TYG-BMI在维生素D和非酒精性脂肪肝中的中介作用

Mediating role of TYG-BMI in vitamin D and nonalcoholic fatty liver disease

摘要:

目的 分析维生素D水平、甘油三酯葡萄糖-体质指数（triglyceride glucose-body mass index，TYG-BMI）与2型糖尿病（type 2 diabetes，T2DM）合并非酒精性脂肪肝（nonalcoholic fatty liver disease，NAFLD）患者的相关性，探讨TYG-BMI在维生素D缺乏对NAFLD影响中的作用。方法 纳入河北省人民医院内分泌科住院的434例成年T2DM患者为研究对象。收集患者的人口学基本信息和血液指标，NAFLD通过超声诊断。维生素D缺乏定义为25-羟基维生素D［25-hydroxyvitamin D，25（OH）D］<20 ng/mL。采用Spearman相关分析方法，探讨25（OH）D、TYG-BMI和T2DM合并NAFLD危险因素之间的相关性。采用多元逻辑回归分析方法探讨25（OH）D、TYG-BMI与NAFLD之间的联系。采用中介分析方法探索TYG-BMI是否介导25（OH）D和NAFLD之间的联系。结果 ①在所有纳入的T2DM患者中，NAFLD组比无NAFLD组的25（OH）D水平更低［15.89（12.33，19.94） vs. 18.27（14.05，24.63），P<0.05］，TYG-BMI水平更高［213.59（191.92，237.60） vs. 176.91（159.55，196.86），P<0.05］，并且男性和女性均有同样的变化趋势（P<0.05）。②按照25（OH）D水平不同分组发现，维生素D缺乏组的NAFLD患病率（60.1%）高于维生素D不足组（45.4%）及维生素D充足组（23.3%），差异存在统计学意义（P<0.05）。③无论是男性患者还是女性患者，血清25（OH）D水平均与TYG-BMI呈负相关（男：r=-0.215，P<0.001；女：r=-0.271，P<0.001）。④采用logistic回归调整混杂因素后发现维生素D缺乏是T2DM患者发生NAFLD的危险因素（Model 1 OR=2.347，95%CI=1.423~3.871，P=0.001；Model 2 OR=2.478，95%CI=1.472~4.172，P=0.001；Model 3 OR=2.057，95%CI=1.172~3.610，P=0.012）。进一步按性别分亚组进行logistic回归分析，仅在女性中发现维生素D缺乏是T2DM患者发生NAFLD的独立危险因素（Model 1 OR=5.52，95%CI=2.008~15.177，P=0.001；Model 2 OR=5.342，95%CI=1.776-16.061，P=0.003；Model 3 OR=3.734，95%CI=1.108~12.578，P=0.034）。⑤在所有患者、男性患者和女性患者中TYG-BMI与NAFLD患病率均呈正相关（P<0.05）。⑥中介分析发现在所有患者或女性患者中，TYG-BMI部分介导了25（OH）D对NAFLD患病率的间接影响（中介百分比：所有患者58.66%，女性患者38.07%），而男性没有。结论 仅在女性T2DM患者中，维生素D缺乏与T2DM合并NAFLD发病率增加相关。其中维生素D缺乏导致T2DM合并NAFLD发生率增加的原因部分由TYG-BMI介导。

Abstract:

Objective To analyze the correlation between the serum vitamin D and triglyceride glucose-body mass index（TYG-BMI） of type 2 diabetes mellitus（T2DM） patients complicated with nonalcoholic fatty liver disease（NAFLD），and to explore the roles played by TYG-BMI in the vitamin D deficiency of T2DM living with NAFLD.Methods A total of 434 patients with T2DM hospitalized at Department of Endocrinology，Hebei General Hospital were included in the study. These patients’ demographics and clinical data were collected. Abdominal ultrasonography was performed to diagnose NAFLD. Vitamin D deficiency was defined as that 25-hydroxyvitamin D［25（OH）D］ vitamin levels were less than 20 ng/mL. Spearman correlation was used to test for an association among 25（OH）D，TYG-BMI and risk factors of NAFLD in T2DM. Multiple logistic regression was used to determine the association in 25（OH）D，TYG-BMI and NAFLD. Mediation analysis was used to explore whether TYG-BMI mediated the association between 25（OH）D and NAFLD.Results ①In all included T2DM patients，the 25（OH）D level in patients with NAFLD was significantly lower［15.89（12.33，19.94） vs. 18.27（14.05，24.63），P<0.05］ and TYG-BMI was significantly higher［213.59（191.92，237.60） vs. 176.91（159.55，196.86），P<0.05］ compared with those without NAFLD. The data showed the same trends for males and females（P<0.05）. ②According to different 25（OH）D levels，the prevalence of NAFLD in the vitamin D deficiency group（60.1%） was higher than that in the vitamin D insufficiency group（45.4%） and the vitamin D sufficiency group（23.3%），and the difference was statistically significant（P<0.05）. ③Serum 25（OH）D level was negatively correlated with TYG-BMI， both in women and in men（men： r=-0.215，P<0.001；women： r=-0.271，P<0.001）. ④After adjusting for confounding factors，multivariate logistic regression analysis revealed that Vitamin D deficiency was a risk factor for NAFLD in T2DM patients（Model 1 OR=2.347，95%CI=1.423-3.871，P=0.001；Model 2 OR=2.478，95%CI=1.472-4.172，P=0.001；Model 3 OR=2.057，95%CI=1.172–3.610，P=0.012）. Gender-specific subgroup logistic regression analyses showed vitamin D deficiency was an independent risk factor for NAFLD in T2DM for women（Model 1 OR=5.52，95%CI=2.008-15.177，P=0.001；Model 2 OR=5.342，95%CI=1.776-16.061，P=0.003；Model 3 OR=3.734，95%CI=1.108-12.578，P=0.034）. ⑤TYG-BMI was positively correlated with the prevalence of NAFLD in all T2DM patients，male patients and female patients（P<0.05）. ⑥Mediation analysis indicated that TYG-BMI partly mediated the indirect effect of 25（OH）D on NAFLD incidence（percentage of mediation： 58.66% of all patients，and 38.07% of female patients）.Conclusion Vitamin D deficiency is associated with an increased incidence of NAFLD only in female subjects with T2DM. The association between vitamin D deficiency and higher prevalence of NAFLD in T2DM may be at least partially mediated by TYG-BMI.