Table 2.
Selected characteristic of 3 case-control studies of childhood overweight/obesity and early puberty.
| References | Geographic region | Gender | Sample size | Definition of overweight/obesity | Definition of early puberty | Adjustments or matches made | Quality score |
|---|---|---|---|---|---|---|---|
| Chen et al. (27) | China | Girls and boys | 15,937 | Obesity: WHO Child Growth Standards BMI ≥2 SD Overweight: WHO Child Growth Standards BMI ≥1 SD | Under 8 years for Tanner stage two or above for breast (B2) or pubic hair development (PH2), 10 years for menstruation in girls, and under 9 years for Tanner stage two or above for pubic hair or testicle development (T2) (testicular volume, TV ≥4 mL) in boys | None | 8 |
| He et al. (28) | China | Girls and boys | 1,472 | Obesity/overweight: Chinese Working Group on Obesity | Quartiles of the decimal age of each Tanner stage (>P25) | None | 8 |
| Xu et al. (29) | China | Girls and boys | 2,908 | Obesity/overweight: Chinese Working Group on Obesity | Puberty Development Scale (PDS) score > + s | Region, age, whether the only child, family economic status, parents' educational level | 9 |