Association between Life's Essential 8 and women infertility from the National Health and Nutrition Examination...

Women infertility is associated with cardiovascular diseases. Life's Essential 8 (LE8), a recently updated measure of cardiovascular health (CVH), has been investigated for its association with women infertility.

The study adopted a cross-sectional design with national scope, incorporating 2534 women aged 20-49 years, selected from the National Health and Nutrition Examination Survey dataset from 2013 to 2018. The LE8 metric, which varies from 0 to 100, was evaluated based on the criteria set by the American Heart Association and then classified into three levels of CVH: low level (0-49), moderate level (50-79) and high level (80-100). Infertility status was determined based on self-report. To evaluate these correlations, we employed models with multivariable logistic variables and a restricted cubic spline. For subgroup assessment in relation to the LE8 score, a stratified multivariate logistic regression model was utilised.

Among 2534 participants (mean weighted age 34.96 years), 314 experienced infertility (weighted percentage 13.20%). Higher LE8 scores (mean 73.87) were associated with lower odds of infertility (odds ratio (OR) 0.77 per 10-point increase; 95% confidence interval (CI) 0.68-0.86), even after adjusting for confounders. Similar trends were observed for associations between health behaviour scores, health factor scores and infertility rates, with diet, sleep health, body mass index (BMI), blood glucose and blood pressure showing more pronounced influences. LE8 scores exhibited an inverse dose-response relationship with female infertility, with a significant interaction with age (p for interaction <0.001). Among women under 35 years, the association between LE8 scores and infertility was stronger (OR 0.65 per 10-point increase; 95% CI 0.56-0.74).

Our study demonstrates that increased LE8 scores are associated with reduced infertility risk, providing an effective strategy for female infertility prevention.