2Alexander A. Kremzer, Clinical Pharmacology Department, State Medical University, Zaporozhye, Ukraine
3Tatyana A. Berezina, MD, Private center "Vita-Center", Zaporozhye, Ukraine
4Yulia V. Martovitskaya, Pathology Department, State Medical University, Zaporozhye, Ukraine
Methods: The study retrospectively evolved 101 patients (54 subjects with T2DM and 47 patients with MetS) and 35 healthy volunteers. The flow cytometry was used for predictably distinguishing cell subsets, which depend on expression of CD45, CD34, CD14, Tie-2, and VEGFR2. Biomarkers were measured at baseline of the study.
Results: Patients with MetS have demonstrated lower incidence of dyslipidemia, lower concentrations of HbA1c, fasting blood glucose, insulin, and LDL-C when compared with T2DM subjects. Higher HDL-C and HOMA-IR were found in T2DM patients than in MetS subjects. There is a significant difference between the medians of absolute numbers and frequencies of CD14+CD309+ and CD14+CD309+Tie2+ in healthy volunteers and patients with dysmetabolic disorders respectively. CD14+CD309+ and CD14+CD309+Tie2+ subsets of circulating EPCs were determined in higher concentration among MetS subjects in comparison with T2DM patients. Osteoprotegerin (OPG) and hs-C-reactive protein (CRP), improve significantly predictive model based on T2DM + number of multiple cardiovascular risk factors (MCRFs) >3 for decreased both angiopoetic phenotypes of circulating EPCs.
Conclusion: we suggest that inflammatory biomarkers (hs-CRP, OPG) may consider statistically significant predictors for decreased EPCs labeled CD14+CD309+ and CD14+CD309+Tie2+ among dysmetabolic patients without preexisting atherosclerotic lesions of coronary arteries.
Keywords: Diabetes Mellitus; Metabolic Syndrome; Circulating Endothelial-Derived Progenitor Cells; Cardiovascular Risk Factors
Endothelial Progenitor Cells (EPCs) is a population of mononuclear cells that expresses endothelial and progenitor markers i.e., CD34+ antigen and VEGFR-2+ vascular growth ligands (Vascular Endothelial Growth Factor Rreceptor-2), CD133+, as well as CD14+, and Tie2+ (tyrosine kinase ligand) [8]. EPCs may play a pivotal role in mechanisms of tissue repair, maturation of endothelial cells, angiogenesis, and revascularization [9]. EPCs are mobilized from bone marrow and probably from peripheral tissues upon injury in result in growth factors and inflammatory cytokines over production [10]. There are evidences regarding elevated EMPs as a marker of ED [11]. Indeed, increased production of reactive oxygen species, insulin resistance, reduced NO bioavailability have been identified as mediators of tissue injury and ED [12,13]. In contrast, T2DM has well characterized as dysmetabolic state with depletion of circulating EPCs resulting in severely reduced angiogenic capacity in vivo [14]. Although decreased number and impaired functions of CD34+CD133+ EPCs in T2DM patients might lead to increased frequency of CVD events [15,16], the role of angiogenic subsets of EPCs in T2DM and MetS is still not fully understood. The aim of the study: to investigate the pattern of circulating EMPs in T2DM patients in comparison with MetS subjects.
T2DM was diagnosed with revised criteria provided by American Diabetes Association when source documents were reviewed [17]. When one or more of the following components were found (glycated hemoglobin [HbA1c] ≥ 6.5%; fasting plasma glucose ≥ 7 mmol/L; 2-h plasma glucose ≥ 11.1 mmol/L during an oral glucose tolerance test; a random plasma glucose ≥ 11.1 mmol/L; exposure of insulin or oral antidiabetic drugs; a previous diagnosis of T2DM) T2DM was determined. MetS was diagnosed based on the National Cholesterol Education Program Adult Treatment Panel III criteria [18]. Patients were enrolled in the MetS cohort when at least three of the following components were defined: waist circumference ≥ 90 cm or ≥ 80 cm in men and women respectively; high density lipoprotein (HDL) cholesterol < 1.03 mmol/l or < 1.3 mmol/l in men and women respectively; triglycerides ≥ 1.7 mmol/l; blood pressure ≥ 130/85 mmHg or current exposure of antihypertensive drugs; fasting plasma glucose ≥ 5.6 mmol/L or previously defined as T2DM or treatment with oral antidiabetic agents or insulin. Current smoking was defined as consumption of one cigarette daily for three months. Anthropometric measurements were made using standard procedures. No untreated subjects were enrolled. Patients with T2DM were treated with life-style modification, diet and orally taken antidiabetic drugs except sulfonylurea derivates and glitazones. Metformin in monotherapy or in combination with glinides and / or gliptines was given in individually optimized daily doses to be achieving full or partly full control for T2DM. Therefore, insulin was not used in enrolled patients. Subjects with MetS were treated with life-style modification and diet, therefore metformin was given in 12 patients.
