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.

[The association between sleep and obesity in Korean adults].

OBJECTIVES: Obesity is currently an epidemic in Korea, and sleep duration is thought to be one of the risk factors for obesity. The objective of this study was to test the hypothesis that short sleep duration is associated with obesity in Korean adults. METHODS: The data from the 2001 Korean National Health and Nutrition Survey were used, and 6,174 subjects aged 18 approximately 80 years were included in the analysis. Sleep duration was measured using information obtained from self-reported questionnaires. Obesity, the main outcome variable, was measured according to body mass index. Multiple regression modeling was used to adjust for potential confounding variables. RESULTS: The study results revealed a negative association between sleep duration and body mass index among Korean adults. These associations persisted after controlling for the potential confounding variables. CONCLUSIONS: These findings support the hypothesis that sleep duration is associated with obesity in Korean adults. In addition, these observations support earlier experimental sleep studies and provide a basis for future studies on weight control intervention by increasing the amount of sleep.