Louise C. Greenspan

Pubertal Assessment Method and Baseline Characteristics in a Mixed Longitudinal Study of Girls

OBJECTIVES: The objective of this study was to describe the assessment methods and maturation status for a multisite cohort of girls at baseline recruitment and at ages 7 and 8 years. METHODS: The method for pubertal maturation staging was developed collaboratively across 3 sites. Girls at ages 6 to 8 years were recruited at 3 sites: East Harlem, New York; greater Cincinnati metropolitan area; and San Francisco Bay area, California. Baseline characteristics were obtained through interviews with caregivers and anthropometric measurements by trained examiners; breast stage 2 was defined as onset of pubertal maturation. The κ statistic was used to evaluate agreement between master trainers and examiners. Logistic regression models were used to identify factors that are associated with pubertal maturation and linear regression models to examine factors that are associated with height velocity. RESULTS: The baseline cohort included 1239 girls. The proportion of girls who had attained breast stage 2 varied by age, race/ethnicity, BMI percentile, and site. At 7 years, 10.4% of white, 23.4% of black non-Hispanic, and 14.9% of Hispanic girls had attained breast stage ≥2; at 8 years, 18.3%, 42.9%, and 30.9%, respectively, had attained breast stage ≥2. The prime determinant of height velocity was pubertal status. CONCLUSIONS: In this multisite study, there was substantial agreement regarding pubertal staging between examiners across sites. The proportion of girls who had breast development at ages 7 and 8 years, particularly among white girls, is greater than that reported from studies of girls who were born 10 to 30 years earlier.

Onset of Breast Development in a Longitudinal Cohort

BACKGROUND AND OBJECTIVES: There is growing evidence of pubertal maturation occurring at earlier ages, with many studies based on cross-sectional observations. This study examined age at onset of breast development (thelarche), and the impact of BMI and race/ethnicity, in the 3 puberty study sites of the Breast Cancer and the Environment Research Program, a prospective cohort of >1200 girls. METHODS: Girls, 6 to 8 years at enrollment, were followed longitudinally at regular intervals from 2004 to 2011 in 3 geographic areas: the San Francisco Bay Area, Greater Cincinnati, and New York City. Sexual maturity assessment using Tanner staging was conducted by using standardized observation and palpation methods by trained and certified staff. Kaplan-Meier analyses were used to describe age at onset of breast maturation by covariates. RESULTS: The age at onset of breast stage 2 varied by race/ethnicity, BMI at baseline, and site. Median age at onset of breast stage 2 was 8.8, 9.3, 9.7, and 9.7 years for African American, Hispanic, white non-Hispanic, and Asian participants, respectively. Girls with greater BMI reached breast stage 2 at younger ages. Age-specific and standardized prevalence of breast maturation was contrasted to observations in 2 large cross-sectional studies conducted 10 to 20 years earlier (Pediatric Research in Office Settings and National Health and Nutrition Examination Survey III) and found to have occurred earlier among white, non-Hispanic, but not African American girls. CONCLUSIONS: We observed the onset of thelarche at younger ages than previously documented, with important differences associated with race/ethnicity and BMI, confirming and extending patterns seen previously. These findings are consistent with temporal changes in BMI.

Prehypertension and Hypertension in Community-Based Pediatric Practice

OBJECTIVE: To examine the prevalence of prehypertension and hypertension among children receiving well-child care in community-based practices. METHODS: Children aged 3 to 17 years with measurements of height, weight, and blood pressure (BP) obtained at an initial (index) well-child visit between July 2007 and December 2009 were included in this retrospective cohort study across 3 large, integrated health care delivery systems. Index BP classification was based on the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents: normal BP, <90th percentile; prehypertension, 90th to 94th percentile; hypertension, 3 BP measurements ≥95th percentile (index and 2 subsequent consecutive visits). RESULTS: The cohort included 199 513 children (24.3% aged 3–5 years, 34.5% aged 6–11 years, and 41.2% aged 12–17 years) with substantial racial/ethnic diversity (35.9% white, 7.8% black, 17.6% Hispanic, 11.7% Asian/Pacific Islander, and 27.0% other/unknown race). At the index visit, 81.9% of participants were normotensive, 12.7% had prehypertension, and 5.4% had a BP in the hypertension range (≥95th percentile). Of the 10 848 children with an index hypertensive BP level, 3.8% of those with a follow-up BP measurement had confirmed hypertension (estimated 0.3% prevalence). Increasing age and BMI were significantly associated with prehypertension and confirmed hypertension (P < .001 for trend). Among racial/ethnic groups, blacks and Asians had the highest prevalence of hypertension. CONCLUSIONS: The prevalence of hypertension in this community-based study is lower than previously reported from school-based studies. With the size and diversity of this cohort, these results suggest the prevalence of hypertension in children may actually be lower than previously reported.