High-sensitive C-reactive protein (hs-CRP) was measured by commercially available standard kit (R&D Systems GmbH, Wiesbaden-Nordenstadt, Germany). The intra-assay and interassay coefficients of variation were < 5%. Serum uric acid level (SUA) was determined by enzymatic methods using a Beckman Synchron LX20 chemistry analyzer. The analytical average range for SUA was 0.5–12 mg/dL.
Fasting insulin level was measured by a double-antibody sandwich immunoassay (Elecsys 1010 analyzer, F. Hoffmann- La Roche Diagnostics, Mannheim, Germany). The intra-assay and inter-assay coefficients of variation were < 5%. The lower detection limit of insulin level was 1.39 pmol/L.
Concentrations of total cholesterol (TC) (Catalog Number 3460-06, MaxDiscovery™ Cholesterol Enzymatic Assay Kit, Bioo Scientific Corporation, USA), cholesterol of high-density lipoproteins (LDL-C) (Catalog Number DZ128A-KB1, Diazyme Europe GmbH, Germany), and cholesterol of high-density lipoproteins (HDL-C) (Catalog Number DZ129A-KY1, Diazyme Europe GmbH, Germany) were measured by enzymatic colorimetric method according standardized methodology on Beckman Synchron LX20 chemistry analyzer [22].
Direct Enzymatic HbA1c Assay was used for glycated hemoglobin A1c (HbA1c) measurements (Catalog Number DZ168A-K, Diazyme Europe GmbH, Germany) on Beckman Synchron LX20 chemistry analyzer.
According to Table 2, patients with MetS have demonstrated lower incidence of dyslipidemia, lower concentrations of HbA1c, fasting blood glucose, insulin, and LDL-C when compared with T2DM subjects. Higher HDL-C and HOMA-IR were found in T2DM patients than in MetS subjects. Interestingly, similarities of circulating levels of EPCs different origin were determined in both cohorts apart from absolute numerous of CD14+CD309+ and CD14+CD309+Tie2+ EPCs. CD14+CD309+ and CD14+CD309+Tie2+ subsets of circulating EPCs were determined in higher concentration among MetS subjects in comparison with T2DM patients (P=0.18 and P=0.012 respectively).
The univariate linear correlations between both absolute numerous of EPCs with immune phenotypes labelled CD14+CD309+ and CD14+CD309+Tie2+, cardiovascular risk factors, hemodynamic performances, and other biomarkers were evaluated. The data have shown that absolute numerous of CD14+CD309+were inversely related with T2DM (r=-0.542, P=0.003), BMI (r=-0.54, P=0.001), OPG (r=-0.518, P=0.001), number of multiple cardiovascular risk factors (MCRFs) (r=- 0.486, P=0.001), hs-CRP (r=-0.478, P=0.001), sRANKL (r=-0.477, P=0.001), adiponectin (r=-0.402, P=0.001), eGFR (r=-0.398, P=0.001), Framingham risk score (r=-0.394, P=0.001), TG (r=- 0.392, P=0.001), creatinine (r=-0.387, P=0.001), SUA (r=-0.315, P < 0.001), gender (r=-0.318, P < 0.001 for male), dyslipidemia (r=-0.313, P=0.001), age (r=-0.275, P=0.001), smoking (r=- 0.212, P=0.001), and positively related with HOMA-IR (r=0.465, P=0.001).
