Rufino M, Barbero P, Hernández D, Torres A, Lorenzo V
Nefrología, Hospital Universitario de Canarias, Santa Cruz de Tenerife.
Nefrologia. 2007;27(1):30-7.
A pathological Oral Glucose Tolerance test (OGTT) is early marker of peripheral insulin resistance. Nevertheless, its utility in nondiabetic patients with CRF stage IV-V is undetermined.
We wanted to detect, in a population of non diabetic patients with CRF, the presence of carbohydrates metabolism anomalies, by means of the OGTT and to relate it with metabolic, anthropometric, cardiovascular parameters and renal function. We studied 45 non diabetic patients with advanced CRF (stage IV-V), 26 men, mean age 66.5 years, with average Cockroft-Gault of 23.6 ml/min. We measured weight, height, waist and BMI. BIOCHEMICAL: glucose, insulin, OGTT, C peptide, lipid profile, HbA1C and Hto. Cardiovascular comorbidity, mean proteinuria and systolic and diastolic blood pressure (6 months pre and post analytical measure) were measured. Pulse pressure was also calculated.
47% of the patients presented normal fasting glucose, whereas 53% had isolated impaired fasting glucose (IFG). After the OGTT, 36% of the patients presented impaired glucose tolerance (IGT) and 14% diabetes (>200 mg/dl). Of the patients with normal fasting glucose, 38% had IGT after OGTT and 5% diabetes. Patients with abnormal OGTT were older (71+/-13.6 versus 60+/- 18.8 years, p=0.03), had greater HbA1C (5.6+/-0.5 versus 5.2+/-0.3%, p=0.02), total cholesterol (193+/-37.7 versus 169.8+/-44.9 mg/dl, p=0.03), pulse pressure (63.4+/- 14.5 versus 52.3+/-9.7 mmHg, p=0.0001) and greater prevalence of ischemic heart disease (28% versus 5%, p=0.05). Creatinine Clerance negatively correlated with the OGTT (r=-0.39, p=0.01) and plasma creatinine positively with fasting insulin (r=0.33, p=0.02) and C-peptide (r=0.42, p=0.006). Urinary Proteins were correlated with fasting glucose (r=0.30, p=0.04), C-peptide (r=0.52, p=0.001), triglycerides (r=0.36, p=0.01) and with the HOMA-IR index (r=0.30, p=0.05).
Fasting Glucose did not predict OGTT results in patients with CRF. For this reason, we think that the OGTT can be very usefull tool to identify states of "prediabetes" and diabetes in patients with CRF, specially in those whose present an elevated Pulse Pressure, age greater than 65 years, hyperlipidaemia and HbA1C above 5.2%. The early detection of these metabolic anomalies, may lead to intensify dietetic and pharmacological measures directed to delay or to attenuate the appearance of diabetes and its serious complications in a population in which the cardiovascular risks factors are very elevated.
病理性口服葡萄糖耐量试验（OGTT）是外周胰岛素抵抗的早期标志物。然而，其在慢性肾功能衰竭（CRF）IV - V期非糖尿病患者中的效用尚不确定。
我们希望通过OGTT检测慢性肾功能衰竭非糖尿病患者群体中碳水化合物代谢异常的存在情况，并将其与代谢、人体测量、心血管参数及肾功能相关联。我们研究了45例晚期慢性肾功能衰竭（IV - V期）非糖尿病患者，其中26例男性，平均年龄66.5岁，平均Cockcroft - Gault肌酐清除率为23.6 ml/min。我们测量了体重、身高、腰围和体重指数（BMI）。生化指标：血糖、胰岛素、OGTT、C肽、血脂谱、糖化血红蛋白（HbA1C）和血细胞比容（Hto）。测量了心血管合并症、平均蛋白尿以及分析测量前后6个月的收缩压和舒张压。还计算了脉压。
47%的患者空腹血糖正常，而53%的患者存在单纯空腹血糖受损（IFG）。OGTT后，36%的患者出现糖耐量受损（IGT），14%的患者患有糖尿病（血糖>200 mg/dl）。空腹血糖正常的患者中，38%在OGTT后出现IGT，5%患有糖尿病。OGTT异常的患者年龄更大（71±13.6岁对60±18.8岁，p = 0.03），HbA1C更高（5.6±0.5%对5.2±0.3%，p = 0.02），总胆固醇更高（193±37.7 mg/dl对169.8±44.9 mg/dl，p = 0.03），脉压更高（63.4±14.5 mmHg对52.3±9.7 mmHg，p = 0.0001），缺血性心脏病患病率更高（28%对5%，p = 0.05）。肌酐清除率与OGTT呈负相关（r = -0.39，p = 0.01），血浆肌酐与空腹胰岛素呈正相关（r = 0.33，p = 0.02）以及与C肽呈正相关（r = 0.42，p = 0.006）。尿蛋白与空腹血糖（r = 0.30，p = 0.04）、C肽（r = 0.52，p = 0.001）、甘油三酯（r = 0.36，p = 0.01）以及与胰岛素抵抗指数（HOMA - IR）（r = 0.30，p = 0.05）相关。
空腹血糖不能预测慢性肾功能衰竭患者的OGTT结果。因此，我们认为OGTT是识别慢性肾功能衰竭患者“糖尿病前期”和糖尿病状态的非常有用的工具，特别是对于那些脉压升高、年龄大于65岁、高脂血症且HbA1C高于5.2%的患者。这些代谢异常的早期检测可能会加强饮食和药物措施，以延迟或减轻糖尿病及其严重并发症在心血管危险因素非常高的人群中的出现。
