退化性關節炎病人之抗氧化營養素濃度與氧化壓力、抗氧化酵素活性及肌少症相關性之探討

退化性關節炎（osteoarthritis，OA）是老化相關之疾病。關節發炎反應可能影響其活動度而增加肌少症之發生風險。本研究目的為了解OA病人抗氧化營養素濃度與氧化壓力、抗氧化酵素活性及肌少症之相關性。本觀察性研究招募之受試者為膝關節經X光診斷為OA之病人（n = 100）。研究期間收集受試者基本資料，利用雙能量X光吸收儀測量體組成，以握力計、前臂啞鈴彎舉、背筋力計、坐姿起立及6分鐘步行評估其肌力適能。利用退化性膝關節炎量表（The Western Ontario and McMaster Universities Osteoarthritis Index，WOMAC）評估關節疼痛、僵硬及活動困難狀況。收集血液檢體分析其抗氧化營養素（輔酶Q10、維生素A、E及β-胡蘿蔔素）濃度、血液生化值、發炎指標、氧化壓力、抗氧化酵素活性及總抗氧化力。結果發現，有75%之OA病人處於輔酶Q10缺乏之情形，維生素A及β-胡蘿蔔素濃度缺乏比例分別為24%及10%，而維生素E則無缺乏。經關節分級分組後，中重度關節退化組之血漿輔酶Q10濃度（p = 0.04）、血漿輔酶Q10/總膽固醇濃度（p = 0.04）及紅血球總抗氧化力（p = 0.01）顯著低於輕度關節退化組；在肌力適能方面，中重度關節退化組之左手啞鈴彎舉次數（p = 0.02）、6分鐘步行速率（p < 0.01）顯著低於輕度關節退化組。WOMAC之關節疼痛及活動困難分數於中重度關節退化組顯著高於輕度關節退化組（p < 0.01）。經肌少（前）症次分組後，中重度肌少（前）症組之輔酶Q10濃度/總膽固醇濃度及紅血球總抗氧化力顯著低於輕度無肌少症組（p < 0.05）。此外，輔酶Q10/總膽固醇濃度與肌肉量、全身及四肢肌肉質量指數呈顯著正相關（p < 0.05），與肌力適能呈顯著正相關（p < 0.05）；而與WOMAC各項分數則呈顯著負相關（p < 0.05）。另輔酶Q10/總膽固醇濃度亦與麩胱甘肽過氧化酶、血清及紅血球總抗氧化力呈顯著正相關（p < 0.05）。因此推論，OA病人有較高比例輔酶Q10缺乏之情形；且OA受試者之輔酶Q10濃度與肌肉質量、肌力適能及關節疼痛僵硬程度有顯著之相關，未來研究可進一步以輔酶Q10介入型試驗了解輔酶Q10對OA病人肌肉質量與肌力適能之表現。

Osteoarthritis (OA) is an aging-related disease. Synovial inflammation may decrease physical activity in patients with OA to increase the risk of sarcopenia. The purpose of this study was to investigate the relationship between the level of antioxidant nutrients and oxidative stress, antioxidative enzymes activity, and the parameters of sarcopenia in patients with OA. This study was an observational study. We recruited 100 patients who diagnosed with OA by X-ray. The characteristic data was collected during the study. Body composition was measured by dual-energy X-ray absorptiometry. The muscle strength and endurance was assessed by hand grip, dumbbell curl, back dynamometer, chair stand test, and 6-minute walk test. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were used to assess the joint pain, stiffness and difficulty. The blood samples were collected to measure the levels of antioxidant nutrients (coenzyme Q10, vitamin A, vitamin E, and β-carotene), hematological data, inflammation, oxidative stress, antioxidative enzymes activity, and Trolox equivalent antioxidant capacity (TEAC). The results showed that 75% of patients with OA had coenzyme Q10 deficiency, and the proportion of vitamin A and β-carotene deficiency were 24% and 10% respectively, however, there was no vitamin E deficiency. Patients with moderate and severe OA had significantly lower levels of coenzyme Q10 (p = 0.04), coenzyme Q10/total cholesterol (TC) ratio (p = 0.04) and erythrocyte TEAC (p = 0.01) than those with mild OA. With regard to the muscle strength and endurance, patients with moderate and severe OA had significantly lower repetitions of left dumbbell curl (p = 0.02), and 6-minute walk speed (p < 0.01) than those with mild OA. Patients with moderate and severe OA had significantly higher WOMAC scores than those with mild OA (p < 0.01). Besides, moderate and severe OA patients with (pre-)sarcopenia had significantly lower levels of coenzyme Q10/TC and erythrocyte TEAC than mild OA without (pre-)sarcopenia (p < 0.05). The level of coenzyme Q10/TC was significantly positively related to muscle mass, whole and appendicular skeletal muscle mass index, and muscle strength and endurance (p < 0.05), while significantly negatively related to WOMAC scores (p < 0.05). Moreover, the level of coenzyme Q10/TC was significantly positively related to glutathione peroxidase activity and serum and erythrocyte TEAC (p < 0.05). In conclusion, patients with OA had a high percentage of coenzyme Q10 deficiency, and the level of coenzyme Q10 was significantly related with muscle mass, muscle strength and endurance and joint pain and stiffness. Further study is needed to investigate the effects of coenzyme Q10 supplementation on antioxidant capacity, muscle mass and muscle strength and endurance in patients with OA.