Pubertal Timing and Cardiometabolic Markers at Age 16 Years.

OBJECTIVE: To examine the association between pubertal timing and cardiometabolic markers among adolescents. STUDY DESIGN: We used data from Dutch adolescents participating in a birth cohort study. The study population for the current study consisted of 799 adolescents of whom data were available for at least 1 of the exposure variables (pubertal timing and/or age at menarche) and any of the cardiometabolic markers (waist circumference, cholesterol, blood pressure [BP], glycated hemoglobin) measured at age 16 years. Adolescents self-reported pubertal development at ages 11, 14, and 16 years. We categorized participants with early (84 girls, 88 boys), intermediate (240 girls, 211 boys), or late pubertal timing (89 girls, 85 boys). We estimated differences in cardiometabolic markers using linear regression analysis. RESULTS: Girls with early pubertal timing had 1.54 cm larger waist circumference (95% CI .05; 3.03) and 3.98 mm Hg higher systolic BP (95% CI 1.69; 6.27) at age 16 years than girls with intermediate pubertal timing. The association with systolic BP remained after adjusting for childhood body mass index (BMI) (age 8 years) but attenuated after adjusting for BMI in adolescence (age 16 years). Boys with early pubertal timing had 0.79 mmol/mol lower glycated hemoglobin (95%CI -1.38; -0.20) than boys with intermediate pubertal timing. CONCLUSIONS: Girls with early pubertal timing had unfavorable BP levels at age 16 years, independent of BMI in childhood. Girls and boys with late pubertal timing had a tendency for lower waist circumference, but no differences in other cardiometabolic markers. Late pubertal timing does not appear to be a risk factor for unfavorable cardiometabolic markers in adolescence.

Cesarean Delivery, Overweight throughout Childhood, and Blood Pressure in Adolescence.

OBJECTIVES: To investigate whether children delivered by cesarean had a higher risk of being overweight from early until late childhood and whether they had a higher blood pressure in adolescence compared with children delivered vaginally. STUDY DESIGN: We used data from a Dutch birth cohort study with prenatal inclusion in 1996 and 1997. Mode of delivery (cesarean or vaginal delivery) was ascertained at 3 months after birth by questionnaire. During clinical examinations, height and weight (at age 4, 8, 12, and 16 years) and blood pressure (at age 12 and 16 years) were measured. We used mixed model analysis to estimate associations of cesarean delivery with overweight and blood pressure z scores in 2641 children who participated in at least 1 of the 4 examinations. RESULTS: Children born by cesarean delivery (n = 236, 8.9%) had a 1.52 (95% CI 1.18, 1.96) higher odds of being overweight throughout childhood than children delivered vaginally. Children born by cesarean delivery had no higher systolic blood pressure z-score (0.11 SD, 95% CI -0.04, 0.26), nor a different diastolic blood pressure z-score (-0.00 SD, 95% CI -0.10, 0.09) in adolescence than children delivered vaginally. CONCLUSIONS: Compared with children delivered vaginally, children delivered by cesarean had a 52% higher risk of being overweight throughout childhood, but this was not accompanied by a higher blood pressure in adolescence.

The role of early life factors in the development of ethnic differences in growth and overweight in preschool children: a prospective birth cohort.

BACKGROUND: Ethnic differences in childhood and adulthood are known, but ethnic differences in preschool overweight and associated factors are less studied. We assessed ethnic differences in pre-school age overweight, and studied the mediating role of early life factors in this association. Furthermore, we assessed body mass index (BMI) z-score development from birth to age 4 years to study ethnic-specific differences in BMI z-score trajectory. METHODS: We used data on 4581 children participating in a birth cohort who were born between 2002 and 2006 in Rotterdam, the Netherlands. Child's ethnicity was defined according to country of birth of the parents. Weight and length/height was repeatedly measured between 1 and 45 months of age. Overweight at age 4 years was defined according to cut-off points for BMI from the international obesity task force. We performed logistic regression to obtain independent estimates of the association between ethnicity and preschool-age overweight, and to assess the mediating role of early life risk factors. Mixed models were used to describe BMI-z development for each ethnic group from birth to preschool age. RESULTS: Relative to native Dutch children, non-Dutch children were more likely to be overweight at age 4 years, except for Surinamese-Hindustani children. Socio-demographic factors, parental BMI, and infant weight change in the first 6 months after birth reduced associations. After full adjustment, Turkish (OR: 2.02, 95% CI: 1.34-3.04) and Antillean/Surinamese Creole (OR: 1.78, 95% CI: 1.06-3.02) children were still more likely to be overweight at age 4 years. CONCLUSION: Ethnic differences on the prevalence of overweight in preschool children can be partially explained by maternal educational level, parental overweight and early infant weight change. These may be possible targets to reduce ethnic inequalities in preschool age overweight.

Socioeconomic status is not inversely associated with overweight in preschool children.

OBJECTIVE: To assess whether socioeconomic inequalities were already present in preschool children. STUDY DESIGN: We used data from 2954 Dutch children participating in a longitudinal birth cohort study. Indicators of socioeconomic status were mother's educational level and household income. Body mass index (BMI)-for-age standard deviation scores were derived from a national reference. Overweight was defined at 24 and 36 months according to age- and sex-specific cut-off points for BMI. Multivariable regression analyses were performed. RESULTS: Relative to children from mothers with the highest educational level, mean BMI standard deviation scores was lower at age 24 months in children from mothers with the low, mid-low, and mid-high educational level, and in the mid-low group at 36 months (P < .001). Prevalence of overweight was lower in children from mothers with the mid-low educational level at age 24 and 36 months (adjusted odds ratio at 24 months: 0.61; 95% confidence interval: 0.43-0.87 and at 36 months: 0.65; 95% confidence interval: 0.44-0.96) but was not significantly different for the other educational levels. There were no significant differences in childhood overweight by income level. CONCLUSIONS: The inverse association between socioeconomic status and childhood overweight presumably emerges after age 3 years. Before this age, the gradient may be the reverse.