The association of variants in the FTO gene with longitudinal body mass index profiles in non-Hispanic white children and adolescents.

OBJECTIVE: To investigate possible age-related changes in associations between polymorphisms in the fat mass and obesity-associated (FTO) gene and higher body mass index (BMI). DESIGN AND SUBJECTS: Multilevel mixed regression models were used to examine associations between four FTO variants and longitudinal BMI profiles in non-Hispanic white and African American children and adolescents 8-17 years of age from two different longitudinal cohort studies, the Bogalusa Heart Study (BHS) and Project HeartBeat! (PHB). In the BHS, there were 1551 examinations of 478 African Americans and 3210 examinations of 1081 non-Hispanic whites; in PHB, there were 971 examinations of 131 African Americans and 4458 examinations of 505 non-Hispanic whites. RESULTS: In African Americans, no significant FTO associations with BMI were found. In non-Hispanic whites, linkage disequilibrium among all four variants made haplotype analysis superfluous, so we focused on the single-nucleotide polymorphism, rs9939609. In longitudinal multilevel models, the A/A genotype of rs9939609 was associated with higher BMI in non-Hispanic whites in both cohorts at all ages. A significant age-by-genotype interaction found only in the BHS cohort predicted that in those with the A/A genotype, BMI would be ∼0.7 kg m(-2) higher at age 8 and ∼1.6 kg m(-2) higher at age 17 than in those with A/T or T/T genotypes. The design of PHB limited follow-up of any single individual to 4 years, and may have reduced the ability to detect any age-by-genotype interaction in this cohort. CONCLUSIONS: The A/A genotype of rs9939609 in the FTO gene is associated with higher longitudinal BMI profiles in non-Hispanic whites from two different cohorts. The association may change with age, with the A/A genotype being associated with a larger BMI difference in late adolescence than in childhood, though this was observed only in the BHS cohort and requires verification.

Higher blood pressure in middle-aged American adults with less education-role of multiple dietary factors: the INTERMAP study.

Extensive evidence exists that an inverse relation between education and blood pressure prevails in many adult populations, but little research has been carried out on reasons for this finding. A prior goal of the INTERMAP Study was to investigate this phenomenon further, and to assess the role of dietary factors in accounting for it. Of the 4680 men and women aged 40-59 years, from 17 diverse population samples in Japan, People's Republic of China, UK, and USA, a strong significant inverse education-BP relation was manifest particularly for the 2195 USA participants, independent of ethnicity. With participants stratified by years of education, and assessment of 100+ dietary variables from four 24-h dietary recalls and two 24-h urine collections/person, graded relationships were found between education and intake of many macro- and micronutrients, electrolytes, fibre, and body mass index (BMI). In multiple linear regression analyses with systolic BP (SBP) and diastolic BP (DBP) of individuals the dependent variables (controlled for ethnicity, other possible nondietary confounders), BMI markedly reduced size of education-BP relations, more so for women than for men. Several nutrients considered singly further decreased size of this association by > or =10%: urinary 24-h Na and K excretion, Keys dietary lipid score, vegetable protein, fibre, vitamins C and B6, thiamin, riboflavin, folate, calcium, magnesium, and iron. Combinations of these dietary variables and BMI attenuated the education-SBP inverse coefficient by 54-58%, and the education-DBP inverse coefficient by 59-67%, with over half these effects attributable to specific nutrients (independent of BMI). As a result, the inverse education-BP coefficients ceased to be statistically significant. Multiple specific dietary factors together with body mass largely account for the more adverse BP levels of less educated than more educated Americans. Special efforts to improve eating patterns of less educated strata can contribute importantly to overcoming this and related health disparities in the population.

Anger expression, body fat, and blood pressure in adolescents: Project HeartBeat!

This study explores the potential influence of growth, body/composition, and sexual maturity on the relation of anger expression and blood pressure in adolescents. Baseline data from Project HeartBeat! (82 boys and 85 girls, 14 years of age) examined the ability of anger expression (STAXI scale) to predict blood pressure, after controlling for the effects of ethnicity (African-American/ non-African-American), height, weight, percentage body fat, and sexual maturity. Blood pressures were unrelated to anger expression in models that included the above developmental variables. However, girls scoring high on healthy anger expression ("anger-control") had significantly lower levels of percentage body fat (P = 0.015) independent of the above factors. The literature suggests that body fat or body mass is often, though not unanimously, associated with unhealthy forms of anger expression in adolescents. Research is required into the biological, social, and behavioral origins of the association between body fat and anger expression. Height and sexual maturity, virtually ignored in this literature, should be included in future research.

