Long-term Sustainability of Diabetes Prevention Approaches

Abstract

IMPORTANCE Diabetes prevention is imperative to slow worldwide growth of diabetes-related morbidity and mortality. Yet the long-term efficacy of prevention strategies remains unknown.OBJECTIVE To estimate aggregate long-term effects of different diabetes prevention strategies on diabetes incidence.DATA SOURCES Systematic searches of MEDLINE, EMBASE, Cochrane Library, and Web of Science databases. The initial search was conducted on January 14, 2014, and was updated on February 20, 2015. Search terms included prediabetes, primary prevention, and risk reduction.STUDY SELECTION Eligible randomized clinical trials evaluated lifestyle modification (LSM) and medication interventions (>6 months) for diabetes prevention in adults (age Ն18 years) at risk for diabetes, reporting between-group differences in diabetes incidence, published between January 1, 1990, and January 1, 2015. Studies testing alternative therapies and bariatric surgery, as well as those involving participants with gestational diabetes, type 1 or 2 diabetes, and metabolic syndrome, were excluded. DATA EXTRACTION AND SYNTHESISReviewers extracted the number of diabetes cases at the end of active intervention in treatment and control groups. Random-effects meta-analyses were used to obtain pooled relative risks (RRs), and reported incidence rates were used to compute pooled risk differences (RDs). MAIN OUTCOMES AND MEASURESThe main outcome was aggregate RRs of diabetes in treatment vs control participants. Treatment subtypes (ie, LSM components, medication classes) were stratified. To estimate sustainability, post-washout and follow-up RRs for medications and LSM interventions, respectively, were examined. RESULTS Forty-three studies were included and pooled in meta-analysis (49 029 participants; mean [SD] age, 57.3 [8.7] years; 48.0% [n = 23 549] men): 19 tested medications; 19 evaluated LSM, and 5 tested combined medications and LSM. At the end of the active intervention (range, 0.5-6.3 years), LSM was associated with an RR reduction of 39% (RR, 0.61; 95% CI, 0.54-0.68), and medications were associated with an RR reduction of 36% (RR, 0.64; 95% CI, 0.54-0.76). The observed RD for LSM and medication studies was 4.0 (95% CI, 1.8-6.3) cases per 100 person-years or a number-needed-to-treat of 25. At the end of the washout or follow-up periods, LSM studies (mean follow-up, 7.2 years; range, 5.7-9.4 years) achieved an RR reduction of 28% (RR, 0.72; 95% CI, 0.60-0.86); medication studies (mean follow-up, 17 weeks; range, 2-52 weeks) showed no sustained RR reduction (RR, 0.95; 95% CI, 0.79-1.14). CONCLUSIONS AND RELEVANCEIn adults at risk for diabetes, LSM and medications (weight loss and insulin-sensitizing agents) successfully reduced diabetes incidence. Medication effects were short lived. The LSM interventions were sustained for several years; however, their effects declined with time, suggesting that interventions to preserve effects are needed.

Effects of dietary and physical activity interventions on the risk of type 2 diabetes in South Asians: meta-analysis of individual participant data from randomised controlled trials

“…Although ten studies in the latter meta-analysis were conducted in Asia, the results for South Asians were not reported. Of note, the absolute benefit on diabetes prevention was higher in our study than in this meta-analysis (7.4% vs 4.0%, respectively) and so the NNT was lower (14 vs 25) [13]. Our findings compare well with the first efficacy studies, reporting 6.2-12% absolute risk reductions (NNT 16-8, respectively) [8,9], but are somewhat stronger than those of a meta-analysis of translational studies to prevent diabetes in high-risk populations other than South Asians (RR reduction, 29%; absolute risk reduction, 3%) [14].…”

“…Our meta-analysis included efficacy [12,16] and more pragmatic trials [15,17,18,26]. The 35% RR reduction in diabetes incidence resembles the RR reduction (39%) reported in a standard meta-analysis of 19 efficacy and pragmatic diabetes prevention trials in individuals with impaired glucose tolerance or impaired fasting glucose after a mean of 2.6 years of active lifestyle intervention [13]. Although ten studies in the latter meta-analysis were conducted in Asia, the results for South Asians were not reported.…”

“…From 2001, efficacy trials have documented a reduction in diabetes incidence in high-risk adults of up to 58% through lifestyle modification interventions incorporating a healthy diet and/or physical activity [8][9][10][11][12]. Recent meta-analyses of efficacy and pragmatic diabetes prevention trials found a 30-40% reduction in diabetes incidence [13,14]. However, none of these meta-analyses reported effects specifically for South Asians [13,14], although several lifestyle intervention trials, culturally adapted to suit the specific needs, cultural norms and values of the South Asian populations in different contexts, have been developed and tested [15][16][17][18].…”

“…Recent meta-analyses of efficacy and pragmatic diabetes prevention trials found a 30-40% reduction in diabetes incidence [13,14]. However, none of these meta-analyses reported effects specifically for South Asians [13,14], although several lifestyle intervention trials, culturally adapted to suit the specific needs, cultural norms and values of the South Asian populations in different contexts, have been developed and tested [15][16][17][18]. Some trials in South Asian populations appeared moderately successful, but the effectiveness differed across studies.…”

Cost-effectiveness of a faith-based lifestyle intervention for diabetes prevention among African Americans: A within-trial analysis

“…Furthermore, evidence of the importance of investing in lifestyle interventions as a strategy for addressing diabetes continues to accumulate. For example, a recent meta-analysis showed that lifestyle interventions have sustained benefits, whereas glucose lowering medications only suppress glucose while they are in use [22]. …”