| 摘要: | 中文摘要
本研究目的主要係探討大豆異黃酮素對更年期症狀的影響。根據過去的研究報導異黃酮素具有雌激素及抗雌激素效應，因此也被相信可預防因更年期所產生的不適症狀、冠狀動脈粥狀硬化，甚至於預防骨質疏鬆症等。然而在臨床實驗的結果卻是有爭議的，而且異黃酮素在改善更年期症狀的效果上，目前仍缺乏較高劑量的安全數據可參考，因此本研究設計一系列的實驗以探討高劑量異黃酮素對改善更年期症狀的效果及安全性評估。本研究的實驗設計分為四個部份，第一部份為探討台灣中部地區更年期婦女的飲食營養狀況及大豆異黃酮素的攝取量及其食物來源；第二部份係探討大豆異黃酮素對婦女更年期不適症狀的影響，第三部份則以動物模式探討大豆異黃酮素對血脂質及骨質密度的影響，最後係探討大豆異黃酮素對更年期婦女骨質密度的影響。
人體實驗部份係於中國醫藥大學附設醫院進行，以更年期婦女45-65歲為對象，隨機方式分配至三組，包括控制組、100 mg/day (IF100)、200 mg/day (IF200) 等之大豆異黃酮素膳食補充劑改善實驗，連續補充二十四週；實驗期間對受試者進行3天飲食紀錄、24小時回憶法及飲食頻率法收集飲食資料；受試期間每天填寫更年期症狀評估表以計算更年期Kupperman Index；並於補充大豆異黃酮後之第四、八、十六、二十和二十四週回門診複診，於實驗前及後收集受試者之禁食靜脈血液，測定血清雌激素及血清脂質和檢測骨質流失、骨質保留及骨形成等評估骨質疏鬆相關之生化指標試驗；同時於實驗前後以雙能量Ｘ光分析儀偵測腰椎、股骨的骨質密度，並進行預防骨質疏鬆功能性評估。
結果顯示，更年期婦女之巨量營養素攝取量偏高而某些維生素及礦物質如鈣、鎂、維生素E等攝取量低於2006年國人膳食營養素參考攝取量，飲食中異黃酮素之平均攝取量約10.9 mg/day，由飲食頻率法得知異黃酮素的食物來源主要是豆腐佔42%、豆漿佔23%、豆干佔14%、豆皮14%。異黃酮素對更年期症狀之改善以補充 100 mg/day的量，對更年期的潮熱出汗、失眠、骨關節疼痛及Kupperman Index分數等有明顯改善，而補充200 mg/day的異黃酮素除了潮熱、出汗、失眠、骨關節疼痛及更年期指數外，還增加了情緒之抑鬱或疑心、疲乏兩項的改善效果。
另外對骨質的影響，控制組的腰椎 L1-3, L1-4以及股骨頸的骨質密度顯著的下降，而IF 100組L1-3的骨質密度則是顯著增加；然而，IF200組則沒有一致的反應。以骨質專一性鹼性磷酸酶作為評估骨質重吸收之指標，實驗結果顯示補充 100 mg/day劑量之異黃酮素對於骨質專一性鹼性磷酸酶活性有顯著抑制效果，即100 mg/day組似可減緩骨質的流失速度，而200 mg/day組者則無差異。
動物實驗部份則是以切除卵巢之Sprauge Dawley雌鼠的動物模式探討大豆異黃酮素對血脂質代謝及骨質疏鬆症之影響。實驗間餵食含有不同濃度之異黃酮素的飼料配方，A組 (卵巢切除，不含異黃酮素) 、B組 (未進行卵巢切除處理，不含異黃酮素) 、C組 (餵食異黃酮素100 mg/kg wt)、D組 (餵食異黃酮素300 mg/kg wt)、E組 (餵食異黃酮素500 mg/kg wt)。為期四個月的餵養實驗，實驗期中每個月以尾靜脈採集血液，進行血脂質及血鈣濃度之生化分析，取其右大腿骨股骨作病理組織切片以分析骨質及骨小樑數目，結果顯示與控制組相較，顯示異黃酮素之補充具有降低血清三酸甘油酯和低密度脂蛋白膽固醇濃度的效果，其中以D組 (300 mg/kg wt) 最為顯著。在骨質結構方面，隨著異黃酮素攝取量的上升，右腿股骨小樑骨數目呈現有意義的增加；實驗組之皮質骨在整個骨股后端切片組織所占之面積亦顯著增加，尤以D組最為顯著。由以上結果顯示，卵巢切除之成熟雌性大白鼠在予以補充異黃酮素後，對於血脂質調節作用以及骨質疏鬆預防功能上有顯著的效果。
綜合以上實驗結果得知，台灣中部地區更年期婦女的異黃酮素攝取量僅10.9 mg/day，比其他亞洲國家要低。本研究以異黃酮素介入後，結果顯示每日補充100 mg異黃酮素可以幫助更年期婦女改善其更年期不適症及預防骨質流失。在IF100組可以觀察到因缺乏雌激素造成的骨質流失具有保護作用，然而在IF200 組雖然没有副作用發生，但並未呈現劑量效應。因此對於更年期婦女症狀改善及骨質疏鬆的預防以每日 100 mg 即足夠。
關鍵字：更年期症狀、異黃酮素、骨密度、營養補充、血脂質
Abstract
The aim of this study was to investigate the effects of soy isoflavones on climacteric symptom. Although soy isoflavone has been reported showed both estrogen-like and antiestrogen-like effect, it is believed that isoflavone may prevent menopausal syndrome anti-atherosclerosis and even osteoporosis. However, the interventional clinic trials showed controversial results. Furthermore, the safety data of higher dose of isoflavone on such climacteric improvements is still unknown. Thus, we designed a series experiments to explore the efficiency of isoflavone in higher dose. In Part I, we evaluated the daily nutrients intake and source of soy isoflavone in menopausal women in central Taiwan. In the second experiment, the efficiency of isoflavone on menopausal syndrome improvement was evaluated. The third part of this study was to evaluate effects of soy isoflavone on serum lipids and bone density in animal model. In the final portion, the dosage study of isoflavone on bone density assessment was investigated in menopause women.
