Aims
To assess responses to lifestyle interventions (LIs) among individuals with distinct pre-diabetes phenotypes (isolated impaired fasting glucose [i-IFG], isolated impaired glucose tolerance [i-IGT], and combined IFG + IGT) for reducing diabetes incidence, reversing pre-diabetes, and improving glycemic control and insulin sensitivity.
Methods
PubMed, Embase, Cochrane Library, and Web of Science were searched until December 6th, 2023. We included randomized controlled trials examining responses to LIs (including diet and/or physical activity) among adults with i-IFG, i-IGT, and IFG + IGT. Outcomes included diabetes incidence, normoglycemia incidence, fasting plasma glucose (FPG), 2-hour plasma glucose (2 h-PG), hemoglobin A1c, fasting insulin (FI), and homeostasis model assessment-insulin resistance (HOMA-IR). Random-effects meta-analyses were performed to estimate risk ratios (RRs) and mean differences.
Results
Twenty-seven studies were included. Meta-analysis of 10 studies that performed stratified analyses by pre-diabetes phenotype found that LIs significantly reduced diabetes incidence in i-IGT (RR = 0.69 [0.56; 0.85], I(2) = 14 %) and IFG + IGT (RR = 0.56 [0.48; 0.66], I(2) = 0 %) but not in i-IFG (RR = 0.85 [0.66; 1.11], I(2) = 0 %; p(subgroup) = 0.02). Meta-analysis of 20 studies using IGT for participant recruitment showed that LIs significantly decreased diabetes incidence, increased normoglycemia incidence, and improved FPG, 2 h-PG, FI and HOMA-IR.
Conclusions
LIs are effective for IGT (with or without IFG), but tailored LIs are needed for i-IFG to prevent diabetes.