Stature, weight, and body mass among young US children born at term with appropriate birth weights.

OBJECTIVE: To describe weight, stature, and body mass index (BMI) changes occurring before the age of 7 years, which may influence the prevalence of overweight in adolescence and adulthood. METHODS: Regression models predicting height and weight at ages 2 months to 6. 75 years were based on the third National Health and Nutrition Examination Survey. Birth certificate data were used to adjust ethnic-specific models for birth weight for gestational age. RESULTS: Attained height is higher for non-Hispanic black children than for either non-Hispanic white or Mexican American children (P 85th percentile than either non-Hispanic white or black children (boys = 25.6%, SE = 2.7 compared with 14.1%, SE = 1.7 and 16.5%, SE = 1.7, respectively; girls = 21.9%, SE = 3.6 compared with 13.0%, SE = 1.7 and 13.7%, SE = 2.2, respectively). For non-Hispanic whites and Mexican Americans and for non-Hispanic black boys, BMI decreased slightly between ages 2 and 6.75 years; BMI for non-Hispanic black girls did not. CONCLUSION: Size differences before the age of 7 years may influence later ethnic-specific overweight prevalence, independent of prenatal influences.

Food intake patterns and gallbladder disease in Mexican Americans.

OBJECTIVE: Results of previous studies on diet and gallbladder disease (GBD), defined as having gallstones or having had surgery for gallstones, have been inconsistent. This research examined patterns of food intake in Mexican Americans and their associations with GBD. DESIGN: Cross-sectional. SUBJECTS: The study population included 4641 Mexican Americans aged 20-74 years who participated in the 1988-94 third National Health and Nutrition Examination Survey (NHANES III). GBD was diagnosed by ultrasound. Food intake patterns were identified by principal components analysis based on food frequency questionnaire responses. Component scores representing the level of intake of each pattern were categorized into quartiles, and prevalence odds ratios (POR) were estimated relative to the lowest quartile along with 95% confidence intervals (CI). RESULTS: There were four distinct patterns in women (vegetable, high calorie, traditional, fruit) and three in men (vegetable, high calorie, traditional). After age adjustment, none were associated with GBD in women. However, men in the third (POR = 0.42, 95%CI 0.21-0.85) and fourth (POR = 0.53, 95%CI 0.28-1.01) quartiles of the traditional intake pattern were half as likely to have GBD as those in the lowest quartile. CONCLUSIONS: These findings add to a growing literature suggesting dietary intake patterns can provide potentially useful and relevant information on diet-disease associations. Nevertheless, methods to do so require further development and validation.

Country of birth and prevalence of gallbladder disease in Mexican Americans.

OBJECTIVES: This research sought to describe the association between country of birth and gallbladder disease (GBD) in Mexican Americans, identify subgroups at especially high risk, and identify risk factors that may mediate a birthplace-GBD association. DESIGN: Cross-sectional. METHODS: Our study population included 4157 Mexican Americans aged 20-74 who participated in the 1988-94 third National Health and Nutrition Examination Survey. GBD was diagnosed by ultrasound. Information on country of birth, education, income, and selected GBD risk factors was obtained from interviews. Prevalence odds ratios (POR) for GBD in Mexico- vs. US-born Mexican Americans were estimated by unconditional logistic regression, along with 95% confidence intervals (CI). To evaluate the extent to which GBD risk factors mediated the birthplace-GBD association, PORs for country of birth were compared in models with and without additional covariates. RESULTS: Age-adjusted GBD prevalence was lower in Mexico- than in US-born Mexican-American women (POR = 0.70, 95% CI 0.50, 0.98) and men (POR = 0.63, 95% CI 0.40, 0.97). The difference was especially pronounced among subjects of lower socioeconomic status. Despite substantial differences in GBD risk factor distributions by birthplace, none could completely explain the prevalence difference. CONCLUSIONS: The observation that GBD prevalence is higher among US-born Mexican Americans is consistent with research showing poorer health in this group. Further research is needed to identify strategies for reducing morbidity from GBD in Mexican Americans.

