.4 beats per minute (bpm), respectively. The Arg389Gly polymorphism of the beta1 ADR was associated with lower heart rate in the normotensive African-American sample. A beta1 haplotype (Ser49Gly-Arg389Gly) was modestly associated with resting heart rate in the hypertensive African-Americans. The alpha2B C/A polymorphism was associated with heart rate in hypertensive whites, and both whites and African-Americans taking beta-blockers, with carriers of the A allele having a higher mean resting heart rate. In summary, each of the ADR gene polymorphisms was associated with heart rate in at least one stratum studied, but there was no consistent association from which one would infer a large genetic contribution to heart rate.
Assuntos
Frequência Cardíaca/genética , Polimorfismo Genético/genética , Receptores Adrenérgicos/genética , Antagonistas Adrenérgicos beta/farmacologia , Adulto , Negro ou Afro-Americano , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão/epidemiologia , Hipertensão/etnologia , Hipertensão/genética , Masculino , População BrancaRESUMO
OBJECTIVE: To conduct a full genome search for genes potentially influencing two related phenotypes: body mass index (BMI, kg/m2) and percent body fat (PBF) from bioelectric impedance in men and women. DESIGN: A total of 3383 participants, 1348 men and 2035 women; recruitment was initiated with hypertensive sibpairs and expanded to first-degree relatives in a multicenter study of hypertension genetics. MEASUREMENTS: Genotypes for 387 highly polymorphic markers spaced to provide a 10 cM map (CHLC-8) were generated by the NHLBI Mammalian Genotyping Service (Marshfield, WI, USA). Quantitative trait loci for obesity phenotypes, BMI and PBF, were examined with a variance components method using SOLAR, adjusting for hypertensive status, ethnicity, center, age, age2, sex, and age2 x sex. As we detected a significant genotype-by-sex interaction in initial models and because of the importance of sex effects in the expression of these phenotypes, models thereafter were stratified by sex. No genotype-by-ethnicity interactions were found. RESULTS: A QTL influencing PBF in women was detected on chromosome12q (12q24.3-12q24.32, maximum empirical LOD score=3.8); a QTL influencing this phenotype in men was found on chromosome 15q (15q25.3, maximum empirical LOD score=3.0). These QTLs were detected in African-American and white women (12q) and men (15q). QTLs influencing both BMI and PBF were found over a broad region on chromosome 3 in men. QTLs on chromosomes 3 and 12 were found in the combined sample of men and women, but with weaker significance. CONCLUSION: The locations with highest LOD scores have been previously reported for obesity phenotypes, indicating that at least two genomic regions influence obesity-related traits. Furthermore, our results indicate the importance of considering context-dependent effects in the search for obesity QTLs.
Assuntos
Negro ou Afro-Americano , Composição Corporal/genética , Obesidade/genética , Locos de Características Quantitativas , Fatores Sexuais , População Branca , Adulto , Idoso , Índice de Massa Corporal , Cromossomos Humanos Par 12 , Cromossomos Humanos Par 15 , Cromossomos Humanos Par 3 , Feminino , Humanos , Hipertensão/etnologia , Hipertensão/genética , Hipertensão/fisiopatologia , Escore Lod , Masculino , Pessoa de Meia-Idade , Obesidade/etnologia , Obesidade/fisiopatologiaRESUMO
Linkage of body mass index (BMI) to a broad region of chromosome 7q22-35 has been reported in multiple studies. We previously published a multipoint LOD score of 4.9 at D7S1804 for BMI from the National Heart, Lung, and Blood Institute Family Heart Study. Leptin (LEP), the human homolog of the mouse obesity (ob) gene, is positioned near the linkage peak and is the most prominent candidate gene in this region. Interest in LEP as a susceptibility gene for human obesity has led to numerous linkage and association studies, but the results of these studies are still controversial. In the present study, we employed family-based tests of association with both a quantitative measure of BMI adjusted for age and sex and a dichotomously defined obesity trait. We genotyped 29 single-nucleotide polymorphisms (SNPs) spanning 240 kb around the LEP gene in the 82 extended pedigrees with the strongest evidence for linkage. When the programs TRANSMIT and FBAT were used, a number of SNPs showed association in men but not women, for both the quantitative and qualitative trait definitions (P<.05). Five SNPs (H1328084, H1328083, H1328082, H1328081, and H1328080) positioned 2 kb beyond the previously defined promoter region showed strong association in single-marker and multiple-marker haplotype analysis. This five-marker haplotype (frequency 49% in this sample) is overtransmitted to obese offspring (P=.00005). All five of these SNPs are predicted to modify transcription-factor binding sites. This may indicate new functional variants in an extended promoter region of LEP.