Increased incidence in post-transplant diabetes mellitus in children: a case-control analysis.

Abstract. There is limited information regarding the incidence and features of post-transplant diabetes mellitus (PTDM) in pediatric renal transplant recipients. We noted a recent increased frequency of PTDM and reviewed charts of children who underwent renal transplantation from 1 September 1986 to 31 August 1999 to characterize the risk factors and natural history of PTDM. Sixteen children were identified with PTDM, and were each matched with two transplanted controls who did not develop PTDM. Clinical presentation varied from asymptomatic hyperglycemia to hyperosmolar dehydration or diabetic ketoacidosis. The mean time from transplantation to PTDM presentation was 1.2 years (range 1 day to 6.2 years). Significant risk factors for PTDM included: first degree family history of type 2 DM [odds ratio (OR) 23.9]; second degree family history of type 2 DM (OR 5.8); tacrolimus use (OR 9.1 versus cyclosporin); and hyperglycemia in the 2 weeks immediately after transplantation (OR 4.7). Seven of eight children with persistent PTDM continue to receive insulin. Patients with persistent PTDM had later onset disease (mean 1.9 years) compared to those with transient PTDM (0.3 years), suggesting different pathophysiologic processes. We suggest that all children undergoing renal transplantation be screened routinely for PTDM after transplantation, and that such patients may benefit from the avoidance of tacrolimus, as it may cause permanent beta-cell injury.

Puberty in girls of the 21st century

Several studies have noted contemporary girls are undergoing pubertal maturation at younger ages. During this same time period many Western nations have experienced an obesity epidemic, prompting investigators and public health officials to consider the association of these 2 events, and if other exposures might impact this relationship. There are several potential mechanisms that could impact the relationship of pubertal timing in girls with greater body mass, including direct effects of obesity on pubertal timing as well underlying exposures that impact body mass as well as timing of pubertal maturation. These underlying conditions include chemical compounds that could impact synthesis or action of sex hormones, called endocrine disrupting chemicals (EDs). We examine the decline in the age of breast development and potential genetic and environmental influences, the obesity epidemic in the US and other nations, and potential mechanisms to explain the relationship between greater body mass index with earlier puberty in girls.

Parental feeding practices in Mexican American families: initial test of an expanded measure.

BackgroundAlthough obesity rates are high among Latino children, relatively few studies of parental feeding practices have examined Latino families as a separate group. Culturally-based approaches to measurement development can begin to identify parental feeding practices in specific cultural groups. This study used qualitative and quantitative methods to develop and test the Parental Feeding Practices (PFP) Questionnaire for use with Mexican American parents. Items reflected both parent’s use of control over child eating and child-centered feeding practices.MethodsIn the qualitative phase of the research, 35 Latino parents participated in focus groups. Items for the PFP were developed from focus group discussions, as well as adapted from existing parent feeding practice measures. Cognitive interviews were conducted with 37 adults to evaluate items. In the quantitative phase, mothers and fathers of 174 Mexican American children ages 8–10 completed the PFP and provided demographic information. Anthropometric measures were obtained on family members.ResultsConfirmatory factor analyses identified four parental feeding practice dimensions: positive involvement in child eating, pressure to eat, use of food to control behavior, and restriction of amount of food. Factorial invariance modeling suggested equivalent factor meaning and item response scaling across mothers and fathers. Mothers and fathers differed somewhat in their use of feeding practices. All four feeding practices were related to child body mass index (BMI) percentiles, for one or both parents. Mothers reporting more positive involvement had children with lower BMI percentiles. Parents using more pressure to eat had children with lower BMI percentiles, while parents using more restriction had children with higher BMI percentiles. Fathers using food to control behavior had children with lower BMI percentiles.ConclusionsResults indicate good initial validity and reliability for the PFP. It can be used to increase understanding of parental feeding practices, children’s eating, and obesity among Mexican Americans, a population at high risk of obesity.

Prevalence of obesity and extreme obesity in children aged 3–5 years

The prevalence of obesity in the United States has increased dramatically over the past three decades. There is a growing spectrum of severe obesity among children and adolescents. Obesity trends and race/ethnic differences may be evident at a young age.

