Non-invasive investigation of kidney disease in type 1 diabetes by magnetic resonance imaging

作者：Thelwall P E^*; Taylor R; Marshall S M

来源：Diabetologia, 2011, 54(9): 2421-2429.

DOI：10.1007/s00125-011-2163-z

• BOLD
• Diabetic nephropathy
• Magnetic resonance imaging
• Microalbuminuria
• Renal artery flow
• Renal vascular resistance
• Type 1 diabetes mellitus

Pathophysiological abnormalities in early diabetic nephropathy are poorly understood. We employed MRI to characterise renal perfusion, tissue oxygenation and kidney size in non-diabetic volunteers and type 1 diabetic patients without and with early renal disease.
We studied ten control participants (C; age 40.0 [range 31-54] years), nine longstanding normotensive type 1 diabetic patients (T1Normo; age 40.1 [31-50] years, estimated glomerular filtration rate [eGFR] 83.4 +/- 10.6 ml min(-1) 1.73 m(-2)) and eight microalbuminuric type 1 diabetic patients (T1Micro; age 42.4 [33-52] years, eGFR 71.6 +/- 13.7 ml min(-1) 1.73 m(-2)). Six microalbuminuric patients were restudied after 4 weeks without renin-angiotensin-aldosterone system inhibitors. Phase contrast angiography and kidney blood oxygen level dependent (BOLD) (R (2) (*) ) MRI were performed, before and during water diuresis. Contrast-enhanced MRI was performed at baseline urine flow rate. Renal artery flow, renal vascular resistance (RVR), cortical and medullary volumes, and R (2) (*) were determined.
Renal cortical and medullary volumes were similar in all groups (cortex: C 108 +/- 16, T1Normo 112 +/- 21, T1Micro 111 +/- 10 cm(3)/1.73 m(2); medulla: C 35 +/- 14, T1Normo 29 +/- 10, 33 +/- 6 cm(3)/1.73 m(2)). RVR increased from control to normoalbuminuric to microalbuminuric type 1 diabetic patients (C 0.061 +/- 0.018, T1Normo 0.077 +/- 0.014, T1Micro 0.093 +/- 0.024 mmHg ml(-1) min(-1) 1.73 m(-2), ANOVA p = 0.012). RVR correlated inversely with eGFR in normoalbuminuric, but not in microalbuminuric diabetic patients. Renal artery flow was lower in the whole diabetes cohort (control 740 +/- 205 vs diabetes 591 +/- 128 ml min(-1) 1.73 m(-2), p = 0.035).
Cortical and medullary volumes remain normal in early diabetic nephropathy. Decreased renal flow in longstanding normoalbuminuric type 1 diabetic patients may reflect intrarenal vascular stiffening, whereas in the microalbuminuric patients it may also reflect increased intraglomerular pressure.

• 出版日期2011-9