![]()
REVIEW
SA JOURNAL OF DIABETES & VASCULAR DISEASE
64
VOLUME 8 NUMBER 2 • JUNE 2011
normoglycaemia (49%) is nearly as common as abnormal glucose
regulation (51%).
5
In a study including more than 8 800 patients
receiving a coronary artery bypass graft (CABG), 28.2% of patients
had diagnosed T2D, 23.3% had IGT and 5.2% had undiagnosed
T2D. This latter group was characterised by a higher morbidity
and mortality in the peri- and postoperative period.
6
European
epidemiological studies have indicated that about half of all cases
of diabetes in the adult population are undiagnosed. Data from
the KORA-survey 2000 (Cooperative Health Research in the Region
of Augsburg) showed a prevalence of diabetes mellitus of 16.6%
in the age class of 55–74 years.
7
Nearly half of them (8.2%) were
previously undiagnosed cases. The fact that hypertension as well
as dyslipidaemic disorders in this group is as common as in the
group of diagnosed T2D shows an increased risk of cardiovascular
events even if the disease has not become obvious to the patients
in the form of symptoms. Another 16% showed impaired glucose
tolerance, which further increases the number of patients with an
abnormal glucosemetabolism. In theMONICAAugsburgmyocardial
infarction (MI) registry, also a high prevalence of undiagnosed
diabetes (12%) and IGT (27%) was observed in long-term MI
survivors.
8
The decreased survival of diabetic individuals after MI has
been attributed to a more severe atherosclerosis, higher incidence
of cardiac failure, cardiomyopathy, autonomic neuropathy and an
increased risk of arrhythmias.
9
Despite a poor prognosis in such
cases, elevated blood glucose levels are often poorly recognised
or they are often not attributed to the diagnosis of diabetes. A
high prevalence of undiagnosed diabetes was reported in patients
scheduled for coronary angiography in a German centre.
10
Among
3 266 high-risk patients, as many subjects with undiagnosed
diabetes (17.9%) as patients with known diabetes (17.0%) were
observed; representative data of the prevalence of prediabetes and
diabetes in a well-defined population at high risk for macrovascular
complications are lacking for Germany.
The European Society for Cardiology and the European
Association for the Study of Diabetes have recommended taking
the close relation of diabetes and CVD into account in diagnostic
procedures.
11
They provide guidelines that diabetologists should
consider macrovascular complications more attentively, and
for cardiologists to consider glycaemic control in their patient
population. In order to assess the prevalence of abnormal glucose
metabolism in a cardiology patient cohort, this epidemiological
study investigated IGT, IFG, known and newly diagnosed diabetes
mellitus in patients with suspected or established CHD.
The study confirms the observation that nearly one-third of
subjects attending a cardiology care unit for coronary angiography/
procedure suffer from known impaired glucose regulation. Looking
at patients of primary care physicians, 16% are at increased
cardiovascular risk due to diabetes or impaired fasting glucose.
12
A
number of discrete CVD risk factors are known which may cluster
in individuals but may not all necessarily be present.
13
They include
markers of glucose regulation, obesity, hypertension, vascular
inflammation, coagulation, dyslipidaemia, endothelial dysfunction
and microalbuminuria. This study investigates thrombotic markers
(MMP-9, sCD40L, E-selectin), parameters associated with
endothelial dysfunction (ICAM, VCAM), the lipid profile and markers
of chronic vascular inflammation (hsCRP, MCP-1, IL-6). As expected,
the diabetes patients show increased values of hsCRP, MMP-9 and
adhesion molecules. These biological markers are involved with the
pathophysiology of atherosclerosis, one of the major contributors
to CVD. Consistently, these markers are considered predictors for
macrovascular risk.
It is of special interest that patients with IGT/IFG also have
a higher cardiovascular risk according to the pattern of the
investigated markers. There is growing evidence that abnormalities
in glucose homeostasis contribute to an increased cardiovascular
risk. However, IGT/IFG are not suitable for short-term risk
Table 2.
Mean values of the biomedical and clinical markers of this study. Significance was assessed by statistical calculation of the ‘no diabetes’ group versus
each single other cohort.
Parameter
No diabetes
IFG/IGT
Newly diagnosed diabetes
Known diabetes
hsCRP [mg/l]
2.8
±
2.1
3.1
±
2.3
3.6
±
2.6**
3.5
±
2.8*
IL-6 [pg/ml]
5.6
±
4.7
7.9
±
9.3*
4.9
±
2.5
5.4
±
2.2
MMP-9 [mg/l]
441
±
302
644
±
358***
637
±
529**
482
±
220
MCP-1 [ng/l]
409
±
174
505
±
216**
395
±
117
449
±
91
sCD40L [pg/ml]
3783
±
3506
5863
±
3338***
4578
±
2965
3563
±
3130
ICAM [ng/ml]
331
±
112
396
±
105***
371
±
160*
345
±
73
VCAM [ng/ml]
707
±
235
949
±
269***
810
±
319*
841
±
383**
E-selectin [ng/ml]
43
±
19
62
±
30***
63
±
29***
77
±
27***
HbA
1c
[%]
4.8
±
0.6
5.0
±
0.7***
5.3
±
0.7***
6.3
±
1.2***
Fasting plasma glucose [mg/dl]
88
±
13
101
±
12
118
±
28
142
±
43
Insulin sensitivity [HOMA score]
1.8
±
1.5
2.5
±
1.7***
4.0
±
3.4***
5.2
±
5.0***
Triglycerides [mg/dl]
136
±
71
148
±
83
143
±
78
184
±
217**
Cholesterol [mg/dl]
197
±
42
195
±
39
203
±
56
182
±
49**
HDL-C [mg/dl]
54
±
12
52
±
12
52
±
11
51
±
18
LDL-C [mg/dl]
116
±
34
115
±
34
123
±
47
99
±
35***
Significance level is *
p
<
0.05, **
p
<
0.01 or ***
p
<
0.001.
