50 / 76
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 1, January/February 2017
48
AFRICA
The effects of the metabolic syndrome on coronary
artery bypass grafting surgery
Sevil Özkan, Fatih Özdemir, O
ğ
uz U
ğ
ur, Refik Demirtunç, Ahmet Yavuz Balcı, Mehmet Kızılay,
Ünsal Vural, Mehmet Kaplan,
İ
brahim Yekeler
Abstract
Background:
The metabolic syndrome (MS) is a clustering
of factors that are associated with increased cardiovascular
risk. A low-grade inflammatory process acts as the underly-
ing pathophysiology, which suggests that the MS may have a
detrimental effect on coronary interventions, including coro-
nary artery bypass grafting (CABG) surgery performed with
cardiopulmonary bypass (CPB). We aimed to evaluate the
effect of the MS on morbidity and mortality rates in the early
postoperative period in patients undergoing CABG.
Methods:
We prospectively included 152 patients (109 males
and 43 females; mean age 60.1
±
8.6 years) who underwent
elective CABG on CPB between January and September
2011. Early postoperative morbidity and mortality rates
were compared between subjects with and without the MS.
Diagnosis of the MS was based on the American National
Cholesterol Education Program Adult Treatment Panel III
(NCEP ATP III) criteria.
Results:
Of the study group, 64 patients (42%) had the MS.
The two groups were similar in age and gender. In the post-
operative period, rates of atrial fibrillation, wound infection,
pulmonary complications, and lengths of intubation, hospi-
talisation and intensive care unit stay were significantly higher
in MS patients (
p
<
0.01). The MS was significantly associ-
ated with wound infection (OR 6.64, 95% CI: 1.72–25.75),
pulmonary complications (OR 6.44, 95% CI: 1.58–26.33),
arrhythmia (OR 5.47, 95% CI: 1.50–19.97) and prolonged
intubation (OR 1.17, 95% CI: 1.05–1.32). The mortality rate
was 3.1% in the MS group and 1.1% in the non-MS group,
with no significant difference (
p
>
0.05).
Conclusion:
The MS was associated with a higher rate of early
postoperative morbidity following CABG, without having a
significant effect on the mortality rate.
Keywords:
coronary artery bypass grafting surgery, metabolic
syndrome, postoperative morbidity and mortality
Submitted 30/9/14, accepted 5/5/16
Published online 13/7/16
Cardiovasc J Afr
2017;
28
: 48–53
www.cvja.co.zaDOI: 10.5830/CVJA-2016-056
The metabolic syndrome (MS) is a complex metabolic
disturbance characterised by insulin resistance, central obesity,
hypertriglyceridaemia, reduced high-density lipoprotein
cholesterol, hypertension and glucose intolerance.
1
The unifying
mechanism responsible for the cluster of cardiovascular risk
factors in the MS is insulin resistance, which is also a hallmark
of the MS.
2
It has been proposed that insulin resistance plays a
major unifying role in increased ischaemic events in MS patients,
but this mechanism and ensuing processes need clarification.
3-5
As
described by the the American National Cholesterol Education
Program Adult Treatment Panel III (NCEP ATP III), at least
three of five criteria (Table 1) have to be met for a MS diagnosis.
6
Prevalence of the MS has been reported as approximately
35–40% in industrialised countries.
7
It is an inflammatory state
characterised by increased levels of adipocytokines such as
tumour necrosis factor-
α
, interleukin-6 and C-reactive protein,
as well as free fatty acids, which cause vasoconstriction and
endothelial dysfunction. The MS is also described as a low-grade
inflammatory state manifested by increased circulating levels
of inflammatory cytokines. Reduced plasma adiponectin and
elevated leptin and resistin levels have been observed in MS
patients. However, unlike leptin and resistin, which stimulate the
immune system, adiponectin inhibits the inflammatory process
in the vascular wall, mainly by inhibiting the nuclear factor
kappa B pathway.
2
The pro-inflammatory state associated with
the MS may play a contributory role in exacerbation of the
systemic inflammatory response induced by cardiopulmonary
bypass (CPB) and surgical trauma, and therefore may predispose
patients to peri-operative complications.
8
The MS is a cluster of metabolic perturbations largely
resulting from abdominal obesity, which is associated with
increased risk for type 2 diabetes and cardiovascular disease.
9
Although it has been shown to be a predictor of adverse events
Department of Internal Medicine, Haydarpasa Numune
Training and Research Hospital, Istanbul, Turkey
Sevil Özkan, MD,
sevilfurkan@hotmail.comRefik Demirtunç, MD
Department of Cardiovascular Surgery, Dr Siyami
Ersek Training and Research Hospital on Thoracic and
Cardiovascular Surgery, Istanbul, Turkey
Fatih Özdemir, MD
O
ğ
uz U
ğ
ur, MD
Ahmet Yavuz Balcı, MD
Mehmet Kızılay, MD
Ünsal Vural, MD
Mehmet Kaplan, MD
İ
brahim Yekeler, MD
Table 1. Metabolic syndrome diagnostic criteria (NCEP ATP-III)
Metabolic syndrome diagnostic criteria
1. Abdominal obesity (waist circumference)
• Male
>
102 cm
• Female
>
88 cm
2. Triglycerides
>
150 mg/dl (1.7 mmol/l)
3. High-density lipoprotein cholesterol
• Male
<
40 mg/dl (1.04 mmol/l)
• Female
<
50 mg/dl (1.3 mmol/l)
4. Blood pressure
>
130/85 mmHg
5. Fasting blood glucose
>
110 mg/dl (6.11 mmol/l)
American National Cholesterol Education Program Adult Treatment Panel
(NCEP ATP III) diagnostic criteria for the metabolic syndrome.