Therefore, absolute numerous of CD14+CD309+Tie2+ EPCs
|
Healthy volunteers (n=35) |
Entire cohort of enrolled patients (n=101) |
P value |
Age, years |
46.12±4.22 |
48.34±7.80 |
0.68 |
males, n (%) |
23 (65.7%) |
64 (63.3%) |
0.86 |
BMI, kg/m2 |
21.5 (25-75% IQR=16.1–23.5) |
28.7 (25-75% IQR 16.5–32.4) |
0.001 |
Waist circumference, sm |
78 (25-75% IQR=63–89) |
91 (25-75% IQR=71–103) |
0.001 |
Hypertension, n (%) |
- |
68 (67.3%) |
0.001 |
Dyslipidemia, n (%) |
- |
59 (58.4%) |
0.001 |
T2DM, n (%) |
- |
54 (53.5%) |
0.001 |
MetS, n (%) |
- |
47 (46.5%) |
0.001 |
Adherence to smoking, n (%) |
6 (17.1%) |
31 (30.7%) |
0.001 |
Framingham risk score |
2.55± 1.05 |
8.12 ± 2.88 |
0.001 |
Systolic BP, mm Hg |
122±5 |
136±6 |
0.001 |
Diastolic BP, mm Hg |
72±4 |
86±6 |
0.001 |
Heart rate, beats per 1 min. |
66±6 |
72±7 |
0.01 |
GFR, mL/min/1.73 m2 |
102.1 (95% CI=91.4–113.2) |
93.1 (95% CI=79.5–109.7) |
0.12 |
HbA1c, % |
4.75 (95% CI =4.36-5.12) |
7.0 (95% CI =4.3-9.2) |
0.001 |
fasting blood glucose, mmol/L |
4.52 (95% CI =4.43-4.76) |
5.40 (95% CI =3.4-9.1) |
0.01 |
Insulin, µU/mL |
4.98 (25-75% IQR =1.5–14.1) |
15.15 (25-75% IQR =13.69-16.62) |
0.001 |
HOMA-IR, mmol/L × µU/mL |
1.01 (25-75% IQR =0.91-1.07) |
3.83 (25-75% IQR =3.47-4.20) |
0.001 |
creatinine, μmol/L |
62.1 (95% CI =55.7–82.4) |
70.5 (95% CI =59.6–88.3) |
0.24 |
Total cholesterol, mmol/L |
4.76 (95% CI =4.21-5.05) |
5.3 (95% CI =4.6-6.0) |
0.001 |
LDL-C, mmol/L |
3.10 (95% CI =2.78–3.21) |
3.60 (95% CI =3.20–4.18) |
0.001 |
HDL-C, mmol/L |
1.13 (95% CI = 1.05–1.17) |
0.94 (95% CI = 0.92–1.06) |
0.001 |
TG, mmol/L |
1,18 (95% CI = 1.07–1.30) |
1,68 (95% CI = 1.44–1.98) |
0.001 |
SUA, mmol/L |
17.1 (95% CI = 9.1–25.7) |
23.8 (95% CI = 15.8–31.3) |
0.05 |
hs-CRP, mg / L |
4.11 (25-75% IQR=0.97 – 5.03) |
7.96 (25-75% IQR=4.72 – 9.34) |
0.001 |
16.10 (25-75% IQR=2.1-30.1) |
0.002 |
||
Osteoprotegerin, pg / mL |
88.3 (25-75% IQR = 37.5-136.6) |
0.001 |
|
Adiponectin, mg / L |
6.17 (25-75% IQR = 3.44-10.15) |
13.65 (25-75% IQR = 10.12-24.93) |
0.001 |
CD45+CD34+, % |
1.90 (25-75% IQR = 1.49–2.10) |
2.10 (25-75% IQR = 1.70–2.35) |
0.66 |
CD45+CD34+, cells × 103/μL |
0.114 (25-75% IQR = 0.095–0.120) |
0.112 (25-75% IQR = 0.090–0.121) |
0.76 |
CD45−CD34+ × 10−4, % |
1.00 (25-75% IQR = 0.69–1.35) |
1.02 (25-75% IQR = 0.86–1.28) |
0.84 |
CD45−CD34+, cells × 10−1/μL |
0.06 (25-75% IQR = 0.05–0.07) |
0.057 (25-75% IQR = 0.053–0.067) |
0.86 |
CD14+CD309+ × 10−4, % |
71.00 (25-75% IQR = 61.50–96.00) |
57.00 (25-75% IQR = 43.20–81.50) |
0.02 |
CD14+CD309+, cells × 10−1/μL |
4.26 (25-75% IQR = 3.70–5.74) |
2.96 (25-75% IQR = 2.25–4.21) |
0.01 |
CD14+CD309+Tie2+ × 10−4, % |
