Sex Differences in Associations of Adiposity Measures and Insulin Resistance in US Hispanic/Latino Youth: The Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth)

Abstract

Context: US Hispanic/Latino youth are disproportionally affected by the obesity and diabetes.

Objective: We examined associations of adiposity measures with insulin resistance (IR) and hyperglycemia and the influences of sex and pubertal development on these associations.

Design, setting, and participants: We performed a cross-sectional analysis of 1223 8- to 16-year-old Hispanic/Latino youth from a community-based study in the United States (SOL Youth).

Main outcome measures: We measured IR (≥75th percentile of sex-specific Homeostatic Model Assessment of Insulin Resistance) and hyperglycemia (fasting glucose ≥100 mg/dL or hemoglobin a1c ≥5.7%).

Results: In boys, body mass index (BMI) showed the strongest association with IR [prevalence ratio (PR), 2.10; 95% confidence interval (CI), 1.87 to 2.36 per standard deviation], which was not statistically different compared with body fat percentage (%BF) (PR, 2.03; 95% CI, 1.81 to 2.29) and waist circumference (WC) (PR, 1.89; 95% CI, 1.67 to 2.13) but was significantly stronger compared with fat mass index (FMI) (PR, 1.79; 95% CI, 1.63 to 1.96), waist-to-hip ratio (WHR) (PR, 1.32; 95% CI, 1.21 to 1.44), and waist-to-height ratio (WHtR) (PR, 1.76; 95% CI, 1.54 to 2.01) (P for difference, <0.05). In girls, %BF (PR, 2.73; 95% CI, 2.34 to 3.20) showed a significantly stronger association with IR compared with BMI (PR, 1.48; 95% CI, 1.29 to 1.70), FMI (PR, 1.71; 95% CI, 1.49 to 1.95), WC (PR, 1.96; 95% CI, 1.70 to 2.27), WHR (PR, 1.95; 95% CI, 1.70 to 2.23), and WHtR (PR, 1.79; 95% CI, 1.53 to 2.09) (P for difference, <0.003). Associations between adiposity measures and IR were generally stronger among children in puberty versus those who had completed puberty, with significant interactions for WC and WHtR in boys and for BMI in girls (P for interaction, <0.01). Adiposity measures were modestly associated with hyperglycemia (PR, 1.14 to 1.25), with no interactions with sex or pubertal status.

Conclusions: Sex and puberty may influence associations between adiposity measures and IR in US Hispanic/Latino youth. Multiple adiposity measures are needed to better assess IR risk between boys and girls according to pubertal status.

Figure 1.

Differences (95% CIs) in glycemic traits with 1 SD increment in adiposity measures in Hispanic/Latino youth. (A) Log-fasting insulin. (B) Log-HOMA-IR. (C) Fasting glucose. (D) Hemoglobin A1C. Adiposity measures are transformed to age-adjusted, sex-specific z scores. Models adjusted for sex, pubertal status, Hispanic background, field center, nativity, parental education level, annual family income, and self-reported physical activity. Error bars are 95% CIs. *P < 0.05 for interaction between sex and adiposity measures on glycemic traits.

Figure 2.

Prevalence ratios (95% CIs) for insulin resistance with 1 SD increment in adiposity measures by sex and pubertal status. Adiposity measures are transformed to age-adjusted, sex-specific z scores. Models adjusted for Hispanic/Latino background, field center, nativity, parental education level, annual family income, and self-reported physical activity. Prepubertal children (Tanner stage 1) were excluded owing to small sample size (n ≤ 50). Subjects missing Tanner staging were also excluded. **P < 0.01 for interaction between puberty development and adiposity measures on insulin resistance in boys. ***P < 0.001 for interaction between puberty development and adiposity measures on insulin resistance in girls.