山之靈氣

山之靈氣

疫情令很多運動處所關閉,但亦令不少人更關注運動及身體健康,唯有轉戰戶外運動。趁未踏入炎熱夏季,正適合行山郊遊,把握做運動最佳時機,今次我們便找來腎病科專科馮振雄醫生,以及腦神經科專科黃家星醫生分享下行山的種種好處!兩位醫生剛好都是行山發燒友,近年更積極「操山」備戰毅行者,他們均指出運動對心臟和腎臟都有裨益,並可提升身體的新陳代謝,增強抵抗力,而行山是最舒服最老少咸宜的活動,即使平日少做運動的人都容易「入門」,不過就切記要量力而為,製定合適路線。

運動由行山開始

運動有益健康是老生常談,但實際上怎樣有助益?雖然有各種研究指出運動可預防多種健康問題及有助改善慢性疾病,不過由馮醫生和黃醫生的角度分享,不妨以他們各自擅長的專科為例子,讓大家可有更具體的概念。

腎病科專科馮振雄醫生
腦神經科專科黃家星醫生

腎病科專科馮振雄醫生(左)、腦神經科專科黃家星醫生(右)

運動防腎病?

有研究指出運動有助改善腎功能及減緩腎衰竭(4,5),不過由於腎病的表徵不明顯(6),需要醫生抽絲剝繭檢查才會得知病情變化,因此別等到有病才做運動,而是應該由日常開始養成運動習慣。

腎科專科馮振雄醫生指,引致腎病的原因很多,其中較普遍的是由糖尿病引致的腎小球炎、血壓高腎小球病變。另外亦會有原發性腎小球炎,或因病人是乙、丙型肝炎帶菌者、或患上如紅斑狼瘡的免疫系統毛病引致腎病,嚴重者更可引致末期腎衰竭(7-10);腎病初期沒有明顯病徵(6),只有在身體檢查後才會得悉病情;若病情嚴重時常見有小便起泡,或出現「血尿」、貧血及胃口欠佳(7),如病徵明顯即代表其腎功能開始衰退至三成以下。因此,除了定期做身體檢查,注意日常飲食及保持運動習慣亦很重要(11)

馮醫生指「蛋白尿」是腎病的先兆,若果尿蛋白一天超過一至三克並起泡需立即求醫(12)。他解釋,正常人腎功能排出的尿蛋白較少,每天約少於300毫克,若從尿液中流出的蛋白量超過此份量便是蛋白尿(13)。他又指「腎病症候群」會因腎小球炎而令尿蛋白增加,當血內蛋白含量明顯降低至20 g/L,會令身體出現水腫情況(14,15)。運動有助促進新陳代謝,有研究指慢性腎衰竭患者每周健行三次,每次四十分鐘,一年後腎功能有明顯改善(16),可見即使是較輕鬆的行山郊遊,對健康的益處也不容忽視!

飲食:腎病與膽固醇的關係

此外,膽固醇的多寡亦會影響腎臟功能,常見的便是由高膽固醇或三酸甘油脂過高引致的「高血脂」問題(17)。高密度脂蛋白膽固醇HDL-C(俗稱好膽固醇),可幫助清除體內過多的壞膽固醇,然而當低密度脂蛋白膽固醇LDL-C (俗稱壞膽固醇)與三酸甘油脂TG超標時,可能產生動脈粥樣硬化,導致血管狹窄、阻塞,使心臟、腎臟、腦部等各個器官的功能受到影響(18,19)

馮醫生補充指,由於腎病病人的肝臟需要製造更多蛋白質以維持肝功能,體內的膽固醇亦會因此提高(20,21),亦有少部份病人因DNA 病變有機會出現罕見的「脂蛋白腎小球病」,原因是腎內脂蛋白沉積增加而導致腎功能失調(22)