7.70 (25-75% IQR = 4.20–12.20) |
5.50 (25-75% IQR = 3.05–8.15) |
0.04 |
CD14+CD309+Tie2+, cells × 10−1/μL |
0.465 (25-75% IQR = 0.253–0.710) |
0.270 (25-75% IQR = 0.241–0.411) |
0.01 |
Abbreviations: CI – Confidence Interval; IQR – Inter Quartile Range; BMI - Body Mass Index, T2DM – Type 2 Diabetes Mellitus, TG – Triglycerides, BP – Blood Pressure, BMI - Body Mass Index, GFR - Glomerular Filtration Rate, EMPs – Endothelial-Derived Microparticles; HDL-C - High-Density Lipoprotein Cholesterol, LDL-C - Low-Density Lipoprotein Cholesterol, hs-CRP – High Sensitive C Reactive Protein, sRANKL – Serum Receptor Activator of NF-κB ligand.
|
MetS patients (n=47) |
T2DM patients (n=54) |
P value |
Age, years |
48.30 ± 3.94 |
48.50±6.60 |
0.88 |
males, n (%) |
30 (63.8%) |
34 (63.0%) |
0.96 |
BMI, kg/m2 |
28.2 (25-75% IQR=16.7–31.0) |
28.5 (25-75% IQR=16.8–32.1) |
0.92 |
Waist circumference, sm |
92 (25-75% IQR=69–105) |
89 (25-75% IQR=72–100) |
0.12 |
Hypertension, n (%) |
32 (68.0%) |
36 (66.7%) |
0.78 |
Dyslipidemia, n (%) |
26 (55.3%) |
33 (61.1%) |
0. 026 |
Adherence to smoking, n (%) |
16 (34.0%) |
15 (27.7%) |
0.44 |
Framingham risk score |
8.09 ± 2.12 |
8.18 ± 2.32 |
0.78 |
Systolic BP, mm Hg |
137 ± 4 |
136±5 |
0.94 |
Diastolic BP, mm Hg |
87 ± 5 |
86±4 |
0.96 |
Heart rate, beats per 1 min. |
71 ± 6 |
72±5 |
0.96 |
GFR, mL/min/1.73 m2 |
92.5 (95% CI = 83.1–107.4) |
93.8 (95% CI = 80.4–106.8) |
0.92 |
HbA1c, % |
6.82 (95% CI = 4.61-5.37) |
7.3 (95% CI = 4.3-9.1) |
0.036 |
fasting blood glucose, mmol/L |
5.46 (95% CI = 4.23-4.76) |
5.54 (95% CI = 4.49-9.0) |
0.042 |
Insulin, µU/mL |
14.2 (25-75% IQR = 12.5–15.7) |
15.6 (25-75% IQR = 12.9-16.8) |
0.048 |
HOMA-IR, mmol/L × µU/mL |
3.45 (25-75% IQR = 3.22-3.78) |
3.86 (25-75% IQR = 3.41-4.10) |
0.012 |
creatinine, μmol/L |
72.3 (95% CI = 56.1–86.9) |
71.2 (95% CI = 59.9–87.2) |
0.94 |
Total cholesterol, mmol/L |
5.3 (95% CI = 4.5-5.9) |
5.4 (95% CI = 4.8-5.8) |
0.96 |
LDL-C, mmol/L |
3.48 (95% CI = 3.30–4.07) |
3.80 (95% CI =3.20–4.20) |
0.012 |
HDL-C, mmol/L |
1.01 (95% CI = 0.90–1.13) |
0.94 (95% CI = 0.88–1.04) |
0.014 |
TG, mmol/L |
1.77 (95% CI = 1.62–1.95) |
1.45 (95% CI =1.42–1.51) |
0.044 |
SUA, mmol/L |
23.1 (95% CI = 16.2–29.7) |
23.9 (95% CI = 15.9–30.1) |
0.86 |
hs-CRP, mg / L |
7.87 (25-75% IQR = 4.92 – 9.43) |
8.10 (25-75% IQR = 4.80 – 9.54) |
0.24 |
sRANKL, pg / mL |
24.10 (25-75% IQR = 14.7-36.9) |
26.20 (25-75% IQR = 15.3-40.7) |
0.26 |
Osteoprotegerin, pg / mL |
718.5 (25-75% IQR = 572.1-846.2) |
732.1 (25-75% IQR= 587.5-866.3) |
0.38 |
Adiponectin, mg / L |
13.61 (25-75% IQR = 9.74-22.35) |
14.12 (25-75% IQR= 10.12-23.10) |
0.88 |
