背景與目的：第2型糖尿病人罹患心血管病變機率是正常人的2~4倍，運動能力較非糖尿病人低。本研究的目的：探討第2型糖尿病患運動測試時之血糖、血漿中的硝酸鹽／亞硝酸鹽與血管傳導性的變化。方法：由新陳代謝科門診篩選46位第2型糖尿病患，依據其糖化血色素(glycosylated hemoglobin, HbAlc)值分組；HbAlc大於等於8.0%為代謝控制差組(poor control of DM, PDM)，HbAlc小於8.0%為代謝控制好組(good control of DM, GDM)。另以13位年齡、身高、體重相符之健康者為正常組(CON)。每位受試者接受一回漸增負荷的腳踏車運動，最大運動強度為心跳達到90%年齡預定的心跳值±5次／分。運動過程持續的收集心電圖及血壓；並於運動前、後以脈搏描記圖測量小腿血管之傳導性及採集血液樣本。血漿中的硝酸鹽／亞硝酸鹽濃度以Griess reagent-based法檢測。結果：運動後三組之靜脈血流、張力和靜脈容量明顯降低(p<0.05)；然而靜脈阻力在運動後上升。正常組運動後的血漿中硝酸鹽／亞硝酸鹽濃度上升，血糖值降低(p<0.05)；糖尿病組則無顯著變化。三組比較顯示：PDM組的最大運動量、動脈血流、靜脈血流和靜脈容量皆低於GDM組(p<0.05)；在運動過程PDM組之舒張壓高於GDM組。GDM與CON組間血管之傳導性則無顯著差異，但GDM組的運動量低於CON組。結論：代謝控制較差的糖尿病患對運動測試引發的血管反應低於控制較好及正常者；糖尿病患之最大運動量低於正常人。糖尿病患運動測試前、後其血漿中的硝酸鹽／亞硝酸鹽的濃度及高血糖並無顯著改變。臨床意義：血糖控制的程度會影響糖尿病患之循環調整及運動能力，HbA1c值可提供糖尿病患運動能力之參考。

Background and Purpose: Patients with type 2 diabetes without cardiovascular disease have a reduced exercise capacity compared with nondiabetic subjects. To assesse the impacts of acute exercise on glycemic control, vascular and plasma nitrate/nitrite reaction in type 2 diabetes mellitus (DM) patients. Methods: A total of 46 patients with type 2 DM and 13 control subjects with age, height and weight matched were studied. Based on the HbAIc levels, the DM patients were further divided into two subgroups: poor DM control (PDM, glycosylated hemoglobin (HbAlc≥8.0%) and good DM control (GDM, HbA1c<8.0%). All patients underwent an incremental exercise test until they exceeded their 90% age-predicated maximal heart rate. Electrocardiogram (ECG) and blood pressure were measured during exercise. The vascular conductivity, plasma nitrate/nitrite and glucose concentration were measured before and immediately after exercise. Results: After exercise, the venous outflow, venous tone, and venous capacity significantly decreased from resting (p<0.05); However, the venous resistance significantly increased from resting in all groups (p<0.05). The pairwise comparisons revealed that the patients in the PDM group had lower levels of rest arterial inflow, venous outflow and venous capacity than the GDM group (p<0.05). Those in the control group had the largest hyperemic arterial inflow among all groups (p<0.05). Furthermore, the postprandial glucose level was significantly decreased and the plasma nitrate/nitrite level was increased significantly after exercise in the control group (p<0.05) only, but unchanged in two diabetic subgroups. Conclusion: Poor metabolic control (HbAlc≥8.0%) may cause impairment of vascular regulation and glucose utilization during exercise testing.