Maternal Hyperglycemia During Pregnancy Predicts Adiposity of the Offspring

OBJECTIVE To investigate associations between maternal pregnancy hyperglycemia, gestational diabetes mellitus (GDM), and offspring adiposity. RESEARCH DESIGN AND METHODS We evaluated these associations in a longitudinal study of 421 mother-daughter pairs at Kaiser Permanente Northern California. Maternal pregnancy glucose values were obtained from maternal medical records. Outcomes included three measures of girls’ adiposity, measured annually: 1) ≥85th age-specific percentile for BMI; 2) percent body fat (%BF); and 3) waist-to-height ratio (WHR). RESULTS Adjusting for maternal age at delivery, race/ethnicity, pregravid BMI, girl’s age, and girl’s age at onset of puberty, having a mother with GDM increased a girl’s risk of having a BMI ≥85th percentile or having %BF or WHR in the highest quartile (Q4), compared with those in the lowest quintile of blood glucose (odds ratio [OR] 3.56 [95% CI 1.28–9.92]; OR 3.13 [95% CI 1.08–9.09]; and OR 2.80 [95% CI 1.00–7.84], respectively). There was a significant interaction between the presence of GDM and pregravid BMI; girls whose mothers had both risk factors had the highest odds of having a BMI ≥85th percentile (OR 5.56 [95%CI 1.70–18.2]; Q4 %BF, OR 6.04 [95%CI 1.76–20.7]; and Q4 WHR, OR 3.60 [95%CI 1.35–9.58]). Similar, although weaker, associations were found in the association between hyperglycemia and offspring adiposity. CONCLUSIONS Girls who were exposed to maternal GDM or hyperglycemia in utero are at higher risk of childhood adiposity; risk increases if the mother is overweight or obese. Screening and intervention for this high-risk group is warranted to slow the intergenerational transmission of obesity and its sequelae.

Change in Weight Status and Development of Hypertension.

OBJECTIVE: To examine the association of BMI percentile and change in BMI percentile to change in blood pressure (BP) percentile and development of hypertension (HTN). METHODS: This retrospective cohort included 101 606 subjects age 3 to 17 years from 3 health systems across the United States. Height, weight, and BPs were extracted from electronic health records, and BMI and BP percentiles were computed with the appropriate age, gender, and height charts. Mixed linear regression estimated change in BP percentile, and proportional hazards regression was used to estimate risk of incident HTN associated with BMI percentile and change in BMI percentile. RESULTS: The largest increases in BP percentile were observed among children and adolescents who became obese or maintained obesity. Over a median 3.1 years of follow-up, 0.3% of subjects developed HTN. Obese children ages 3 to 11 had twofold increased risk of developing HTN compared with healthy weight children. Obese children and adolescents had a twofold increased risk of developing HTN, and severely obese children had a more than fourfold increased risk. Compared with those who maintained a healthy weight, children and adolescents who became obese or maintained obesity had a more than threefold increased risk of incident HTN. CONCLUSIONS: We observed a strong, statistically significant association between increasing BMI percentile and increases in BP percentile, with risk of incident HTN associated primarily with obesity. The adverse impact of weight gain and obesity in this cohort over a short period underscores the early need for effective strategies for prevention of overweight and obesity.

Is it time for bed? Short sleep duration increases risk of obesity in Mexican American children

OBJECTIVE Cross-sectional studies show that sleep is related to childhood obesity. We aimed to examine the longitudinal impact of sleep on the risk of obesity in Mexican American children. DESIGN AND METHODS We evaluated 229 Mexican American 8-10-year-olds and their mothers at baseline and at 12- and 24-month follow-ups. Sleep duration and anthropometrics were collected. Age- and gender-specific body mass index (BMI) z-scores (BMIz) were calculated based on Centers for Disease Control and Prevention guidelines. Sleep duration was estimated using accelerometry. Children were also categorized as long or short sleepers, using the National Sleep Foundations recommendation to define adequate sleep duration (10-11 h for 5-12-year-olds). Using linear regressions, we examined whether sleep duration predicted BMIz, waist-to-height ratio (WHtR), and weight gain at 24 months. RESULTS Children were mostly short sleepers (82%). Children who slept less were more likely to have a higher BMIz, WHtR, and weight gain at the 24-month follow-up (β = -0.07, P = 0.01; β = -0.11, P <0.01; and β = -0.14, P = 0.02, respectively), after controlling for baseline weight status, child gender, maternal BMI, and occupation. CONCLUSION In Mexican American children, shorter sleep duration at baseline was associated with increased weight status over 24 months.