J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website http://www.jocmr.org

Original Article

Volume 9, Number 7, July 2017, pages 560-566

Variables to Predict Nephrological Disease in General, and Glomerulonephritis in Particular, in Patients With Microhematuria

Figure 1. (a) Probability of kidney disease based on clinical findings. Calculated probabilities of kidney disease based on factors found to be significant in the multivariate logistic regression. Any combination of indicators can be present. eGFR, estimated glomerular filtration rate. (b) Probability of glomerulonephritis based on clinical findings. Calculated probabilities of glomerulonephritis based on factors found to be significant in the multivariate logistic regression. Any combination of indicators can be present. Erythrocyte concentration determined by urine stick analysis.

**Table 1.** Patient Characteristics
	Mean ± SD (range) or n/N (%)
Epidemiological data were taken from the whole cohort (N = 805), whereas the other data (N = 543) were taken only from patients with confirmed MH (≥ 3 erythrocytes per high power field of view in urine sediment analysis). BMI: body mass index; CV: cardiovascular; SBP: systolic blood pressure; DBP: diastolic blood pressure; eGFR: estimated glomerular filtration rate.
Epidemiology (N = 805)
Age (years)	56.3 ± 18.1 (6 - 91)
Patients ≥ 40 years	665/805 (82.6%)
Sex (male)	389/805 (48.3%)
BMI (kg/m²)	27.8 ± 6.0 (12.6 - 64.7)
CV risk factors (N = 543)
SBP (mm Hg)	144.7 ± 23.5 (90 - 227)
DBP (mm Hg)	82.4 ± 14.4 (50 - 145)
History of arterial hypertension	359/543 (66.1%)
Diabetes mellitus, type 1 or 2	86/543 (15.8%)
Hyperlipidemia	178/543 (32.8%)
Current smoker	132/543 (24.3%)
Kidney function (N = 543)
eGFR (mL/min)	62.1 ± 34.1 (2 - 186)
eGFR < 90 mL/min	375/502 (74.1%)
eGFR < 60 mL/min	236/502 (47.1%)
Microalbuminuria > 20 mg/L	255/372 (68.5%)
Signs of urinary tract infection (N = 543)
Leukocytes in urine test strip ≥ 25/μL	229/543 (42.2%)
Nitrite in urine	37/543 (6.8%)
Chronic infection of the urinary tract	53/543 (9.8%)

Table 1. Patient Characteristics

Mean ± SD (range) or n/N (%)

Epidemiological data were taken from the whole cohort (N = 805), whereas the other data (N = 543) were taken only from patients with confirmed MH (≥ 3 erythrocytes per high power field of view in urine sediment analysis). BMI: body mass index; CV: cardiovascular; SBP: systolic blood pressure; DBP: diastolic blood pressure; eGFR: estimated glomerular filtration rate.

Epidemiology (N = 805)

Age (years)

56.3 ± 18.1 (6 - 91)

Patients ≥ 40 years

665/805 (82.6%)

Sex (male)

389/805 (48.3%)

BMI (kg/m²)

27.8 ± 6.0 (12.6 - 64.7)

CV risk factors (N = 543)

SBP (mm Hg)

144.7 ± 23.5 (90 - 227)

DBP (mm Hg)

82.4 ± 14.4 (50 - 145)

History of arterial hypertension

359/543 (66.1%)

Diabetes mellitus, type 1 or 2

86/543 (15.8%)

Hyperlipidemia

178/543 (32.8%)

Current smoker

132/543 (24.3%)

Kidney function (N = 543)

eGFR (mL/min)

62.1 ± 34.1 (2 - 186)

eGFR < 90 mL/min

375/502 (74.1%)

eGFR < 60 mL/min

236/502 (47.1%)

Microalbuminuria > 20 mg/L

255/372 (68.5%)

Signs of urinary tract infection (N = 543)

Leukocytes in urine test strip ≥ 25/μL

229/543 (42.2%)

Nitrite in urine

37/543 (6.8%)

Chronic infection of the urinary tract

53/543 (9.8%)

**Table 2.** Characteristics of Hematuria
	n/N (%)
Data from the urine test strip analysis were collected at the first visit to the nephrologist (N = 805). ^†Confirmed hematuria is defined as patients that had ≥ 3 erythrocytes per high power field of view in urine sediment analysis.
Erythrocytes in urine stick analysis (per μL)
< 10	78/805 (9.7%)
≥ 10 - 49	371/805 (46.1%)
≥ 50 - 249	188/805 (23.4%)
≥ 250	167/805 (20.8%)
Macroscopic hematuria	37/805 (4.6%)
Chronic hematuria	20/805 (2.5%)
Confirmed MH (urine sediment)^†	543/805 (67.5%)

Table 2. Characteristics of Hematuria

n/N (%)

Data from the urine test strip analysis were collected at the first visit to the nephrologist (N = 805). ^†Confirmed hematuria is defined as patients that had ≥ 3 erythrocytes per high power field of view in urine sediment analysis.

