Association between triglyceride-glucose-related indices and reproductive lifespan: a cross-sectional study from the NHANES (2007–2020)

Objective The female reproductive lifespan, characterized by the period spanning from menarche to menopause, may be modulated by metabolic health factors. This cross-sectional analysis utilized nationally representative survey data from the National Health and Nutrition Examination Survey (NHANES) to explore the linkages between three triglyceride-glucose (TyG)-related adiposity metrics and parameters of the female reproductive lifespan.Method The study analyzed data from female participants in multiple NHANES cycles (2007–2020). The female reproductive lifespan was computed using self-reported ages at menarche and menopause. Associations of continuous TyG indices (and their tertiles) with female reproductive lifespan, age at menarche, and age at menopause were evaluated using weighted multivariable linear regression. Non-linear patterns were examined using restricted cubic splines, and subgroup analyses were tested for potential effect modifications.Results Following full adjustment (Model 3), all TyG indices displayed significant positive correlations with both female reproductive lifespan (e.g. TyG-BMI: β = 1.23, 95% confidence interval [CI] 0.71 to 1.75, p < 0.001) and age at menopause (e.g. TyG-WC: β = 1.07, 95% CI 0.59 to 1.54, p < 0.001). Conversely, significant negative correlations were noted with age at menarche (e.g. TyG-WHtR: β = –0.24, 95% CI −0.41 to –0.07, p = 0.006). Participants in the highest tertile (T3) of each TyG index consistently showed longer female reproductive lifespans and later menopause compared to the lowest tertile (T1), alongside an earlier onset of menarche. Significant positive trends across tertiles were evident for female reproductive lifespan and age at menopause for all indices, while significant inverse trends emerged for age at menarche.Conclusion Elevated levels of TyG-BMI, TyG-WC and TyG-WHtR – composite indices integrating insulin resistance and adiposity – demonstrate consistent associations with a prolonged female reproductive lifespan.