Association between age at menarche and risk of myopia in the United States: NHANES 1999-2008

We evaluate the effect of menarche on myopia in women in the United States (US). A cross-sectional survey and examination were conducted using data from the 1999-2008 US National Health and Nutrition Examination Survey (NHANES), and 8,706 women aged & GE;20 years (95% confidence interval [CI], 44.23 to 45.37) were enrolled. Characteristics were compared between nonmyopic and myopic participants. Univariable and multivariable logistic regression analysis was performed to evaluate the risk factors for myopia. A minimum p-value approach was used to estimate the cut-off point for age at menarche. The prevalence of myopia was 32.96%. Mean spherical equivalent (SE) were -0.81 diopters (95% CI, -0.89 to -0.73) and the mean age of menarche was 12.67 years (95% CI, 12.62 to 12.72). In the crude logistic regression model, age (odd ratio [OR] 0.98), height (OR, 1.02), astigmatism (OR, 1.57) (all p < 0.0001), age at menarche (OR, 0.95; p = 0.0005), white ethnicity, being born in the US, higher level of education, and higher annual household income (all p trend <0.0001) were significantly associated with myopia. 1-year increments in age at menarche was associated with a 4% decrease in the risk of myopia after adjusting for age, height, body mass index (BMI), ethnicity, and astigmatism (OR, 0.96; 95% CI, 0.93 to 0.99, p = 0.0288). The cut-off value for age at menarche was 15 years by the maximum chi-square test (p < 0.0001). Age at menarche may attribute to myopia progression, along with other environmental and individual risk factors.

Automated summary

We assessed the impact of menarche on myopia in women in the US by conducting a survey and examination using data from the NHANES. 8,706 women aged ≥20 years were enrolled, and a comparison was made between myopic and non-myopic participants. Logistic regression analysis revealed that age at menarche, along with other factors such as ethnicity, education level, and income, significantly influenced the risk of myopia. Higher age at menarche was associated with a decreased risk of myopia, with a 4% decrease for every 1-year increment. The cut-off value for age at menarche was estimated to be 15 years.