Time Trends in Age at Menarche and Related Non-Communicable Disease Risk during the 20th Century in Mexico

Developed countries have shown a time trend towards a younger age at menarche (AAM), which is associated with increased risk of later obesity and non-communicable diseases. This study aimed to assess whether a time trend in AAM is associated with disease risk in Mexican women (n = 30,826), using data from the Mexican National Health Survey (2000). Linear and log binomial regression was used for nutritional and disease outcomes, while Welch⁻ANOVA was used to test for a time trend. AAM (in years) decreased over time (p < 0.001), with a maximal difference of 0.99 years between the 1920s (13.6 years) and 1980s (12.6 years ). AAM was negatively associated with weight (β = -1.01 kg; 95% CI -1.006, -1.004) and body mass index (BMI) (β = -1.01 kg/m²; -1.007, -1.006), and positively with height (β = 0.18 cm; 0.112, 0.231). AAM was associated with diabetes (RR = 0.95; 0.93, 0.98) and hypercholesterolemia (RR = 0.93; 0.90, 0.95), but not with hypertension, breast cancer or arthritis. In Mexico, AAM decreased significantly during the 20th century. AAM was inversely associated with adult weight and BMI, and positively with height. Women with a later AAM had a lower risk of diabetes and hypercholesterolemia.</p

Depressive symptoms among Mexican adolescent girls in relation to iron status, anemia, body weight and pubertal status: results from a Latent Class Analysis.

OBJECTIVE: The study examined the association between depressive symptoms and iron status, anaemia, body weight, and pubertal status among Mexican adolescent girls. DESIGN: In this cross-sectional study, depressive symptoms were assessed by the 6-item Kutcher Adolescent Depressive Scale (6-KADS), and latent class analysis (LCA) was used to identify and characterize groups of girls based on depressive symptoms. Iron status and inflammation were assessed using ferritin and soluble transferrin receptor, C-reactive protein and alpha-1-acid glycoprotein, respectively. Multiple logistic and linear regression were applied to model class membership as a function of iron status, anaemia, body weight, and pubertal status. PARTICIPANTS: We collected data from 408 girls aged 12-20 years. SETTING: public schools in northern Mexico. RESULTS: LCA yielded three classes of depressive symptoms; 44.4% of the adolescents were "unlikely to be depressed", 41.5% were "likely to be depressed", and 14.1% were "highly likely to be depressed". Our analyses demonstrated that iron deficient girls had greater odds of being "likely depressed" (odds ratio, OR=2.01, 95% CI 1.01-3.00) or "highly likely depressed (OR=2.80, 95% CI 1.76-3.84). Linear regression analyses revealed that lower haemoglobin concentrations and higher body weight increased the probability of being "likely depressed". There was no evidence that depressive symptoms were associated to age at menarche and years since menstruation. CONCLUSION: This study shows that iron deficient adolescent girls are more likely to suffer from depressive symptoms, and that lower concentrations of haemoglobin and higher body weight increased the probability of experiencing depressive symptoms