Socioeconomic Status and Age at Menarche in Türkiye.

Objectives: The trend in declining age at menarche (AAM) largely continues while body size increases globally. The aim was to investigate trends in AAM, menstrual characteristics, and post-menarcheal anthropometric parameters in adolescents living in an urban area in Türkiye between 1999 and 2018.

Methods: Female adolescent high school students in the Manisa region were asked about menarche and socioeconomic status (SES). There were 1017 girls in the first study (1999-2001) and 1304 (2016-2018) in the second study. Height and weight were measured. Body mass index (BMI) was calculated. Adolescent girls were grouped into three socioeconomic status (SES) groups based on parental education and occupation, and all parameters were evaluated using SES.

Results: The mean ± standard deviation for AAM in the first period was 12.82 ± 1.07 years and 12.83 ± 0.9 years in the second. AAM did not differ between the two periods nor between SES groups in either period. Post-menarcheal height, weight, and BMI increased in the second period compared to the first study and across all SES groups (p < 0.05). The whole group AAM was similar in both periods, only 3 months earlier in the second period than in the first period. However, the AAM in girls with a post-menarcheal BMI indicating being overweight or obese was significantly earlier than that of those with a normal post-menarcheal BMI in both periods (p < 0.05).

Conclusions: Despite changing sociodemographic characteristics and an increasing trend in height, weight, and BMI in all socioeconomic groups, no change was observed in mean AAM in an urban region of Western Türkiye over 18 years. While the inverse relationship between BMI and postmenarcheal BMI continued in both periods, the decline in AAM became more pronounced over the years in the presence of high postmenarcheal BMI.