Lifestyle intervention is more effective in high 1-hour post-load glucose than in prediabetes for restoring β-cell function, reducing ectopic fat, and preventing type 2 diabetes

Abstract

Background

High 1-h-post-load plasma glucose (1 h-PG) is an early diabetes risk marker. We hypothesized that isolated high 1 h-PG represents an intermediate state between normal glucose regulation (NGR) and impaired glucose regulation (IGR) and is amendable to greater lifestyle intervention (LI) benefit.

Methods

In the Tübingen Lifestyle Intervention Program, 317 people with either NGR, IGR or isolated high 1 h-PG without IGR underwent LI for 9 months to achieve ≥5 % weight loss.

Results

Before LI initiation, insulin sensitivity and β-cell function declined progressively from NGR (n = 106) to high 1 h-PG (n = 96) and to IGR (n = 115). Visceral adipose tissue (VAT) volume and liver fat content increased from NGT to high 1 h-PG and to IGR. LI improved insulin sensitivity and ß-cell function in the high 1 h-PG group to levels observed in NGR together with a marked reduction in hepatic fat content. Compared to the IGR group, T2D risk was reduced by 80 % (37–96 %, p = 0.005) in the high 1 h-PG group during a 12-year follow-up period. The odds of remission to complete normoglycemia were doubled in the high 1 h-PG group compared to the IGR group (2.18 [1.13–4.28], p = 0.021).

Conclusion

High 1 h-PG indicates an intermediate metabolic state with pathophysiological changes more severe than in NGR but milder than in IGR. In people with high 1 h-PG, LI significantly improved insulin sensitivity and β-cell function and reduced ectopic lipid deposition and the risk of developing T2D compared to IGR. These findings highlight the value of 1 h-PG as a clinically useful biomarker, providing a critical window for early intervention to reverse core metabolic defects driving prediabetes and T2D.