Poster Topical Area: Nutritional Epidemiology
Location: Hall D
Poster Board Number: 778
Objectives: Little is known about menarche in relation to adolescent nutritional status and growth in contemporary South Asia. We investigated, in rural Bangladesh, the extent to which attained height and body mass index (BMI) and annualized growth velocities are associated with age at menarche.
Methods: We studied a birth cohort of 12,956 (92%) of 14,059 girls 8-14 years of age, born during the JiVitA-1 antenatal vitamin A or β-carotene supplementation trial from 2001-2007 (West et al JAMA 2011). Starting in September 2015, anthropometry was measured twice 6-18 months apart, scheduled on children's birth month, and dates of menarche obtained. Initial status and growth velocities in height and BMI (kg/m2) of girls by menarcheal status were compared. Restricting data to girls who were premenarcheal at first interview (n=9,806), the risk (hazard) of menarche by incremental cm in attained height and kg/m2 in BMI was computed from multivariate Cox proportional hazards models. We further assessed temporal associations between annualized growth velocities and risk of menarche, adjusting for initial characteristics and the premenarcheal portion of the interim period.
Results: The estimated mean ± SD age at menarche among postmenarcheal girls was 12.8 ± 0.9 years. Adjusting for age, postmenarcheal girls were 7.7 cm taller and 6.9 kg heavier and 1.8 kg/m2 larger than premenarcheal girls (P < 0.001). Adjusting for age, education and SES, premenarcheal girls were, overall, 13% (HR 1.13, 95% CI 1.12-1.14) and 24% (HR 1.24, 95% CI 1.22-1.26) more likely to attain menarche in the next year per increment in initial height and BMI, respectively. In postmenarcheal girls at 1st visit and in girls experiencing menarche in the follow-up period, age-adjusted, annualized linear growth was 4.0 and 0.9 cm/y lower than girls who remained premenarcheal through the 2nd visit (P < 0.001). However, change in BMI was 0.16 and 0.52 kg/m2 higher, respectively. In a Cox model with growth rate as predictor, incremental height and BMI were positively associated with risk of menarche only in younger girls (9-11 y).
Conclusions: Better nourished young adolescent girls reached menarche earlier than their less well-nourished peers. Higher height and BMI velocities were predictive of onset of menarche only in youngest adolescents.
Johns Hopkins Bloomberg School of Public Health