Disertasi

Pengaruh suplementasi isoflavon kedelai terhadap penanda fungsi endotel pada perempuan pascamenopause. Kajian terhadap vascular cell adhesion molecule-1, nitric oxide dan malonildialdehid = The effect of soy isoflavone supplementation on endothelial function in postmenopausal women. Highlights on vascular cell adhesion molecule-1, nitric oxide and malonyldialdehide.

Pendahuluan: Data epidemiologi menunjukkan perempuan di Jepang dan Asia lainnya angka kejadian penyakit kardiovaskular lebih rendah dibandingkan dengan di negara Barat. Hal ini dikaitkan dengann konsumsi makanan mengandung isoflavon kedelai yang tinggi pada perempuan Asia dibandingkan mereka di negara Barat. Isoflavon kedelai merupakan salah satu sumber fitoestrogen. Tujuan: Penelitian ini bertujuan untuk menilai pengaruh suplementasi isoflavon kedelai 100 mg/hari selama 6 bulan dan 12 bulan terhadap penanda fungsi endotel pada perempuan pascamenopause. Metode: Penelitian ini menggunakan desain double blind randomized controlled trial mengikutsertakan 182 perempuan pascamenopause dengan usia 47 tahun – 60 tahun di Kecamatan Mampang Prapatan Jakarta Selatan. Hasil randomisasi terdapat 90 subjek kelompok isoflavon kedelai dan 92 subjek kelompok kontrol. Kelompok isoflavon kedelai mendapat suplementasi yang mengandung isoflavon kedelai 100 mg (genistein 56%, daidzein 41% dan glycitein 3%) dan kalsium karbonat 500 mg sedangkan kelompok kontrol mendapat suplementasi kalsium karbonat 500 mg selama 12 bulan. Studi dilakukan mulai bulan Januari 2010 sampai dengan Februari 2011. Kadar vascular cell adhesion molecule-1 (VCAM- 1), nitric oxide (NO) dan malonildialdehid (MDA) dalam serum diperiksa pada awal penelitian, pascasuplementasi 6 bulan dan 12 bulan. Hasil: Karakteristik subjek penelitian pada kelompok isoflavon kedelai dan kelompok kontrol pada awal penelitian menunjukkan bahwa kedua kelompok setara baik pada karakteristik demografis, fisik, laboratorium dan asupan nutrien. Pascasuplementasi isoflavon kedelai selama 12 bulan terdapat perbedaan kadar MDA yang bermakna antara kelompok isoflavon kedelai dan kelompok kontrol (p =0,001). Kadar VCAM-1 dan NO tidak berbeda bermakna (p= 0,992 dan p=0,759). Kadar MDA pada kedua kelompok mengalami peningkatan tetapi peningkatan kadar MDA pada kelompok kontrol lebih tinggi, Simpulan : Suplementasi isoflavon kedelai 100 mg/hari selama 12 bulan dapat menurunkan stres oksidatif melalui penurunan peroksidasi lipid sedangkan efek antiinflamasi dan perbaikan tonus vaskular pembuluh darah tidak terbukti.
Kata kunci : fungsi endotel, pascamenopause, suplementasi isoflavon kedelai.



Background : Epidemiological evidence showed that women in Japan and other Asia countries had lower incidence of cardiovascular disease compared to women in Western countries. These evidences were related with higher diet contain of soy isoflavones in Asian women compared with those in Western countries. Objective : This study objective was to evaluate the effect of 100 mg/day soy isoflavone supplementation for 6 months and 12 months on endothelial function in postmenopausal women. Method : A randomized double blind controlled trial was conducted to evaluate the effects of daily supplementation with soy isoflavone 100 mg/day for 12 months on 182 postmenopause women aged 47 to 60 years at Mampang Prapatan subdisctrict South Jakarta. The subject were randomized to the intervention group receiving tablets consisting of 100 mg soy isoflavone (containing genistein 55%, daidzein 39% and glycitein 6 %) and calcium carbonate 500 mg and the control group receiving 500 mg calcium carbonate. The number of subjects in the intervention group were 90 subjects and the control group 92 subjects. The study was carried out from January 2010 to February 2011. The levels of vascular cell adhesion molecule-1 (VCAM-1), nitric oxide (NO) and malonyldialdehid (MDA) were measured before supplementation, postsupplementation at 6 months and 12 months. Results : Characteristics of subjects at baseline were comparable between the two groups. After 12 months supplementation the MDA levels were significantly difference between soy isoflavone group and control group (p=0.001). The levels of VCAM-1 and NO were not affected (p = 0.992 and p= 0.759, respectively). The MDA levels in both two groups were increased compared with the baseline levels but the MDA levels in control group were higher compared with the soy isoflavone group. Conclusion : This study demonstrates that supplemental intake of soy isoflavones for 12 month has an effects on oxidative stress by reduction of lipid peroxidation in postmenopausal women but had no anti-inflammatory effect and did not improve vascular tone.
Key words: endothelial function, postmenopausal, soy isoflavone supplementation.