Growth and fatness at three to six years of age of children born small- or large-for-gestational age.

OBJECTIVE: To compare young children 3 to 6 years of age who were born small-for-gestational age (SGA; <10th percentile for gestational age) or large-for-gestational age (LGA; >/=90th percentile) with those who were born appropriate-for-gestational age (10th-89th percentile) to determine whether there are differences in growth and fatness in early childhood associated with birth weight status. DESIGN AND METHODS: National sample of 3192 US-born non-Hispanic white, non-Hispanic black, and Mexican-American children 3 to 6 years of age (36-83 months) examined in the third National Health and Nutrition Examination Survey and for whom birth certificates were obtained. On the birth certificates, length of gestation from the mother's last menstrual period was examined for completeness, validity, and whether the pattern of missing (n = 141) and invalid data (n = 147) on gestation was random. Gestation was considered invalid when >44 weeks, or when at gestations of

Prevalence and ethnic differences in gallbladder disease in the United States.

BACKGROUND & AIMS: Gallbladder disease is one of the most common conditions in the United States, but its true prevalence is unknown. A national population-based survey was performed to determine the age, sex, and ethnic distribution of gallbladder disease in the United States. METHODS: The third National Health and Nutrition Examination Survey (NHANES III) conducted gallbladder ultrasonography among a representative U.S. sample of more than 14, 000 persons. The diagnosis of gallbladder disease by detection of gallstones or cholecystectomy was made with excellent reproducibility. RESULTS: An estimated 6.3 million men and 14.2 million women aged 20-74 years had gallbladder disease. Age-standardized prevalence was similar for non-Hispanic white (8. 6%) and Mexican American (8.9%) men, and both were higher than non-Hispanic black men (5.3%). These relationships persisted with multivariate adjustment. Among women, age-adjusted prevalence was highest for Mexican Americans (26.7%) followed by non-Hispanic whites (16.6%) and non-Hispanic blacks (13.9%). Among women, multivariate adjustment reduced the risk of gallbladder disease for both Mexican Americans and non-Hispanic blacks compared with non-Hispanic whites. CONCLUSIONS: More than 20 million persons have gallbladder disease in the United States. Ethnic differences in gallbladder disease prevalence differed according to sex and were only partly explained by known risk factors.

Growth of infants and young children born small or large for gestational age: findings from the Third National Health and Nutrition Examination Survey.

OBJECTIVES: To compare the growth profiles of infants and young children born small for gestational age (SGA, < 10th percentile birth weight for gestation) or large for gestational age (LGA, > or =90th percentile) with those appropriate for gestational age, and to document the expected growth patterns through early childhood based on national health examination survey data. SAMPLE: Infants and children, 2 to 47 months of age, who were born in the United States and examined using the Third National Health and Nutrition Examination Survey (1988-1994). MAIN OUTCOME MEASURES: Measurements of growth status based on normalized distributions (z scores or standard deviation units [SDUs] for weight, length, and head circumference. RESULTS: Prevalence rates were as follows: SGA infants, 8.6%; appropriate for gestational age infants, 80.9%; and LGA infants, 10.5%. Infants who were SGA appeared to catch up in weight in the first 6 months, but thereafter maintained a deficit of about -0.75 SDUs compared with infants who were appropriate for gestational age. The weight status of LGA infants remained at about +0.50 SDUs through 47 months of age. Length and head circumference were also associated with birth weight status, averaging over -0.60 SDUs for SGA infants and +0.43 SDUs for LGA infants. CONCLUSIONS: Birth weight status is related to growth rates in infancy and early childhood, which underscores the importance of considering child growth relative to birth status when using growth charts. Small for gestational age infants remain shorter and lighter and have smaller head circumferences, while LGA infants grow longer and heavier and have larger head circumferences.

Muscularity and fatness of infants and young children born small- or large-for-gestational-age.

