Biomedical subjects

L D Hammer

Publications and source records attributed to L D Hammer.

At least 19 recordsLinked to original sources

PubMed2001

Early body mass index and other anthropometric relationships between parents and children.

OBJECTIVE: To assess longitudinally the relationship between measures of adiposity in children over the first 8 y of life with that of their parents and to explore the role of parental adiposity in the development of childhood adiposity. DESIGN: Longitudinal study of measures of adiposity in children. SUBJECTS: A community sample from three health service systems including 114 children followed annually from infancy to age 8 and their 228 biological parents. METHODS: Measurements were assessed at baseline for parents (6 months post-partum for mothers) and at regular intervals for children beginning at age 2 months. Measurements included weight, height, triceps skinfold, subscapular skinfold, midarm circumference, waist and hip. RESULTS: The major findings were: (1) significant correlations between parental body mass index (BMI), both maternal and paternal, and their biological offspring first emerged at age 7; (2) children with two overweight parents had consistently elevated BMI compared to children with either no overweight parents or one overweight parent. These differences became significant beginning at age 7. CONCLUSIONS: This study supports the hypothesis that familial factors (biological and/or environmental) affecting the development of adiposity emerge at specific ages and are related to the adiposity of both parents.

Adult↗

PubMed2001

Prolonged bottle feeding in a cohort of children: does it affect caloric intake and dietary composition?

Little is known about the consequences to children of bottle feeding prolonged beyond age 1 year on caloric intake and overall dietary composition. To obtain these data, 165 children, followed up from infancy, were assessed in these respects for a 24-hour period at age 3 1/2 years. Bottle-fed children (n = 14) consumed more milk than their weaned counterparts (p < 0.001), had a higher mean daily calcium intake (p < 0.05), received fewer calories from carbohydrates (p = 0.034), and received a greater percentage of calories from protein (p = 0.033). There were no significant differences between the groups in total caloric intake, total iron intake, total volume ofjuice, or calories from fat. Pediatricians questioned about the effects of continuing to offer children nutritive liquids from bottles as well as cups (versus offering cups alone) may inform parents that this feeding practice is associated with significantly greater milk consumption and daily calcium intake. However, this study could not find evidence that prolonged bottle feeding at age 3 1/2 years is associated with a significantly decreased total daily iron intake or an increased risk for factors associated with adiposity such as a greater daily calorie intake, a higher body mass index, or greater percentage of total calories derived from fat.

Animals↗

PubMed1999

Development of feeding practices during the first 5 years of life.

OBJECTIVE: To understand the transition from breast-and bottle-feeding to solid-feeding and factors that might affect the duration of breast- and bottle-feeding. DESIGN: Cohort followed up from birth with relatively well-educated, middle-class parents. SETTING: Community sample recruited from 3 suburban newborn nurseries (a teaching hospital, community hospital, and large health maintenance organization). PARTICIPANTS: One hundred ninety-one healthy full-term infants. MEASURES: Assessment of feeding practices through the ages of complete weaning from breast- and bottle-feeding. RESULTS: More than 90% of participants breast-fed for at least 2 weeks. Infants of older mothers were weaned from the breast later than infants of younger mothers. First-born infants were weaned from the breast earlier than later-born infants. Eighty-four percent of infants bottle-fed at some time during the first year of life. More than 40% of the cohort was still receiving bottles at 24 months of age, 16% at 36 months, and 8% at 48 months. The duration of breast- and bottle-feeding was related to maternal work status; mothers who returned to work during the first 3 months postpartum weaned sooner from the breast and later from the bottle than women who returned to work after 3 months postpartum. CONCLUSIONS: The frequency of late bottle-weaning in this well-educated, middle-class cohort was unexpected and was related to the timing of the mother's return to work. The impact of prolonged bottle-feeding on later growth and adiposity deserves further investigation.

Adult↗

PubMed1999

Risk factors for the emergence of childhood eating disturbances: a five-year prospective study.

