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Author: Li, Chaoyang
Resulting in 4 citations.
1. Li, Chaoyang
Goran, Michael I.
Kaur, Harsohena
Nollen, Nicole
Ahluwalia, Jasjit S.
Developmental Trajectories of Overweight During Childhood: Role of Early Life Factors
Obesity 15,3 (March 2007): 760-771.
Also: http://www.nature.com/oby/journal/v15/n3/full/oby200790a.html
Cohort(s): Children of the NLSY79, NLSY79
Publisher: Nature Publishing Group
Keyword(s): Birthweight; Body Mass Index (BMI); Breastfeeding; Fertility; Growth Curves; Intergenerational Patterns/Transmission; Modeling, Growth Curve/Latent Trajectory Analysis; Obesity; Pre/post Natal Behavior; Weight

Permission to reprint the abstract has not been received from the publisher.

Objective: Our goal was to identify developmental trajectories of overweight in children and to assess early life influences on these trajectories.

Research Methods and Procedures: Participants consisted of 1739 white, black, and Hispanic children who were younger than 2 years at the first survey and were followed up to 12 years of age. Repeated measures of overweight, defined as BMI ≥95th percentile, were used to identify overweight trajectories with a latent growth mixture modeling approach.

Results: Three distinct overweight trajectories were identified: 1) early onset overweight (10.9%), 2) late onset overweight (5.2%), and 3) never overweight (83.9%). After adjustment for multiple potential risk factors, male gender [odds ratio (OR), 1.5; 95% confidence interval (CI), 1.0 to 2.2], black ethnicity (OR, 1.7; 95% CI, 1.1 to 2.6), maternal 25 ≤ BMI <30 kg/m2 (OR, 2.2; 95% CI, 1.3 to 3.7) or ≥30 kg/m2 (OR, 5.1; 95% CI, 2.9 to 9.1), maternal weight gain during pregnancy ≥20.43 kg (OR, 1.7; 95% CI, 1.0 to 2.9), and birth weight ≥4000 g (OR, 2.0; 95% CI, 1.2 to 3.4) were associated with an increased risk of early onset overweight. These risk factors, except maternal weight gain, exerted similar effects on late onset overweight. In addition, maternal smoking (OR, 1.6; 95% CI, 0.8 to 3.1) and birth order ≥3 (OR, 2.3; 95% CI, 1.0 to 5.2) were associated with an increased risk of late onset overweight only. Breastfeeding ≥4 months was associated with a decreased risk of both early (OR, 0.7; 95% CI, 0.3 to 1.3) and late onset overweight (OR, 0.7; 95% CI, 0.3 to 1.7).

Discussion: Two trajectories of overweight and one never overweight group were identified. Early life predictors may have a significant influence on the developmental trajectories of overweight in children.

Bibliography Citation
Li, Chaoyang, Michael I. Goran, Harsohena Kaur, Nicole Nollen and Jasjit S. Ahluwalia. "Developmental Trajectories of Overweight During Childhood: Role of Early Life Factors." Obesity 15,3 (March 2007): 760-771.
2. Li, Chaoyang
Kaur, Harsohena
Choi, Won S.
Huang, Terry T-K
Lee, Rebecca E.
Ahluwalia, Jasjit S.
Additive Interactions of Maternal Prepregnancy BMI and Breast-feeding on Childhood Overweight
Obesity Research 13,2 (February 2005): 362-371.
Also: http://www.nature.com/oby/journal/v13/n2/abs/oby200548a.html
Cohort(s): Children of the NLSY79, NLSY79
Publisher: International Association for the Study of Obesity (IASO)
Keyword(s): Birthweight; Body Mass Index (BMI); Breastfeeding; Child Health; Children, Health Care; Hispanics; Intergenerational Patterns/Transmission; Obesity; Pre/post Natal Behavior; Pre/post Natal Health Care

Permission to reprint the abstract has not been received from the publisher.

OBJECTIVE: To examine the interactions of maternal prepregnancy BMI and breast-feeding on the risk of overweight among children 2 to 14 years of age.

RESEARCH METHODS AND PROCEDURES: The 1996 National Longitudinal Survey of Youth, Child and Young Adult data in the United States were analyzed (n = 2636). The weighted sample represented 51.3% boys, 78.0% whites, 15.0% blacks, and 7.0% Hispanics. Childhood overweight was defined as BMI >/=95th percentile for age and sex. Maternal prepregnancy obesity was determined as BMI >/=30 kg/m(2). The duration of breast-feeding was measured as the weeks of age from birth when breast-feeding ended. RESULTS: After adjusting for potential confounders, children whose mothers were obese before pregnancy were at a greater risk of becoming overweight [adjusted odds ratio (OR), 4.1; 95% confidence interval (CI), 2.6, 6.4] than children whose mothers had normal BMI (<25 kg/m(2); p < 0.001 for linear trend). Breast-feeding for >/=4 months was associated with a lower risk of childhood overweight (OR, 0.6; 95% CI, 0.4, 1.0; p = 0.06 for linear trend). The additive interaction between maternal prepregnancy obesity and lack of breast-feeding was detected (p < 0.05), such that children whose mothers were obese and who were never breast-fed had the greatest risk of becoming overweight (OR, 6.1; 95% CI, 2.9, 13.1).