OBJECTIVE: There is growing interest in the extent to which body composition, both short- and long-term, differs in infants and children born at the extremes of birth weight. This is because a growing number of studies have linked low birth weight and fetal growth restriction to the chronic diseases in adulthood that often are obesity-related, and there is also evidence to suggest that heavy infants may be at increased risk for obesity in later life, again with the attendant obesity-related chronic diseases. Our objective was to compare anthropometric indices of body composition of infants and young children born small-for-gestational-age (SGA, <10th percentile) or large-for-gestational age (LGA, >/=90th percentile) with those of normal birth weight status (appropriate-for-gestational-age, AGA) in a US sample. DESIGN: National sample of US-born non-Hispanic white, non-Hispanic black, and Mexican-American infants and young children, 2 to 47 months of age, examined in the third National Health and Nutrition Examination Survey (NHANES III, 1988-1994), for whom birth certificates were obtained. The primary outcomes were normalized anthropometric indices (z scores or standard deviation units [SDU]) of nutritional status and body composition (mid-upper arm circumference, triceps and subscapular skinfolds, mid-upper arm muscle and mid-upper arm fat areas (UFA), and the arm fat index). The outcomes thus were scaled to permit comparison across chronologic ages. RESULTS: The prevalence of SGA was 8.6%, appropriate-for-gestational-age 80.9%, and LGA 10.5%. From ages 2 to 47 months, for infants and young children born SGA, there was a persistent overall deficit in muscularity (mid-upper arm circumference and mid-upper arm muscle area) of approximately -0.50 SDU, but less of a deficit in fatness, particularly at the youngest ages. For infants and young children born LGA, there was a surfeit in muscularity of approximately 0.45 SDU, with less of a surfeit in fatness, particularly at the youngest ages. Across all ages, the mean UFA showed a statistically significant deficit for SGA children (-0.27 +/- 0.10 SDU) and surfeit for LGA children (0.24 +/- 0.08 SDU). At individual ages for UFA and at individual and all ages combined for skinfold thicknesses, there were no significant differences in level of subcutaneous fatness in the three birth-weight-for-gestational-age groups. There was a tendency in the first year for the arm fat index (% arm fat) to be significantly higher for SGA infants, but the effect did not persist after the first year. CONCLUSION: SGA infants remain smaller and LGA infants larger in size through early childhood, but the discrepancies in weight are primarily attributable to differences in lean body mass (muscularity). Fatness is less affected. Thus, based on the fatness indicators used, at any given weight for infants and children 2 to 47 months of age, percent body fat appears to be relatively higher for children who were SGA at birth and lower in those who were LGA at birth. These differences in body composition for SGA infants support the evidence documenting a link between disturbances in intrauterine growth and chronic disease associated with subsequent adiposity in adulthood.

Genetic admixture and gallbladder disease in Mexican Americans.

Gallbladder disease is a common source of morbidity in the Mexican American population. Genetic heritage has been proposed as a possible contributor, but evidence for this is limited. Because gallbladder disease has been associated with Native American heritage, genetic admixture may serve as a useful proxy for genetic susceptibility to the disease in epidemiologic studies. The objective of our study was to examine the possibility that gallbladder disease is associated with greater Native American admixture in Mexican Americans. This study used data from the Hispanic Health and Nutrition Examination Survey and was based on 1,145 Mexican Americans who underwent gallbladder ultrasonography and provided usable phenotypic information. We used the GM and KM immunoglobulin antigen system to generate estimates of admixture proportions and compared these for individuals with and without gallbladder disease. Overall, the proportionate genetic contributions from European, Native American, and African ancestries in our sample were 0.575, 0.390, and 0.035, respectively. Admixture proportions did not differ between cases and noncases: Estimates of Native American admixture for the two groups were 0.359 and 0.396, respectively, but confidence intervals for estimates overlapped. This study found no evidence for the hypothesis that greater Native American admixture proportion is associated with higher prevalence of gallbladder disease in Mexican Americans. Reasons for the finding that Native American admixture proportions did not differ between cases and noncases are discussed. Improving our understanding of the measurement, use, and limitations of genetic admixture may increase its usefulness as an epidemiologic tool as well as its potential for contributing to our understanding of disease distributions across populations.

