Silent diabetic nephropathy

Table 2 Renal parameters and evolution n (%)

		Previous renal data (n = 39)	Renal biopsy (n = 45)	End of follow-up (n = 24)
Time prior to biopsy (mo) (range)		7.3 ± 5.2
		(1.1-24.1)
Follow-up period (yr) (range)				3.4 ± 2.9
				(0.2-11.8)
Renal biopsy indication	RPKI		8 (17.8)
	Nephrotic proteinuria		28 (62.2)
	CKD		9 (20)
Serum creatinine (mg/dL) (range)		1.6 ± 0.8	2.3 ± 1.5	2.3 ± 1.8
		(0.8-4.5)	(0.8-6)	(0.7-9.1)
eGFR (mL/min per 1.73 m2) (range)		51.4 ± 20.9	39.1 ± 22.5	40.8 ± 25
		(14.7-97.6)	(8.1-101.2)	(5.1-107.1)
1eGFR category	G5 < 15		7 (15.6)	24 (53.3)
	G4 15-30		8 (17.8)	6 (13.3)
	G3b 30-45		15 (33.3)	5 (11.1)
	G3a 45-60		7 (15.6)	7 (15.6)
	G2 60-90		7 (15.6)	1 (2.2)
	G1 > 90		1 (2.2)	2 (4.4)
> 25% drop in eGFR prior to biopsy		13 (33.3)
2Proteinuria (range)		3.7 ± 3.4	4.5 ± 2.7
		(0-12.9)	(1-8.9)
3Proteinuria category	A1 < 150	3 (8.8)	0
	A2 150-500	2 (5.9)	4 (8.9)
	A3 > 500	29 (85.3)	41 (91.1)
RRT		2	5	21 (46.7)
4CKD progression				7 (15.6)
eGFR improvement > 25%				4 (8.9)
Exitus				5 (11.1)

¹GFR categories (mL/min per 1.73 m²): G1 = GFR ≥ 90; G2 = 60-89; G3a = 45-59; G3b = 30-44; G4 = 15-29; G5 < 15.

²Baseline proteinuria was measured using protein/creatinine ratio in spot urine (mg/g). Renal biopsy proteinuria was measured using excretion rate over 24 h (g/d).

³Proteinuria categories are described based on protein-to-creatinine ratio (mg/g) or protein excretion rate (mg/24 h) in: A1 ≤ 150, A2 = 150-500, A3 ≥ 500.

⁴CKD progression: 25% or greater eGFR decline, accompanied by a decrease in GFR category. RPKI: Rapidly progressive kidney injury; eGFR: Estimated glomerular filtration rate; CKD: Chronic kidney disease; RRT: Renal replacement therapy.