Among 2,380 adults who underwent metabolic and bariatric surgery (MBS) between 2008 and 2023, biological age — measured via an AI-derived electrocardiogram age gap (δage) — declined by 0.192 years per year after the first postoperative year (95% CI: −0.303 to −0.081; P=.001). Before surgery, 69.6% of patients were biologically older than their chronological age, with a median δage of 3.86 years. Notably, weight change within individuals did not independently drive the δage improvement; rather, chronic adiposity burden between individuals was the stronger predictor (+0.548 years per 10 kg). By follow-up, 20.2% of those with elevated baseline δage normalized to δage ≤ 0.
The AI-ECG biological-age gap is an emerging, validated cardiac aging metric, and its application here adds a meaningful dimension to understanding MBS outcomes beyond weight loss alone. The critical insight — that cumulative adiposity burden, not acute within-person weight loss, governs cardiac biological aging — suggests that early and sustained obesity prevention may matter more than post-hoc surgical correction. However, several limitations temper enthusiasm: this is a retrospective, single-institution cohort without a non-surgical control group, making causality uncertain. The modest effect size (~0.2 years/year reversal) and the failure of the piecewise model to outperform a simple linear model suggest incremental rather than dramatic biological rejuvenation. Still, confirming that surgery nudges the cardiac aging clock — even modestly — reinforces MBS as a legitimate longevity-relevant intervention, not merely a metabolic one.