Assuntos
Índice de Massa Corporal , Leptina/genética , Marcadores Genéticos , Genótipo , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , FenótipoRESUMO
BACKGROUND: It is unclear whether the increased risk of colon cancer associated with obesity differs for men and women, by distribution of body fat, or by location of the tumor. The primary goal of this study was to address these questions. METHODS: Eligible subjects from the Framingham Study cohort were classified according to body mass index (BMI) and waist size during two age periods: 30-54 y (n=3764) and 55-79 y (n=3802). All eligible men and women were cancer-free at baseline and had complete information on the following potential confounders: age, sex, education, height, activity, smoking, and alcohol. There were 157 incident lifetime cases of colon cancer among those followed beginning at 30-54 y of age and 149 lifetime cases among those whose follow up began at 55-79 y. Subjects were stratified further by gender, activity, and tumor location. The Cox Proportional Hazards Models were used to adjust for possible confounding by the above-described factors. RESULTS: A BMI >/=30 led to a 50% increased risk (95% CI: 0.92-2.5) of colon cancer among middle-aged (30-54 y) and a 2.4-fold increased risk (95% CI: 1.5-3.9) among older (55-79 y) adults. The BMI effect was stronger for men than for women and for cases occurring in the proximal colon. These adverse effects generally diminished when waist was added to the multivariable models. A larger waist size (>/=99.1 cm (39 in) and 101.6 cm (40 in) for women and men, respectively) was associated with a two-fold increased risk of colon cancer; this risk increased linearly with increasing waist size and was evident for both proximal and distal colon cancer. There was no attenuation of these effects when BMI was added to the multivariable models. A larger waist had a particularly adverse effect among sedentary subjects (relative risk (RR)=4.4 for middle-aged adults; RR=3.0 for older adults). CONCLUSION: These findings suggest that waist circumference is a stronger predictor of colon cancer risk than is BMI, and that central obesity is responsible for an increased risk of cancer of both the proximal and distal colon.
Assuntos
Constituição Corporal , Índice de Massa Corporal , Neoplasias do Colo/etiologia , Obesidade/complicações , Adulto , Idoso , Neoplasias do Colo/epidemiologia , Neoplasias do Colo/patologia , Exercício Físico , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Modelos de Riscos Proporcionais , Fatores de Risco , Estados Unidos/epidemiologiaRESUMO
Cardiovascular reactivity is hypothesized to increase the risk of hypertension and other CVD-related conditions. However, studies to date are inconclusive. We compared the association of blood pressure and pulse responses to three stressors (postural challenge, handgrip test, mental arithmetic) with sociodemographic characteristics and CVD risk factors. We included 782 participants from the Hypertension Genetic Epidemiology Study. Blood pressure and pulse responses to stressors were defined as the difference between post- and pre-stress measurements. Stepwise regression analyses examined change in SBP and pulse in response to stressors as a function of sociodemographic and CVD risk factors. Age, race, and gender were forced into models and other variables (education, BMI, waist circumference, resting SBP and DBP, cigarette smoking, LDL and HDL cholesterol, glucose, and antihypertensive medications (beta-blockers, calcium channel blockers, diuretics, ace inhibitors)) were retained if P<0.10. Age was a significant predictor of SBP response to all stressors. The SBP response to a change in posture was not related to other variables. The SBP response to mental arithmetic was significantly higher among men, those with larger waists, higher SBP, beta-blocker users, and lower among smokers. SBP response to the handgrip was significantly higher among those with higher SBP and beta-blocker users. Similarly, the association of the pulse response to the risk factors varied considerably across the stressors. Overall, the socio-demographic and CVD risk factors accounted for between 9 and 14% of the variance in the SBP response to the stressors and from between 4 and 12% of the variance in the pulse response to the three stressors. The associations between sociodemographic and CVD risk factors and the SBP and pulse response to stress were modest and inconsistent across stressors. The findings suggest that cardiovascular reactivity is a concept that needs to be defined in reference to specific stressors so that mechanisms leading to responses can be better understood.
