原发性醛固酮增多症诊断切点的研究及临床应用

Determination of optimal cut-off point for primary aldosteronism and its diagnostic value in clinical practice

目的探讨原发性醛固酮增多症(primary aldosteronism,PA)患者立卧位醛固酮、醛固酮/肾素比值(ratio of aldosterone/rennin,ARR)的诊断切点,提高PA诊断的准确率。方法收集2006-2014年在我院诊断的PA患者45例及年龄相匹配的原发性高血压患者(essential hypertension,EH)50例。PA患者均行病理诊断,其中34例术后病理证实为肾上腺醛固酮腺瘤,11例为肾上腺皮质增生。患者均行血钾、24 h尿钾、立卧位肾素、血管紧张素Ⅱ、醛固酮、皮质醇节律、儿茶酚胺代谢产物等检测,计算ARR,利用受试者工作曲线(ROC)得到诊断PA立卧位醛固酮、ARR的最佳切点,评价不同指标诊断PA的敏感性及特异性。并比较两种不同病理结果间醛固酮及ARR的差异。结果 PA组与EH组间性别、年龄和血压无明显差异,PA组肾素活性、血钾显著低于EH组,而醛固酮、ARR及24 h尿钾均显著高于EH组。诊断PA的立位醛固酮的最佳切点为0.221 ng/m L,敏感性(Sen)=0.561,特异性(Spe)=0.909;卧位醛固酮为0.175 ng/m L,Sen=0.829,Spe=0.795;立位ARR为19.5(ng·d L-1)/(ng·m L-1·h-1),Sen=0.878,Spe=0.955;卧位ARR为20.5(ng·d L-1)/(ng·m L-1·h-1),Sen=0.902,Spe=0.841。在PA组中肾上腺醛固酮腺瘤的ARR较肾上腺皮质增生患者高,尤其立位ARR最为明显。结论立位醛固酮、ARR诊断PA的敏感性较卧位差,但特异性较强,所以临床对高血压患者行上述激素检查时应综合立卧位激素的检查结果,且其水平与病理有关。

Objective To determine the cut-off points for supine and upright plasma levels of aldosterone （ALD） and for ratio of ALD/rennin （ARR） in primary aldosteronism （PA）, and investigate their diagnostic values to improve the diagnostic accuracy of the disease. Methods Clinical data of 45 patients of pathologically confirmed PA and 50 age- and gender-matched patients of essential hypertension （EH） admitted in our hospital from 2006 to 2014 were collected in this study. Histological examination indicated that 34 PA patients were confirmed as adrenal adenoma and 11 as adrenal cortical hyperplasia. Serum potassium, and 24- hour urinary potassium, corticosteroid rhythm, catecholamine metabolites, and supine and upright plasma levels of rennin, angiotensin Ⅱ and ALl） were measured. Moreover, the levels of ALD and ARR were analyzed to draw the receiver operating characteristic （ROC） curve and obtain the optimal cut-off points, and access the sensitivities and specificities of those indexes. Besides, the difference of ALl） and ARR were compared between 2 kinds of pathological types of PA. Results There was no obvious difference in gender, age and blood pressure between PA and EH groups. Serum potassium and plasma renin activity were lower in PA thanin EH group, but ALD ARR and 24-hour urinary potassium were higher. The optimal cut-off point of uptight plasma ALD was 0.221 ng/mL, with a sensitivity of 0. 561 and specificity of 0.909, that of supine plasma ALD was 0. 175 ng/mL with a sensitivity of 0. 829 and specificity of 0. 795, that of uptight ARR was 19.5 （ng·dL^-1 ）/（ng·mL^-1·h^-1 ） with a sensitivity of 0. 878 and specificity of 0. 955, and that of supine ARR was 20.5 （ng·dL^-1 ）/（ng·mL^-1·h^-1） with a sensitivity of 0.902 and specificity of 0. 841. ARR was higher in patients with adrenal adenoma than those with adrenal cortex hyperplasia, especially the uptight ARR. Conclusion The upright ALD and ARR have lower sensitivity than the supine ones, but higher specificity. So clinician should comprehensively consider the hormone test results on both supine and uptight positions for hypertensive patients, moreover the results are associated with pathologic characteristics.