OBJECTIVE: Research suggests that eating problems are often present by preadolescence, yet little is known about the age of emergence of these early eating disturbances or risk factors for these behaviors. Thus, we investigated the timing of onset of disturbed eating during childhood and the predictors of these behaviors. METHOD: These aims were addressed by following a sample of children and their parents (N = 216) for the first 5 years of the children's lives. RESULTS: Data suggested that the risk for emergence of inhibited eating, secretive eating, overeating, and vomiting increased annually through age 5. Maternal body dissatisfaction, internalization of the thin-ideal, dieting, bulimic symptoms, and maternal and paternal body mass prospectively predicted the emergence of childhood eating disturbances. Infant feeding behavior and body mass during the first month of life also predicted the emergence of these behaviors. DISCUSSION: Results suggest that eating disturbances emerge during childhood and may be a function of certain parental and child characteristics.

Adult↗

PubMed1999

Can mothers influence their child's eating behavior?

This study examined the relationship between general maternal parenting style, maternal eating cues, and a child's eating behavior during mealtime. We expected that the general style would relate to the number of specific eating cues and that mothers who used more eating prompts would have children that ate more and at a faster rate. Seventy-seven children (39 girls, 38 boys), aged 3.5 years, visited the laboratory with their mothers for a videotaped lunch. Videotapes of each laboratory visit were coded for the child's eating rate and maternal parenting style, which was measured as the level of maternal control and support and the number and type of eating prompts given during a meal. Caloric intake was also calculated. The number and rate of verbal and physical encouragements and discouragements were significantly related to measures of general maternal parenting style and meal duration. The rates of food offers, food presentations, and total prompts were all significantly related to the child's rate of calorie intake. However, a mother's level of support or control was not related to the child's eating behavior. Although general maternal parenting style did not predict the child's eating behavior, these behaviors were related to the frequency of maternal eating prompts, which in turn were significantly related to the number of calories eaten and the time spent eating by the child. Children who ate the fastest had mothers who delivered eating prompts at a higher frequency. These findings may have implications for the development of obesity later in childhood, as a function of rapid eating or of poor self-regulation.

Child Behavior↗

PubMed1997

Prospective study of risk factors for the initiation of cigarette smoking.

Risk factors for the initiation of cigarette smoking were examined in 2 consecutive cohorts of teenagers (N = 1,901). Students in Cohort 1 were followed over 4 years from 9th to 12th grade; those in Cohort 2 were followed over 3 years from 9th to 11th grade. Among girls with no history of smoking at baseline, those with more friends who smoked at baseline (p < .001) and those with higher sociability scores (p < .05) were significantly more likely to have tried smoking over the study interval. Among boys with no history of smoking at baseline, those with more friends who smoked at baseline (p < .05) and those with higher depression symptoms scores (p < .01) were significantly more likely to have tried smoking over the study interval. The data suggest that future research is needed to examine potential gender differences that may have implications for the next generation of smoking-prevention programs.

Adolescent↗

PubMed1997

Psychiatric risk associated with early puberty in adolescent girls.

OBJECTIVE: This study prospectively evaluated the relationship between early puberty and the onset of internalizing symptoms and disorders in adolescent girls. METHOD: The sample was drawn from 1,463 sixth-, seventh-, and eighth-grade girls who participated in a longitudinal school-based study of growth and development. Pubertal stage was determined by self-assessment of Tanner stage. Psychiatric assessments included self-report instruments and structured diagnostic interviews. Survival methods were utilized for data analysis. RESULTS: Girls with onset of internalizing symptoms were on average 5 months earlier in pubertal development than those who were asymptomatic (p < .001). In addition, girls with earlier maturation (earliest quartile) were more likely to develop internalizing symptoms than were nonearly matures (hazard ratio = 1.8, confidence interval = 1.2, 2.7). In a subsample of girls followed into high school, early-maturing girls were at marginally higher risk (p < .10) for developing internalizing disorders by the study's end. The highest risk for internalizing disorders was for those girls with both early puberty and prior internalizing symptoms (odds ratio = 3.3). CONCLUSION: Early puberty increases the risk of internalizing symptoms and perhaps internalizing disorders in adolescent girls.

Chi-Square Distribution↗

PubMed1996

Ethnicity and body dissatisfaction: are Hispanic and Asian girls at increased risk for eating disorders?

