Frazier Al

Reproducibility and Validity of Maternal Recall of Pregnancy-related Events

We assessed the reproducibility and validity of a questionnaire that asks mothers to recall pregnancy-related events from thirty or more years ago. Among 146 women who completed the questionnaire twice, responses were highly reproducible for pre-pregnancy height and weight (r = 0.95), pregnancy complications (r = 0.74), substance use (r = 0.80), preterm delivery (r = 0.82), birthweight (r = 0.94), and breastfeeding (r = 0.89). Among 154 women whose questionnaire responses were compared to data collected during their pregnancies, recall was highly accurate for height (r = 0.90), pre-pregnancy weight (r = 0.86), birthweight (r = 0.91), and smoking (sensitivity = 0.86, specificity = 0.94). These findings suggest that long-term maternal recall is both reproducible and accurate for many factors related to pregnancy and delivery.

Overweight, weight concerns, and bulimic behaviors among girls and boys.

OBJECTIVE To assess the prevalence rates and correlates of overweight, concern with weight, and bulimic behaviors. METHOD A survey was completed by a population-based sample of 16,114 boys and girls aged 9 to 14 years. RESULTS Although fewer girls (19%) than boys (26%) were overweight, more girls (25% versus 22%) perceived themselves as overweight (p < .001). The proportion of girls reporting trying to lose weight increased with age (p < .001). The prevalence of binge eating at least monthly increased with age among the girls, but remained stable among the boys. The prevalence of purging was low (< or = 1%) and comparable between genders until age 13. Among the 13- and 14-year-olds, girls were significantly more likely than boys to report using laxatives or vomiting to control weight (p < or = .001). Purging was independently positively associated with stage of pubertal development (girls: odds ratio [OR] = 2.1, 95% confidence interval [CI] 1.6-2.7; boys: OR = 1.5, 95% CI 1.0-2.2) and overweight (girls: OR = 1.9, 95% CI 1.2-3.0; boys: OR = 2.7, 95% CI 1.4-5.1). CONCLUSIONS Misperception of being overweight and concern with weight were common. Purging was a very rare behavior, but increased with pubertal development. Among the girls, the prevalence increased sharply around the onset of adolescence.

Randomized Trial of Vitamin D Supplementation and Risk of Acute Respiratory Infection in Mongolia

OBJECTIVE: Observational studies suggest that serum levels of 25-hydroxyvitamin D (25[OH]D) are inversely associated with acute respiratory infections (ARIs). We hypothesized that vitamin D supplementation of children with vitamin D deficiency would lower the risk of ARIs. METHODS: By using cluster randomization, classrooms of 744 Mongolian schoolchildren were randomly assigned to different treatments in winter (January–March). This analysis focused on a subset of 247 children who were assigned to daily ingestion of unfortified regular milk (control; n = 104) or milk fortified with 300 IU of vitamin D3 (n = 143). This comparison was double-blinded. The primary outcome was the number of parent-reported ARIs over the past 3 months. RESULTS: At baseline, the median serum 25(OH)D level was 7 ng/mL (interquartile range: 5–10 ng/mL). At the end of the trial, follow-up was 99% (n = 244), and the median 25(OH)D levels of children in the control versus vitamin D groups was significantly different (7 vs 19 ng/mL; P < .001). Compared with controls, children receiving vitamin D reported significantly fewer ARIs during the study period (mean: 0.80 vs 0.45; P = .047), with a rate ratio of 0.52 (95% confidence interval: 0.31–0.89). Adjusting for age, gender, and history of wheezing, vitamin D continued to halve the risk of ARI (rate ratio: 0.50 [95% confidence interval: 0.28–0.88]). Similar results were found among children either below or above the median 25(OH)D level at baseline (rate ratio: 0.41 vs 0.57; Pinteraction = .27). CONCLUSIONS: Vitamin D supplementation significantly reduced the risk of ARIs in winter among Mongolian children with vitamin D deficiency.

