Ekinci Elif I, Jerums George, Skene Alison, Crammer Paul, Power David, Cheong Karey Y, Panagiotopoulos Sianna, McNeil Karen, Baker Scott T, Fioretto Paola, Macisaac Richard J
Corresponding author: Elif I. Ekinci,
Diabetes Care. 2013 Nov;36(11):3620-6. doi: 10.2337/dc12-2572. Epub 2013 Jul 8.
The structural basis of normoalbuminuric renal insufficiency in patients with type 2 diabetes remains to be elucidated. We compared renal biopsy findings in patients with type 2 diabetes and estimated glomerular filtration rate (eGFR) and measured GFR of <60 mL/min/1.73 m2, associated with either normo-, micro-, or macroalbuminuria.
In patients with normo- (n = 8) or microalbuminuria (n = 6), renal biopsies were performed according to a research protocol. In patients with macroalbuminuria (n = 17), biopsies were performed according to clinical indication. Findings were categorized according to the Fioretto classification: category 1 (C1), normal/near normal; category 2 (C2), typical diabetic nephropathy (DN) with predominantly glomerular changes; and category 3 (C3), atypical with disproportionately severe interstitial/tubular/vascular damage and with no/mild diabetic glomerular changes.
In our study population (mean eGFR 35 mL/min/1.73 m2), typical glomerular changes (C2) of DN were observed in 22 of 23 subjects with micro- or macroalbuminuria compared with 3 of 8 subjects with normoalbuminuria (P = 0.002). By contrast, predominantly interstitial or vascular changes (C3) were seen in only 1 of 23 subjects with micro- or macroalbuminuria compared with 3 of 8 normoalbuminuric subjects (P = 0.08). Mesangial area increased progressively from normal controls to patients with type 2 diabetes and normo-, micro-, and macroalbuminuria. Varying degrees of arteriosclerosis, although not necessarily the predominant pattern, were seen in seven of eight subjects with normoalbuminuria.
Typical renal structural changes of DN were observed in patients with type 2 diabetes and elevated albuminuria. By contrast, in normoalbuminuric renal insufficiency, these changes were seen less frequently, likely reflecting greater contributions from aging, hypertension, and arteriosclerosis.
2型糖尿病患者正常白蛋白尿性肾功能不全的结构基础仍有待阐明。我们比较了2型糖尿病患者的肾活检结果，这些患者的估算肾小球滤过率（eGFR）及测定的肾小球滤过率<60 mL/（min·1.73 m²），伴有正常白蛋白尿、微量白蛋白尿或大量白蛋白尿。
对正常白蛋白尿（n = 8）或微量白蛋白尿（n = 6）患者，按照研究方案进行肾活检。对大量白蛋白尿患者（n = 17），根据临床指征进行活检。根据Fioretto分类对结果进行分类：1类（C1），正常/接近正常；2类（C2），典型糖尿病肾病（DN），主要为肾小球改变；3类（C3），非典型，伴有不成比例的严重间质/肾小管/血管损伤且无/轻度糖尿病性肾小球改变。
在我们的研究人群中（平均eGFR为35 mL/（min·1.73 m²）），23例微量或大量白蛋白尿患者中有22例观察到DN的典型肾小球改变（C2），而8例正常白蛋白尿患者中有3例出现该改变（P = 0.002）。相比之下，23例微量或大量白蛋白尿患者中只有1例出现主要的间质或血管改变（C3），而8例正常白蛋白尿患者中有3例出现该改变（P = 0.08）。系膜面积从正常对照到2型糖尿病及正常、微量和大量白蛋白尿患者逐渐增加。8例正常白蛋白尿患者中有7例出现不同程度的动脉硬化，尽管不一定是主要类型。
2型糖尿病和白蛋白尿升高患者中观察到DN的典型肾脏结构改变。相比之下，在正常白蛋白尿性肾功能不全患者中，这些改变较少见，这可能反映了衰老、高血压和动脉硬化的更大影响。
