亚临床甲状腺功能减退对老年人2型糖尿病大血管并发症的影响

Impact of subclinical hypothyroidism on macro-vascular complications in elderly type 2 diabetic patients

目的探讨亚临床甲状腺功能（甲功）减退（subclinical hypothyroidism，SCH）对老年2型糖尿病患者大血管并发症的影响。方法选取北京同仁医院住院2型糖尿病患者1170例，经系统抽样后，对其中老年患者甲状腺功能、生化指标、干预措施、各时点C肽（CP。～s）释放试验检测结果及大血管并发症（踝／臂指数、经颅多普勒血管超声、心电图、射血分数、冠心病史、高血压分级）进行分析。结果据促甲状腺激素（TSH）水平将观察对象分为甲功正常组（TSH0．4～4mU／L）及SCH组（TSH〉4mU／L），再将SCH组分为轻度SCH（TSH〉4～10mU／L）组及重度SCH（TSH〉10mU／L）组。sCH组踝／臂指数（右／左0．86／0．92）显著降低（P〈0．01）；scH组CP0～3分别为（2．16±0．93）pg／L、（0．53±0．25）pg／L、（0．72±0．23）pg／L和（6．21±2．69）pg／L，高于甲功正常组[（1．56±1．05）pg／L、（O．38±0．37）pg／L、（0．56±0．32）pg／L和（4．46±2．62）pg／L3（P〈0．01），SCH组左心室射血分数升高[（70．87士6．66）％比（65．10±8．08）%，P〈O．013；其他生化指标、异常心电图、经颅多普勒血管超声、冠心病、高血压患病情况及干预措施等，差异均无统计学意义（P〉0．05）。结论SCH可能使老年2型糖尿病患者下肢动脉硬化更为明显，其发生早于其他大血管并发症，TSH水平升高及胰岛素抵抗可能为重要原因。

Objective To investigate the impact of subclinical hypothyroidism （SCH） on macro- vascular complications in elderly type 2 diabetic patients. Methods A total of 1170 hospitalized elderly patients with type 2 diabetes mellitus were enrolled in the study through systematic sampling and underwent testing for blood biochemical indicators, thyroid function and C peptide. Parameters for macro-vascular complications, including the ankle/brachial index （ABI）, transcranial Doppler vascular ultrasound （TCD）, electrocardiogram （ECG）, ejection fraction （EF）, history of coronary heart disease, and hypertension grading were also monitored. Results All the subjects were divided into two groups based on the thyroid stimulating hormone （TSH） level： the euthyroid group （4 mU/L≥TSH〉0. 4 mU/L） and the SCH group （TSH〉4 mU/L）, and the latter was further sub-grouped into the mild SCH group （10 mU/L≥TSH〉4 mU/L） and the severe SCH group （TSH〉10 mU/L）. ABI was significantly decreased in SCH （R/L： 0.86/0.92, P〈0.01）. Levels of basal C-peptide （CP0） and post glucose-challenge C-peptide （CP13） were higher in the SCH group than in the euthyroid group （（2.16±0. 93）pg/L w （1.56±1.05）pg/L, （0.53±0.25）pg/L w （0.38±0.37）, （0.72±0.23） pg/L vs （0.56! 0.32） pg/L, （6.21±2.69） pg/L vs. （4.46±2.62） pg/L, respectively, P〈0.01 for all]. EF was higher in the SCH group than in the euthyroid group[（70.87±6.66）% w （65.10±8.08%）, P〈0. 011 . There were no significant differences in other biochemical indicators, ECG, TCD, history of coronary heart disease, hypertension grading and intervention treatment （P〉0.05 for all）. Conclusions Lower extremity atherosclerotic disease has a higher incidence in elderly type 2 diabetic patients with SCH and occurs earlier than other macro- vascular complications. Elevated TSH levels and insulin resistance may be the major causes.