Racial and ethnic differences in serum cotinine levels of cigarette smokers: Third National Health and Nutrition Examination Survey, 1988-1991.

CONTEXT: Cotinine, a metabolite of nicotine, is a marker of exposure to tobacco smoke. Previous studies suggest that non-Hispanic blacks have higher levels of serum cotinine than non-Hispanic whites who report similar levels of cigarette smoking. OBJECTIVE: To investigate differences in levels of serum cotinine in black, white, and Mexican American cigarette smokers in the US adult population. DESIGN: Third National Health and Nutrition Examination Survey, 1988-1991. PARTICIPANTS: A nationally representative sample of persons aged 17 years or older who participated in the survey. OUTCOME MEASURES: Serum cotinine levels by reported number of cigarettes smoked per day and by race and ethnicity. RESULTS: A total of 7182 subjects were involved in the study; 2136 subjects reported smoking at least 1 cigarette in the last 5 days. Black smokers had cotinine concentrations substantially higher at all levels of cigarette smoking than did white or Mexican American smokers (P<.001). Serum cotinine levels for blacks were 125 nmol/L (22 ng/mL) (95% confidence interval [CI], 79-176 nmol/L [14-31 ng/mL]) to 539 nmol/L (95 ng/mL) (95% CI, 289-630 nmol/L [51-111 ng/mL]) higher than for whites and 136 nmol/L (24 ng/mL) (95% CI, 85-182 nmol/L [15-32 ng/mL]) to 641 nmol/L (113 ng/mL) (95% CI, 386-897 nmol/L [68-158 ng/mL]) higher than for Mexican Americans. These differences do not appear to be attributable to differences in environmental tobacco smoke exposure or in number of cigarettes smoked. CONCLUSIONS: To our knowledge, this study provides the first evidence from a national study that serum cotinine levels are higher among black smokers than among white or Mexican American smokers. If higher cotinine levels among blacks indicate higher nicotine intake or differential pharmacokinetics and possibly serve as a marker of higher exposure to cigarette carcinogenic components, they may help explain why blacks find it harder to quit and are more likely to experience higher rates of lung cancer than white smokers.

The burden of environmental tobacco smoke exposure on the respiratory health of children 2 months through 5 years of age in the United States: Third National Health and Nutrition Examination Survey, 1988 to 1994.

OBJECTIVE: To measure the effect of environmental tobacco smoke (ETS) on respiratory health in a national sample of young children. METHODS: The study evaluated children 2 months through 5 years of age participating in the Third National Health and Nutrition Examination Survey, 1988 to 1994. The group was a representative sample of the US population (N = 7680). A parental report of household smoking or maternal smoking during pregnancy ascertained ETS exposure. Respiratory outcomes were based on parental report of wheezing, cough, upper respiratory infection, or pneumonia in the last 12 months and chronic bronchitis or physician-diagnosed asthma at any time. Logistic regression was used to adjust for age, sex, race/ethnicity, birth weight, day care, family history of allergy, breastfeeding, education level of head of household, and household size. RESULTS: Approximately 38% of children were presently exposed to ETS in the home, whereas 23.8% were exposed by maternal smoking during pregnancy. ETS exposure increased chronic bronchitis and three or more episodes of wheezing among children 2 months to 2 years old and asthma among children 2 months to 5 years old. For household exposure, a consistent effect was seen only at >/=20 cigarettes smoked per day. Adjusted odds ratios for increased risk (95% confidence interval) for household exposures (>/=20 cigarettes smoked per day vs none smoked) and maternal prenatal exposure (prenatal smoking vs no smoking), respectively, for children 2 months to 2 years old were chronic bronchitis, 2.5 (1.6, 4.1); 2.2, (1.6, 3); three or more episodes of wheezing, 2.7 (1.7, 4.2), 2.1 (1. 5, 2.9); and for children 2 months to 5 years old were asthma, 2.1 (1.4, 3.2); 1.8 (1.3, 2.6). Reported use within the past month of prescription medications for asthma (beta-agonists or inhaled steroids) was not different between those with asthma reporting ETS exposure and those reporting no exposure; percent of patients with asthma reporting use of medication by household exposure was 0, 25. 7%; 1 to 19 cigarettes smoked per day, 32.9%; and >/=20 cigarettes smoked per day, 23.1%; percent of patients with asthma reporting use of medication by maternal smoking during pregnancy was no, 28.9%; yes, 22.7%. Among children 2 months to 2 years of age exposed to ETS, 40% to 60% of the cases of asthma, chronic bronchitis, and three or more episodes of wheezing were attributable to ETS exposure. For diagnosed asthma among children 2 months through 5 years old, there were 133 800 to 161 600 excess cases. Among exposed children 2 months through 2 years of age, there were 61 000 to 79 200 excess cases of chronic bronchitis and 126 700 to 172 000 excess cases of three or more episodes of wheezing. CONCLUSIONS: ETS exposure is common among children in the United States. The reported prevalence of asthma, wheezing, and chronic bronchitis was increased with ETS exposures. No statistically significant increase in the prevalence of upper respiratory infection, pneumonia, or cough was associated with ETS exposure. ETS exposure has little effect on the respiratory health of children between 3 and 5 years of age, with the exception of asthma. ETS appears to increase the prevalence of asthma rather than the severity as measured by medication use. These findings reinforce the need to reduce the exposure of young children to ETS.