Assuntos
Pressão Sanguínea , Doenças Cardiovasculares/etiologia , Força da Mão , Hipertensão/fisiopatologia , Postura , Pulso Arterial , Estresse Fisiológico/fisiopatologia , Estresse Psicológico/fisiopatologia , Adulto , Idoso , Envelhecimento , Demografia , Feminino , Humanos , Hipertensão/complicações , Hipertensão/etnologia , Modelos Lineares , Masculino , Matemática , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , Estresse Psicológico/complicações , Estresse Psicológico/etnologia , População BrancaAssuntos
Doença das Coronárias/genética , Doença das Coronárias/psicologia , Genômica , Hostilidade , Escore Lod , Proteínas de Membrana Transportadoras , Proteínas de Transporte/genética , Feminino , Humanos , Masculino , Glicoproteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Proteínas da Membrana Plasmática de Transporte de SerotoninaRESUMO
OBJECTIVE: To prospectively examine the relation between television watching and body fat change in children from preschool to early adolescence. METHODS: In a longitudinal study, 106 children were enrolled during preschool years (mean age 4.0 y) and followed into early adolescence (mean age 11.1 y). Parents completed an annual questionnaire on the child's television and video habits. Body mass index (BMI), triceps skinfolds, and sum of five skinfolds were recorded yearly at annual clinic visits. Longitudinal statistical analyses were carried out using mixed modeling procedures to control for potential confounding by a number of factors. RESULTS: Television watching was an independent predictor of the change in the child's BMI, triceps, and sum of five skinfolds throughout childhood. Its effect was only slightly attenuated by controlling for the baseline body fat, level of physical activity (as measured repeatedly by Caltrac accelerometer), percent of calories from fat, total calorie intake, or the parents' BMI or education. By age 11, children who watched 3.0 h or more of television per day had a mean sum of skinfolds of 106.2 mm, compared with a mean sum of skinfolds of 76.5 mm for those who watched less than 1.75 h per day (P=0.007). Furthermore, the adverse effect of television viewing was worse for those children who were also sedentary or had a higher-fat diet. CONCLUSIONS: Children who watched the most television during childhood had the greatest increase in body fat over time. Healthy lifestyle education designed to prevent obesity and its consequences should target television-watching habits of children.
Assuntos
Obesidade/etiologia , Televisão , Adolescente , Fatores Etários , Índice de Massa Corporal , Criança , Pré-Escolar , Exercício Físico , Humanos , Estilo de Vida , Aptidão Física , Estudos ProspectivosRESUMO
BACKGROUND: Epidemiologic studies suggest that a higher consumption of eicosapentaenoic acid and docosahexaenoic acid is associated with a reduced risk of cardiovascular disease. Studies in humans and animals also reported an inverse association between alpha-linolenic acid and cardiovascular disease morbidity and mortality. OBJECTIVE: We examined the relation between dietary linolenic acid and prevalent coronary artery disease (CAD). DESIGN: We studied 4584 participants with a mean (+/-SD) age of 52.1 +/- 13.7 y in the National Heart, Lung, and Blood Institute Family Heart Study in a cross-sectional design. Participants' diets were assessed with a semiquantitative food-frequency questionnaire. For each sex, we created age- and energy-adjusted quintiles of linolenic acid, and we used logistic regression to estimate prevalent odds ratios for CAD. RESULTS: From the lowest to the highest quintile of linolenic acid, the prevalence odds ratios of CAD were 1.0, 0.77, 0.61, 0.58, and 0.60 for the men (P for trend = 0.012) and 1.0, 0.57, 0.52, 0.30, and 0.42 for the women (P for trend = 0.014) after adjustment for age, linoleic acid, and anthropometric, lifestyle, and metabolic factors. Linoleic acid was also inversely related to the prevalence odds ratios of CAD in the multivariate model (0.60 and 0.61 in the second and third tertiles, respectively) after adjustment for linolenic acid. The combined effect of linoleic and linolenic acids was stronger than the individual effects of either fatty acid. CONCLUSIONS: A higher intake of either linolenic or linoleic acid was inversely related to the prevalence odds ratio of CAD. The 2 fatty acids had synergistic effects on the prevalence odds ratio of CAD.
