Background and aims
Patients with obesity are at high risk of suffering from arterial and venous peripheral vascular disease (PVD). Bariatric surgery is an effective strategy to achieve weight reduction for patients with obesity. The long-term impact of bariatric surgery on obesity-related morbidity is subject to increasing research interest. This study aimed to ascertain the impact of bariatric surgery on the long-term occurrence of PVD in patients with obesity.

Methods
The study population was extracted from the Clinical Practice Research Datalink, a nation-wide database containing primary and secondary care records of consenting patients. The intervention cohort was 2959 patients who had undergone bariatric surgery during follow-up; their controls were 2959 propensity-score-matched counterparts. The primary endpoint was development of any PVD: arterial or venous. Secondary endpoints were incident peripheral arterial disease alone, incident peripheral venous disease alone.

Results
Three hundred forty-six patients suffered a primary endpoint during follow-up. Bariatric surgery did not improve peripheral vascular disease rates as a whole, but it was associated with significantly lower event rates of arterial disease (HR = 0.560, 95%CI 0.327–0.959, p = 0.035) but higher event rates of venous disease (HR = 1.685, 95%CI 1.256–2.262, p < 0.001).

Conclusions
Bariatric surgery was associated with significantly reduced long-term occurrence of arterial disease but increased occurrence of venous disease in patients with obesity.