Erythrocytes in urine stick analysis (per μL)

< 10

78/805 (9.7%)

≥ 10 - 49

371/805 (46.1%)

≥ 50 - 249

188/805 (23.4%)

≥ 250

167/805 (20.8%)

Macroscopic hematuria

37/805 (4.6%)

Chronic hematuria

20/805 (2.5%)

Confirmed MH (urine sediment)^†

543/805 (67.5%)

**Table 3.** Potential Sources of MH Identified in the Nephrology Office (Multiple Selections Are Possible)
	n/N (%)
NOAC: non-vitamin-K oral anticoagulant; NSAID: non-steroidal anti-inflammatory drug. *Includes multiple myeloma and renal amyloidosis; multiple myeloma; scleroderma; and suspected or non-proven glomerulonephritis. ^#Thrombocytopenia, increased INR, or elevated prothrombin time. ^†Includes aspirin, clopidogrel, dipyridamol, ticlopidine. ^‡CRP > 5 mg/L or ESR > 20 mm/h or leukocytes > 10/nL.
Nephrological disease (all)	262/543 (48.3%)
Glomerulonephritis (all)	68/543 (12.4%)
Rapid progressive glomerulonephritis	16/543 (2.9%)
Interstitial nephritis	33/543 (6.1%)
Congenital kidney disease	15/543 (2.8%)
Diabetic nephropathy	51/543 (9.4%)
Hypertensive nephropathy	144/543 (26.5%)
Other kidney diseases*	16/543 (2.9%)
Urological source	113/543 (20.8%)
Infection of the urinary tract	55/543 (10.1%)
Pyelonephritis	10/543 (1.8%)
Coagulation abnormality^#	64/541 (11.8%)
Vitamin K antagonist/NOAC use	44/543 (8.1%)
Anti-platelet drug use^†	97/543 (17.9%)
NSAID use	66/543 (12.2%)
Systemic inflammation^‡	124/543 (22.8%)
Number of potential sources of MH
1	147/543 (27.1%)
2	127/543 (23.4%)
3	76/543 (14.0%)
4	19/543 (3.5%)
Unclear diagnosis, benign MH	174/543 (32.0%)

Table 3. Potential Sources of MH Identified in the Nephrology Office (Multiple Selections Are Possible)

n/N (%)

NOAC: non-vitamin-K oral anticoagulant; NSAID: non-steroidal anti-inflammatory drug. *Includes multiple myeloma and renal amyloidosis; multiple myeloma; scleroderma; and suspected or non-proven glomerulonephritis. ^#Thrombocytopenia, increased INR, or elevated prothrombin time. ^†Includes aspirin, clopidogrel, dipyridamol, ticlopidine. ^‡CRP > 5 mg/L or ESR > 20 mm/h or leukocytes > 10/nL.

Nephrological disease (all)

262/543 (48.3%)

Glomerulonephritis (all)

68/543 (12.4%)

Rapid progressive glomerulonephritis

16/543 (2.9%)

Interstitial nephritis

33/543 (6.1%)

Congenital kidney disease

15/543 (2.8%)

Diabetic nephropathy

51/543 (9.4%)

Hypertensive nephropathy

144/543 (26.5%)

Other kidney diseases*

16/543 (2.9%)

Urological source

113/543 (20.8%)

Infection of the urinary tract

55/543 (10.1%)

Pyelonephritis

10/543 (1.8%)

Coagulation abnormality^#

64/541 (11.8%)

Vitamin K antagonist/NOAC use

44/543 (8.1%)

Anti-platelet drug use^†

97/543 (17.9%)

NSAID use

66/543 (12.2%)

Systemic inflammation^‡

124/543 (22.8%)

Number of potential sources of MH

147/543 (27.1%)

127/543 (23.4%)

76/543 (14.0%)

19/543 (3.5%)

Unclear diagnosis, benign MH

174/543 (32.0%)

