# Salivary vascular growth factor responses to prolonged and interrupted sitting in young, healthy adults

## TL;DR

This study found that sitting for 4 hours lowers a blood vessel growth factor in saliva, while walking breaks raise another, but not enough to reverse the effects.

## Contribution

The study is the first to examine salivary VEGF, EGF, and angiogenin responses to prolonged and interrupted sitting in young adults.

## Key findings

- Salivary VEGF decreased after 4 hours of sitting, regardless of walking breaks.
- Angiogenin levels increased significantly after all sitting sessions.
- Walking breaks did not significantly alter the biomarker responses compared to prolonged sitting.

## Abstract

We aimed to determine salivary vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and angiogenin responses to prolonged and interrupted sitting in young, healthy adults. Each participant completed 4 h of prolonged sitting and two interrupted‐sitting sessions incorporating 3‐min walking breaks every 27 min at 35% or 50% of heart rate reserve, in random order. Saliva was collected immediately before and after each session and analyzed using enzyme‐linked immunosorbent assays. VEGF decreased from pre to post across all conditions (Pre: 0.63 ± 0.63; Post: 0.53 ± 0.67; p = 0.0013; partial η
2 = 0.09), while angiogenin increased (Pre: 7.42 ± 7.43; Post: 16.90 ± 12.80; p = 2.61 × 10−12; partial η
2 = 0.35), and EGF did not change (Pre: 6.14 ± 5.14; Post: 5.10 ± 4.37; p = 0.6885; partial η
2 = 0.0015). Time‐by‐condition interactions were not significant for any biomarker, indicating that light‐ and moderate‐intensity walking interruptions did not alter pre to post responses. These findings indicate that 4 h of sitting acutely lowers VEGF when interrupted by light‐ or moderate‐intensity walking, and elevates angiogenin in saliva; brief low‐to‐moderate walking breaks may be insufficient to modify responses in angiogenin. Future research should investigate whether higher‐intensity interruptions are needed to mitigate the effects of prolonged sitting.