Birth cohort evidence of population influences on blood pressure in the United States, 1887-1994.

PURPOSE: Mean blood pressure (BP) has declined in the U.S. for several decades. It is unknown to what extent this decline was due to treatment of persons with recognized high BP or to population-wide influences on BP. Treatment would shift only the highest values lower, whereas, population-wide influences on BP would shift the entire distribution downward. METHODS: We examined changes in the distributions of systolic and diastolic BP (SBP, DBP) across birth cohorts born between 1887 and 1975 in 52,646 individuals examined in the National Health (and Nutrition) Examination Surveys between 1960 and 1994. The BP distributions were estimated as functions of age and birth-year to examine changes between birth cohorts. We postulated that the age-adjusted 10th, 50th and 90th percentiles of SBP and DBP had decreased in more recent versus earlier birth cohorts. RESULTS: The series of birth cohorts exhibited successively lower SBP and DBP at low, middle and high percentiles. In general, the 10th percentile of SBP decreased approximately 1.19 mmHg per decade of birth-year, whereas the 50th percentile decreased 2.40 mmHg per decade, and the 90th percentile decreased 4.62 mmHg per decade. A similar pattern of results was seen for DBP. CONCLUSIONS: The entire distribution of both SBP and DBP shifted downward. The downward shifts at the 50th percentile and below unequivocally demonstrate a strong prevention effect in the U.S. population during the period 1887 through 1975. This epidemiologic analysis indicates that population-wide influences can alter favorably the distribution of BP throughout the whole population.

Community-wide coronary heart disease mortality in Mexican Americans equals or exceeds that in non-Hispanic whites: the Corpus Christi Heart Project.

PURPOSE: Previous comparisons of coronary heart disease mortality between Mexican Americans and non-Hispanic whites have given paradoxic results: despite their adverse cardiovascular risk profiles, especially a greater prevalence of diabetes, Mexican Americans are reported to have lower rates of mortality from coronary heart disease. SUBJECTS AND METHODS: We performed a community-based surveillance among all residents of Nueces County, Texas, aged 25 to 74 years, from 1990 to 1994. All death certificates were obtained and coded, and deaths potentially related to coronary heart disease were selected and validated by standardized methods blinded to ethnicity. Validated in-hospital and out-of-hospital coronary heart disease mortality was compared between 785 Mexican Americans and 862 non-Hispanic white women and men. RESULTS: Validated coronary heart disease mortality in Mexican Americans exceeded that for non-Hispanic whites in the same community. Among women, definite coronary heart disease mortality was 40% greater among Mexican Americans (rate ratio [RR] 1.43, 95% confidence interval [CI]: 1.12 to 1.82), as was all coronary heart disease mortality (RR, 1.32, 95% CI: 1.08 to 1.63). Among men, Mexican Americans had greater rates of all (RR, 1.11; 95% CI: 0.96 to 1.28) and definite coronary heart disease mortality (RR, 1.16; 95% CI: 0.91 to 1.47), but the associations were not statistically significant. CONCLUSIONS: When community-wide mortality rates from coronary heart disease are properly validated, Mexican Americans have rates equal to or higher than those of non-Hispanic whites. Community-based surveillance with validation of coronary heart disease as the cause of death is necessary to avoid the errors that occur with the use of death certificates alone.

Tracking body fat distribution during growth: using measurements at two occasions vs one.

