Social cognitive theory-based intervention to promote physical activity among prediabetic rural people: a cluster randomized controlled trial

BACKGROUND: The present randomized controlled trial (RCT) evaluated the effectiveness of a theory-based physical activity (PA) intervention for rural patients with prediabetes. It was hypothesized that a PA intervention program based on the social cognitive theory (SCT) will modify fasting blood sugar (FBS) among rural people with prediabetes, which in turn will result in a decrease in diabetes incidence in the rural area. METHODS: A cluster RCT on prediabetic people was conducted in Ahar, East Azerbaijan Province, Iran. A PA intervention in prediabetes was performed over 16 weeks of follow-ups in 12 villages (six per arm). Residents (n = 272; n = 136 per arm) were invited to participate in the study through rural health care centers during screening for eligibility. Participants in the intervention and control groups were informed of their prediabetic conditions and encouraged to make appropriate changes to their lifestyles to modify their prediabetes. The intervention was an educational program delivered over 16 weeks and involved behavioral change techniques. Through the education program, the intervention group received one session per week lasting about 90 min (a total of 16 sessions). The importance of risk control with PA, the duration of hill climbing, as well as exercise and safety tips were explained in a brochure that was given to the participants. Anthropometric measures, glycemic status, and PA were evaluated at the beginning of the program and after 16 weeks of follow-up. RESULTS: The PA program showed a reduction in FBS mg/dl at 16 weeks (large-effect-size Cohen’s d = −0.63, p = 0.001) compared to the control condition. PA intervention led to a large effect size on diastolic blood pressure (BP, − 1.01) and a medium effect size for systolic BP (− 0.57), body mass index (BMI, − 0.33), and weight (− 0.35). Based on generalized linear mixed model analysis, significant reductions in FBS (mg/dl), BMI, weight, and diastolic BP were found in the intervention group compared to the control group. CONCLUSION: Our results support the effectiveness of an SCT-based PA intervention to reduce the risk of prediabetes developing into diabetes among rural patients with prediabetes. Findings suggest that implementation of SCT-based PA intervention for a rural population at risk of diabetes has potential benefits. TRIAL REGISTRATION: Iranian Registry of Clinical Trials, IRCT201607198132N4. Registered on 1 September 2017. Prospectively registered.