PURPOSE: To compare prevalences and correlates of body dissatisfaction among white, Hispanic, and Asian girls. METHODS: A total of 939 6th and 7th grade girls (mean age 12.4 years) attending four middle schools in northern California completed self-administered assessments of age, ethnicity, desired body shape, parent education levels, mother's and father's body shapes, pubertal stage, and body dissatisfaction. Body dissatisfaction was assessed with the Body Dissatisfaction scale of the Eating Disorder Inventory. Height, weight, triceps skinfold thickness, and waist and hip circumferences were measured by trained examiners. RESULTS: Hispanic girls reported significantly greater body dissatisfaction than white girls, with Asian girls in-between. After adjustment for body mass index (weight/height), normal and overweight white, Hispanic, and Asian girls reported similar levels of body dissatisfaction. However, among the leanest 25% of girls, Hispanics and Asians reported significantly more body dissatisfaction than white girls. Body mass index was the strongest independent predictor of increased body dissatisfaction in all three ethnic groups. Shorter height among white girls and taller height among Asian girls also made significant independent contributions. Parent education level, a measure of socioeconomic status, was not significantly associated with body dissatisfaction. CONCLUSIONS: Body dissatisfaction is not limited to white girls in middle and upper socioeconomic strata. These findings suggest Hispanic and Asian girls may be at greater risk for adopting eating disorder behaviors than previously recognized.

Adolescent↗

PubMed1994

Timing and rate of sexual maturation and the onset of cigarette and alcohol use among teenage girls.

OBJECTIVE: To test the hypothesis that the patterns of pubertal progression, early vs late puberty and fast vs slow, are associated with the age at which girls start to drink alcohol and smoke cigarettes. DESIGN: The study included 1463 female students, 10.7 to 18.2 years of age, who were assessed five times during the 2.7-year study. Data regarding pubertal stage, alcohol use, and cigarette use were obtained at each assessment. These data were used to calculate two indexes of pubertal development, the age at which the midpoint of puberty was achieved and the rate of progression through puberty, and the ages when each subject first drank, first drank moderate amounts of alcohol, and first smoked. RESULTS: Girls with earlier puberty (midpoint < 12.2 years) first reported drinking any alcohol at a median age of 12.5 years, 0.7 years younger than girls whose puberty was later. Similarly, girls with earlier puberty reported drinking moderate amounts of alcohol at a median age of 13.7 years, 0.9 years younger than girls with later puberty. Girls with earlier puberty further reported first smoking cigarettes at a median age of 12.8 years, 0.6 years younger than girls with later puberty. The rate of pubertal progression was significantly associated only with the age when girls first drank moderate amounts of alcohol. CONCLUSION: Earlier puberty is associated with a younger age of onset for both drinking and smoking among adolescent girls.

Adolescent↗

PubMed1994

Pursuit of thinness and onset of eating disorder symptoms in a community sample of adolescent girls: a three-year prospective analysis.

Community-based prospective studies are needed to shed light on mechanisms that may influence development of eating disorders and identify variables that could serve as potential targets for prevention efforts. In this paper we examine level of weight preoccupation and other variables prospectively associated with age of onset of eating disorder symptoms over a 3-year interval in a community sample (N = 939) of young adolescent girls. 3.6% (32/887) experienced onset of symptoms over the interval. Only one factor, a measure of Weight Concerns, was significantly associated with onset (p < .001). Girls scoring in the highest quartile on the measure of Weight Concerns had the shortest survival time (12% incidence by age 14.5) and those scoring in the lowest quartile had the highest survival time (2% incidence by age 14.5; p < .001). This finding is consistent with both theoretical and clinical perspectives and represents one of the first prospective demonstrations of a linkage between weight and body shape concerns and later onset of eating disorder symptoms. An understanding of the independent variables that predispose girls to development of symptoms is a useful step towards the establishment of a rational basis for the choice of a prevention intervention target.

Adolescent↗

PubMed1994

Factors associated with eating disorder symptoms in a community sample of 6th and 7th grade girls.

Nine hundred thirty-nine 6th and 7th grade girls participated in the baseline phase of a prospective study designed to examine a set of potential risk factors for the development of eating disorders. Of the 939,839 girls (89%) completed the bulimia nervosa section of the Structured Clinical Interview for DSM-III-R disorders. One girl received the diagnosis of bulimia nervosa, another 35 were classified as a symptomatic group. Using analysis of covariance (ANCOVA), controlling for age and stage of sexual maturation, symptomatic and asymptomatic groups were compared on the following measures: Eating Disorders Inventory (EDI), BMI, triceps skinfold thickness, waist-to-hip ratio, depression symptoms (CES-D and DSRS), Restraint Scale, and a measure of family adaptability and cohesion (FACES). Symptomatic girls were more developmentally mature, significantly heavier, reported greater fear of weight gain, experienced greater dysphoria, indicated increased body dissatisfaction, and reported greater feelings of inadequacy and personal worthlessness. Their status on these dimensions may indicate potential vulnerability to eating disorders and, ultimately, suggest the choice of targets for intervention. Our future goal is to conduct the prospective analyses needed to confirm the hypothesized linkages.

