Tesis

Hubungan antara rasio asupan asam lemak omega-6/ omega-3 dengan kadar malondialdehid plasma pada osteoartritis lutut = Association between the ratio of omega-6/omega-3 fatty acid intake and malondialdehyde plasma levels in knee osteoarthritis patients.

Osteoartritis (OA) adalah penyakit sendi kronis yang merupakan penyebab utama disabilitas menahun di dunia saat ini. Salah satu faktor yang berperan penting dalam patogenesis OA adalah terjadinya stres oksidatif berlebih, yang menginduksi kerusakan kondrosit akibat dan ditandai dengan peningkatan kadar malondialdehid (MDA). Asam lemak omega-3 memiliki peran dalam menghambat terjadinya stres oksidatif, namun sebaliknya asam lemak omega-6 memiliki fungsi yang berlawanan. Kedua asam lemak ini bersifat esensial di dalam tubuh, dan kadarnya ditentukan oleh asupan dari bahan makanan sumber. Rasio antara asupan asam lemak omega-6/omega-3 yang optimal dapat mengurangi terjadinya stres oksidatif dalam tubuh. Tujuan penelitian ini untuk melihat hubungan antara rasio asupan asam lemak omega-6/omega-3 terhadap kadar MDA plasma pada pasien OA lutut. Penelitian ini menggunakan desain potong lintang, dilakukan di poli ortopedi RS Bhayangkara Tk I RS. Sukanto dan RSUPN Cipto Mangunkusumo Jakarta, terhadap pasien OA lutut derajat 2-4, berusia 40-60 tahun, pada bulan April-Mei 2018. Asupan asam lemak omega-3 dan omega-6 untuk 1 bulan ke belakang didapatkan dengan menggunakan semi-quantitative food frequency questionnaire. Besarnya rasio asupan asam lemak omega-6/omega-3 dihitung dengan cara membagi rata-rata asupan harian asam lemak omega-6 total dengan rata-rata asupan harian asam lemak omega-3 total. Kadar MDA plasma diukur dengan metode spektrofotometri. Dari 57 subjek yang mengikuti penelitian, didapatkan rerata usia 50 tahun, sebanyak 87,7% adalah subjek perempuan, serta sebagian besar (89,5%) masuk dalam kategori obesitas. Persentase asupan kedua asam lemak masih kurang bila dibandingkan dengan Angka Kecukupan Gizi (AKG), dengan nilai tengah asupan asam lemak omega-3 total subjek adalah 0,864 (0,351-2,200) g/hari, sedangkan asupan asam lemak omega-6 total sebesar 6,830 (3,066-19,110) g/hari. Didapatkan rerata rasio asupan asam lemak omega-6/omega-3 yaitu 8,8:1, dan rerata kadar MDA plasma pada subjek sebesar 0,773 ± 0,199 nmol/mL. Setelah mengontrol faktor usia, IMT dan skor aktivitas fisik dengan uji regresi linear ganda, didapatkan hasil setiap kenaikan 1 unit rasio asupan asam lemak omega-6/omega-3 dapat meningkatkan kadar MDA plasma sebesar 0,023 nmol/mL (β = 0,023, 95% CI = 0,004 – 0,042, p = 0,017). Rasio asupan asam lemak omega-6/omega-3 yang tinggi berhubungan dengan peningkatan kadar MDA plasma pada pasien OA lutut derajat II-IV. Oleh karena itu diperlukan edukasi untuk mendapatkan rasio yang optimal sehingga dapat mecegah peningkatan progresivitas OA lutut.
Kata kunci : malondialdehid; osteoartritis lutut; rasio asupan asam lemak omega6/omega-3


Osteoarthritis (OA) is a chronic disease characterized by joint pain, and is a major cause of disability in the patient. One of several factors in the pathogenesis of OA is the generation of oxidative stress, inducing chondrocytes apoptosis due to lipid peroxidation, characterized by the increasing of malondialdehyde (MDA) level. Omega3 fatty acids have role in inhibiting the oxidative stress, meanwhile omega-6 hold contradicting role. Both fatty acids are essential in human body, and their levels are determined by the intake from the food sources. The omega-6/omega-3 ratio should be optimal in order to reduce the oxidative stress. This study aims to investigate the association between the ratio of omega-6/omega-3 fatty acids intake to MDA plasma level in patients with knee OA. This was a cross-sectional study, conducted at orthopedic clinic at Bhayangkara RS. Sukanto Hospital and Cipto Mangunkusumo Hospital Jakarta, in patients with II-IV grade (Kellgren-Lawrence) of knee OA, aged between 40-60 years. The 1-month-history of omega-3 and omega-6 intake was obtained by using semi-quantitative food frequency questionnaire. The omega-6/omega3 ratio was calculated by dividing the average daily intake of total omega-6 fatty acids by the average daily intake of total omega-3 fatty acids. The MDA plasma level was measured by spectrophotometry method. Of 57 subjects participated, the mean age was 50 years, 87,7% were female, and mostly (89,5%) were obese. The percentage of both fatty acids intake was below the Recommended Dietary Allowance (RDA), the median for omega-3 and omega-6 intake were 0,864 (0,351-2,200) g/day and 6,830 (3,06619,110) g/day. Thus the ratio of omega-6/omega-3 intake was 8,8:1, and the mean MDA plasma level was 0,773 ± 0,199 nmol/mL. The age, BMI, and physical activity score variables were then controlled through multiple linear regression test. The results found were the increase of 1 unit of omega-6/omega-3 intake ratio would increase MDA level of 0,023 nmol/mL (β = 0,023, 95% CI = 0,004 – 0,042, p = 0,017). A high ratio of omega-6/omega-3 intake is associated with elevated plasma MDA level in knee OA patients. Therefore, a subsequent education is necessary in achieving optimal ratio thus prevent the progressivity of knee OA.
Keywords : knee osteoarthritis; malondialdehyde; ratio of omega-6/omega-3 fatty acid intake