Elements of the metabolic syndrome except for hypertension such as dyslipidemia and central adiposity are not consistently associated with knee osteoarthritis once obesity is adjusted for. However, after adjustment for obesity, hypertension is modestly associated with an increased risk of knee and even, in some studies, hand OA. A recent meta-analysis reported consistency across large cohort and case control studies; those with hypertension had a 1.49 fold increased odds of OA (p<0.001).

There a several possible explanations for this association especially if hypertension compromises the supply of nutrients to the joint. First, as OA develops, subchondral bone remodelling is accompanied by angiogenesis which could be inhibited by vascular insufficiency. In findings that are probably related, bone marrow lesions seen on MRI in OA represent lesions of bone trauma and, in these lesions, the number of vessels increases and the vessels have especially thick walls for their size. Bone marrow lesions have been linked to intraosseous hypertension that is probably not a consequence of arterial but rather of venous hypertension within bone. Further, NSAID use in persons with OA could raise blood pressure and create a spurious association of OA with hypertension. Given this range of potential explanations and the potential for identification of causal factors that may offer clues to OA treatment, further exploration of the biology of this relationship is needed.

Disclosure of Interest: None declared

DOI: 10.1136/annrheumdis-2018-eular.7863