Adolescent↗

PubMed1993

An attempt to modify unhealthful eating attitudes and weight regulation practices of young adolescent girls.

This is the first long-term, controlled study evaluating the effectiveness of a prevention curriculum designed to modify the eating attitudes and unhealthful weight regulation practices of young adolescent girls. Nine hundred sixty-seven sixth and seventh-grade girls were randomized to experimental healthy weight regulation curriculum or no-treatment control classes. A prevention intervention was developed around three principal components: (1) Instruction on the harmful effects of unhealthful weight regulation; (2) promotion of healthful weight regulation through the practice of sound nutrition and dietary principles and regular aerobic physical activity; (3) development of coping skills for resisting the diverse sociocultural influences that appear linked to the current popular obsessions with thinness and dieting. The intervention failed to achieve the hoped-for impact. We did observe a significant increase in knowledge among girls receiving the intervention and among high-risk students only, there was a small albeit statistically significant effect on body mass index. These findings question the wisdom of providing a curriculum directed at all young adolescents, most of whom are not at risk to develop an eating disorder. Rather than targeting the entire population, a healthy weight curriculum designed to modify the eating attitudes and unhealthful weight regulation practices of young adolescent girls might better focus on "at risk" students.

Adolescent↗

PubMed1993

Does television viewing increase obesity and reduce physical activity? Cross-sectional and longitudinal analyses among adolescent girls.

To examine the relationships between hours of television viewing and adiposity and physical activity among female adolescents, a cohort study with follow-up assessments 7, 14, and 24 months after baseline was conducted. All sixth- and seventh-grade girls (N = 971) attending four northern California middle schools were eligible to participate. Six hundred seventy-one students had sufficient data for baseline cross-sectional analyses, and 279 students in a no-intervention cohort had sufficient data for longitudinal analyses. The baseline sample had a mean age of 12.4 years and was 43% white, 22% Asian, 21% Latino, 6% Pacific Islander, 4% black, 2% American Indian, and 2% other. Hours of after-school television viewing, level of physical activity, and stage of sexual maturation were assessed with self-report instruments. Height, weight, and triceps skinfold thickness were measured and body mass index (ratio of weight [in kilograms] to height [in meters] squared) and triceps skinfold thickness were adjusted by level of sexual maturity for the analyses. Baseline hours of after-school television viewing was not significantly associated with either baseline or longitudinal change in body mass index or triceps skinfold thickness. Baseline hours of after-school television viewing was weakly negatively associated with level of physical activity in cross-sectional analyses but not significantly associated with change in level of physical activity over time. All results were essentially unchanged when adjusted for age, race, parent education, and parent fatness. Among adolescent girls, television viewing time appears to have only weak, if any, meaningful associations with adiposity, physical activity, or change in either over time.

Adolescent↗

PubMed1992

Is puberty a risk factor for eating disorders?

OBJECTIVE: To examine the association between stage of sexual maturation and eating disorder symptoms in a community-based sample of adolescent girls. PARTICIPANTS: All sixth- and seventh-grade girls (N = 971) enrolled in four northern California middle schools. MAIN VARIABLES EXAMINED: Pubertal development measured using self-reported Tanner stage and body mass index (kg/m2). The section of the Structured Clinical Interview for DSM-III-R Disorders (SCID) discussing bulimia nervosa was used to evaluate symptoms of bulimia nervosa. RESULTS: Girls manifesting eating disorder symptoms, while not significantly older than their peers without such symptoms, were more developmentally advanced as determined with Tanner self-staging. The odds ratio for the association between sexual maturity and symptoms was 1.8 (95% confidence interval, 1.2 to 2.8); ie, at each age, an increase in sexual maturity of a single point was associated with a 1.8-fold increase in the odds of presenting symptoms. The odds ratio for the association between body mass index (adjusted for sexual maturity) and symptoms was 1.02 (95% confidence interval, 1.0 to 1.05). There was no independent effect of age or of the interaction between age and the sexual maturity index. CONCLUSIONS: These results suggest that (1) puberty may be a risk factor for the development of eating disorders, and (2) prevention efforts might best be directed at prepubertal and peripubertal adolescents.

