AIP and diabetes mellitus: Specifically, when compared to individuals aged ≥ 45 years, prediabetic patients aged < 45 exhibited a weaker negative association of AIP with reversion to NFG (HR: 0.94 vs. 0.82, P-interaction = 0.0010) and a stronger positive association with progression to diabetes (HR: 1.86 vs. 1.26, P-interaction = 0.0230).