CD45+CD34+, % |
2.11 (25-75% IQR = 1.72–2.28) |
2.06 (25-75% IQR = 1.73–2.25) |
0.86 |
CD45+CD34+, cells × 103/μL |
0.114 (25-75% IQR = 0.094–0.122) |
0.109 (25-75% IQR = 0.091–0.117) |
0.56 |
CD45−CD34+ × 10−4, % |
1.02 (25-75% IQR = 0.89–1.25) |
1.01 (25-75% IQR = 0.88–1.22) |
0.88 |
CD45−CD34+, cells × 10−1/μL |
0.060 (25-75% IQR = 0.055–0.066) |
0.056 (25-75% IQR = 0.052–0.064) |
0.82 |
CD14+CD309+ × 10−4, % |
59.12 (25-75% IQR = 48.10–82.30) |
52.37 (25-75% IQR = 44.60–76.20) |
0.054 |
CD14+CD309+, cells × 10−1/μL |
3.35 (25-75% IQR = 2.57–4.18) |
2.71 (25-75% IQR = 2.31–3.52) |
0.018 |
CD14+CD309+Tie2+ × 10−4, % |
6.03 (25-75% IQR = 3.42–8.05) |
4.95 (25-75% IQR = 3.14–7.44) |
0.052 |
CD14+CD309+Tie2+, cells × 10−1/μL |
0.294 (25-75% IQR = 0.245–0.396) |
0.253 (25-75% IQR = 0.232–0.311) |
0.012 |
Using multivariate age and gender adjusted logistic regression analysis, independent impact of T2DM (odds ratio [OR]=1.08, P=0.003), hs-CRP per 4.50 mg/L (OR=1.12, P=0.001), OPG per 125.5 pg / mL (OR=1.14, P=0.001), number of MCRFs >3 (OR=1.15, P=0.001), HOMA-IR per 0.65 mmol/L × μU/mL (OR=1.04, P=0.001) on decreased of CD14+CD309+ EPCs was determined (Table 3). Therefore, CD14+CD309+Tie2+ EPCs were prone negatively impact by T2DM (OR=1.10, P=0.001), hs- CRP per 4.50 mg/L (OR=1.12, P=0.001), number of MCRFs >3 (OR=1.17, P=0.001), OPG per 125.5 pg / mL (OR=1.11, P=0.001), and HOMA-IR per 0.65 mmol/L × μU/mL (OR=1.06, P=0.001).
Recent studies have shown a closely association of serum levels of OPG and hs-CRP with T2DM [24,25]. Indeed, OPG is considered a candidate for biomarker, which modulating vascular remodeling effects and CVD development and progression [26]. In fact, OPG is over expressed on endothelial and smooth muscle cells in vasculature in dysmetabolic states [27]. Moreover, epidemiological studies have examined the relations of OPG to CVD events and mortality [28-31]. Strong associations of hs-CRP with components of MetS, T2DM, other inflammatory cytokine levels, as well as CVD events were found in several investigations [32-34]. Higher level of OPG and hs-CRP in MetS and T2DM reflected chronic low grade inflammation possibly mediates the development of diabetic complications and clinical CVD outcomes through ED [35]. ED may be realized as result in altered endothelial cell activity and endothelial integrity due to dysregulation of vascular wall repair processes [36] mediatied angiogenic EPCs [37]. Indeed, there are evidences that decreased number and / or functionally impaired EPCs are one of the major risk factors for the development of micro vascular complications in dysmetabolic patients [38].