Assuntos
Doença da Artéria Coronariana/epidemiologia , Ácido Linoleico/administração & dosagem , Ácido alfa-Linolênico/administração & dosagem , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/prevenção & controle , Estudos Transversais , Sinergismo Farmacológico , Feminino , Humanos , Ácido Linoleico/uso terapêutico , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Análise de Regressão , Fatores de Risco , Inquéritos e Questionários , Estados Unidos/epidemiologia , Ácido alfa-Linolênico/uso terapêuticoRESUMO
There are lingering questions regarding the relation between alcohol consumption and breast cancer risk in women. The authors performed a meta-analysis of epidemiologic studies carried out through 1999 to examine the dose-response relation and to assess whether effect estimates differed according to various study characteristics. Overall, there was a monotonic increase in the relative risk of breast cancer with alcohol consumption, but the magnitude of the effect was small; in comparison with nondrinkers, women averaging 12 g/day of alcohol consumption (approximately one typical drink) had a relative risk of 1.10 (95% confidence interval (CI): 1.06, 1.14). Estimates of relative risk were 7% greater in hospital-based case-control studies than in cohort studies or community-based case-control studies, 3% greater in studies published before 1990 than in studies published later, and 5% greater in studies conducted outside of the United States than in US studies. The findings of five US cohort studies published since 1990 yielded a relative risk of 1.06 (95% CI: 1.00, 1.11) for consumers of 12 g/day, as compared with nondrinkers. Cohort studies with less than 10 years of follow-up gave estimates 11% higher than cohort studies with longer follow-up periods. No meaningful difference was seen by menopausal status or type of beverage consumed.
Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Neoplasias da Mama/etiologia , Neoplasias da Mama/epidemiologia , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Seguimentos , Humanos , Fatores de RiscoRESUMO
Previous studies have examined the relation of endogenous estrogen levels or estrogen replacement therapy to the risk of poor cognitive function, but results have been inconclusive. Bone mineral density has been proposed as a marker for cumulative estrogen exposure. The authors studied the relation of bone mineral density to the prevalence of verbal memory impairment among 4,304 elderly subjects in the Third National Health and Nutrition Examination Survey (1988-1994). Bone mineral density was measured in five regions of the proximal femur with dual-energy x-ray absorptiometry. Verbal memory was assessed using delayed recall of a three-item word list and a six-item story. Verbal memory impairment was defined as a combined score of <4. The prevalence of verbal memory impairment for each increasing bone mineral density quintile at the femoral neck was 8.35, 5.74, 5.22, 5.00, and 3.38% in women and 11.54, 7.27, 8.47, 6.29, and 5.89% in men, respectively. With adjustment for age, sex, and other covariates, the prevalence ratios of verbal memory impairment for each increased bone mineral density quintile were 1.00, 0.64, 0.65, 0.55, and 0.44, respectively (p for trend < 0.001). These results suggest that bone mineral density in the elderly is associated with verbal memory impairment. The mechanisms underlying this relation are not understood, but cumulative exposure to estrogen may play a role.