Distributions and trends of serum lipid levels among United States children and adolescents ages 4-19 years: data from the Third National Health and Nutrition Examination Survey.

BACKGROUND: Atherosclerosis begins in childhood and progresses into adulthood. The reduction of cardiovascular risk factors, such as elevated serum total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels, in childhood may reduce cardiovascular morbidity and mortality in adulthood. Lipid distributions among children and adolescents were examined using the most recent nationally representative data. METHODS: Data from 7,499 examinees in NHANES III (1988-1994) were used to estimate mean and percentile distributions of serum total cholesterol, LDL-C, high-density lipoprotein cholesterol (HDL-C), and triglycerides in children and adolescents aged 4 to 19 years. The estimates were analyzed by age, sex, and race/ethnic groups. Trends in mean total cholesterol were examined for 12- to 17-year-olds using data from NHES III (1966-1970), NHANES I (1971-1974), and NHANES III (1988-1994). RESULTS: For children and adolescents 4 to 19 years of age, the 95th percentile for serum total cholesterol was 216 mg/dL and the 75th percentile was 181 mg/dL. Mean age-specific total cholesterol levels peaked at 171 mg/dL at 9-11 years of age and fell thereafter. Females had significantly higher mean total cholesterol and LDL-C levels than did males (P < 0.005). Non-Hispanic black children and adolescents had significantly higher mean total cholesterol, LDL-C, and HDL-C levels compared to non-Hispanic white and Mexican American children and adolescents. The mean total cholesterol level among 12- to 17-year-olds decreased by 7 mg/dL from 1966-1970 to 1988-1994 and is consistent with, but less than, observed trends in adults. Black females have experienced the smallest decline between surveys. CONCLUSIONS: The findings provide a picture of the lipid distribution among U.S. children and adolescents and indicate that, like adults, adolescents have experienced a fall in total cholesterol levels. Total cholesterol levels in U.S. adolescents declined from the late 1960s to the early 1990s by an average of 7 mg/dL. This information is useful for planning programs targeting the prevention of cardiovascular disease beginning with the development of healthy lifestyles in childhood.

Exposure of the US population to environmental tobacco smoke: the Third National Health and Nutrition Examination Survey, 1988 to 1991.

