PROJECT SUMMARY
Hand osteoarthritis is a painful polyarticular disorder that impairs an individual's ability to perform
manipulative activities of daily life. Hand osteoarthritis has been the subject of little research and has few
therapeutic options. Local inflammation, altered bone structure, and metabolic syndrome are pivotal to the
pathogenesis of hand osteoarthritis. Per- and poly-fluoroalkyl substances (PFAS) – synthetically produced
grease-resistant chemicals universally detectable in the United States population – can stay in the body for a
long time and affect inflammation, bone metabolism, and metabolic factors that contribute to osteoarthritis.
PFAS became commercially available in the 1950s. Since then, the prevalence of osteoarthritis has doubled in
the United States – a finding that cannot simply be explained by increases in longevity or body mass index.
Cross-sectional studies demonstrate that exposure to PFAS may exacerbate osteoarthritis development. While
prior research has inspired efforts to reduce the production of certain PFAS, older PFAS persist in the
environment, and newer PFAS are entering the global markets and may present their own health risk. Given
the ongoing use of PFAS and the scale of contamination, there is an urgent need for longitudinal studies to
clarify the relationship between PFAS and osteoarthritis and to identify susceptible populations to inform public
health policies and suggest therapeutic approaches. Our interdisciplinary team, which has expertise in
osteoarthritis and environmental health, will benefit from the wealth of annually collected data and
biospecimens from the Osteoarthritis Initiative, the largest and most comprehensive cohort study of
osteoarthritis. Furthermore, we selected a case-cohort sample with radiographic assessments of hand
osteoarthritis and measures of systemic bone health, inflammation, and metabolic factors. To achieve our
overall goal of testing whether each PFAS and a mixture of PFAS relate to hand osteoarthritis, we will
complete 3 aims using environmental mixture modeling. Specifically, we will determine if PFAS increase the
risk for hand osteoarthritis incidence (Aim 1) and relate with greater changes in disease burden, articular
cartilage, and bone (Aim 2). We will also perform exploratory analyses to assess whether bone health,
inflammation, and metabolic factors mediate the relationship between PFAS and osteoarthritis. Furthermore,
we will consider sex, age, and obesity as effect modifiers because investigators reported these interactions in
cross-sectional studies. The findings from this study will help inform public health policies, identify susceptible
populations, and suggest therapeutic targets.