Assuntos
Densidade Óssea/efeitos dos fármacos , Transtornos Cognitivos/epidemiologia , Inquéritos Epidemiológicos , Transtornos da Memória/epidemiologia , Avaliação Nutricional , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Cognição/efeitos dos fármacos , Transtornos Cognitivos/complicações , Transtornos Cognitivos/diagnóstico por imagem , Estudos Transversais , Estrogênios/farmacologia , Feminino , Fêmur/diagnóstico por imagem , Humanos , Masculino , Memória/efeitos dos fármacos , Transtornos da Memória/complicações , Transtornos da Memória/diagnóstico por imagem , Pessoa de Meia-Idade , PrevalênciaRESUMO
BACKGROUND: Moderate alcohol consumers have lower rates of cardiovascular disease than abstainers. One proposed mechanism is a beneficial effect on hemostatic parameters, but previous studies have provided conflicting results. METHODS AND RESULTS: We measured levels of fibrinogen, plasma viscosity, von Willebrand factor, factor VII, plasminogen activator inhibitor antigen-1, and tissue plasminogen activator antigen in a cross-sectional analysis of 3223 adults free of cardiovascular disease enrolled in the Framingham Offspring Study. We assessed their alcohol consumption with a standardized questionnaire. Light-to-moderate alcohol consumption was associated with lower levels of fibrinogen, plasma viscosity, von Willebrand factor, and factor VII. This association was most pronounced for consumers of 3 to 7 drinks weekly for viscosity and 7 to 21 drinks weekly for the other hemostatic measures. Alcohol intake of 7 to 21 drinks weekly or more was associated with impaired fibrinolytic potential, reflected by higher levels of plasminogen activator inhibitor antigen-1 and tissue plasminogen activator antigen. Wine drinkers had lower plasminogen activator inhibitor antigen-1 levels than other drinkers, particularly at 3 to 21 drinks weekly, but beverage type did not otherwise consistently affect the results. CONCLUSIONS: Light-to-moderate alcohol consumption is associated with lower levels of coagulatory factors, but higher intake is associated with impaired fibrinolytic potential. These findings are consistent with the hypothesis that a balance between hemostatic and fibrinolytic activity may contribute to the complex relation of alcohol use with coronary heart disease.
Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/metabolismo , Hemostasia/fisiologia , Bebidas Alcoólicas/classificação , Viscosidade Sanguínea/fisiologia , Estudos de Coortes , Estudos Transversais , Demografia , Fator VII/análise , Feminino , Fibrinogênio/análise , Fibrinólise/fisiologia , Humanos , Masculino , Massachusetts/epidemiologia , Pessoa de Meia-Idade , Inibidor 1 de Ativador de Plasminogênio/sangue , Inquéritos e Questionários , Ativador de Plasminogênio Tecidual/sangue , Fator de von Willebrand/análiseAssuntos
Consumo de Bebidas Alcoólicas/legislação & jurisprudência , Vinho/estatística & dados numéricos , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/psicologia , American Heart Association , Consultores , Doença das Coronárias/etiologia , Ética Médica , Política de Saúde , Humanos , Estados Unidos , Vinho/efeitos adversosAssuntos
Bilirrubina/sangue , Doenças Cardiovasculares/sangue , Adulto , Doenças Cardiovasculares/genética , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Análise Multivariada , Infarto do Miocárdio/sangue , Infarto do Miocárdio/genética , Modelos de Riscos Proporcionais , Fatores de RiscoRESUMO
Although postmenopausal estrogen use has been associated with a lower risk of colon cancer in women, some studies do not confirm such findings. No known study has examined the effect of cumulative estrogen exposure on colon cancer risk. Bone mass has been proposed as a marker of cumulative exposure to endogenous and exogenous estrogens. By using data on 1,394 Massachusetts women in the Framingham Study who underwent hand radiography in 1967-1970, the authors examined the association between bone mass (from relative areas of the second metacarpal) and colon cancer incidence. Over 27 years of follow-up, 44 incident colon cancer cases occurred. Colon cancer incidence decreased from 2.19 per 1,000 person-years among the women in the lowest age-specific tertile of bone mass to 1.59 and 1.08 among women in the middle and the highest tertiles, respectively. After adjustment for age and other potential confounding factors, the rate ratios of colon cancer were 1.0, 0.7 (95% confidence interval: 0.3, 1.3), and 0.4 (95% confidence interval: 0.2, 0.9) from the lowest to the highest tertile (p for trend = 0.033). No association was found between bone mass and rectal cancer. The findings suggest that women with higher bone mass, perhaps reflecting greater cumulative estrogen exposure, have a decreased risk of colon cancer.