OBJECTIVE: To estimate the extent of exposure of the US population to environmental tobacco smoke and the contribution of the home and workplace environment to environmental tobacco smoke exposure. DESIGN: Nationally representative cross-sectional survey including questionnaire information from persons aged 2 months and older (n=16818) and measurements of serum cotinine (a metabolite of nicotine) from persons aged 4 years and older (n=10642). SETTING/PARTICIPANTS: Participants in the Third National Health and Nutrition Examination Survey, October 25, 1988, to October 21, 1991. RESULTS: Of US children aged 2 months to 11 years, 43% lived in a home with at least 1 smoker, and 37% of adult non-tobacco users lived in a home with at least 1 smoker or reported environmental tobacco smoke exposure at work. Serum cotinine levels indicated more widespread exposure to nictoine. Of non-tobacco users, 87.9% had detectable levels of serum cotinine. Both the number of smokers in the household and the hours exposed at work were significantly and independently associated (P<.001, multiple regression t test) with increased serum cotinine levels. Serum cotinine levels of children, non-Hispanic blacks, and males indicated that these groups had higher exposure to environmental tobacco smoke. Dietary variables showed no consistent association with serum cotinine levels, and dietary contribution to serum cotinine level, if any, appeared to be extremely small. CONCLUSIONS: The high proportion of the population with detectable serum cotinine levels indicates widespread exposure to environmental tobacco smoke in the US population. Both the home and workplace environments significantly contribute to environmental tobacco smoke exposure in the United States.

Sample design: Third National Health and Nutrition Examination Survey.

This report presents a detailed description of the sample design for the Third National Health and Nutrition Examination Survey, 1988-94, including a brief description of research that led to the choice of the final design. The National Health and Nutrition Examination Survey (NHANES) is one of the major surveys of the National Center for Health Statistics, Centers for Disease Control. Information on the health and nutritional status of the noninstitutionalized population of the United States is collected through the NHANES household interviews and standardized physical examinations.

Risk factors for gallstone disease in the Hispanic populations of the United States.

The 1982-1984 Hispanic Health and Nutrition Examination Survey used ultrasonography to investigate risk factors for gallstone disease (gallstones or cholecystectomy). Mexican American, Cuban American, and Puerto Rican men (n = 968) and women (n = 1,325) aged 20-74 years were selected from household samples in nine states. Among men, the risk of gallstone disease increased with age, education, and subscapular skinfold thickness. Among women, the risk of gallstone disease increased with age, body mass index, four skinfold measures, diabetes, impaired glucose tolerance, and oral contraceptive usage, but not with parity. Women currently using oral contraceptives were also found to be at increased risk of current gallstones. Menopause was a risk factor for gallstone disease and cholecystectomy. Alcohol consumption was negatively related to the risk of gallstone disease. In men, the cholesterol/high density lipoprotein cholesterol ratio was positively related to gallstone disease and, in women, this ratio was negatively related. This interaction between the effect of sex and the cholesterol/high density lipoprotein cholesterol ratio on gallstone disease was highly significant (p = 0.002). Mexican Americans were at increased risk of gallstone disease even when other risk factors were controlled in multiple logistic regression analysis.

Prevalence of gallstone disease in Hispanic populations in the United States.

The 1982-1984 Hispanic Health and Nutrition Examination Survey used ultrasonography to investigate the epidemiology of gallstone disease. Mexican American, Cuban American, and Puerto Rican men and women, aged 20-74 yr, were selected from household samples in Texas, New Mexico, Arizona, Colorado, California, Connecticut, New Jersey, New York, and Florida. Ultrasonography was performed on 2299 persons. The age-adjusted prevalence of gallstone disease (gallstones + cholecystectomy) among Mexican American men (7.2%) was 1.7 times that of Cuban American men and 1.8 times that of Puerto Rican men. The prevalence for Mexican American women (23.2%) was 1.5 times that of Cuban American women and 1.7 times that of Puerto Rican women. Rates were about three times higher among women than men and increased with age in both sexes and all ethnic groups except older Puerto Rican women. Among Mexican American women aged 60-74 yr, the prevalence of gallstone disease reached 44.1%. These results support the hypothesis that Mexican Americans are at increased risk of gallstone disease.