C-reactive protein and body mass index in children: findings from the Third National Health and Nutrition Examination Survey, 1988-1994.

OBJECTIVES: To examine the relationship between C-reactive protein (CRP) concentration and body mass index (BMI) in children. STUDY DESIGN: With the use of data from 5305 children aged 6 to 18 years in the Third National Health and Nutrition Examination Survey (1988 to 1994), a cross-sectional health survey, we examined whether CRP concentrations were elevated among overweight children. RESULTS: Among children whose BMI was below the age- and sex-specific 15th percentile, 6.6% of boys and 10.7% of girls had an elevated CRP concentration (>2.1 mg/L) compared with 24.2% of boys and 31.9% of girls whose BMI was > or =95th percentile. After adjustment was done for age, sex, race or ethnicity, poverty income ratio, high-density lipoprotein cholesterol concentration, white blood cell count, and history of chronic bronchitis, the adjusted odds of having an elevated CRP concentration were 2.20 (95% CI 1.30, 3.75) for children with a BMI of 85th to <95th percentile and 4.92 (95% CI 3.39, 7.15) for children with a BMI of > or =95th percentile compared with children who had a BMI of 15th to <85th percentile. The associations did not differ significantly by age, sex, or race or ethnicity. CONCLUSIONS: In a large representative sample of US children, CRP concentration was significantly elevated among children with a BMI > or=85th percentile, thus confirming previous findings of this association in children and extending previous research in adults to children. Excess body weight may be associated with a state of chronic low-grade inflammation in children.

Prevalence of abnormal serum aminotransferase values in overweight and obese adolescents.

OBJECTIVES: (1) To determine the prevalence of abnormal liver enzymes in overweight and obese adolescents and (2) to determine the relationship of alcohol ingestion and serum antioxidants to the presence of abnormal liver enzymes in overweight and obese adolescents. METHODS: Serum alanine aminotransferase (ALT) and gamma-glutamyl transpeptidase levels were measured in 2450 children between the ages of 12 and 18 years, enrolled in the National Health and Examination Survey, cycle III (NHANES III). Obesity was defined as a body mass index >95th percentile for age and sex. Overweight was defined as a body mass index >85th percentile for age and sex. Nutritional intake was assessed by 24-hour dietary recall and food frequency questionnaires. Serum antioxidants were measured by high-pressure liquid chromatography. RESULTS: Sixty percent of adolescents with elevated ALT levels were either overweight or obese. Overall, 6% of overweight adolescents had elevated ALT levels (odds ratio: 3.4 [95% CI: 3.5-12.8]). Ten percent of obese adolescents had elevated ALT levels (odds ratio: 6.7 [95% CI: 3.5-12.8]). In addition, approximately 1% of obese adolescents demonstrated ALT levels over twice normal. Approximately 50% of of obsese adolescents who reported modest alcohol ingestion (4 times per month or more) had elevated ALT levels (odds ratio: 10.8, 95% CI: 1.5-77). Other factors associated with elevated ALT levels in overweight and obese adolescents include increased age, elevated glycolated hemoglobin, elevated triglycerides, and decreased levels of serum antioxidants-vitamin E, beta-carotene, and vitamin C. CONCLUSION: Overweight and obesity are the most common findings in adolescents with elevated ALT levels. Even modest alcohol consumption may significantly increase the likelihood of obese adolescents developing obesity-related liver disease.

Establishing a standard definition for child overweight and obesity worldwide: international survey.

OBJECTIVE: To develop an internationally acceptable definition of child overweight and obesity, specifying the measurement, the reference population, and the age and sex specific cut off points. DESIGN: International survey of six large nationally representative cross sectional growth studies. SETTING: Brazil, Great Britain, Hong Kong, the Netherlands, Singapore, and the United States. SUBJECTS: 97 876 males and 94 851 females from birth to 25 years of age. MAIN OUTCOME MEASURE: Body mass index (weight/height(2)). RESULTS: For each of the surveys, centile curves were drawn that at age 18 years passed through the widely used cut off points of 25 and 30 kg/m(2) for adult overweight and obesity. The resulting curves were averaged to provide age and sex specific cut off points from 2-18 years. CONCLUSIONS: The proposed cut off points, which are less arbitrary and more internationally based than current alternatives, should help to provide internationally comparable prevalence rates of overweight and obesity in children.

PIP: This study aimed to develop an internationally acceptable definition of child overweight and obesity, specifying the measurement, reference population, and age and sex specific cut off points. Data on body mass index (weight/height) were obtained from 6 large nationally representative cross sectional surveys on growth from Brazil, Great Britain, Hong Kong, the Netherlands, Singapore, and the US. The study included 97,876 males and 94,851 females from birth to 25 years of age. For each of the surveys, centile curves were drawn that at age 18 years passed through the widely used cut-off points of 25 and 30 kg/sq. m for adult weight and obesity. The resulting curves were averaged to provide age- and sex-specific cut-off points from 2 to 18 years. The proposed cut off points, which are less arbitrary and more internationally based than current alternatives, should help to provide internationally comparable prevalence rates of overweight and obesity in children.

