Wood Lisa G, Fitzgerald Dominic A, Lee Alexander K, Garg Manohar L
Discipline of Nutrition and Dietetics, Faculty of Health, University of Newcastle, Callaghan, NSW, Australia.
Am J Clin Nutr. 2003 Jan;77(1):150-9. doi: 10.1093/ajcn/77.1.150.
Oxidative stress, as measured by 8-iso-prostaglandin F(2)(alpha) (8-iso-PGF(2)(alpha)), and depleted antioxidant defenses were shown in stable cystic fibrosis (CF) patients. The plasma fatty acid status of CF patients was linked to oxidative stress after respiratory exacerbations.
We examined changes in plasma 8-iso-PGF(2)(alpha), antioxidant defenses, plasma fatty acid status, and clinical markers resulting from short-term antioxidant supplementation.
Forty-six CF patients were randomly assigned to either group A [low dose of supplement (10 mg vitamin E and 500 micro g vitamin A)] or group B [high dose of supplement (200 mg vitamin E, 300 mg vitamin C, 25 mg beta-carotene, 90 micro g Se, and 500 micro g vitamin A)]. Plasma concentrations of 8-iso-PGF(2)(alpha), vitamins E and C, beta-carotene, zinc, selenium, and copper; plasma fatty acid composition; erythrocyte glutathione peroxidase (EC 1.11.1.9) and superoxide dismutase (EC 1.15.1.1) activities; lung function; and dietary intake were measured before and after 8 wk of supplementation.
Antioxidant defenses in group B improved, whereas those in group A did not: in groups B and A, the mean (+/- SEM) changes (Delta) in vitamin E were 10.6 +/- 1.5 and -1.9 +/- 0.9 micro mol/L, respectively (P < 0.001), (Delta)beta-carotene were 0.1 +/- 0.04 and -0.01 +/- 0.02 micro mol/L, respectively (P = 0.007), (Delta)selenium were 0.51 +/- 0.10 and -0.09 +/- 0.04 micro mol/L, respectively (P < 0.001), and (Delta)glutathione peroxidase activity were 1.3 +/- 0.3 and -0.3 +/- 0.6 U/g hemoglobin, respectively (P = 0.016). There were no significant differences between the groups in Delta8-iso-PGF(2)(alpha), (Delta)vitamin C, (Delta)fatty acid composition, (Delta)superoxide dismutase activity, (Delta)lung function, or (Delta)white cell count. Within group B, (Delta)beta-carotene correlated with (Delta)percentage of forced vital capacity (r = 0.586, P = 0.005), (Delta)selenium correlated with (Delta)percentage of forced expiratory volume in 1 s (r = 0.440, P = 0.046), and (Delta)plasma fatty acid concentrations correlated with (Delta)percentage of forced expiratory volume in 1 s (r = 0.583, P = 0.006) and Delta8-iso-PGF(2)(alpha) (r = 0.538, P = 0.010).
Whereas increased beta-carotene, selenium, and fatty acid concentrations are linked to improved lung function, increased plasma fatty acid concentrations are linked to oxidative stress. If oxidative stress is deemed to be important to the clinical outcome of CF patients, means of reducing oxidative stress while maintaining a high-fat, high-energy diet must be investigated.
通过8-异前列腺素F2α（8-iso-PGF2α）测定，稳定期囊性纤维化（CF）患者存在氧化应激以及抗氧化防御功能受损。CF患者的血浆脂肪酸状态与呼吸道加重后的氧化应激有关。
我们研究了短期补充抗氧化剂后血浆8-异前列腺素F2α、抗氧化防御功能、血浆脂肪酸状态及临床指标的变化。
46例CF患者被随机分为A组[低剂量补充剂（10mg维生素E和500μg维生素A）]或B组[高剂量补充剂（维生素E 200mg、维生素C 300mg、β-胡萝卜素25mg、硒90μg和维生素A 500μg）]。在补充8周前后，检测血浆8-异前列腺素F2α、维生素E和C、β-胡萝卜素、锌、硒和铜的浓度；血浆脂肪酸组成；红细胞谷胱甘肽过氧化物酶（EC 1.11.1.9）和超氧化物歧化酶（EC 1.15.1.1）活性；肺功能以及饮食摄入量。
B组的抗氧化防御功能得到改善，而A组则未改善：B组和A组中，维生素E的平均（±标准误）变化（Δ）分别为10.6±1.5和-1.9±0.9μmol/L（P<0.001），β-胡萝卜素分别为0.1±0.04和-0.01±0.02μmol/L（P = 0.007），硒分别为0.51±0.10和-0.09±0.04μmol/L（P<0.001），谷胱甘肽过氧化物酶活性分别为1.3±0.3和-0.3±0.6U/g血红蛋白（P = 0.016）。两组间在Δ8-异前列腺素F2α、Δ维生素C、Δ脂肪酸组成、Δ超氧化物歧化酶活性、Δ肺功能或Δ白细胞计数方面无显著差异。在B组中，Δβ-胡萝卜素与用力肺活量百分比的变化相关（r = 0.586，P = 0.005），Δ硒与第1秒用力呼气量百分比的变化相关（r = 0.440，P = 0.046），Δ血浆脂肪酸浓度与第1秒用力呼气量百分比的变化相关（r = 0.583，P = 0.006）以及与Δ8-异前列腺素F2α相关（r = 0.538，P = 0.010）。
β-胡萝卜素、硒和脂肪酸浓度升高与肺功能改善有关，而血浆脂肪酸浓度升高与氧化应激有关。如果氧化应激被认为对CF患者的临床结局很重要，那么必须研究在维持高脂肪、高能量饮食的同时降低氧化应激的方法。