Weight Concerns, Weight Control Behaviors, and Smoking Initiation

Objective. To examine the cross-sectional relationships between weight concerns, weight control behaviors, and initiation of tobacco use among youths. Study Design. Smoking status, weight concerns, and weight control behaviors were assessed in a cross-sectional sample of 16 862 children, 9 to 14 years of age, in 1996. Logistic regression was used to examine the relationship between weight concerns, weight control behaviors, and early stages of smoking initiation (precontemplation, contemplation, and experimentation). All analyses were adjusted for age, body mass index, and known predictors of initiation. Results. Approximately 9% of participants had experimented with cigarettes, and 6% were contemplating cigarette smoking. Contemplation of tobacco use was associated with misperception of being overweight (boys: odds ratio [OR], 1.65; 95% confidence interval [CI], 1.10–2.48), unhappiness with appearance (girls: OR, 2.05; 95% CI, 1.48–2.84; boys: OR, 1.60; 95% CI, 1.05–2.42), and a tendency to change eating patterns around peers (girls: OR, 2.87; 95% CI, 2.28–3.62; boys: OR, 1.83; 95% CI, 1.25–2.66). Experimentation with cigarettes was associated with daily exercise to control weight among boys (OR, 1.92; 95% CI, 1.07–3.43) and with monthly purging (OR, 2.54; 95% CI, 1.27–5.07) and daily dieting among girls (OR, 1.79; 95% CI, 1.09–2.96). Conclusions. Our findings suggest that, among both girls and boys, contemplation of smoking is positively related to weight concerns. Experimentation seems to be positively related to weight control behaviors. It is important for both pediatricians and comprehensive school health programs to address healthy methods of weight maintenance and to dispel the notion of tobacco use as a method of weight control.

Adolescent diet and risk of breast cancer

Objectives: To investigate the components of adolescent diet that may influence risk of breast cancer as an adult. Methods: Retrospective cohort study among 47,355 participants in the Nurses Health Study II who answered a 131-item food frequency questionnaire about diet during high school. Cox proportional hazards regression was used to estimate relative risks and 95% confidence intervals among incident cases of breast cancer between 1989 (inception of the study) and 1998 (when high school diet was assessed). Results: Intakes of fat and fiber were not significantly related to risk of breast cancer in multivariate analysis, but increased intake of vegetable fat (Q5versusQ1 multivariate RR = 0.58, 95% CI (0.38–0.86); test for trend p = 0.005) and vitamin E (Q5versusQ1 multivariate RR = 0.61, 95% CI (0.42–0.89); test for trend p = 0.003) were associated with a lower risk. A higher dietary glycemic index (Q5versusQ1 multivariate RR = 1.47, 95% CI (1.04–2.08); test for trend p = 0.01) was associated with increased risk of breast cancer. Conclusions: The apparent protective effects of vegetable fat and vitamin E and adverse effect of high glycemic foods on risk of breast cancer need confirmation in prospective analyses.

Longitudinal relationship between television viewing and leisure-time physical activity during adolescence.

OBJECTIVE. The goal was to examine the longitudinal associations of changes in television viewing and other sources of sedentary behavior with changes in leisure-time moderate/vigorous physical activity in adolescence. METHODS. We studied a cohort of 6369 girls and 4487 boys who were 10 to 15 years of age in 1997. During each of 4 years of follow-up assessments, participants self-reported their weekly hours of television viewing. By using a seasonal questionnaire, we also obtained detailed information on physical activities over the previous year, from which we calculated total leisure-time moderate/vigorous physical activity. We performed linear regression analyses to assess the longitudinal associations between 1-year changes in television viewing and 1-year changes in leisure-time moderate/vigorous physical activity during the same year, using data from 1997 through 2001. RESULTS. One-year changes (mean ± SD) were −0.13 ± 7.2 hours/week for leisure-time moderate/vigorous physical activity, −0.55 ± 7.0 hours/week for television viewing, and −1.02 ± 11.0 hours/week for total sedentary behaviors. In longitudinal models adjusted for age, age2, gender, race/ethnicity, Tanner stage, menarche (in girls), baseline physical activity, and baseline television viewing, we found no substantive relationship between year-to-year changes in television viewing and changes in leisure-time moderate/vigorous physical activity (0.03 hours/week, for each 1-hour/week change in television viewing). There were no material associations in age or gender subgroups. CONCLUSIONS. In this longitudinal study, changes in television viewing were not associated with changes in leisure-time moderate/vigorous physical activity. Our findings suggest that television viewing and leisure-time physical activity are separate constructs, not functional opposites.