Growth and development of term children born with low birth weight: effects of genetic and environmental factors.

OBJECTIVE: To evaluate the role of intrauterine growth retardation (IUGR) on childhood growth and development, controlling for environmental and genetic factors. METHODS: Women and infants enrolled in the National Collaborative Perinatal Project were analyzed. Weight, length, and IQ were assessed at birth and at 7 years in the entire National Collaborative Perinatal Project population in term infants born with and without IUGR ("population cohort"). To control for genetic and environmental factors, growth and development were also compared in 220 similar-sex term sibling pairs in which one sibling was born with IUGR and one was born without IUGR ("sibling cohort"). RESULTS: At 7 years of age heights and weights of infants born with IUGR remained approximately 0.5 SD less than infants born without IUGR (weight-for-age: p < 0.001, height-for-age: p < 0.001). In the entire National Collaborative Perinatal Project population, IQ (p < 0.001) and Bender-Gestalt (p < 0.001) scores were significantly lower in infants born with IUGR compared with those in infants born without IUGR. There were no significant differences in IQ or Bender-Gestalt scores between siblings born with and without IUGR. However, siblings with IUGR and large deficits in head circumference demonstrated both decreased IQ (p < 0.05) and Bender-Gestalt (p < 0.05) scores. CONCLUSION: Long-term growth deficits associated with IUGR appear largely independent of prenatal or postnatal environmental factors. IUGR had little impact on intelligence and motor development except when associated with large deficits in head circumference.

Role of the prenatal environment in the development of obesity.

Establishing that prenatal life is a critical or sensitive period for the development of obesity may focus basic research and clinical prevention efforts on this period. This review summarizes evidence that the intrauterine environment influences the risk of later obesity and considers the mechanisms by which this may occur. The association between birth weight and adult weight suggests that there are enduring effects of the intrauterine environment on later obesity risk. We examine whether the maternal factors of diabetes, obesity, and pregnancy weight gain alter the intrauterine environment and thereby increase the risk of later obesity in the offspring. Of these maternal factors, evidence is strongest for the role of maternal diabetes. No single mechanism explains how these maternal factors could change the intrauterine environment to increase obesity risk. However, all potential mechanisms involve an altered transfer of metabolic substrates between mother and fetus, which may influence the developing structure or function of the organs involved in energy metabolism.

Effects of intrauterine growth retardation in premature infants on early childhood growth.

OBJECTIVE: To evaluate in preterm infants the role of intrauterine growth retardation and infant body proportionality on subsequent childhood growth. METHODS: Preterm infants (818) prospectively enrolled in the Infant Health and Development Program were studied from birth to 36 months of corrected age. Weights and lengths were recorded at eight intervals. Growth parameters were compared in preterm infants with differing body symmetry at birth, defined by length-for-age and weight-for-age. Infants with both low length-for-age and low weight-for-age at birth were categorized as symmetrically growth retarded, and infants with normal length-for-age and low weight-for-age were categorized as asymmetrically growth retarded. RESULTS: Infants born with low length-for-age demonstrated increased growth velocity until 8 months of corrected age (p <0.001). However, infants born with low weight-for-age demonstrated decreased weight-gain velocity compared with preterm infants with appropriate weight for gestational age (AGA) until 40 weeks of corrected age (p <0.001). Heights and weights of infants with either symmetric or asymmetric intrauterine growth retardation remained significantly retarded compared with AGA preterm patients and the National Child Health Survey (NCHS) reference population (p <0.001). Infants born short but with normal weight did not significantly differ from AGA preterm infants in either weight or length at 36 months of corrected age. Preterm infants with both symmetric and asymmetric growth retardation demonstrated limited catch-up growth in weight until age 4 months and then paralleled the AGA preterm patients and the NCHS reference population. Very low birth weight (< or = 1250 gm), gestational age, and a broad-based day-care intervention did not influence growth outcome after control for the presence of intrauterine growth retardation. CONCLUSIONS: Preterm infants with both symmetric and asymmetric intrauterine growth retardation demonstrate limited catch-up growth. Intrauterine growth deficits persist into early childhood.

Estimates of metabolic rate in obese and nonobese adolescents.