OBJECTIVE: To investigate whether within-individual variation is a factor in the generally reported poor tracking of central body fat distribution (CBFD) during development and whether two measurements of CBFD during each measurement occasion would improve the estimate of tracking over time. METHODS: A longitudinal study compared the results of two measurements of body fat (BF) and CBFD during each measurement occasion to the results of one measurement of BF and CBFD during each occasion every 4 months over 1-3 y. A total of 345 boys and 333 girls in three age cohorts of 8, 11 and 14 y at baseline were examined. BF variables were: body mass index (BMI); fat mass and percentage body fat from bioelectrical impedance; two skinfold sums; and abdominal circumference. CBFD variables were: waist/hip and waist/thigh ratios; conicity; and log upper-lower skinfold ratio. RESULTS: Three-year tracking of BF varied from 0.79 to 0.90 for one- and from 0.81 to 0.93 for two-occasion measurements showing no apparent sex- or cohort-effects. Three-year tracking of CBFD was lower than that of BF (0.68-0.75), but improved significantly with two-occasion measurements (0.75-0.82). CONCLUSIONS: Within-individual variation is a significant factor in reported low tracking of CBFD in childhood. Estimates of tracking currently in the literature may underestimate the predictive value of CBFD, possibly because this research has used one-occasion measurement. The increased use of two-occasion measurement should significantly improve the tracking of CBFD during development and provide a more realistic understanding of its predictive value.

Change in level of physical activity and risk of all-cause mortality or reinfarction: The Corpus Christi Heart Project.

BACKGROUND: The role of physical activity (PA) in reducing the risk of all-cause mortality or reinfarction after a first myocardial infarction (MI) remains unresolved, particularly for minority populations. The association between change in level of PA and risk of death or reinfarction was studied in 406 Mexican American and non-Hispanic white women and men who survived a first MI. METHODS AND RESULTS: MI patients were interviewed at baseline and annually thereafter about PA, medical history, and risk factors of coronary heart disease. Change in level of PA after the index MI was categorized as (1) sedentary, no change (referent group), (2) decreased activity, (3) increased activity, and (4) active, no change. Over a 7-year period, the relative risk (95% CI) of death was as follows: 0.21 (0.10 to 0.44) for the active, no change group; 0.11 (0.03 to 0.46) for the increased activity group; and 0.49 (0.26 to 0.90) for the decreased activity group. The relative risk of reinfarction was as follows: 0.40 (0.24 to 0.66) for the active, no change group; 0.22 (0.09 to 0.50) for the increased activity group; and 0.93 (0.59 to 1.42) for the decreased activity group. CONCLUSIONS: These findings are consistent with a beneficial role of PA for Mexican American and non-Hispanic white women and men who survive a first MI and have practical implications for the management of MI survivors.

Effect of a community intervention on patient delay and emergency medical service use in acute coronary heart disease: The Rapid Early Action for Coronary Treatment (REACT) Trial.

CONTEXT: Delayed access to medical care in patients with acute myocardial infarction (AMI) is common and increases myocardial damage and mortality. OBJECTIVE: To evaluate a community intervention to reduce patient delay from symptom onset to hospital presentation and increase emergency medical service (EMS) use. DESIGN AND SETTING: The Rapid Early Action for Coronary Treatment Trial, a randomized trial conducted from 1995 to 1997 in 20 US cities (10 matched pairs; population range, 55,777-238,912) in 10 states. PARTICIPANTS: A total of 59,944 adults aged 30 years or older presenting to hospital emergency departments (EDs) with chest pain, of whom 20,364 met the primary population criteria of suspected acute coronary heart disease on admission and were discharged with a coronary heart disease-related diagnosis. INTERVENTION: One city in each pair was randomly assigned to an 18-month intervention that targeted mass media, community organizations, and professional, public, and patient education to increase appropriate patient actions for AMI symptoms (primary population, n=10,563). The other city in each pair was randomly assigned to reference status (primary population, n=9801). MAIN OUTCOME MEASURES: Time from symptom onset to ED arrival and EMS use, compared between intervention and reference city pairs. RESULTS: General population surveys provided evidence of increased public awareness and knowledge of program messages. Patient delay from symptom onset to hospital arrival at baseline (median, 140 minutes) was identical in the intervention and reference communities. Delay time decreased in intervention communities by -4.7% per year (95% confidence interval [CI], -8.6% to -0.6%), but the change did not differ significantly from that observed in reference communities (-6. 8% per year; 95% CI, -14.5% to 1.6%; P=.54). EMS use by the primary study population increased significantly in intervention communities compared with reference communities, with a net effect of 20% (95% CI, 7%-34%; P<.005). Total numbers of ED presentations for chest pain and patients with chest pain discharged from the ED, as well as EMS use among patients with chest pain released from the ED, did not change significantly. CONCLUSIONS: In this study, despite an 18-month intervention, time from symptom onset to hospital arrival for patients with chest pain did not change differentially between groups, although increased appropriate EMS use occurred in intervention communities. New strategies are needed if delay time from symptom onset to hospital presentation is to be decreased further in patients with suspected AMI. JAMA. 2000;284:60-67

Comparison of stroke hospitalization rates among Mexican-Americans and non-Hispanic whites.

