Lactose Intolerance (LCT-13910C>T) Genotype Is Associated with Plasma 25-Hydroxyvitamin D Concentrations in Caucasians: A Mendelian Randomization Study
Lactose Intolerance (LCT-13910C>T) Genotype Is Associated with Plasma 25-Hydroxyvitamin D Concentrations in Caucasians: A Mendelian Randomization Study
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DOI：
10.3945/jn.116.246108
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发表时间：
2017-06-01
影响因子：
4.2
通讯作者：
El-Sohemy, Ahmed
中科院分区：
文献类型：
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作者：
Alharbi, Ohood;El-Sohemy, Ahmed
背景：LCT-13910 C>T基因变异与不同种族人群的乳糖不耐受（LI）相关。LI患者经常限制或避免乳制品消费，乳制品是北美维生素D的主要膳食来源，这可能导致维生素D摄入不足。目的：目的是确定生活在加拿大的不同种族群体中预测LI的基因型的患病率，并确定LCT基因型是否与血浆25（OH）D浓度相关。从来自多伦多营养基因组学和健康研究的总共1495名年龄在20-29岁的男性和女性中抽取血液样品用于基因分型和血浆25（OH）D分析。乳制品的摄入量采用196项食物频率问卷进行评估。采用x（2）分析比较LCT-13910 C>T基因型的分布情况。使用孟德尔随机化方法，我们研究了LCT基因型和25（OH）D concentration.Results之间的关联：约32%的高加索人，99%的东亚人，74%的南亚人，和59%的其他或混合种族的CC基因型与LI。与TT基因型相比，CC基因型的平均+/- SE总乳制品摄入量较低（2.15 +/- 0.09对比2.67 +/- 0.12份/天，P = 0.003），较低的脱脂牛奶摄入量（0.20 +/- 0.03对比0.46 +/- 0.06份/天，P = 0.0004），血浆25（OH）D浓度较低（63 +/- 1.9对比75.8 +/- 2.4 nmol/L，P < 0.0001）。CT和CC基因型分别与次优血浆25（OH）D浓度（< 75 nmol/L）增加50%和2倍的风险相关。结论：在高加索人中，预测LI的CC基因型与较低的血浆25（OH）D浓度相关，这至少部分归因于较低的乳制品摄入量，尤其是脱脂乳。在CT基因型人群中也观察到维生素D浓度低于最佳水平的风险增加，这表明杂合基因型的中间效应。
Background: The LCT-13910C>T gene variant is associated with lactose intolerance (LI) in different ethnic groups. Individuals with LI often limit or avoid dairy consumption, a major dietary source of vitamin D in North America, which may lead to inadequate vitamin D intake.Objective: The objective was to determine the prevalence of genotypes predictive of LI in different ethnic groups living in Canada and to determine whether the LCT genotype is associated with plasma 25(OH) D concentrations.Methods: Blood samples were drawn from a total of 1495 men and women aged 20-29 y from the Toronto Nutrigenomics and Health Study for genotyping and plasma 25(OH) D analysis. Intakes of dairy were assessed by using a 196-item food frequency questionnaire. The prevalence of LCT-13910C>T genotypes was compared by using x(2) analysis. Using a Mendelian randomization approach, we examined the association between LCT genotypes and 25(OH) D concentrations.Results: Approximately 32% of Caucasians, 99% of East Asians, 74% of South Asians, and 59% of those with other or mixed ethnicities had the CC genotype associated with LI. Compared with those with the TT genotype, those with the CC genotype had a lower mean +/- SE total dairy intake (2.15 +/- 0.09 compared with 2.67 +/- 0.12 servings/d, P = 0.003), a lower skim-milk intake (0.20 +/- 0.03 compared with 0.46 +/- 0.06 servings/d, P = 0.0004), and a lower plasma 25(OH) D concentration (63 +/- 1.9 compared with 75.8 +/- 2.4 nmol/L, P < 0.0001). The CT and CC genotypes were associated with a 50% and a 2-fold increased risk, respectively, of a suboptimal plasma 25(OH) D concentration (< 75 nmol/L).Conclusions: In Caucasians, the CC genotype that predicts LI is associated with a lower plasma 25(OH) D concentration, which is attributable at least in part to a lower intake of dairy, particularly skim milk. Increased risk of suboptimal concentrations of vitamin D was also observed among those with the CT genotype, suggesting an intermediate effect of the heterozygous genotype.