To evaluate the validity of equations for the calculation of basal metabolic rate, we compared measured metabolic rates in a population that included obese and nonobese adolescents with metabolic rates calculated from five equations commonly used to estimate metabolic rate. Of the available options, neither the Mayo Clinic nomogram nor the Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU) equations produced estimates that differed significantly from measured values. In a second cohort of severely obese adolescent girls, the FAO/WHO/UNU equation that included both height and weight provided the most accurate estimate of metabolic rate. Because of their simplicity, we recommend use of the FAO/WHO/UNU equations to estimate metabolic rate in adolescent populations (boys: BMR = 17.5 weight (kg) + 651; girls: BMR = 12.2 weight (kg) + 746). However, when obese cohorts are studied, the FAO/WHO/UNU equation that includes both weight and height predicts metabolic rate most accurately (boys: BMR = 16.6 weight (kg) + 77 height (m) + 572; girls: BMR = 7.4 weight (kg) + 482 height (m) + 217).

Epidemiological significance of Venezuelan equine encephalomyelitis virus in vitro markers.

One hundred and fifty-eight strains of Venezuelan equine encephalomyelitis virus were typed antigenically and classified epidemiologically as either epizootic or enzootic. Plaque sizes for 148 of these strains were determined, and the pH requirements for hemagglutination (HA) of goose erythrocytes of 131 were studied. Only antigenic variant group IABC strains could be classified epidemiologically as epizootic. In vitro these strains were characterized by the formation of small plaques in Vero cells and a relatively narrow pH range for optimum HA reactivity. Experimental studies in horses confirmed the fact that only IABC strains have epizootic potential. We concluded that plaque size in Vero cell monolayers would be a useful method of screening VEE viruses for equine virulent strains. Indirect evidence suggested that small plaques resulted from sensitivity to an anionic substance present in the agar overlay medium.

Optimal dietary therapy for obese adolescents: comparison of protein plus glucose and protein plus fat.

Nitrogen balance in six obese adolescent boys and three obese girls was studied during two nonconsecutive three-week dietary periods. Protein intake was based on an ideal body weight calculated from the measurement of total body water. The diets consisted of 1.5 gm meat protein/kg IBW/day plus 1.0 gm glucose/kg IBW/day, or an isonitrogenous diet made isocaloric with fat. Each dietary period was preceded by a controlled five-day diet designed to achieve weight maintenance. The first dietary period was followed by a one-month period of re-equilibration. The addition of carbohydrate to protein produced a significantly better cumulative nitrogen balance than P + F. Significant nitrogen losses persisted throughout the entire dietary period of P + F in three patients, but were observed in only one patient during P + G. Lymphopenia occurred in one subject on P + F but did not occur during P + G. Serum albumin concentrations were unchanged on both diets. Transferrin values decreased during P + F, but did not differ significantly from prediet levels during P + G. However, the observation of prolonged nitrogen losses in one subject on P + G and the limited experience with highly restrictive diets in obese adolescents emphasize that such diets must be used with caution and monitored carefully.

Eastern equine encephalomyelitis in Panama: the epidemiology of the 1973 epizootic.

In late June 1973, a small outbreak of equine encephalitis caused by eastern equine encephalomyelitis (EEE) virus occurred in the Republic of Panama. At least 100 horses were affected by the disease and 40 died. More than 1,700 human sera were obtained from areas of virus activity but no serological evidence for infection was found. Four isolates of EEE virus were recovered, one of which was from a small pool of Culex taeniopus mosquitoes. Serologic studies of infected horses and classification by the short incubation hemagglutination-inhibition tests revealed that these isolates were South American strains. Our evidence suggests that another agent virulent for horses was active during this outbreak.

Ten clinical cases of human infection with venezuelan equine encephalomyelitis virus, subtype I-D.

The clinical and laboratory findings in ten humans infected with Venezuelan equine encephalitis virus, subtype I-D, are described in this report. Clinical and laboratory data indicate that, in contrast to equine infections, human infection with these enzootic virus strains (I-D) is similar to human infection with epizootic strains (I-ABC). In most cases there was an abrupt onset of fever, muscle pain, and vomiting. Virus was recovered from sera obtained during the first 3 days of illness. Lymphopenia occurred in all patients, and neutropenia occurred in three. No sequelae of these infections were apparent.

Enzootic and epizootic Venezuelan equine encephalomyelitis virus in horses infected by peripheral and intrathecal routes.

Forty-five horses were infected peripherally or intrathecally with enzootic or epizootic strains of Venezuelan equine encephalomyelitis (VEE) virus. Low titers of virus appeared in cerebrospinal fluid (CSF) after peripheral inoculation of enzootic or epizootic VEE virus strains. Intrathecal infection with either epizootic or enzootic VEE virus produced higher titers of virus in CSF than did peripheral infection. In contrast to peripheral infections with enzootic strains, intrathecal infections with these strains caused death. The animals that died had widespread histopathologic changes and large amounts of virus in brain tissue. The attenuated VEE virus vaccine strain, TC-83, also multiplied in the brain of horses inoculated intrathecally but caused no clinical disease and little histopathologic damage.