The authors performed a prospective, community-based pilot stroke surveillance project in Nueces County, TX. Mexican-Americans showed a trend toward higher completed ischemic stroke hospitalization rates compared with non-Hispanic whites. Mexican-Americans were more commonly uninsured (p = 0.007) and were less likely to receive neuroimaging (p = 0.001). Additional studies are needed to confirm this finding and to determine the role of stroke risk factors and access to care variables.

[Pattern of the distribution of total cholesterol and cHDL cholesterol Spanish children and adolescents: RICARDIN Study]. / Patrón de la distribución de colesterol total y cHDL en niños y adolescentes españoles: estudio RICARDIN.

BACKGROUND: The RICARDIN Study multicenter study of cardiovascular risk factors in children and adolescents has described the standards of normality of blood cholesterol levels in the Spanish school population. The objective of the present study was to compare mean values of cholesterol between different regions of Spain, and to compare the global mean with a pool international study. Also, the pattern of total cholesterol and cHDL by age and sex using mathematical model is described, and comparison with two international studies carried out in USA and Japan is performed. SUBJECTS AND METHODS: 10,683 children aged 6 to 18 were selected from 7 different Spanish provinces (Madrid, Vizcaya, Lugo, Badajoz, Murcia, Asturias and Barcelona). Blood samples were obtained by capilar puncture (Reflotron). RESULTS: Mean values of total cholesterol was different among provinces, and globally, were lower than the international pooled population, although the pattern observed in each population was very similar. Total cholesterol curve for Spanish boys showed a curvilinear trend that can be estimated through a cubic function that explains 89% of observed data, while for girls the best estimate was obtained through an inverse function (R2 = 0.40). cHDL for boys showed a cubic function as the best estimate (R2 = 0.90), while for girls the best estimate was obtained through a quadratic function (R2 = 0.59). CONCLUSIONS: There are important physiological variations of total cholesterol level by age and sex in children and adolescents. The pattern of cholesterol does not follow a linear model but a curvilinear one, that need to be considered in clinically assessing individual determinations of cholesterol, since highest percentiles can vary by age and sex.

Population studies of ambulatory blood pressure monitoring in Brazilian children.

BACKGROUND: The determination of hypertension in a given population depends on the knowledge of population norms for blood pressure. This is true for both casual blood pressure (CBP) measurements and the newest and most promising technology of ambulatory blood pressure monitoring (ABPM). OBJECTIVE: To design an ambitious multinational co-operative study to determine normal blood pressure data in Brazilian children. METHODS: The study was designed to determine normative data for CBP, using the Task Force technical recommendations for age-, sex- and height-percentile-specific blood pressure values. The proposed procedure is as follows. ABPM will be studied in a random subgroup of individuals, to develop similar normative data. These data will be correlated to CBP measurements and to echocardiographic findings as a measure of end-organ damage. All patients who are diagnosed by CBP measurement to be hypertensive will also be studied by ABPM, and studies of target-organ damage will be performed. Family and medical histories will be evaluated by questionnaire and first-degree relatives will be evaluated for CBP measurement. Hypertensive patients will form a cohort for long-term follow-up. These data will be the foundation for studies of hypertension in Brazilian children.

Greater stroke rate during hospitalization for acute heart disease among Mexican Americans than non-Hispanic whites.

