Short-term structured dietary and exercise interventions delay diabetes onset in prediabetic patients: a prospective quasi-experimental study

Abstract

Hypothesis: Prediabetes indicates an increased risk of developing diabetes mellitus. We hypothesized that structured anti-inflammatory and antioxidant dietary and exercise interventions (SAIDEs) can reduce the onset of diabetes in prediabetic patients. Methods: This study included 542 prediabetic patients who met at least one of the three common criteria for prediabetes: fasting blood glucose (FBG), 2-h oral glucose tolerance (2h OGTT), or hemoglobin A1c (HbA1C). Patients were randomly assigned to one of four groups using the block randomization method: routine community intervention, dietary intervention, exercise intervention, or SAIDEs for 6 months. Follow-up assessments were conducted at 6 months and 7.5 years, monitoring diabetes-related outcomes, inflammatory markers, and diabetes progression. Results: At baseline, most tested variables, including age, gender, body weight, blood lipids, blood sugar, β-cell function, blood inflammatory and immunological markers, and energy intake, did not differ among the groups. After 6 months of short-term interventions (diet, exercise, and SAIDEs) and 6 months of follow-up, all intervention groups exhibited reduced total energy intake, body weight, blood pressure, blood cholesterol, and glucose levels, along with improved β-cell functions (all p < 0.001). Regardless of time considerations, intervention consistently increased total physical activity (p < 0.001). Short-term interventions also reduced blood IgE, high-sensitivity C-reactive protein, IL-6, and TNF-α, while increasing blood IL-4 and IL-10 (all p < 0.001). The prevalence of abnormal blood glucose markers—FBG, 2h OGTT, and HbA1C—significantly decreased within each intervention group after short-term intervention and 6 months of follow-up. The time-dependent Cox regression test did not indicate a significant effect of dietary or exercise intervention on diabetes incidence over the 8-year follow-up period. However, the log-rank test revealed significant differences in “survival” distribution among the four intervention groups (χ2 = 15.63, p = 0.001). The mean survival time before diabetes onset was significantly longer in prediabetic patients who received SAIDEs than in those in other groups. Conclusions: Short-term intervention with SAIDEs exhibited significant anti-inflammatory activity and reduced the prevalence of abnormal blood glucose markers. These benefits persisted even after 6 months of follow-up. However, over the 8-year follow-up period, intensive SAIDEs did not reduce diabetes incidence among prediabetic patients but did delay its onset. Clinical trial registration: https://www.chictr.org.cn/searchproj.html, identifier ChiCTR-IOR-16008445.