Discussion
T2D, GDM, overweight, T2DM, dysglycemia, diabetes
GDM, OBESE, DIABETES
In this study, we demonstrated that ILSM significantly reduced T2D risk scores and obtained statistically significant benefits for FBG, BMI, and intention to eat low-index glycemic food at an 18-month follow-up based on the intention-to-treat analysis. This is encouraging as previous studies reported that the benefit of lifestyle interventions for diabetes prevention was typically sustained at 6 to 12 months [Consistent with our result in the six-month follow-up, the intervention effect on reducing T2D risk scores was sustained at 18-month [Improvement of glucose markers has been identified as the key indicator of delaying progression to T2D among people with dysglycemia [Over 18 months, a significant reduction in BMI and waist circumference were determined in the intervention group compared with the control group. However, consistent with most previous studies, the maximum reduction was achieved at 6-month with a plateau occurred after 6 months [At 18-month, we found that women in the ILSM group have increased intentions to eat low glycemic-index food (e.g., dark green leafy vegetables, fish and seafood, whole grains or mixed) compared with the control group, although this difference between groups was not demonstrated at 6-months [The difference in physical activity was not statistically significant between the two groups over 18 months. Similar results were also reported in other lifestyle interventions for women with a history of GDM. According to literature, barriers to exercise among this population include competing demands for childcare, career pressure and family responsibility as well as an established ethic of care that prioritizes the needs of others (e.g., family and friends) above their own [We found significant improvement in social support and perceived stress over 18 months, which is consistent with other studies [The results of our subgroup analyses suggest that women with glycemic intolerance and overweight or abdominal obese women are more sensitive to the ILSM than women with relatively normal blood glucose, weight, and waist circumference in reducing T2D risk score. As glycemic markers and weight-related outcomes are important predictive indicators for future T2D risk, and women with glycemic intolerance or weight issues have a higher risk for T2DM. This intervention is particularly helpful in reducing their risk. Thus, we can reasonably infer that higher-risk groups may benefit more from lifestyle intervention programs as their physical health is in jeopardy, and they have more room for improvement in terms of glycemic level and weight [This study is one of the few intervention studies with a long-term follow-up. This study has several strengths. First, we conducted a multi-dimensional evaluation of an evidence-based intervention, adapted to the local context, and adhered to the theoretical framework of behavior maintenance. Second, we designed a contextually-tailored lifestyle intervention, which was implemented effectively by local nurses with few resources; thus, it provides the possibility to improve primary healthcare in impoverished health system. More importantly, the ILSM may be used as a model for designing health-related interventions at underserved public health settings. Lastly, a robust RCT study design, including cluster randomization, excellent protocol implementation, and well-validated questionnaires are study strengths.There were several study limitations. Due to budget and energy constraints, the sample size was calculated based on the power of our primary outcome; thus, we may not have enough power to detect meaningful, significant differences in all outcomes. Second, the improvement of the ILSM group may be due to the fact that they were given more attention (six biweekly group seminars and eight telephone consultation sessions) than the control group who did not have the same time engagement. Thirdly, the self-report measurements for physical activity may have recall bias. Lastly, the findings of subgroup analysis should be considered exploratory and should not be over-interpreted given the number of comparisons reported. Future researches are needed to confirm our findings.Despite these limitations, our findings have several implications. First, it is important to modify lifestyle interventions to the context of women’s lives and to address their barriers to long-term lifestyle change. For example, maintenance interventions via smartphones may be feasible in this population; and strategies that promote self-directed behavior change could be incorporated [