BACKGROUND AND PURPOSE: This study compared the risk for stroke during acute myocardial infarction (AMI), percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) between Mexican Americans (MAs) and non-Hispanic whites. METHODS: We examined the age-specific rate ratios (RR) of acute stroke during hospitalization for AMI, CABG and PTCA in a population-based study in Corpus Christi, Tex. by searching the cardiac surveillance data for ICD-9 codes for stroke (430-437). ICD-9 stroke codes were validated by comparing medical chart abstraction with ICD-9 discharge diagnoses. RESULTS: Stroke codes were found in 220 of the 5,697 admissions for AMI, CABG and PTCA. In the 45- to 59-year age-group MAs had a RR of 2.66 (95% CI 1.36-5.23) relative to non-Hispanic whites. In the 60- to 74-year age-group the RR was 1.52 (95% CI 1.11-2.08). There were no significant differences in the 25- to 44-year age-group. These ethnic relationships were found in nondiabetics but not in diabetics. Women in the 45- to 59-year age-group had a RR of 1.88 (95% CI 1.09-3.25) compared with men, but there were no significant sex differences in the 25- to 44- or 59- to 74-year age-groups. Stroke ICD-9 codes have a poor positive predictive value for acute stroke ranging from 10 to 76%. The stroke misclassifications were nondifferential with respect to ethnicity or sex. CONCLUSIONS: MAs have a higher stroke rate complicating acute heart disease in Corpus Christi. A rigorous stroke surveillance project is needed to study the burden of stroke in MAs, the United States' largest Hispanic population.

Validity of echocardiographic measurement in an epidemiological study. Project HeartBeat!

In Project HeartBeat!, a longitudinal study of cardiovascular disease risk factors in healthy children and adolescents, 3 samples of 40, 80, and 182 echocardiograms, respectively, were randomly selected and reread to evaluate intraobserver and interobserver variabilities and comparability between measurements of field echocardiographic technicians and reference readings at Texas Children's Hospital. Included in the evaluation were 8 M-mode echocardiographic measurements, ie, aortic root diameter, left atrial diameter, and end-diastolic and end-systolic measurements of interventricular septal thickness, left ventricular (LV) diameter, and LV posterior wall thickness; 8 Doppler measurements; and a calculated LV mass. Means and SDs of the differences of the paired measurements were used to assess the relative bias and random error of the measurements. For the intraobserver comparison, means and SDs of the differences were very small, indicating that the echo measurements were performed consistently by each project echo technician. Interobserver comparison showed statistically but not clinically significant differences between the paired readings of end-diastolic septal thickness, end-systolic LV posterior wall thickness, and 5 Doppler measurements. Comparison with reference readings at Texas Children's Hospital showed significant differences in diastolic LV diameter, systolic septal thickness, and right ventricular ejection time. These differences, however, were minimal with limited clinical significance. Mean differences in LV mass for the corresponding comparisons were -1.82, 4.50, and 0.0013 g, and the SDs were 18.79, 24.16, and 12.35 g, respectively. We conclude that the echocardiographic measurements taken from healthy children in a longitudinal study can be made accurately with acceptable reproducibility.

Apolipoprotein E affects serial changes in total and low-density lipoprotein cholesterol in adolescent girls: Project HeartBeat!

Apolipoprotein E (apo E) polymorphism is a genetic determinant of lipid and lipoprotein levels and the risk for coronary heart disease. The extent to which serial patterns of change in total cholesterol and low-density lipoprotein cholesterol (LDL-C) concentrations varied by apo E genotype was therefore investigated in 247 Caucasian girls aged 8 to 14 at baseline who were participating in Project HeartBeat!, a mixed longitudinal study of cardiovascular disease (CVD) risk factor development in children. Plasma lipid concentrations were determined for each participant three times per year (every 4 months) for up to 4 years from October 1991 through August 1995. Mean total cholesterol values for individuals with epsilon2/3, epsilon3/3, and epsilon3/4 genotypes were 141.7, 161.6, and 165.9 mg/dL, respectively (P < .001). Corresponding LDL-C values for individuals with epsilon2/3, epsilon3/3, and epsilon3/4 genotypes were 74.6, 94.8, and 98.7 mg/dL, respectively (P < .001). The results of longitudinal modeling indicated that age trajectories for total cholesterol and LDL-C varied significantly by apo E genotype. Individuals with epsilon3/3 and epsilon3/4 genotypes exhibited similar patterns of change in total cholesterol and LDL-C from ages 8 to 18, while individuals with the epsilon2/3 genotype demonstrated a significantly different pattern of change (age2 x genotype interaction, P < .05). For example, individuals with the epsilon2/3 genotype showed a slight increase in total cholesterol from approximately 141 to 146 mg/dL from ages 8 to 10; total cholesterol then decreased monotonically from ages 10 to 18 from 146 to 115 mg/dL. The apo E effect on total cholesterol and LDL-C and their change during adolescence is strong and may be modified by factors affecting growth, maturation, and reproductive function.