Assuntos
Densidade Óssea , Neoplasias do Colo/epidemiologia , Estrogênios , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Incidência , Estudos Longitudinais , Massachusetts/epidemiologia , Pessoa de Meia-Idade , Pós-MenopausaRESUMO
The validity of the recent Global Burden of Disease Study (GBDS) was compromised by the lack of adult mortality data in developing countries, particularly in Sub-Saharan Africa. Verbal autopsies, in which health workers (HW), using questionnaires and algorithms, interview surviving family members to determine the cause of death, have proven useful in establishing priorities for the allocation of limited health care resources. Most reports, however, have come from large population centers. The feasibility of using health workers trained in verbal autopsy methodology to operate in remote rural areas of Africa has had limited testing. The records of 40 villagers who died in a Mission Hospital of the Northwest Province of Cameroon were reviewed, and the hospital discharge diagnosis, made by the attending physician, compared with that obtained by HW who administered a verbal autopsy to the family. In 70% of the cases the physician and HW were in exact agreement. Such a method, if confirmed in other studies among rural populations, may be an important approach to determining cause of death in many developing countries.
Assuntos
Causas de Morte , Comunicação , Serviços de Saúde Rural , Camarões/epidemiologia , Estudos de Viabilidade , Feminino , Humanos , Entrevistas como Assunto , Masculino , Mortalidade , Inquéritos e Questionários , Comportamento VerbalRESUMO
This cross-sectional study investigates the association of hostility and social support (measured by standardized instruments) to carotid artery atherosclerosis in men and women with a high familial risk for coronary heart disease (CHD) and those with low to medium risk. The hypothesis was that high hostility and low social support would have a stronger association in subjects with a familial predisposition to CHD. There were 535 low- to medium-risk women, 491 low- to medium-risk men, 1,950 high-risk women, and 1,667 high-risk men in the study. The extent of carotid artery atherosclerosis was assessed by B-mode ultrasound imaging. A lesion was defined as an intimal-medial far wall thickness of 1 mm in the common, internal, or carotid bifurcation, or identification of plaque at any site. Odds ratios and their 95% confidence intervals were calculated using generalized estimating equations (GEE) for logistic regression. Family was specified as the clustering variable, and robust SEEs were obtained that account for dependence of the data within families. After controlling for age, education, body mass index, ever having smoked, ever drinking > 5 drinks a day, and metabolic index, hostility was significantly associated with increased odds of carotid lesions in only high-risk women. High-risk women showed a significantly reduced odds of carotid lesions with high social support, but the extent of this protection was reduced when age and education were included in the equation. A combination of high hostility and low social support was associated with higher odds than hostility alone in both high-risk men and women. These results suggest that women with a high familial predisposition for CHD may be more vulnerable to cardiovascular influences from hostility and social support than high-risk men or men and women with low to medium risk.
Assuntos
Arteriosclerose/genética , Arteriosclerose/psicologia , Doenças das Artérias Carótidas/genética , Doenças das Artérias Carótidas/psicologia , Predisposição Genética para Doença/genética , Hostilidade , Apoio Social , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Arteriosclerose/diagnóstico por imagem , Arteriosclerose/epidemiologia , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/epidemiologia , Análise por Conglomerados , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , Índice de Gravidade de Doença , Caracteres Sexuais , Distribuição por Sexo , Fatores Sexuais , Ultrassonografia , Estados Unidos/epidemiologiaRESUMO
OBJECTIVE: To investigate the extent to which parents' degree of dietary self-control, as measured by self-reported dietary restraint, disinhibition, and perceived hunger, affects the development of excess body fat in the child. DESIGN: Prospective observational study. SUBJECTS: Ninety-two 3-5y old children and their parents, enrolled in 1987 in the Framingham Children's Study. MEASUREMENTS: Self-reported levels of parental dietary restraint, disinhibition and perceived hunger were estimated using Stunkard and Messick's Three-Factor-Eating Questionnaire. Anthropometric measurements (height, weight and skinfold measurements at five sites) were obtained yearly for children and parents. The child's activity level was measured on multiple days each year using Caltrac accelerometers. Energy intake and percentage of calories from total fat were estimated from multiple sets of food diaries, collected each year. All analyses were adjusted for the following potential confounders: child's sex and baseline values for age, height, mean physical activity level, total calories and percentage of calories from fat as well as the educational levels of the