PROINFLAMMATORY CYTOKINE LEVELS AND INDEXES OF ENDOTHELIAL FUNCTION IN PATIENTS WITH OSTEOARTHRITIS IS DEPENDENT ON THE PAIN INTENSITY

Abstract

Prevalence of hypertension in patients with osteoarthritis is rather high. According to published data, a combination of osteoarthritis and hypertension is registered in 45 to 80% of the patients, dependent on the age group. Pathogenesis of arterial hypertension developing in patients with osteoarthritis is of sufficient interest to the clinicians. We studied systolic and diastolic blood pressure, levels of some cytokines (IL-1β, IL-6, IL-18, TNFα) and markers of endothelial function (EDN1, vWF activity) in 83 patients (mean age 45.7±6.3 years) with osteoarthritis of knee and hip joints (radiographic stage II-III) accompanied by chronic pain. Local pain intensity over last month was evaluated by means of a visual analogue scale. According to the data obtained, the patients were divided into three groups. Group 1 consisted of 27 patients with mild pain (the pain index ≤ 3 points), the 2nd group included 34 persons with moderate pain (3 to 7 points), and the 3rd group consisted of 22 people with highest pain ratings (pain index ≥ 7). Increased pain intensity correlated with elevation of systolic and diastolic blood pressure. Meanwhile, higher levels of proinflammatory cytokines, and increased activity of EDN1 and vWF were observed in patients with moderate osteoarthritis and severe pain syndrome. Minimal values of cytokines were observed in patients with mild pain, whereas maximal levels, in the patients with severe pain and arterial hypertension. Inflammatory mediators are able to induce activation and injury of endothelium causing its dysfunction. vWF activity and EDN1 contents increased in all the studied groups, along with increased pain intensity. Higher EDN1 concentration and vWF activity may be considered objective signs of endotheliosis in the osteoarthritis patients. In turn, endothelial dysfunction is among major pathophysiological mechanisms of arterial hypertension. This may suggest a sufficient contribution of pain to occurrence and development of artherial hypertension in this group of patients. Chronic pain is likely to be a factor of early development of cardiovascular complications in the patients with osteoarthritis.

Keywords

• osteoarthritis
• arterial hypertension
• cytokines
• endothelial function
• pain syndrome