Prevention of cardiovascular risk factors in the first place.

Cardiovascular disease (CVD) prevention can address the major risk factors-blood lipids, blood pressure, and smoking-and their determinants throughout the lifespan, with approaches varying according to age and risk. The Task Force on Research in Epidemiology and Prevention of Cardiovascular Diseases gave new impetus to the concept of early intervention: Their highest priority in CVD prevention was "to prevent the development of CVD risk in the first place." Six issues follow: (1) the relation between "primordial prevention" of CVD and "prevention of the risk factors in the first place"; (2) the place of youth in context with older and younger age groups; (3) the importance of bridging institutional gaps between youth and adulthood; (4) the need to strengthen the scientific base linking the major risk factors (e.g., blood cholesterol concentration) with their determinants; (5) the value of rate of change in risk factors with age, and not only incidence of "treatable" levels of risk factors, as an outcome in assessing interventions; and (6) the role and appropriate design strategies for both observational and intervention studies. It is time for a radical expansion of our investment in preventing the risk factors in the first place.

Assessing the burden of cancer in Texas using vital statistics data.

BACKGROUND: Vital statistics data were used to describe the burden of cancer in Texas. METHODS: Average annual age-adjusted mortality data in Texas (1986 to 1990) for 17 cancer types were compared with the US data for whites and blacks and with California data for Hispanics. Trends were examined from 1980 to 1990 for the entire state and from 1976 to 1989 for 24 geographic regions within the state. RESULTS: Mortality excesses were detected for lung and liver cancer, and deficits for colorectal, breast, and prostate cancers. Rates were generally stable from 1980 to 1990 with several exceptions (lung, liver, colon). Six areas of Texas, including four areas along the Gulf Coast, had relatively more excesses of various cancers, without a discernible pattern by cancer type. CONCLUSIONS: Overall, Texas has fared favorably in cancer mortality when compared with the United States. Enhanced evaluation of the frequency of cancer, as well as the conduct of etiologic research, must await the availability of statewide long-term cancer incidence data.

Quality control for blood pressure measurement in population studies: Shibata Children's Heart Study.

To investigate the relation between observer performance for blood pressure measurement in a training process and in field conditions, measurement values were studied under training and field conditions among 21 blood pressure observers of 1434 subjects aged 6-15 years in Japan. The observers received training by a videotape, which included six audiovisual presentations of a falling mercury column in a standard sphygmomanometer with Korotkoff sounds. Observer bias was measured for each trainee as the mean difference between the observed and the standard values for each blood pressure reading, including systolic (SBP), fourth-phase diastolic (K4), and fifth-phase diastolic (K5) values. In multiple linear regression analyses, each 1 mmHg increment in observer bias was equivalent to 1.27, 0.88, and 1.25 mmHg difference in actual readings of SBP, K4, and K5, respectively, in the field. This finding indicates that observer performance in videotape training is predictive of measurement behavior in the field.

Cardiovascular risk factors in Mexican-American and non-Hispanic white children: The Corpus Christi Child Heart Study.

BACKGROUND: Information concerning differences in cardiovascular disease risk factors between Mexican-American and non-Hispanic white children is limited. We conducted a study to determine if there were ethnic differences in cardiovascular disease risk factors in children and whether such differences were explained by differences in body mass index. METHODS AND RESULTS: Fasting glucose, insulin, and blood lipid concentrations, blood pressure, weight, and height were measured in a cross-sectional survey among 403 third-grade children in Corpus Christi, Tex. We found significantly higher fasting insulin and glucose concentrations among Mexican-American than among non-Hispanic white children. Mexican-American boys had slightly lower levels of HDL cholesterol and higher systolic blood pressure than non-Hispanic white boys. Ethnic differences in insulin and glucose were not explained by body mass index. CONCLUSIONS: These results provide preliminary evidence that ethnic differences in insulin, glucose, body mass index, and other risk factors occur as early as age 8 to 10 years. Additional research is warranted on differences in risk factors in Mexican-American and non-Hispanic white children and the potential importance of insulin in influencing the natural history of these characteristics.