Adolescent↗

PubMed1992

The development of eating behavior in childhood.

Eating behavior must be viewed as a complex phenomenon involving the coordination of motor, cognitive, social and emotional development, all under the regulation of both central and peripheral factors. Eating provides not only the necessary biologic substrate for human growth and normal physiologic function but is strongly involved in the full range of social interaction from the formation of the mother-infant relationship to later social interaction. Eating is associated with a variety of pleasurable and painful affective experiences. The pediatrician, working closely with the parents, can facilitate the development of healthy attitudes toward eating and healthy eating behaviors.

Adolescent↗

PubMed1992

Pubertal stage and panic attack history in sixth- and seventh-grade girls.

OBJECTIVE: Although the incidence of first panic attacks appears to peak during adolescence, little is known about which features of adolescence contribute to the risk of a first panic episode. The purpose of this study was to compare the relative importance of age and pubertal stage in explaining the occurrence of panic attacks in adolescents. METHOD: From a school-based sample of sixth- and seventh-grade girls, 754 subjects completed both a structured clinical interview determining history of one or more panic episodes and a self-assessment of Tanner stages of pubertal development. A multiple logistic regression analysis was performed with panic attack history as the dependent variable and pubertal stage, age, and their interaction as the independent variables. RESULTS: A history of one or more four-symptom panic attacks was found in 5.3% of the girls (N = 40). After age was controlled for, pubertal stage was significantly related to panic attack history. At each age, higher rates of panic attacks were found in the more physically mature girls. CONCLUSIONS: Pubertal stage, after adjustment for the effects of age, appears to predict panic attack occurrence in young adolescent girls. Understanding the link between puberty and panic may offer clues regarding the onset and etiology of panic attacks.

Adolescent↗

PubMed1992

Insulin-like growth factor binding protein-3 in normal pubertal girls.

IGFBP-3 concentrations rise in the second decade of life. To test the hypothesis that the stage of pubertal development, independent of chronological age, was associated with these increases we measured serum IGFBP-3 concentrations by radioimmunoassay in 324 sixth and seventh grade girls (12.3 +/- 0.7 years) at the beginning of a multisite school-based health curriculum. The mean (+/- SD) serum IGFBP-3 among the 242 girls with complete data was 4.0 +/- 0.7 mg/l. Pubertal stage was significantly associated with IGFBP-3 (p less than 0.0001, ANOVA). Mean concentrations rose from 3.5 +/- 0.7 mg/l among those with the earliest pubertal stages to 4.2 +/- 0.7 mg/l among the mature girls. IGF-I and IGFBP-3 concentrations were significantly correlated (Spearman's r = 0.43, p less than 0.0001). After controlling for the association between pubertal development and IGFBP-3 concentrations, only the waist/hip ratio, among the various measures of body composition, was significantly associated with IGFBP-3 concentration (Spearman's r = -0.23, p = 0.0002). Likewise, none of the measures of nutrition: intake of total calories, protein, fat and carbohydrate; serum iron; red cell mean corpuscular volume; or cholesterol; were significantly associated with IGFBP-3 concentrations. There was, however, a small, but significant association between IGFBP-3 concentrations and both serum transferrin and blood hemoglobin concentrations. Pubertal stage has a significant impact on IGFBP-3 concentrations and those attempting to utilize IGFBP-3 concentrations during adolescence should be cognizant of the subject's pubertal stage.

Adolescent↗

PubMed1991

Standardized percentile curves of body-mass index for children and adolescents.

Weight-for-height indexes are often used in the clinical assessment of obesity in children and adolescents. The direct measurement of adiposity, using hydrostatic weighing and other techniques, is not feasible in studies involving young children or with large numbers of older subjects. Ratios of weight relative to height, such as the body-mass index (weight/height), may be used as indirect measures of obesity and correlate with more direct measures of adiposity. Using data from the First National Health and Nutrition Examination Study, 1971 to 1974, standardized percentile curves of body-mass index for white children and adolescents were developed. These curves may be used to monitor the body-mass index of white children and adolescents longitudinally and for comparing an individual with others of the same sex and age.

Adolescent↗