Household and schooling rather than diet offset the adverse associations of height with school competence and emotional disturbance among Taiwanese girls

Abstract

Objective: Short stature may reflect health in early life and be an enduring disability. How birth weight, gender, household, elementary schooling and diet play a role in associations between stature and overall school competence (OSC) have been assessed. Design: The 2001-2002 Nutrition and Health Survey in Taiwan (NAHSIT) for elementary schoolchildren (n 2274, 52·1 % boys) was linked to birth records. It provided sociodemographic, dietary quality, body compositional and school performance (as Scale for Assessing Emotional Disturbance, SAED; OSC as an SAED subscale) data. Lower birth weight was ≤15th percentile: 2850 g for boys and 2700 g for girls, and stature as z-scores for Taiwanese. Multivariable linear regression was used for relationships between OSC and stature. Trends in OSC by stature and school grade were assessed. Setting: The 2001-2002 NAHSIT for elementary schoolchildren. Participants: Totally, 2274 schoolchildren aged 6-13 years. Results: Compared to normal height (-2< height for age z-score (HAZ) <2), shorter girls (HAZ ≤ -2) had a lower OSC (8·87 v. 10·5, P < 0·05) and taller girls (HAZ ≥ 2) had a better OSC (12·3 v. 10·5, P < 0·001). Maternal education and household income each contributed more than 5 % of OSC variance. OSC and HAZ among girls were positively associated and emotional disturbance negatively associated. Shortness-associated lower OSC underwent remediation with advancing school grade. Stature and OSC were not evidently related in boys. Conclusions: Shorter stature can compromise OSC among school girls. The major determinants in shorter girls are less household income and limited parental education.