BEST DIABETOLOGISTS IN HEBBALA BANGALORE
Type 1 and type 2 diabetes and impaired glucose tolerance (IGT) are associated with
an increased risk of coronary disease, peripheral vascular disease and cerebrovascular disease.21
Diabetics have a two- to threefold risk of coronary disease at all ages and those with IGT have a
1.5-fold risk. Diabetes is a stronger risk factor for women (3.3 times) than for men (1.9 times).
The excess risk for type 1 patients is largely confined to those with diabetic renal disease. All
type 2 patients are at increased risk.22
Diabetes is thought to increase coronary heart disease because:
n increased insulin levels result in increased hepatic synthesis of LDL and triglycerides, causing
a mixed dyslipidaemia
n insulin resistance, which is characteristic of type 2 diabetes, is associated with numerous
other cardiovascular risk factors: dyslipidaemia, hypertension, endothelial dysfunction and
n hyperglycaemia itself may cause endothelial damage
n glycosylated LDL may be more atherogenic than non-glycosylated LDL.
Table 1.12 Glucose tolerance, current WHO definitions (venous plasma glucose)
2-hour post-glucose load
Normal glucose regulation < 6.0 < 7.8
Impaired fasting glucose 6.1–6.9 < 7.8
Impaired glucose tolerance < 7.0 7.8–11.0
Diabetes > 7.0 > 11.1
16 PRACTICAL CARDIOLOGY
The UKPDS Trial has shown a very significant reduction in the microvascular complications
of diabetes with improved glycaemic control but the improvement in macrovascular complications
did not quite reach significance. Nevertheless, the UKPDS trialists estimate that each 1%
reduction in HbA1c leads to a 14% reduction in cardiovascular risk.
Diabetics tend to have more diffuse coronary disease. shows a diffusely diseased
right coronary artery from a type 2 diabetic patient before and after coronary stenting .
Coronary artery surgery involves a higher risk for diabetics, and graft disease and progression
of native disease occur earlier in these patients. Nevertheless, diabetics probably have a better
prognosis after surgical revascularisation than after angioplasty because of their higher risk of
restenosis following angioplastY