Department of Medical Sciences, University of Milan, Endocrinology and Diabetology Unit, Fondazione IRRCS Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy.
Diabetes Care. 2011 Oct;34(10):2186-91. doi: 10.2337/dc11-0764. Epub 2011 Aug 18.
To investigate factors associated with bone mineral density (BMD) in type 1 diabetes by classic statistic and artificial neural networks.
A total of 175 eugonadal type 1 diabetic patients (age 32.8 ± 8.4 years) and 151 age- and BMI-matched control subjects (age 32.6 ± 4.5 years) were studied. In all subjects, BMI and BMD (as Z score) at the lumbar spine (LS-BMD) and femur (F-BMD) were measured. Daily insulin dose (DID), age at diagnosis, presence of complications, creatinine clearance (ClCr), and HbA(1c) were determined.
LS- and F-BMD levels were lower in patients (-0.11 ± 1.2 and -0.32 ± 1.4, respectively) than in control subjects (0.59 ± 1, P < 0.0001, and 0.63 ± 1, P < 0.0001, respectively). LS-BMD was independently associated with BMI and DID, whereas F-BMD was associated with BMI and ClCr. The cutoffs for predicting low BMD were as follows: BMI <23.5 kg/m(2), DID >0.67 units/kg, and ClCr <88.8 mL/min. The presence of all of these risk factors had a positive predictive value, and their absence had a negative predictive value for low BMD of 62.9 and 84.2%, respectively. Data were also analyzed using the TWIST system in combination with supervised artificial neural networks and a semantic connectivity map. The TWIST system selected 11 and 12 variables for F-BMD and LS-BMD prediction, which discriminated between high and low BMD with 67 and 66% accuracy, respectively. The connectivity map showed that low BMD at both sites was indirectly connected with HbA(1c) through chronic diabetes complications.
In type 1 diabetes, low BMD is associated with low BMI and low ClCr and high DID. Chronic complications negatively influence BMD.
通过经典统计学和人工神经网络研究 1 型糖尿病患者骨密度（BMD）的相关因素。
共研究了 175 名生育正常的 1 型糖尿病患者（年龄 32.8 ± 8.4 岁）和 151 名年龄和 BMI 匹配的对照组（年龄 32.6 ± 4.5 岁）。在所有受试者中，测量了腰椎（LS-BMD）和股骨（F-BMD）的 BMI 和 BMD（Z 评分）。测定了每日胰岛素剂量（DID）、诊断时年龄、并发症存在情况、肌酐清除率（ClCr）和糖化血红蛋白（HbA1c）。
患者的 LS-BMD 和 F-BMD 水平均低于对照组（分别为-0.11 ± 1.2 和-0.32 ± 1.4 比 0.59 ± 1，P < 0.0001 和 0.63 ± 1，P < 0.0001）。LS-BMD 与 BMI 和 DID 独立相关，而 F-BMD 与 BMI 和 ClCr 相关。预测低 BMD 的截止值如下：BMI <23.5 kg/m2，DID >0.67 单位/kg，ClCr <88.8 mL/min。这些危险因素的存在具有阳性预测值，其不存在具有阴性预测值，分别为 62.9%和 84.2%的低 BMD。数据还使用 TWIST 系统结合有监督人工神经网络和语义连接图进行了分析。TWIST 系统分别选择 11 个和 12 个变量来预测 F-BMD 和 LS-BMD，对高和低 BMD 的区分准确率分别为 67%和 66%。连接图显示，两个部位的低 BMD 通过慢性糖尿病并发症与 HbA1c 间接相关。
在 1 型糖尿病中，低 BMD 与低 BMI 和低 ClCr 以及高 DID 相关。慢性并发症对 BMD 有负面影响。
