血糖变异影响血糖-HbA1c线性关系

　　来自糖化平均血糖（ADAG）研究工作组的一项临床试验表明，1型糖尿病患者存在的血糖变异（GV），对平均血浆葡萄糖水平-糖化血红蛋白（MPG- HbA1c）相关性有显著交互作用，这种影响在高HbA1c水平时更为明显。不过，GV对1型糖尿病HbA1c水平的影响不大，尤其是当HbA1c接近于 7％的治疗目标时。该研究2011年6月23日在线发表于《糖尿病护理》（Diabetes care）杂志。

　　ADAG研究证实了HbA1c水平与MPG水平之间的线性关系。鉴于GV可能有促进糖化的作用，该研究评价了多种葡萄糖变异指数与MPG-HbA1c关系之间的相关性。

　　研究共纳入1型糖尿病患者268例和2型糖尿病患者159例。根据3个月的7点自我监测血糖和持续血糖监测计算MPG。通过计算三种不同的GV测量指标，并采用多元逐步回归模型确定各个GV测量指标对MPG-HbA1c关系的影响。

　　研究结果显示，通过标准差（SD）和连续重叠净血糖作用（continuous overlapping net glycemic action，CONGA）等指标反映出的GV对1型糖尿病患者的MPG-HbA1c相关性有显著影响，表现为，在相同MPG水平下，高GV可导致更高的 HbA1c水平。对于1型糖尿病患者，MPG水平为160 mg/dL时低SD比高SD的混杂作用和效果修饰对HbA1c水平的影响分别为7.02比 7.43和6.96比7.41。所有的GV测量指标显示了相同的趋势。

链接：Does Glucose Variability Influence the Relationship Between Mean Plasma Glucose and HbA_1cLevels in Type 1 and Type 2 Diabetic Patients?

英文摘要：

OBJECTIVE The A1C-Derived Average Glucose (ADAG) study demonstrated a linear relationship between HbA(1c) and mean plasma glucose (MPG). As glucose variability (GV) may contribute to glycation, we examined the association of several glucose variability indices and the MPG-HbA(1c) relationship. RESEARCH DESIGN AND METHODS Analyses included 268 patients with type 1 diabetes and 159 with type 2 diabetes. MPG during 3 months was calculated from 7-point self-monitored plasma glucose and continuous glucose monitoring. We calculated three different measures of GV and used a multiple-step regression model to determine the contribution of the respective GV measures to the MPG-HbA(1c) relationship. RESULTS GV, as reflected by SD and continuous overlapping net glycemic action, had a significant effect on the MPG-HbA(1c) relationship in type 1 diabetic patients so that high GV led to a higher HbA(1c) level for the same MPG. In type 1 diabetes, the impact of confounding and effect modification of a low versus high SD at an MPG level of 160 mg/dL on the HbA(1c) level is 7.02 vs. 7.43 and 6.96 vs. 7.41. All GV measures showed the same tendency. CONCLUSIONS In only type 1 diabetic patients, GV shows a significant interaction with MPG in the association with HbA(1c). This effect is more pronounced at higher HbA(1c) levels. However, the impact of GV on the HbA(1c) level in type 1 diabetes is modest, particularly when HbA(1c) is close to the treatment target of 7%.