Obesity is positively associated with dehydroepiandrosterone sulfate concentrations at 7 y in Chilean children of normal birth weight

Abstract

Background: In low-birth-weight girls, obesity increases the risk of premature adrenarche and metabolic complications. However, the consistency of this association in normal-birth-weight children and its potential mediators remain unknown.

Objectives: The objectives were to assess the associations between obesity indicators and dehydroepiandrosterone sulfate (DHEAS) at 7 y of age and to evaluate the role of hormonal markers on these associations.

Design: We assessed in 969 participants (6.9 y; 48% girls; all Tanner I) in the Growth and Obesity Chilean Cohort Study the associations between DHEAS and weight, BMI, waist circumference (WC), waist-to-height ratio, skinfold thickness, and percentage total fat (bioimpedance) and determined whether these associations were related to insulin, insulin-like growth factor I (IGF-I), and leptin. We also compared BMI and height growth from 0 to 7 y of age in nonobese and obese children with normal and high DHEAS (≥75th percentile) at 7 y.

Results: DHEAS concentrations were similar between girls (30.3 ±1.86 μg/dL) and boys (29.4 ±1.73 μg/dL) (P > 0.05); 17.3% of children were obese (BMI-for-age z score ≥2 SD). Adiposity indicators were positively and similarly associated with DHEAS [ie, BMI, β standardized regression coefficient: 0.23 (95% CI: 0.17, 0.29); WC, β standardized regression coefficient: 0.23 (95% CI: 0.16, 0.30)]; these associations were only partially related to IGF-I and leptin. Obese children had twice the risk of high DHEAS (OR: 2.16; 95% CI: 1.51, 3.09); at 7 y, obese children with high DHEAS were fatter and more centrally obese than their counterparts (P < 0.05), although their previous growth was similar (P > 0.05). None of the results differed by sex (P > 0.05).

Conclusion: In children of normal birth weight, obesity is positively associated with DHEAS at 7 y of age.

FIGURE 1.

Standardized regression coefficients (and 95% CIs) for DHEAS concentrations at 7 y of age per sample-specific 1-SD increments in adiposity indicators at 7 y in 969 prepubertal Chilean children. Multiple linear models adjusted by age and sex. Fat index = fat mass based on skinfold thickness/height²; fat mass index BIA = fat mass based on bioimpedance/height²; waist/height = waist-to-height ratio. Each of the following values corresponds to the standard deviation: DHEAS: 1.83; weight: 4.71; BMI: 2.33; %fat: 4.82; fat mass index: 1.26; fat mass index BIA: 1.33; waist: 6.49; waist-to-height ratio: 0.05. BIA, bioimpedance analysis; DHEAS, dehydroepiandrosterone sulfate.

FIGURE 2.

BMI and linear growth of 996 prepubertal Chilean children by nutritional status and DHEAS concentrations at 7 y of age. Dotted lines indicate 95% superior CIs for OH and 95% inferior CIs for ON. Dotted and dashed lines indicate 95% superior CIs for NOH and 95% inferior CIs for NON. Generalized linear models were adjusted for age and sex. Obesity = BAZ ≥2, WHO 2007; anthropometric z scores are based on WHO 2006–2007. Differences between nonobese and obese children were significant (P < 0.05) from 12 mo on (BMI and BAZ) and from 48 mo on (HAZ); all remaining differences and interactions between obesity and high DHEAS concentrations were not significant (P > 0.05). BAZ, BMI-for-age z score; DHEAS, dehydroepiandrosterone sulfate; HAZ, height-for-age z score; NOH, nonobese high DHEAS; NON, nonobese normal DHEAS; OH, obese high DHEAS; ON, obese normal DHEAS.