Occupational standing and change in the Ankle-Brachial Index: the Jackson Heart Study

A growing interest in reducing occupational sitting has resulted in public health efforts to encourage intermittent standing in workplaces. However, concerns have been raised that standing for prolonged periods may expose individuals to new health hazards, including lower limb atherosclerosis. These concerns have yet to be corroborated or refuted. The purpose of this study was to investigate the association between occupational standing and adverse changes in the Ankle-Brachial Index (ABI).

We studied 2121 participants from the Jackson Heart Study, a single-site community-based study of African-Americans residing in Jackson, MS. Occupational standing ('never/seldom', 'sometimes', 'often/always') was self-reported at baseline (2000-2004). ABI was measured at baseline and again at follow-up (2009-2013).

Over a median follow-up of 8 years, 247 participants (11.6%) exhibited a significant decline in ABI (eg, ABI decline >0.15). In multivariable-adjusted models, higher occupational standing was not significantly associated with ABI decline (occupational standing sometimes vs never/seldom: OR 1.05; 95% CI 0.67, 1.66; occupational standing often/always vs never/seldom: OR 1.22; 95% CI 0.77, 1.94). Similarly, higher occupational standing was not associated with low ABI at follow-up reflective of peripheral artery disease (ABI <0.90) or high ABI at follow-up reflective of incompressible vessels (ABI >1.40).

In this community-based study of African-Americans, we found no evidence that occupational standing is deleteriously associated with adverse changes in ABI over a median follow-up of 8.0 years. These findings do not provide evidence implicating occupational standing as a risk factor for lower limb atherosclerosis.