In clinical study, we recruited diagnostic 45-65 year-old postmenopausal outpatients at China Medical University Hospital, Taichung, Taiwan. All subjects were randomized assigned to three groups such as control group (C), soy isoflavone 100 mg/day (IF100), and soy isoflavone 200 mg/day (IF200) for an open-labeled self-controlled isoflavones intervention from February, 2002 to May 20, 2003 for 24 weeks. Subjects were asked to fill out the menopausal syndrome chart for calculation of Kuppermen index and the dietary record for 3 days, food frequency questionnaire and the 24 hour dietary recall questionnaire at the 1st, 4th, 8th, 16th, 20th, and 24th week. During the isoflavone intervention, subjects were check for blood biochemistry, estrogen, bone loss parameters and bone density via Dual X-ray at the beginning and the end of study.
In results, the dietary intake level of macronutrients on menopause women was higher than the 2006 DRIs (Recommended Daily Intakes) in Taiwan. The dietary intake levels of contain vitamins and minerals were lower than the DRIs in Taiwan. In FFQ, the major dietary isoflavone sources of these subjects were tofu (42%), dry tofu (14%), soybean milk (23%), and dry tofu skin (14%). In climacteric symptom, some marked improvement of Kuppermen index (Green Climacteric Scale) on decreased frequency of hot flashes, insomnia and joint pain in IF100 subjects. Furthermore, the symptoms such as depression, suspicion and fatigue were also improved in IF200 group. In bone density, the decrease in bone mineral density (BMD) was significant for lumbar vertebrae L1-3, L1-4 and the femur neck in the C group; surprisingly, the BMD of L1-3 was significantly elevated in the IF100 group; however, there were no consistent responses in the IF200 group. The data from the bone specific alkaline phosphatase showed a significant inhabitation in IF100 group, however, no significant changes in IF200 subjects.
In animal study, we investigated the effects of isoflavone in serum lipid metabolism and osteoporosis on an ovariectomic Sprague Dawley (SD) rat model. In the experiment, various doses of isoflavone were offered in the following groups: Group A (Bilateral ovariectomy, isoflavone free), Group B (Bilateral pseudo ovariectomy, isoflavone free), Group C (isoflavone feeding 100 mg/kg wt), Group D (isoflavone feeding 300 mg/kg wt) and Group E (isoflavone feeding 500 mg/kg wt). Blood samples were collected from the tails vein every month for 4 months. The rats were sacrificed at the end of the experiment to collect blood for analysis of lipids and calcium. Right femur was dissected for pathological study of total thickness of the compact bone and the number of trabecula bone. The results indicated that isoflavone group D (300 mg/kg wt) had the most significant effect of lowering serum triglyceride and LDL-cholesterol. In bone trabecula formation, the numbers of right femur trabecula bone significant increased and showed dose dependent. The group D had the most significant effect of increasing the areas of cortex in cross section studies of right femur. In brief, feeding of isoflavone in rats had significant effects of adjusting serum lipids and improving treatment of osteoporosis in bilateral ovariectomy adult rats.
In summary, isoflavone intake of menopause women in Taichung area is only 10.9 mg/day. This interventional study suggests that the 100 mg/day isoflavones may help the improvement of climacteric symptoms and prevent the bone loss. A protective effect of IF100 on estrogen-related bone loss was observed. A lack of a benefit such as high safety in the IF200 group for 1-year administration was ensured and lacked undesirable side effects.
Key words: climacteric symptom menopause, isoflavone, bone density, nutritional supplement, serum lipids |