Results of the presented study have shown that increased circulating level of inflammatory cytokines in T2DM patients may lead to more much deficiency of angiogenic EPCs when compared with MetS, while frequencies and absolute numbers of other immune phenotype EPCs may be comparable. Probably, OPG and hs-CRP seems to be determinant for depleted circulating EPCs levels and relates a progress from MetS and prediabetes to T2DM. Interestingly, that glycemic control, BMI, insulin resistance were not defined as independent predictors for decreased CD14+CD309+ and CD14+CD309+Tie2+ EPCs in dysmetabolic patients, but T2DM, numbers of CVD risk factors, OPG and hs- CRP were determined. These data sort with opinion provided by investigators regarding EPCs as a potential novel marker of vascular integrity, homeostasis process, metabolic abnormalities, and cardiovascular risk [39]. As it has been postulated, the reduction and dysfunction of EPCs associates with inflammatorydependent impairment of vascular function and relates to progress from MetS to T2DM. Overall, these results suggest that vascular reparative dysfunction associated with OPG and hs- CRP over production among T2DM subjects without preexisting atherosclerotic lesions of coronary arteries is superior to MetS patients.
Factors |
CD14+CD309+ EPCs |
CD14+CD309+Tie2+ EPCs |
||
OR (95% CI) |
P Value |
OR (95% CI) |
P Value |
|
Hypertension (present vs abcent ) |
0.99 (0.87–1.04) |
0.001 |
1.05 (0.97–1.11) |
0.001 |
Dyslipidemia (present vs abcent ) |
1.04 (0.92–1.22) |
0.001 |
1.02 (0.96–1.15) |
0.001 |
T2DM (present vs abcent ) |
1.08 (1.04–1.12) |
0.003 |
1.10 (1.02–1.20) |
0.001 |
BMI per 5.0 kg/ m2 |
1.05 (0.97–1.18) |
0.001 |
1.05 (0.95–1.07) |
0.002 |
hs-CRP per 4.50 mg/ L |
1.12 (1.03–1.20) |
0.001 |
1.12 (1.06–1.24) |
0.001 |
Number of MCRFs >3 |
1.15 (1.07–1.30) |
0.001 |
1.17 (1.11–1.22) |
0.001 |
TC per 0.65 mmol/ L |
1.03 (0.88–1.10) |
0.002 |
1.01 (0.98–1.10) |
0.001 |
SUA per 4.5 mmol/ L |
1.02 (0.94–1.14) |
0.001 |
1.04 (0.96–1.10) |
0.002 |
OPG per 125.5 pg / mL |
1.14 (1.07–1.26) |
0.002 |
1.11 (1.08–1.21) |
0.001 |
Adiponectin, per 9.5 mg/ L |
1.02 (0.99–1.04) |
0.002 |
1.01 (0.98–1.05) |
0.001 |
HOMA-IR per 0.65 mmol/ L × µU/ mL |
1.04 (1.00–1.06) |
0.001 |
1.06 (1.02–1.07) |
0.001 |
sRANKL per 12.5 pg / mL |
1.03 (0.98–1.07) |
0.001 |
1.02 (0.99–1.04) |
0.002 |
In conclusion, we suggest that inflammatory biomarkers (hs-CRP, OPG) may consider statistically significant predictors for decreased both angiopoetic phenotypes of circulating EPCs labeled CD14+CD309+ and CD14+CD309+Tie2+ among dysmetabolic patients without preexisting known atherosclerotic lesions of coronary arteries.
Ethical principles: All the patients have given their voluntary written informed consent for participation in the study. The study was approved by the local ethics committee of State Medical University, Zaporozhye, Ukraine. The study was performed in conformity with the Declaration of Helsinki.
Funding information: This research received no specific grant from any funding agency in the public, commercial, or notfor- profit sectors.
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