當出現腎病有關病徵便需透過腎組織檢查確診(7),馮醫生補充,若於早期發現腎病及即時治療,病人可完全康復(23,24),但要視乎腎病原因,例如急性腎炎或缺血性腎功能退化引致的腎病,便難以令腎功能完全復原。至於針對控制膽固醇的藥物治療,除了他汀類藥物,近年出現的注射藥物PCSK9抑制劑亦可配合他汀類藥物使用,將膽固醇控制至目標水平(25)

馮醫生認為要預防腎病,最好的方法是透過飲食習慣及運動,其中飲食比起運動更能直接預防腎病。他解釋,運動能幫助減低血糖及降低血壓(26),只能間接預防腎病,因此改變飲食習慣更為關鍵,尤其經常食肉會令膽固醇增加,身體並會製造大量尿素;相反以素食為主的話身體所製造的尿素較低,能減慢腎功能退化,所以良好飲食習慣配合適當運動效果就更佳(8,27-29)
 

運動促進腦部健康?

腦神經科專科黃家星醫生指,膽固醇高以及缺乏運動者會容易腦中風,提醒大家切勿掉以輕心(30)。他指雖然腦中風是老人病,但現今都市人缺乏運動、甚至吸煙酗酒,又經常吃加工食品,容易令血管內皮細胞出現異樣,這些都會增加中風的機會(30-32)

此外,他又指中風常見於患有三高的患者(30),可惜大部份人都忽略了三高對健康的影響嚴重程度。以高血脂症為例,它對人體造成最主要的影響就是「動脈粥樣硬化」,動脈硬化若發生在腦部會造成腦中風、如發生在心臟會造成心肌梗塞、發生在四肢則會造成周邊動脈阻塞(19,31)。黃醫生解釋指,大腦是人體的「中央系統」,倘膽固醇累積過多而積聚於血管,使腦血管收窄,便有機會造成缺血性中風,腦細胞因而缺氧死亡,如失去半邊腦功能而導致半身癱瘓(30)

意想不到如此嚴重的疾病,可以有簡單方法預防――就是做運動!他提到運動可促進腦部健康,亦能減低膽固醇,預防血脂阻塞血管(30,33)。黃醫生指,有很多研究證實,每星期進行恆常運動,便可減低約兩成中風的機會(34)。由於運動能增加心跳率及出汗,有助減低血液中膽固醇的含量、降低高血壓患者的血壓,並改善腦部的血液循環(35)。不過,他提醒大家做運動要循序漸進,若平日少運動者不妨由急步行或行山開始,沒有恆常運動習慣的人,不宜突然進行激烈的高強度運動,別誤以為運動愈劇烈效果愈好。突然大幅度提高運動強度,輕則引致肌肉痠痛或拉傷,重則可能令心肺功能承受不住,甚至引致心腦血管病突發情況(36-38)

運動連結腎與腦健康

腎病和腦神經疾病看似沒有直接關係,不過黃醫生指有時腎病有機會影響腦部健康,他解釋說:「腎部的功能是『清潔』,消毒排毒,清潔腦部,因此腦部是User(使用者)(39)。」腎功能失調有機會造成高血壓,令心臟及神經系統的負荷增加(40);另外腎臟能過濾血液中的雜質以供應給腦部,若患有腎病亦有機會引致中風(8)。他補充,腎病患者中風機會比一般人高四倍(41),即使患者的血凝固指標較好,尿蛋白低,但血管內壁功能及心臟功能亦會較差,故患者仍較易有心律不正,血塊因而形成並流動到腦部,阻塞腦血管引致中風(42)

兩位醫生強調,患上腎病和中風的機會除了家族遺傳,亦與年紀有關(30,43)。器官退化難以避免,而做運動除了可預防並減慢其退化速度,更重要是可控制危險因素,令人體退化速度減慢(4,30,35);此外他們認為運動亦有助預防認知障礙症,減低血壓和血糖,令新陳代謝更好(2,44,45),故兩位醫生經常一起行山,推介各位齊齊加入山人行列!

MAT-HK-2101155-1.0-06/2022
This article is supported by Sanofi Hong Kong Limited

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