Table 1 Baseline characteristics

Age at diagnosis, n (%)

400 (100)

Median, years (IQR)

36 (25–50)

Sex, n (%)

400 (100)

 Female

113 (28)

 Male

287 (72)

Systolic blood pressure at diagnosis, n (%)

381 (95)

 Median, mm Hg (IQR)

132 (120–148)

Diastolic blood pressure at diagnosis, n (%)

380 (95)

 Median, mm Hg (IQR)

80 (75–90)

Middle arterial pressure at diagnosis, n (%)

380 (95)

 Median, mm Hg (IQR)

98 (93–110)

Hypertension at diagnosis, n (%)

380 (95)

 Yes

138 (36)

 No

242 (64)

Body mass index at diagnosis, n (%)

278 (70)

 Median, kg/m² (IQR)

24.3 (22.2–27.2)

Indication for kidney biopsy, n (%) – Can be more than one per patient

400 (100)

 Nephrotic syndrome

27 (7)

 Nephritic syndrome

28 (7)

 Suspicion of rapidly progressive glomerulonephritis

2 (0.5)

 Proteinuria

266 (67)

 Hematuria

316 (79)

Proteinuria at diagnosis, n (%)

367 (92)

 Median, g/24 h (IQR)

1.0 (0.4–2.0)

Hematuria at diagnosis – urinary dipstick^a, n (%)

335 (84)

 0 (< 10 cells/μL)

19 (6)

 1 (10–24 cells/μL)

150 (45)

 2 (25–49 cells/μL)

33 (10)

 3 (50–249 cells/μL)

91 (27)

 4 (≤ 250 cells/μL)

42 (13)

eGFR at diagnosis, n (%)

396 (99)

Median, mL/min/1.73 m² (IQR)

75 (52–98)

CKD stage at diagnosis, n (%)

396 (99)

 Stage 1

134 (34)

 Stage 2

132 (33)

 Stage 3a

53 (13)

 Stage 3b

42 (11)

 Stage 4

27 (7)

 Stage 5

8 (2)

RAAS inhibitor at diagnosis, n (%)

400 (100)

 Yes

74 (18)

 No

326 (82)

Corticosteroids at diagnosis, n (%)

400 (100)

 Yes

2 (0.5)

 No

398 (99.5)

Glomeruli in diagnostic kidney biopsy, n (%)

400 (100)

 Median, n (IQR)

12 (8–16)

Proportion of sclerotic glomeruli in diagnostic kidney biopsy, n (%)

262 (66)

 Median, % (IQR)

14 (0–30)