Huai 'an Center for Disease Control and Prevention, Huaian, 223001, China.
School of public health, Xuzhou Medical University, Xuzhou, 221004, China.
BMC Public Health. 2023 Mar 10;23(1):468. doi: 10.1186/s12889-022-14856-5.
To analyze the effects of different dietary types on in type 2 diabetes mellitus (T2DM) and determine the mediating effects of Body Mass Index (BMI) on dietary type with Fasting Plasma Glucose (FPG), Glycosylated Hemoglobin (HbA1c) on the associations in T2DM.
Data of community-based cross-sectional study with 9602 participants including 3623 men and 5979 women were collected from the project 'Comprehensive Research in prevention and Control of Diabetes mellitus (CRPCD)' conducted by Jiangsu Center for Disease Control and Prevention in 2018. The dietary data were collected from a food frequency qualitative questionnaire (FFQ) and dietary patterns were derived through Latent Class Analysis (LCA). Then, Logistics regression analyses were used to evaluate the associations of FPG, HbA1c with different dietary patterns. The BMI (BMI = height/weight) was used as a moderator to estimate the mediating effect. Mediation analysis was performed using hypothetical variables, the mediation variables, to identify and explain the observed mechanism of association between the independent and dependent variables while the moderation effect was tested with multiple regression analysis with interaction terms.
After completing Latent Class Analysis (LCA), the dietary patterns were divided into three categories: TypeI, TypeII, TypeIII. After adjusting for confounding factors such as gender, age, education level, marital status, family income, smoking, drinking, disease course, HDL-C, LDL-C, TC, TG, oral hypoglycemic drugs, insulin therapy, Hypertension, Coronary heart disease, Stroke, Type III were all significantly associated with HbA1c compared to those with Type I (P < 0.05), and the research showed the patients with Type III had High glycemic control rate. Taking type I as the reference level, the 95% Bootstrap confidence intervals of the relative mediating effect of TypeIII on FPG were (-0.039, -0.005), except 0, indicating that the relative mediating effect was significant (α = 0.346*, β = -0.060*). The mediating effect analysis was performed to demonstrate that BMI was used as a moderator to estimate the moderation effect.
Our findings demonstrate that consuming Type III dietary patterns associates with good glycemic control in T2DM and the BMI associations would be playing a two-way effect between diet and FPG in Chinese population with T2DM, indicated that Type III could not only directly affect FPG, but also affect FPG through the mediating effect of BMI.
分析不同饮食类型对 2 型糖尿病（T2DM）的影响，并确定体质指数（BMI）对饮食类型与空腹血糖（FPG）、糖化血红蛋白（HbA1c）之间关联的中介作用。
本研究为 2018 年江苏省疾病预防控制中心开展的“糖尿病综合防治研究（CRPCD）”的一项基于社区的横断面研究，共纳入 9602 名参与者，其中包括 3623 名男性和 5979 名女性。饮食数据来自食物频率定性问卷（FFQ），通过潜在类别分析（LCA）得出饮食模式。然后，使用 Logistics 回归分析评估 FPG、HbA1c 与不同饮食模式的关系。BMI（BMI=身高/体重）作为调节变量，使用假设变量、中介变量来估计独立变量和依赖变量之间的关联的观察机制，而调节效应则使用具有交互项的多元回归分析进行检验。
完成潜在类别分析（LCA）后，将饮食模式分为三类：TypeI、TypeII、TypeIII。调整性别、年龄、教育水平、婚姻状况、家庭收入、吸烟、饮酒、病程、HDL-C、LDL-C、TC、TG、口服降糖药、胰岛素治疗、高血压、冠心病、脑卒中后，与 TypeI 相比，TypeIII 与 HbA1c 呈显著相关（P<0.05），且研究显示 TypeIII 患者的血糖控制率较高。以 TypeI 为参考水平，TypeIII 对 FPG 的相对中介效应的 95%Bootstrap 置信区间为（-0.039，-0.005），除 0 外均小于 0，表明相对中介效应显著（α=0.346*，β=-0.060*）。进行中介效应分析以证明 BMI 作为调节变量来估计调节效应。
我们的研究结果表明，在中国 T2DM 人群中，摄入 TypeIII 饮食模式与良好的血糖控制相关，BMI 与饮食和 FPG 之间的关联将发挥双向作用，表明 TypeIII 不仅可以直接影响 FPG，还可以通过 BMI 的中介作用影响 FPG。