parents at baseline. RESULTS: Over 6y, children's body fat increased linearly with increasing levels of self-reported parental disinhibition (eg 6y increase in the child's sum of five skinfolds was 34.4, 45.8 and 59.2 mm across increasing tertiles of parental disinhibition, P=0.012). Overall, children whose parents had higher dietary restraint scores had greater increases in body fatness than children whose parents had the lowest levels of restraint. When both parents had above average scores on dietary disinhibition or restraint, the children had greater increases in body fat (on all anthropometry measures) than when only one parent or when neither parent had high scores on those factors. Parental scores on the perceived hunger scale had no clear effect on body fat change of children. Since disinhibition and dietary restraint frequently co-exist, we then examined the joint effect of these two factors. The children with the greatest increases in body fat were those whose parents scored high on both factors. In the final analysis, we found that dietary restraint adversely affected the child's body fat only when associated with high parental disinhibition. CONCLUSION: This study suggests that parents who display high levels of disinhibited eating, especially when coupled with high dietary restraint, may foster the development of excess body fat in their children. This association may be mediated by direct parental role modeling of unhealthy eating behaviors, or through other indirect, and probably subconscious, behavioral consequences such as the suppression of the child's innate regulation of dietary intake.
Assuntos
Atitude , Ingestão de Alimentos/psicologia , Obesidade/prevenção & controle , Relações Pais-Filho , Poder Familiar , Antropometria , Peso Corporal , Criança , Pré-Escolar , Ingestão de Energia , Exercício Físico , Comportamento Alimentar , Feminino , Humanos , Estudos Longitudinais , Masculino , Obesidade/etiologia , Estudos Prospectivos , Inquéritos e QuestionáriosRESUMO
Apolipoprotein E allele 4 (apo epsilon4) and smoking each have been associated with an unfavorable lipid profile. We used data collected on 1,472 subjects in the National Heart, Lung, and Blood Institute Family Heart Study to assess whether smoking interacts with apo epsilon4 to influence the levels of plasma lipids. We dichotomized smoking and apo epsilon4 and used analysis of covariance to estimate the means of lipids. Smokers had lower body mass index, were younger, and consumed less fruits and vegetables. Among individuals without apo epsilon4, comparing nonsmokers with smokers, mean low density lipoprotein cholesterol (LDL) was 129.3 and 134.4 mg/dL, respectively, for women and 126.1 and 127.6 mg/dL, respectively, for men. Among subjects with an apo epsilon4 allele, corresponding means were 132.0, and 152.9 mg/dL, respectively, for women and 131.3 and 137.3 mg/dL, respectively, for men (Pfor interaction <0.001 for women and 0.11 for men). A similar interaction was observed for total cholesterol among women (P = 0.02). This study shows a statistically significant effect modification of the relation of apo epsilon4 to LDL and total cholesterol by smoking among women. Smoking may enhance genetic susceptibility to an unfavorable lipid profile among subjects with apo epsilon4.
Assuntos
Apolipoproteínas E/sangue , Lipídeos/sangue , Fumar , Adulto , Fatores Etários , Idoso , Alelos , Análise de Variância , Apolipoproteína E4 , Índice de Massa Corporal , Saúde da Família , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Menopausa , Pessoa de Meia-Idade , Análise Multivariada , National Institutes of Health (U.S.) , Fumar/efeitos adversos , Estados UnidosRESUMO
Mildly elevated plasma total homocysteine (tHcy) levels have been associated with increased risk of coronary heart disease (CHD). Carotid artery intimal-medial wall thickening is a predictor of cardiovascular disease and has been previously shown to be positively associated with plasma tHcy in studies of asymptomatic subjects. In the current study we examined 1467 subjects with regard to their fasting plasma tHcy levels and intimal-medial wall thickness as measured by B-mode ultrasound and early onset CHD. The results showed that there is a significant positive association between plasma tHcy levels and carotid-artery wall thickness in participants 55 years or older even after the tHcy levels are adjusted for age, smoking and anti-hypertensive medication. The direction and magnitude of the relationship is similar although the result was not statistically significant in younger participants ( < 55 years). Early onset CHD at any age was not significantly different across the tHcy quintiles. The lack of an association of tHcy and CHD in the presence of a positive association with intimal-medial wall thickening may be a reflection of increased statistical power of quantitative versus qualitative traits. We conclude that the present finding of a positive association between tHcy and intimal-medial wall thickness strengthens the in vitro finding of the stimulating effect of homocysteine on vascular smooth muscle cell growth. Vascular smooth muscle cell proliferation may be an important mechanism through which mildly elevated plasma tHcy promotes atherosclerosis.
