BACKGROUND: A decline in the age of menarche was observed from early 1900s to the 1970s. However, it is not known if a further decline occurred thereafter. AIM: To evaluate the age of menarche in girls from Santiago, Chile and its relationship with body mass index (BMI) and socioeconomic status. MATERIAL AND METHODS: We studied 1302 healthy girls aged 7 to 19 years. Age of menarche was evaluated through a questionnaire to the patient and her parents. Kaplan-Meier curves were used to determine age of menarche and Cox regression analysis was employed to evaluate the effect of the type of school and BMI on the age of menarche. RESULTS: The mean age at menarche was 12.7+/-0.04 years. Girls from public and private schools had their period at 12.5+/-0.1 and 13.05+/-0.05 years respectively. A negative correlation between z scores for BMI and age of menarche was observed (r-0.3: p =0.001). Girls whose menarche occurred before 11.5 years had higher z scores for BMI and a larger proportion were overweight, compared to girls who had menarche later. Cox regression analysis showed that after adjustment for BMI, age of menarche was similar in both types of schools. CONCLUSIONS: Age of menarche is occurring three months earlier in girls from public schools, which is associated with higher z scores for BMI. Type of school, a marker of socio-economic status in Chile, affects timing of menarche due to differences in body mass index.
BACKGROUND: A decline in the age of menarche was observed from early 1900s to the 1970s. However, it is not known if a further decline occurred thereafter. AIM: To evaluate the age of menarche in girls from Santiago, Chile and its relationship with body mass index (BMI) and socioeconomic status. MATERIAL AND METHODS: We studied 1302 healthy girls aged 7 to 19 years. Age of menarche was evaluated through a questionnaire to the patient and her parents. Kaplan-Meier curves were used to determine age of menarche and Cox regression analysis was employed to evaluate the effect of the type of school and BMI on the age of menarche. RESULTS: The mean age at menarche was 12.7+/-0.04 years. Girls from public and private schools had their period at 12.5+/-0.1 and 13.05+/-0.05 years respectively. A negative correlation between z scores for BMI and age of menarche was observed (r-0.3: p =0.001). Girls whose menarche occurred before 11.5 years had higher z scores for BMI and a larger proportion were overweight, compared to girls who had menarche later. Cox regression analysis showed that after adjustment for BMI, age of menarche was similar in both types of schools. CONCLUSIONS: Age of menarche is occurring three months earlier in girls from public schools, which is associated with higher z scores for BMI. Type of school, a marker of socio-economic status in Chile, affects timing of menarche due to differences in body mass index.
Authors: Isabel V Wagner; Mathew A Sabin; Roland W Pfäffle; Andreas Hiemisch; Elena Sergeyev; Antje Körner; Wieland Kiess Journal: Nat Rev Endocrinol Date: 2012-01-31 Impact factor: 43.330
Authors: Anna Cabanes; Nieves Ascunce; Enrique Vidal; María Ederra; Ana Barcos; Nieves Erdozain; Virginia Lope; Marina Pollán Journal: BMC Public Health Date: 2009-12-04 Impact factor: 3.295
Authors: Jorge Jimenez de la Jara; Gabriel Bastias; Catterina Ferreccio; Cristian Moscoso; Sofia Sagues; Camilo Cid; Eduardo Bronstein; Cristian Herrera; Bruno Nervi; Alejandro Corvalan; Ethel V Velasquez; Pamela Gonzalez; Enrique Castellon; Eva Bustamante; Sergio Oñate; Eileen McNerney; Richard Sullivan; Gareth I Owen Journal: Biol Res Date: 2015-01-26 Impact factor: 5.612