Aravind Eye Hospital Pondicherry, Aravind Eye Care, Pondicherry, India.
Ophthalmology. 2011 Oct;118(10):1958-1965.e2. doi: 10.1016/j.ophtha.2011.03.016. Epub 2011 Jun 25.
To examine the association between vitamin C and cataract in the Indian setting.
Population-based cross-sectional analytic study.
A total of 5638 people aged ≥60 years.
Enumeration of randomly sampled villages in 2 areas of north and south India to identify people aged ≥60 years. Participants were interviewed for socioeconomic and lifestyle factors (tobacco, alcohol, household cooking fuel, work, and diet); attended a clinical examination, including lens photography; and provided a blood sample for antioxidant analysis. Plasma vitamin C was measured using an enzyme-based assay in plasma stabilized with metaphosphoric acid, and other antioxidants were measured by reverse-phase high-pressure liquid chromatography.
Cataract and type of cataract were graded from digital lens images using the Lens Opacity Classification System III (LOCS III), and cataract was classified from the grade in the worse eye of ≥4 for nuclear cataract, ≥3 for cortical cataract, and ≥2 for posterior subcapsular cataract (PSC). Any cataract was defined as any unoperated or operated cataract.
Of 7518 enumerated people, 5638 (75%) provided data on vitamin C, antioxidants, and potential confounders. Vitamin C was inversely associated with cataract (adjusted odds ratio [OR] for highest to lowest quartile = 0.61; 95% confidence interval (CI), 0.51-0.74; P=1.1×10(-6)). Inclusion of other antioxidants in the model (lutein, zeaxanthin, retinol, β-carotene, and α-tocopherol) made only a small attenuation to the result (OR 0.68; 95% CI, 0.57-0.82; P < 0.0001). Similar results were seen with vitamin C by type of cataract: nuclear cataract (adjusted OR 0.66; CI, 0.54-0.80; P < 0.0001), cortical cataract (adjusted OR 0.70; CI, 0.54-0.90; P < 0.002), and PSC (adjusted OR 0.58; CI, 0.45-0.74; P < 0.00003). Lutein, zeaxanthin, and retinol were significantly inversely associated with cataract, but the associations were weaker and not consistently observed by type of cataract. Inverse associations were also observed for dietary vitamin C and cataract.
We found a strong association with vitamin C and cataract in a vitamin C-depleted population.
FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
在印度人群中研究维生素 C 与白内障的关系。
基于人群的横断面分析研究。
共有 5638 名年龄≥60 岁的人。
在印度北部和南部的两个地区，通过列举随机抽样的村庄来确定年龄≥60 岁的人群。对参与者进行社会经济和生活方式因素（烟草、酒精、家庭烹饪燃料、工作和饮食）的访谈；进行临床检查，包括晶状体摄影；并提供血液样本进行抗氧化剂分析。使用基于酶的测定法在稳定于偏磷酸中的血浆中测量血浆维生素 C，并用反相高压液相色谱法测量其他抗氧化剂。
使用 Lens Opacity Classification System III（LOCS III）从数字晶状体图像中分级白内障和白内障类型，根据更严重眼中的等级将白内障分类为核性白内障≥4 级、皮质性白内障≥3 级和后囊下白内障（PSC）≥2 级。任何白内障都定义为未经手术或已手术的白内障。
在列举的 7518 人中，有 5638 人（75%）提供了有关维生素 C、抗氧化剂和潜在混杂因素的数据。维生素 C 与白内障呈负相关（最高四分位至最低四分位的调整比值比[OR]为 0.61；95%置信区间[CI]，0.51-0.74；P=1.1×10（-6））。在模型中包含其他抗氧化剂（叶黄素、玉米黄质、视黄醇、β-胡萝卜素和α-生育酚）仅使结果略有减弱（OR 0.68；95%CI，0.57-0.82；P<0.0001）。按白内障类型观察到维生素 C 的类似结果：核性白内障（调整 OR 0.66；CI，0.54-0.80；P<0.0001）、皮质性白内障（调整 OR 0.70；CI，0.54-0.90；P<0.002）和 PSC（调整 OR 0.58；CI，0.45-0.74；P<0.00003）。叶黄素、玉米黄质和视黄醇与白内障呈显著负相关，但关联较弱，且按白内障类型观察并不一致。饮食中维生素 C 与白内障也呈负相关。
在维生素 C 缺乏的人群中，我们发现维生素 C 与白内障之间存在很强的关联。
作者没有任何与本文讨论的材料有关的专有或商业利益。