**Table 4.** Relationship Between MH and Renal Disease
	Renal disease (all) (N = 262)	Glomerulonephritis (N = 68)
OR: odds ratio; BMI: body mass index; eGFR: estimated glomerular filtration rate; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate. A P-value of < 0.05 was considered to be significant. *Variables entered in the multivariate analysis “Renal Disease (all)” were age > 40 years, male sex, BMI > 30 kg/m², GFR < 90 mL/min, history of hypertension, diabetes mellitus type 1 and 2, microalbuminuria > 20 mg/L); other variables were not included owing to low numbers of patients. #Variables entered in the multivariate analysis “Glomerulonephritis” were erythrocytes in the urine test strip ≥ 250/µL, age > 40 years, male sex, microalbuminuria > 20 mg/L), and severe systemic inflammation; other variables were not included owing to low numbers of patients. ^†Systemic inflammation: CRP > 5 mg/L or ESR > 20 mm/h or leukocytes > 10/nL. Severe systemic inflammation: CRP > 50 mg/L or ESR > 75/h or leukocytes > 15/nL.
Erythrocytes in urine test strip analysis (per μL)
< 10	0.88 (0.54 - 1.42)	0.61	0.97 (0.45 - 2.07)	0.94	0.47 (0.15 - 1.06)	0.10	0.47 (0.06 - 1.66)	0.30
10 - 49	1.18 (0.82 - 1.71)	0.37	1.28 (0.68 - 2.47)	0.44	0.43 (0.20 - 0.80)	0.012	1.15 (0.39 - 3.06)	0.78
50 - 249	0.63 (0.42 - 0.92)	0.017	0.71 (0.38 - 1.27)	0.25	0.62 (0.31 - 1.14)	0.14	1.46 (0.55 - 3.98)	0.44
≥ 250	1.42 (0.98 - 2.07)	0.067	1.18 (0.63 - 2.22)	0.61	5.09 (2.44 - 7.00)	< 0.001	3.49 (1.75 - 7.32)	< 0.001
Epidemiological data
Age ≥ 40 years	2.64 (1.69 - 4.27)	< 0.001	0.55 (0.25 - 1.17)	0.13	0.74 (0.41 - 1.41)	0.32	0.55 (0.24 - 1.33)	0.16
Male sex	1.94 (1.38 - 2.74)	< 0.001	1.22 (0.69 - 2.16)	0.48	3.24 (1.87 - 6.05)	< 0.001	2.01 (0.94 - 4.91)	0.082
BMI > 30 kg/m²	1.91 (1.29 - 2.86)	0.001	1.81 (0.96 - 3.57)	0.072	0.68 (0.33 - 1.24)	0.23	0.88 (0.33 - 2.01)	0.77
Blood pressure
History of hypertension	6.03 (4.03 - 9.30)	< 0.001	4.10 (2.23 - 8.02)	< 0.001	1.25 (0.73 - 2.25)	0.43	1.09 (0.50 - 2.59)	0.84
Hypertension (> 140/90 mm Hg)	2.73 (1.92 - 3.91)	< 0.001	1.43 (0.78 - 2.67)	0.25	1.15 (0.69 - 1.94)	0.59	1.10 (0.54 - 2.33)	0.79
Kidney function
eGFR < 90 mL/min	3.61 (2.34 - 5.66)	< 0.001	1.91 (1.01 - 3.64)	0.047	1.25 (0.70 - 2.42)	0.47	0.82 (0.37 - 1.93)	0.62
eGFR < 60 mL/min	7.50 (5.07 - 11.3)	< 0.001	5.38 (3.17 - 9.66)	< 0.001	1.50 (0.90 - 2.54)	0.12	1.05 (0.52 - 2.15)	0.88
Microalbuminuria > 20 mg/L (=A2)	5.38 (3.45 - 8.63)	< 0.001	3.90 (2.27 - 7.03)	< 0.001	6.79 (2.93 - 21.8)	< 0.001	5.93 (2.42 - 20.3)	< 0.001
Further risk factors
Current smoker	0.79 (0.53 - 1.17)	0.25	1.55 (0.83 - 3.01)	0.17	0.80 (0.41 - 1.45)	0.48	0.46 (0.16 - 1.06)	0.083
Diabetes mellitus	5.43 (3.18 - 10.0)	< 0.001	2.76 (1.24 - 7.06)	0.017	0.42 (0.13 - 1.04)	0.061	0.47 (0.12 - 1.28)	0.18
Systemic inflammation^†
CRP > 5 mg/L	2.32 (1.34 - 4.09)	0.003	1.14 (0.48 - 2.59)	0.76	1.84 (0.87 - 3.98)	0.11	1.06 (0.39 - 2.77)	0.90
Leukocytes > 10/nL	1.46 (0.93 - 2.33)	0.11	2.46 (1.18 - 5.56)	0.019	2.31 (1.28 - 4.02)	0.004	3.97 (1.77 - 9.19)	< 0.001

Table 4. Relationship Between MH and Renal Disease

Renal disease (all) (N = 262)

Glomerulonephritis (N = 68)

