Effect of maternal age at childbirth on insulin resistance: The 2010 Korean National Health and Nutrition Examination Survey

Objective This study aimed to assess insulin resistance according to maternal age at childbirth. Patients and methods The data used in this study were obtained from the 2010 Korean National Health and Nutrition Examination Survey. This study included a total of 2233 nondiabetic female subjects ≥30 years of age that were subdivided into groups according to their obesity and abdominal obesity (AOB) statuses. The homoeostasis model assessment of insulin resistance (HOMA-IR) was used to quantify the insulin resistance according to age at first childbirth and last childbirth. Results Age at first childbirth showed a negative relationship with HOMA-IR in both the nonobese and non-AOB groups, while age at last childbirth showed a positive relationship with HOMA-IR in both the nonobese and non-AOB groups. A multivariate logistic regression analysis revealed that ages at first and last childbirth were significantly associated with the highest HOMA-IR quartile. The odds ratio was 0·9 (95% confidence interval: 0·82-0·98) for age at first childbirth, and 1·07 (95% confidence interval: 1·01-1·14) for age at last childbirth in the nonobese and non-AOB groups. Conclusion In conclusion, this study suggests that insulin resistance is increased in females who experienced their first childbirth at a younger age or their last childbirth at a later age, particularly in nonobese individuals. Because these data suggest that childbearing age could be an independent risk factor for diabetes, a high-quality prospective study assessing the relationship between childbearing age and insulin resistance should be performed.