Assuntos
Artérias Carótidas/diagnóstico por imagem , Doença das Coronárias/sangue , Doença das Coronárias/diagnóstico por imagem , Homocisteína/sangue , Túnica Íntima/diagnóstico por imagem , Túnica Média/diagnóstico por imagem , Idoso , Doença das Coronárias/genética , Jejum/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , UltrassonografiaRESUMO
PURPOSE: Hypertension is a common precursor of serious disorders including stroke, myocardial infarction, congestive heart failure, and renal failure in whites and to a greater extent in African Americans. Large genetic-epidemiological studies of hypertension are needed to gain information that will improve future methods for diagnosis, treatment, and prevention of hypertension, a major contributor to cardiovascular morbidity and mortality. METHODS: We report successful implementation of a new structure of research collaboration involving four NHLBI "Networks," coordinated under the Family Blood Pressure Program. The Hypertension Genetic Epidemiology Network (HyperGEN) involves scientists from six universities and the NHLBI who seek to identify and characterize genes promoting hypertension. Blood samples and clinical data were projected to be collected from a sample of 2244 hypertensive siblings diagnosed before age 60 from 960 sibships (half African-American) with two or more affected persons. Nonparametric sibship linkage analysis of over one million genotype determinations (20 candidate loci and 387 anonymous marker loci) was projected to have sufficient power for detecting genetic loci promoting hypertension. For loci showing evidence for linkage in this study and for loci reported linked or associated with hypertension by other groups, genotypes are compared in hypertensive cases versus population-based controls to identify or confirm genetic variants associated with hypertension. For some of these genetic variants associated with hypertension, detailed physiological and biochemical characterization of untreated adult offspring carriers versus non-carriers may help elucidate the pathophysiological mechanisms that promote hypertension. RESULTS: The projected sample size of 2244 hypertensive participants was surpassed, as 2407 hypertensive individuals (1262 African-Americans and 1145 whites) from 917 sibships were examined. Detailed consent forms were designed to offer participants several options for DNA testing; 94% of participants gave permission for DNA testing now or in the future for any confidential medical research, with only 6% requesting restrictions for tests performed on their DNA. Since this is a family study, participants also are asked to list all first degree relatives (along with names, addresses, and phone numbers) and to indicate for each relative whether they were willing to allow study staff to make a contact. Seventy percent gave permission to contact some relatives; about 30% gave permission to contact all first degree relatives; and less than 1% asked that no relatives be contacted. Successes after the first four years of this study include: 1) productive collaboration of eight centers from six different locations; 2) early achievement of recruitment goals for study participants including African-Americans; 3) an encouraging rate of consent for DNA testing (including future testing) and relative contacting; 4) completed analyses of genetic linkage and association for several candidate gene markers and polymorphisms; 5) completed genotyping of random markers for over half of the full sample; and 6) early sharing of results among the four Family Blood Pressure Program networks for candidate and genome search analyses. CONCLUSIONS: Experience after four years of this five-year program (1995-2000) suggests that the newly initiated NHLBI Network Program mechanism is fulfilling many of the expectations for which it was designed. It may serve as a paradigm for future genetic research that can benefit from large sample sizes, frequent sharing of ideas among laboratories, and prompt independent confirmation of early findings, which are required in the search for common genes with relatively small effects such as those that predispose to human hypertension.