OR (95% CI), univariate

P-value

OR (95% CI), multivariate*

P-value

OR (95% CI), univariate

P-value

OR (95% CI), multivariate#

P-value

OR: odds ratio; BMI: body mass index; eGFR: estimated glomerular filtration rate; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate. A P-value of < 0.05 was considered to be significant. *Variables entered in the multivariate analysis “Renal Disease (all)” were age > 40 years, male sex, BMI > 30 kg/m², GFR < 90 mL/min, history of hypertension, diabetes mellitus type 1 and 2, microalbuminuria > 20 mg/L); other variables were not included owing to low numbers of patients. #Variables entered in the multivariate analysis “Glomerulonephritis” were erythrocytes in the urine test strip ≥ 250/µL, age > 40 years, male sex, microalbuminuria > 20 mg/L), and severe systemic inflammation; other variables were not included owing to low numbers of patients. ^†Systemic inflammation: CRP > 5 mg/L or ESR > 20 mm/h or leukocytes > 10/nL. Severe systemic inflammation: CRP > 50 mg/L or ESR > 75/h or leukocytes > 15/nL.

Erythrocytes in urine test strip analysis (per μL)

< 10

0.88 (0.54 - 1.42)

0.61

0.97 (0.45 - 2.07)

0.94

0.47 (0.15 - 1.06)

0.10

0.47 (0.06 - 1.66)

0.30

10 - 49

1.18 (0.82 - 1.71)

0.37

1.28 (0.68 - 2.47)

0.44

0.43 (0.20 - 0.80)

0.012

1.15 (0.39 - 3.06)

0.78

50 - 249

0.63 (0.42 - 0.92)

0.017

0.71 (0.38 - 1.27)

0.25

0.62 (0.31 - 1.14)

0.14

1.46 (0.55 - 3.98)

0.44

≥ 250

1.42 (0.98 - 2.07)

0.067

1.18 (0.63 - 2.22)

0.61

5.09 (2.44 - 7.00)

< 0.001

3.49 (1.75 - 7.32)

< 0.001

Epidemiological data

Age ≥ 40 years

2.64 (1.69 - 4.27)

< 0.001

0.55 (0.25 - 1.17)

0.13

0.74 (0.41 - 1.41)

0.32

0.55 (0.24 - 1.33)

0.16

Male sex

1.94 (1.38 - 2.74)

< 0.001

1.22 (0.69 - 2.16)

0.48

3.24 (1.87 - 6.05)

< 0.001

2.01 (0.94 - 4.91)

0.082

BMI > 30 kg/m²

1.91 (1.29 - 2.86)

0.001

1.81 (0.96 - 3.57)

0.072

0.68 (0.33 - 1.24)

0.23

0.88 (0.33 - 2.01)

0.77

Blood pressure

History of hypertension

6.03 (4.03 - 9.30)

< 0.001

4.10 (2.23 - 8.02)

< 0.001

1.25 (0.73 - 2.25)

0.43

1.09 (0.50 - 2.59)

0.84

Hypertension (> 140/90 mm Hg)

2.73 (1.92 - 3.91)

< 0.001

1.43 (0.78 - 2.67)

0.25

1.15 (0.69 - 1.94)

0.59

1.10 (0.54 - 2.33)

0.79

Kidney function

eGFR < 90 mL/min

3.61 (2.34 - 5.66)

< 0.001

1.91 (1.01 - 3.64)

0.047

1.25 (0.70 - 2.42)

0.47

0.82 (0.37 - 1.93)

0.62

eGFR < 60 mL/min

7.50 (5.07 - 11.3)

< 0.001

5.38 (3.17 - 9.66)

< 0.001

1.50 (0.90 - 2.54)

0.12

1.05 (0.52 - 2.15)

0.88

Microalbuminuria > 20 mg/L (=A2)

5.38 (3.45 - 8.63)

< 0.001

3.90 (2.27 - 7.03)

< 0.001

6.79 (2.93 - 21.8)

< 0.001

5.93 (2.42 - 20.3)

< 0.001

Further risk factors

Current smoker

0.79 (0.53 - 1.17)

0.25

1.55 (0.83 - 3.01)

0.17

0.80 (0.41 - 1.45)

0.48

0.46 (0.16 - 1.06)

0.083

Diabetes mellitus

5.43 (3.18 - 10.0)

< 0.001

2.76 (1.24 - 7.06)

0.017

0.42 (0.13 - 1.04)

0.061

0.47 (0.12 - 1.28)

0.18

Systemic inflammation^†

CRP > 5 mg/L

2.32 (1.34 - 4.09)

0.003

1.14 (0.48 - 2.59)

0.76

1.84 (0.87 - 3.98)

0.11

1.06 (0.39 - 2.77)

0.90

Leukocytes > 10/nL

1.46 (0.93 - 2.33)

0.11

2.46 (1.18 - 5.56)

0.019

2.31 (1.28 - 4.02)

0.004

3.97 (1.77 - 9.19)

< 0.001