Effect Of Environmental Factors On Age Of Menarche Among Elementary School Girls in Kermanshah

Document Type : Research Paper

Authors

1 Professor, Department of Endocrinology and Metabolism, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran

2 Professor, Department of Nutrition, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

3 Professor, Health Sciences Research Center, Department of Biostatistics and Epidemiology, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran

4 MSc, Department of Nutrition, School of Medicine, Mashhad University of Medical Sciences, Mashhad Iran. (corresponding author)

Abstract

Background and objective: the age when menarche start as a reproductive trait has undergone a significant decline over the twentieth century which is widely attributed to the environmental factors. The current study aims to investigate the environmental factors impacting on menarche in the girl’s school in Kermanshah, Iran.
Materials and Method: in this case-control study, 400 participants of age 12 and over were recruited based on a cluster sampling strategy from three neighborhoods in Kermanshah, Iran. The questionnaires were measured based on demography, physical and socio-economical statues items. Logistic regression, Independent sample T test, Mann-Whitney and chi-square were used for statistical calculations.
Findings: It was observed that the girls with early menarche were significantly taller and heavier than non-menarcheal. The obese and overweight girls had respectively 3.36 and 2.55 higher chance to early age at menarche in comparison with normal BMI ones. The mean birth weight of early menarche girls was 0.18 kg lower than the healthy girls. However, there were no significant difference in the age of complementary feeding and the breast-feeding period among the two groups. The girls who had low physical activity(OR=0/56, 95% CI 0/32-0/98), medium , and high, had respectively 44%,48% and 59% lower risk of early menarche compared to inactive students. The statistical findings approved a correlation between the family income and premature menarche, whereas there was no correlation between parental education, occupational status and early menarche. Finally, girls whose mothers had also early menarche tended to have the same experience compared to control group.

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