Calprotectin and CRP as biomarkers of cardiovascular disease risk in patients with chronic kidney disease: a follow-up study at 5 and 10 years

Figures & data

Table 1. Baseline characteristics.

	All participants, n = 153	Without cardiovascular event, n = 109	With cardiovascular event, n = 44	p Value
Demographics
Age (years)	60 (45–70)	53 (38–66)	69 (61.5–76)	<.001
Male, n (%)	108 (70.6)	78 (71.6)	30 (68.2)	.68
Medical history
Previous CVD (%)^a	43 (28.1)	18 (16.5)	25 (56.8)	<.001
Current smoker (%)	26 (17.1)	21 (19.4)	5 (11.4)	.23
Diabetes (%)	28 (18.3)	16 (14.7)	12 (27.3)	.068
Hypertension (%)^b	152 (99.4)	108 (99.1)	44 (100)	.52
Clinical measurements
Systolic BP (mmHg)	125 (120–140)	125 (115–135)	135 (120–150)	.0007
Diastolic BP (mmHg)	80 (70–82)	80 (70–83)	80 (70–81)	.69
Body mass index (kg/m^2)	26.6 (23.7–29.7)	27.0 (23.8–29.8)	25.9 (23.7–29.0)	.53
Laboratory measurements
Estimated GFR (mL/min/1.73 m^2)	34.9 (23.5–54.8)	41.0 (27.4–61.3)	29.2 (21.6 − 38.5)	<.001
Creatinine (µmol/L)	159 (118–221)	147 (97–214)	180 (145–250)	.002
Cystatin C (mg/L)	1.9 (1.37–2.57)	1.82 (1.18–2.34)	2.32 (1.84–2.91)	<.001
Haemoglobin (g/L)	135 (124–144)	136 (127–145)	131 (120–143)	.042
Albumin (g/L)	42 (40–44)	43 (40–45)	42 (40–44)	.31
HbA1c (mmol/mol)	41 (38–45)	40 (37–43)	42 (39–49)	.006
Total cholesterol (mmol/L)	4.9 (4.0–5.7)	4.9 (4.0–5.7)	4.8 (4.0–5.7)	.97
HDL cholesterol (mmol/L)	1.2 (1.0–1.6)	1.3 (1.0–1.6)	1.2 (1.0–1.4)	.096
Triglycerides (mmol/L)	1.7 (1.3–2.5)	1.6 (1.2–2.5)	1.8 (1.4–2.4)	.38
Urine albumin/creatinine ratio (mg/mmol)	12.8 (2.8–65.3)	14.4 (2.9–72.6)	6.9 (1.9–54.7)	.32
Calprotectin (mg/L)	2.38 (1.70–3.05)	2.27 (1.46–2.91)	2.71 (2.11–3.44)	.003
C-reactive protein (mg/L)	1.9 (0.91–4.12)	1.59 (0.73–3.06)	3.06 (1.66–7.49)	<.001
Medication
RAAS inhibitors (%)^c	114 (74.5)	81 (74.3)	33 (75)	.93
Platelet inhibitors (%)^d	35 (22.8)	11 (10.1)	24 (54.5)	<.001
Other antihypertensives (%)^e	152 (99.4)	108 (99)	44 (100)	.524
Statins (%)	77 (50.3)	45 (41.3)	32 (72.7)	<.001

GFR: glomerular filtration rate (as calculated using the Modification of Diet in Renal Disease study equation); HDL: high-density lipoprotein; CVD: cardiovascular disease.

Data are reported as medians (interquartile range) or as frequencies (%) for continuous and dichotomous variables.

^aHistory of coronary disease, cerebrovascular disease or peripheral artery disease.

^bSystolic blood pressure (BP) ≥140 mmHg and/or diastolic BP ≥90 mmHg or use of antihypertensive medication.

^cRAAS – renin–angiotensin–aldosterone inhibitors.

^dAcetylsalicylic acid, clopidogrel or Gp2a/3b-inhibitors.

^eTreatment with beta blockers, alpha blockers or calcium channel blockers.

Figure 1. Hazard ratios for biomarkers associated with cardiovascular events. HR is expressed per 1 SD increase of log_e calprotectin and log_e CRP at 5 and 10 years follow-up. Age was used as time axis and thereby adjusted for in all models. Step 1: adjusted for age. Step 2: adjusted for age, sex and cystatin C. Step 3: adjusted for age, sex, cystatin C and previous CVD. Step 4: adjusted for age, sex, cystatin C, previous CVD, systolic blood pressure, high-density lipoprotein (HDL) cholesterol and HbA1c. Step 5: adjusted for age, sex, cystatin C, previous CVD, HDL cholesterol, HbA1c, CRP and calprotectin. HR: hazard ratio; CI: confidence interval; CVD: cardiovascular disease; CRP: C-reactive protein.