Bolton-Smith C, Woodward M, Tavendale R
Cardiovascular Epidemiology Unit, University of Dundee, Ninewells Hospital and Medical School.
Eur J Clin Nutr. 1997 Sep;51(9):619-24. doi: 10.1038/sj.ejcn.1600455.
To test the null-hypothesis that no age difference in adipose tissue fatty acid composition exists independent of dietary fat intake.
A cross-sectional survey of coronary heart disease risk factors, the Scottish Heart Health Study, provided needle biopsy adipose tissue fatty acid data and food frequency-derived dietary data.
Twenty-two Scottish Districts between 1984 and 1986.
A total of 10,359 men and women aged 40-59 y were randomly recruited in sex and five-year age bands from GP lists. A sub-set of 2308 men and 2049 women (42%) provided satisfactory adipose tissue and dietary data.
Multiple regression analysis (adjusting for dietary fats, body mass index and smoking, with and without menopause status for women) of the relationship between individual fatty acids in adipose tissue and age, and between age and the ratio of linoleic acid (C18:2, n-6) to gamma-linolenic acid (C18:3, n-6) as an indicator of delta-6 desaturase activity.
Sex-consistent changes with age occurred for linoleate (adjusted regression slope +/- s.e. for men -0.299 +/- 0.1339 and for women -0.504 +/- 0.1731) and gamma-linolenate (adjusted regression slope +/- s.e. for men -0.141 +/- 0.0341 and for women -0.154 +/- 0.0469) both P < 0.0001. These changes gave rise to a significant increase (P < or = 0.005) in the C18:2, n-6 to C18:3, n-6 ratio with age). Dihomo-gamma-linolenic acid (C20:3, n-6) and docosahexa- plus docosapentaenoic acids (C22:5 + C22:6, n-3) also increased significantly with age (P < or = 0.01). For the latter, the adjusted regression slopes were far greater for women (0.596 +/- 0.0575) than men (0.131 +/- 0.0417).
The results show that ageing does influence adipose tissue fatty acid composition independent of diet. The sex differences may partially be due to inadequate adjustment for changes in sex hormone status in males with ageing. Using the current indicator, a decline in the rate limiting step of beta-6 desaturation appeared to occur with age, and was greater in women than in men. These results may indicate that an increase in dietary gamma-linolenic acid (C18:3, n-6) is necessary with age to offset the relative imbalance between PUFA levels which appears to occur. However, any direct health benefit regarding the common diseases of ageing from such a strategy still remain to be clarified.
检验零假设，即脂肪组织脂肪酸组成不存在与膳食脂肪摄入量无关的年龄差异。
一项关于冠心病危险因素的横断面调查——苏格兰心脏健康研究，提供了针吸活检脂肪组织脂肪酸数据和食物频率得出的膳食数据。
1984年至1986年间的22个苏格兰地区。
从全科医生名单中按性别和五岁年龄组随机招募了总共10359名40至59岁的男性和女性。2308名男性和2049名女性（42%）的子集提供了满意的脂肪组织和膳食数据。
对脂肪组织中单个脂肪酸与年龄之间的关系，以及年龄与作为δ-6去饱和酶活性指标的亚油酸（C18:2，n-6）与γ-亚麻酸（C18:3，n-6）之比之间的关系进行多元回归分析（针对膳食脂肪、体重指数和吸烟进行调整，女性纳入或不纳入绝经状态）。
亚油酸（男性调整后的回归斜率±标准误为-0.299±0.1339，女性为-0.504±0.1731）和γ-亚麻酸（男性调整后的回归斜率±标准误为-0.141±0.0341，女性为-0.154±0.0469）随年龄出现了性别一致的变化，P均<0.0001。这些变化导致C18:2，n-6与C18:3，n-6之比随年龄显著增加（P≤0.005）。二高-γ-亚麻酸（C20:3，n-6）以及二十二碳六烯酸加二十二碳五烯酸（C22:5+C22:6，n-3）也随年龄显著增加（P≤0.01）。对于后者，女性的调整回归斜率（0.596±0.0575）远大于男性（0.131±0.0417）。
结果表明，衰老确实会独立于饮食影响脂肪组织脂肪酸组成。性别差异可能部分归因于男性随年龄增长性激素状态变化的调整不足。使用当前指标，β-6去饱和的限速步骤似乎随年龄下降，且女性比男性下降幅度更大。这些结果可能表明，随着年龄增长，有必要增加膳食γ-亚麻酸（C18:3，n-6）的摄入量，以抵消似乎出现的多不饱和脂肪酸水平相对失衡。然而，这种策略对常见衰老疾病的任何直接健康益处仍有待阐明。
