Long-term Outcomes of Lifestyle Intervention to Prevent Diabetes in American Indian and Alaska Native Communities: The Special Diabetes Program for Indians Diabetes Prevention Program

Abstract

Objective: Evidence for long-term translational effectiveness of lifestyle interventions in minority populations is scarce. This article reports long-term outcomes, for up to 10 years, of such an intervention to prevent diabetes in American Indian and Alaska Native (AI/AN) communities.

Research design and methods: From January 2006 to July 2016, the Special Diabetes Program for Indians Diabetes Prevention Program implemented the Diabetes Prevention Program lifestyle intervention among 46 AI/AN health care programs. Enrolled participants underwent a thorough clinical assessment at baseline, after completing the Lifestyle Balance Curriculum (postcurriculum assessment), and annually thereafter. Proportional hazards regression was used to estimate the association between diabetes incidence and postcurriculum weight loss status.

Results: Of 8,652 enrolled participants, 65% finished the postcurriculum assessment. The assessment completion rate diminished over time to 13% in year 10. Among those with postcurriculum weight measurements, 2,028 (36%) lost >5% of their initial weight, 978 (17%) lost 3-5%, whereas 2,604 (47%) had <3% weight loss (average weight loss 3.8%). Compared with those with <3% weight loss, participants with >5% weight loss had a 64% (95% CI 54-72) lower risk of developing diabetes during the first 6 years of follow-up, whereas those with 3-5% weight loss had 40% (95% CI 24-53) lower risk.

Conclusions: Moderate to small weight loss was associated with substantially reduced long-term risk of diabetes in diverse AI/AN communities. High participant attrition rates and nonoptimal postcurriculum weight loss are important challenges found in this translational effort implemented in an underserved population.

Figure 1

SDPI-DP assessment completion rates (percentage of potential participants completing the assessment, in which potential participants are defined as the participants who initiated the intervention early enough to reach the time point of a specific assessment by 31 July 2016).

Figure 2

A: SDPI-DP cumulative incidence of diabetes by weight loss groups at postcurriculum assessment. B: Adjusted (by sex, baseline age, glucose status, BMI, HDL-C, and smoking status) HRs of weight loss groups for diabetes incidence.

Figure 3

Changes in secondary outcomes among SDPI-DP participants based on paired data. Means compared with paired t tests; medians compared with signed rank test. Numbers in parentheses in the second row of the horizontal axis are sample sizes. *P < 0.05; **P < 0.001; ***P < 0.0001. DBP, diastolic BP; P-C, postcurriculum assessment; SBP, systolic BP.