DISCUSSION: The combination of maternal prepregnancy obesity and lack of breast-feeding may be associated with a greater risk of childhood overweight. Special attention may be needed for children with obese mothers and lack of breast-feeding in developing childhood obesity intervention programs.

Bibliography Citation
Li, Chaoyang, Harsohena Kaur, Won S. Choi, Terry T-K Huang, Rebecca E. Lee and Jasjit S. Ahluwalia. "Additive Interactions of Maternal Prepregnancy BMI and Breast-feeding on Childhood Overweight." Obesity Research 13,2 (February 2005): 362-371.
3. Li, Chaoyang
Mayo, M.S.
Ahluwalia, Jasjit S.
Maternal Smoking during Pregnancy, Birth Weight, and Childhood Overweight: A Suppression Effect Model
Annals of Epidemiology 13,8 (September 2003): 569.
Also: http://www.sciencedirect.com/science/article/pii/S1047279703001637
Cohort(s): Children of the NLSY79, NLSY79, NLSY79 Young Adult
Publisher: Elsevier
Keyword(s): Birthweight; Body Mass Index (BMI); Breastfeeding; Child Health; Cigarette Use (see Smoking); Hispanics; Intergenerational Patterns/Transmission; Obesity; Pre-natal Care/Exposure; Pre/post Natal Behavior; Pregnancy and Pregnancy Outcomes; Smoking (see Cigarette Use)

METHODS: Children aged 2 to 15 years (mean, 8.6 yrs; SD, 3.5 yrs) in 1996 born to mothers in the National Longitudinal Survey of Youth (NLSY) were studied. The sample (n = 4,850) was 21.4% Hispanic, 29.9% Black, and 48.7% White. Body mass index (BMI) was calculated from measured weight and height, and the BMI-for-age percentile was determined using the revised CDC growth charts. Children with BMI-for-age at or above 85th percentile were defined as overweight. The suppression effects were tested based on the framework proposed by Baron and Kenny (1986) using a series of multiple logistic regression models with SAS-callable SUDAAN program.

RESULTS: After adjusting for sex, ethnicity, gestational age, breastfeeding, mother's age, education, and alcohol use during pregnancy, maternal smoking during pregnancy was significantly associated with childhood overweight without adjusting for birth weight (model 1, total effect tau1 = 0.36, p = 0.006). Maternal smoking during pregnancy was significantly associated with reduced birth weight (model 2, alpha = - 0.21, p<0.0001). The direct effect of maternal smoking on childhood overweight with adjusting for birth weight was increased (model 3, direct effect tau2 = 0.42, p = 0.002). Birth weight was also significantly associated with childhood overweight (model 3, beta = 0.23, p = 0.03). The suppression effect (product of alpha and beta = -0.05, p = 0.04) of birth weight accounted for 14% of the total effects of maternal smoking on childhood overweight.

Bibliography Citation
Li, Chaoyang, M.S. Mayo and Jasjit S. Ahluwalia. "Maternal Smoking during Pregnancy, Birth Weight, and Childhood Overweight: A Suppression Effect Model." Annals of Epidemiology 13,8 (September 2003): 569.
4. Mahnken, Jonathan D.
Li, Chaoyang
Nazir, Niaman
So, Joseph
Kaur, Harsohena
Ahluwalia, Jasjit S.
Analyzing the National Longitudinal Survey of Youth: A Comparison of Statistical Methods
Presented: Minneapolis, MN, Joint Statistical Meetings, August 2005
Cohort(s): Children of the NLSY79, NLSY79
Publisher: American Statistical Association
Keyword(s): Alcohol Use; Birthweight; Child Health; Cigarette Use (see Smoking); Modeling; Morbidity; Mortality; Obesity; Pre/post Natal Behavior; Weight

Recent trends in obesity incidence and prevalence among America's youth have raised concern among the public health community. Although much ongoing research is aimed at addressing the concerns of obesity and its related morbidity and mortality, many questions remain unanswered. We used the National Longitudinal Survey of Youth NLSY79 Child and Youth data to investigate obesity incidence. These data contain not only factors of the children such as birth weight, gender and race, but also maternal factors such as mother's age at pregnancy, prenatal care, and alcohol and tobacco use during pregnancy. While these data are rich in many ways, they present interesting statistical challenges. For this data set, respondents were surveyed biennially. Censored and missing data in both outcome and predictor variables are some of the problems that must be taken into account when determining the influence of the individual and maternal factors on adolescent obesity incidence. We applied different statistical methods (parametric survival analysis, GLMM, and GEE) to these data and compared the results, describing the merits and drawbacks of each approach.
Bibliography Citation
Mahnken, Jonathan D., Chaoyang Li, Niaman Nazir, Joseph So, Harsohena Kaur and Jasjit S. Ahluwalia. "Analyzing the National Longitudinal Survey of Youth: A Comparison of Statistical Methods." Presented: Minneapolis, MN, Joint Statistical Meetings, August 2005.