Correlation between cardiometabolic index and female infertility: a cross-sectional analysis

Background Obesity and adverse lipid profile leads to female infertility. The cardiometabolic index (CMI) is a promising indicator for predicting obesity-related diseases. The correlation between CMI and female infertility merits further investigation. Methods The data for this study were acquired from the 2013-2020 National Health and Nutrition Examination Survey (NHANES), with 2333 women enrolled. The cardiometabolic index (CMI) of each participant was calculated as the ratio of triglycerides and high-density lipoprotein cholesterol multiplied by waist-to-height ratio. Weighted multivariate logistic regression models were used to assess the independent correlation between the log-transformed CMI and infertility. Subgroup analyses were carried out to assess the reliability of the findings. Interaction tests were employed to determine whether variables affected infertility by interacting with log CMI. Results A total of 2333 participants aged 18-45 years were enrolled, 274 of whom were infertile. Log CMI of the infertility group was significantly higher than that of the non-infertility group (P < 0.001). After adjustment for potential confounders, women with higher CMI were at an increased risk of infertility (OR = 2.411, 95% CI: 1.416-4.112), and this correlation was still consistent in subgroups aged under 35 years (P < 0.001). Furthermore, restricted cubic spline analysis showed a positive non-linear relationship between log CMI and infertility. Conclusions Cardiometabolic index levels are positively correlated with increased risk of infertility in American females. Our study demonstrates the predictive capacity of CMI for female infertility.