Adherence to healthy lifestyles and incidence of diabetes and mortality among individuals with diabetes: a systematic review and meta-analysis of prospective studies

Introduction Lifestyle factors in combination have been hypothesised to be associated with the prevention of type 2 diabetes (T2D) and mortality among individuals with T2D. The aim was to conduct a systematic review and meta-analysis to quantify the association between lifestyle indices and incident T2D as well as mortality in individuals with T2D. Methods PubMed and Web of Science were searched up to September 2019. We included prospective cohort studies investigating at least three lifestyle factors in association with T2D, or all-cause mortality in individuals with diabetes. We conducted pairwise and dose-response meta-analyses to calculate summary relative risks (SRR) by using random effects model. Results In total, 19 studies were included. Adhering to a healthy lifestyle (mostly favourable diet, physical activity, non-smoking, moderate alcohol intake and normal weight) was associated with a reduced SRR of 78% for T2D (SRR: 0.22; 95% CI: 0.16 to 0.32; n=14) and 57% for mortality (SRR: 0.43; 95% CI: 0.31 to 0.58; n=5) compared with low adherence to a healthy lifestyle. In dose-response analyses, the adherence to every additional healthy lifestyle factor was associated with a reduced relative risk of 32% (95% CI: 28% to 36%) for T2D and 21% (95% CI: 15% to 26%) for mortality. Conclusions Our findings underline the importance of the joint adherence to healthy lifestyle factors to prevent T2D and improve survival among individuals with diabetes. Adherence to every additional health lifestyle factor play a role in the T2D prevention and progression. PROSPERO registration number CRD42018091409.