Supplementary Material for: High glycemic variability is associated with worse Continuous Glucose Monitoring metrics in children and adolescents with type 1 diabetes

Objective: The primary aim of this study was to quantify the prevalence of children and adolescents with T1D who achieve the recommended target for CV identifying the determining factors to reach this target. The secondary aim was to examine the relationship between CV, the other metrics derived from CGM data and clinical parameters. Method: CGM data were collected from 805 children/adolescents with T1D. Several CGM metrics and patients' characteristics were evaluated. Participants were stratified by CV≤36% and CV>36%. Binary logistic regression analysis was run to identify the determining factors of high CV. Results CV was positively correlated with %TBR<70mg/dL, %TBR<54 mg/dL, %TAR>250 mg/dL, LBGI, HBGI and negatively with %TIR. CV≤36% was found in 31.4% of the subjects. The CV>36% group spent less time in %TIR, more time in hypoglycemia and hyperglycemia with lower proportion of subjects using rtCGM and CSII. Percentage of TBR<70mg/dL and TAR>250mg/dL were significant predictors of CV>36%, whereas age, gender, BMI, duration of diabetes, type of CGM device, type of insulin therapy administration and %TIR were not significant predictors (p<0.001,R2Nagelkerke=0.48). Conclusions: CV identifies children and adolescents with worse glycemic control at higher risk of both hypoglycemia and hyperglycemia.

研究目的：本研究的首要目标是量化1型糖尿病（Type 1 Diabetes, T1D）儿童及青少年群体中，达成血糖变异系数（Coefficient of Variation, CV）推荐目标的人群占比，并明确达成该目标的影响因素。次要目标为分析血糖变异系数、动态血糖监测（Continuous Glucose Monitoring, CGM）衍生的其他指标与临床参数之间的关联。
研究方法：本研究纳入805名1型糖尿病儿童及青少年，收集其动态血糖监测数据，对多项动态血糖监测指标及受试者的临床特征进行评估。按照血糖变异系数≤36%与>36%对受试者进行分组，通过二元逻辑回归分析筛选血糖变异系数升高的影响因素。
研究结果：血糖变异系数与<70mg/dL目标血糖低于范围时间占比（Time Below Range, %TBR<70mg/dL）、<54mg/dL目标血糖低于范围时间占比（%TBR<54mg/dL）、>250mg/dL目标血糖高于范围时间占比（Time Above Range, %TAR>250mg/dL）、低血糖指数（Low Blood Glucose Index, LBGI）及高血糖指数（High Blood Glucose Index, HBGI）呈正相关，与目标血糖范围内时间占比（Time in Range, %TIR）呈负相关。31.4%的受试者血糖变异系数≤36%。血糖变异系数>36%的组别，其目标血糖范围内时间占比更低，低血糖与高血糖持续时间更长，且使用实时动态血糖监测（real-time Continuous Glucose Monitoring, rtCGM）与胰岛素泵治疗（Continuous Subcutaneous Insulin Infusion, CSII）的受试者比例更低。<70mg/dL目标血糖低于范围时间占比与>250mg/dL目标血糖高于范围时间占比是血糖变异系数>36%的显著预测因子，而年龄、性别、BMI、糖尿病病程、动态血糖监测设备类型、胰岛素治疗方案及目标血糖范围内时间占比均无显著预测效应（p<0.001，内格尔克尔克R²=0.48）。
研究结论：血糖变异系数可用于识别血糖控制较差、同时面临低血糖与高血糖风险更高的1型糖尿病儿童及青少年群体。