Prospective Study of Adolescent Alcohol Consumption and Risk of Benign Breast Disease in Young Women

OBJECTIVE: To investigate prospectively, using alcoholic beverage consumption data collected in real time, the association between adolescent drinking and risk of biopsy-confirmed benign breast disease (BBD) in young women. PARTICIPANTS AND METHODS: The Growing Up Today Study is a prospective cohort study of US girls, aged 9 to 15 years at baseline, with annual questionnaires from 1996 through 2001, followed by questionnaires in 2003, 2005, and 2007. On the 2003 survey, the participants (then aged 16–23 years) provided information about their alcoholic beverage consumption in the previous year. On the 2005 and 2007 surveys, a total of 6899 women (aged 18–27 years) reported whether a health care provider had ever diagnosed them with BBD (n = 147 cases) and whether it was confirmed by biopsy (n = 67 cases); 6752 women reported never being diagnosed with BBD. RESULTS: Adjusted for age and BMI, quantity of alcohol consumed was associated with increased risk of biopsy-confirmed BBD (odds ratio: 1.50 per drink per day [95% confidence interval: 1.19–1.90]). Girls who typically drank 6 or 7 days/week were at higher risk (odds ratio: 5.50 [95% confidence interval: 1.23–24.53]) compared with those who never drank or who drank less than once per week. CONCLUSIONS: Higher amounts consumed, and more frequent consumption, of alcoholic beverages in adolescence may increase the occurrence of BBD in young women. Advising teenagers to avoid alcoholic beverages, along with smoking and sun exposure, may reduce cancer incidence in adulthood.

Breast-feeding and overweight in adolescence: within-family analysis [corrected].

Background: Previous reports have found associations between having been breast-fed and a reduced risk of being overweight. These associations may be confounded by sociocultural determinants of both breast-feeding and obesity. We addressed this possibility by assessing the association of breast-feeding duration with adolescent obesity within sibling sets. Methods: We surveyed 5614 siblings age 9 to 14 years and their mothers. These children were a subset of participants in the Growing Up Today Study, in which we had previously reported an inverse association of breast-feeding duration with overweight. We compared the prevalence of overweight (body mass index exceeding the age-sex-specific 85th percentile) in siblings who were breast-fed longer than the mean duration of their sibship with those who were breast-fed for a shorter period. Then we compared odds ratios from this within-family analysis with odds ratios from an overall (ie, not within-family) analysis. Results: Mean ± standard deviation breast-feeding duration was 6.4 ± 4.0 months, and crude prevalence of overweight was 19%. On average, siblings who were breast-fed longer than their family mean had breast-feeding duration 3.7 months longer than their shorter-duration siblings. The adjusted odds ratio (OR) for overweight among siblings with longer breast-feeding duration, compared with shorter duration, was 0.92 (95% confidence interval = 0.76-1.11). In overall analyses, the adjusted OR was 0.94 (0.88-1.00) for each 3.7-month increment in breast-feeding duration. Conclusion: The estimated OR for the within-family analysis was close to the overall estimate, suggesting that the apparent protective effect of breast-feeding on later obesity was not highly confounded by unmeasured sociocultural factors. A larger study of siblings, however, would be needed to confirm this conclusion.

Dairy Intakes in Older Girls and Risk of Benign Breast Disease in Young Women

Previous investigations found high dairy intakes in girls associated with rapid height growth and excess weight gain, which had opposite relationships with benign breast disease (BBD) in young women. We use data from the longitudinal Growing Up Today Study (GUTS) to investigate whether dairy intakes, in older children/adolescents, are associated with BBD risk in young women. GUTS includes 9,039 females, ages 9–15 years in 1996, who completed questionnaires annually through 2001, then in 2003, 2005, 2007, and 2010. Dietary food frequencies (1996–2001) obtained milk, yogurt, and cheese intakes. On 2005–2010 surveys, 7,011 females (18–29 years) reported whether a health care provider ever diagnosed them with BBD (n = 250) and if confirmed by breast biopsy (n = 105). Logistic regression models estimated associations between prevalent biopsy-confirmed BBD and dairy intakes, adjusted for age and energy. Multivariable-adjusted models additionally included menarche age, childhood adiposity, adolescent alcohol consumption, and pregnancy. Further analyses stratified by family history. Age-energy–adjusted models of dairy (milk, yogurt, cheese, total dairy servings, dairy protein, dairy fat) intakes at 14 yr found no significant associations with BBD risk [milk: OR, 0.90/(serving/d); 95% confidence interval (CI), 0.76–1.05; dairy protein: OR, 0.98/(10 g/d); 95% CI, 0.82–1.17). Separate analyses of dairy intakes at 10 yr, intakes before the growth spurt, during the growth spurt, before menses-onset, and after menses-onset provided no significant associations with BBD. Multivariable adjustment, and family history stratification, did not alter the above findings. We conclude that dairy intakes by older girls have no strong relation with BBD risk in young women. Because of small number of cases, it is important to continue follow-up and re-examine later. Cancer Epidemiol Biomarkers Prev; 22(4); 670–4. ©2013 AACR.