Shehata Elaine, Qayyum Rehan
*Department of Medicine, University of Tennessee College of Medicine at Chattanooga, Chattanooga, TN †Division of General Internal Medicine, Johns Hopkins School of Medicine, Baltimore, MD.
J Clin Gastroenterol. 2016 Oct;50(9):e81-4. doi: 10.1097/MCG.0000000000000459.
Several studies have examined the relationship between vitamin D (VD) and liver disease but none have explored this relationship in adults with normal liver enzymes. Our aim was to explore an independent association of VD with alanine aminotransferase (ALT) in a large sample of the US adults with liver enzymes in normal range (≤39 U/L).
We used the continuous National Health and Nutrition Examination Survey from 2001 to 2006. We excluded individuals with serum ALT>39 U/L. We built linear regression models to estimate unadjusted and adjusted (age, sex, race, diabetes, hypertension, alcohol use, smoking, and body mass index) effect sizes, taking into account the complex probability survey design.
Of the 12,155 participants, 6635 (54.6%) were women, mean±SD age was 49.9±19.4 years, VD was 21.9±9.2 ng/mL, and ALT was 20.9±6.9 U/L. In unadjusted analysis, VD was significantly associated with serum ALT (0.02 U/L/ng/mL of VD, P=0.007). After adjustment for confounders, VD remained statistically significantly associated with serum ALT levels (0.04 U/L, P<0.001). Similarly, individuals in the highest quartile of VD had significantly higher serum levels of ALT than those in the lowest quartile (unadjusted difference=0.98 U/L, P<0.001; adjusted difference=1.21 U/L, P<0.001).
We found a positive association between VD and ALT after excluding individuals with suspected active liver injury (ALT>39 U/L). The underlying mechanisms for this association are not known and needs further study.
多项研究探讨了维生素D（VD）与肝脏疾病之间的关系，但均未在肝酶正常的成年人中探究这种关系。我们的目的是在大量肝酶处于正常范围（≤39 U/L）的美国成年人样本中，探讨VD与丙氨酸氨基转移酶（ALT）之间的独立关联。
我们使用了2001年至2006年连续的国家健康和营养检查调查。我们排除了血清ALT>39 U/L的个体。我们建立了线性回归模型，以估计未调整和调整后（年龄、性别、种族、糖尿病、高血压、饮酒、吸烟和体重指数）的效应大小，同时考虑到复杂的概率调查设计。
在12155名参与者中，6635名（54.6%）为女性，平均年龄±标准差为49.9±19.4岁，VD为21.9±9.2 ng/mL，ALT为20.9±6.9 U/L。在未调整分析中，VD与血清ALT显著相关（每ng/mL VD为0.02 U/L，P = 0.007）。在对混杂因素进行调整后，VD与血清ALT水平仍具有统计学显著关联（0.04 U/L，P<0.001）。同样，VD处于最高四分位数的个体血清ALT水平显著高于最低四分位数的个体（未调整差异=0.98 U/L，P<0.001；调整差异=1.21 U/L，P<0.001）。
在排除疑似活动性肝损伤（ALT>39 U/L）的个体后，我们发现VD与ALT之间存在正相关。这种关联的潜在机制尚不清楚，需要进一步研究。
