Samiy A H
Med Clin North Am. 1983 Mar;67(2):463-80. doi: 10.1016/s0025-7125(16)31215-9.
With advancing age and in the absence of any disease, there is a significant alteration in kidney structure and a gradual decline in renal function. While RPF, GFR, and tubular reabsorptive capacity decrease with age, abnormal signs or symptoms cannot be detected under ordinary circumstances. The aging kidneys, however, have limited capacity to cope with rapid hemodynamic changes or disturbances in fluid and water balance, and this results in signs and symptoms of renal dysfunction. In the elderly, the incidence of primary renal diseases declines while the incidence of renal diseases secondary to systemic disease increases. AGN, while essentially a disease of the young, does occur in the older age group. RPGN, however, is the most common form of acute primary glomerulonephropathy, followed by membranous glomerulonephritis and glomerulosclerosis. Glomerulonephritis secondary to vasculitis and Wegener's granulomatosis and amyloidosis constitutes the most common secondary glomerulonephropathy. Drug-induced acute or chronic tubulointerstitial nephropathy is seen more frequently in the geriatric age group because of the high incidence of multiple-drug treatment. There is a high incidence of ARF in the elderly which is frequently precipitated by hypovolemia, hypotension, nephrotoxic drugs, surgery, and anesthesia. Clinical manifestations of renal disease in the elderly are often atypical and nonspecific. Abnormal signs and symptoms are frequently attributed to extrarenal diseases or to previously existing disorders. For these reasons, renal disease in the elderly may go undetected. Serum creatinine level may remain within normal range despite a drop in GFR because of a reduction in muscle mass with aging. Therefore, creatinine clearance is a more accurate test for assessment of renal function. A decrease in creatinine clearance should not be ignored or attributed to aging; it is an indication for further renal evaluation.
随着年龄的增长且无任何疾病时，肾脏结构会发生显著改变，肾功能也会逐渐下降。虽然肾血浆流量（RPF）、肾小球滤过率（GFR）和肾小管重吸收能力会随年龄降低，但在一般情况下无法检测到异常体征或症状。然而，衰老的肾脏应对快速血流动力学变化或液体和水平衡紊乱的能力有限，这会导致肾功能不全的体征和症状。在老年人中，原发性肾脏疾病的发病率下降，而继发于全身性疾病的肾脏疾病发病率增加。急性肾小球肾炎（AGN）虽然本质上是一种年轻人的疾病，但在老年人群中也确实会发生。然而，急进性肾小球肾炎（RPGN）是急性原发性肾小球肾炎最常见的形式，其次是膜性肾小球肾炎和肾小球硬化症。继发于血管炎、韦格纳肉芽肿病和淀粉样变性的肾小球肾炎是最常见的继发性肾小球肾炎。由于多药治疗的高发生率，药物性急性或慢性肾小管间质性肾病在老年人群中更为常见。老年人急性肾衰竭（ARF）的发病率很高，常由血容量不足、低血压、肾毒性药物、手术和麻醉诱发。老年人肾脏疾病的临床表现往往不典型且无特异性。异常体征和症状常常归因于肾外疾病或既往存在的疾病。由于这些原因，老年人的肾脏疾病可能未被发现。尽管GFR下降，但由于随着年龄增长肌肉量减少，血清肌酐水平可能仍保持在正常范围内。因此，肌酐清除率是评估肾功能更准确的检测方法。肌酐清除率的降低不应被忽视或归因于衰老；这是进一步进行肾脏评估的指征。
