What are the Complications
of Diabetes?
Diabetes is the
sixth leading cause of death from the disease alone and the seventh
leading cause of death from complications in the United States. Each
year, at least 190,000 people die as a result of diabetes and its complications.
Blindness due to diabetic retinopathy. Each year 12,000 to 24,000
people lose their sight because of diabetes. Diabetes is the leading
cause of new blindness in people 20-74 years of age.
Kidney Disease due to diabetic nephropathy. Ten to twenty-one
percent of all people with diabetes develop kidney disease. Diabetic
nephropathy is the most common cause of end-stage renal disease (ESRD),
a condition where the patient requires dialysis or a kidney transplant
in order to live. Diabetes accounts for approximately 40% of new ESRD
cases.
Heart Disease and Stroke. People with diabetes are 2 to 4 times
more likely to have heart disease (more than 77,000 deaths due to heart
disease annually). Heart disease death rates are also 2 to 4 times as
high as adults without diabetes. And, people with diabetes are 2 to
4 times more likely to suffer a stroke.
Nerve Disease and Amputations. About 60-70% of people with diabetes
have mild to severe forms of diabetic nerve damage, which, in severe
forms, can lead to lower limb amputations. In fact, diabetes is the
most frequent cause of non-traumatic lower limb amputations. The risk
of a leg amputation is 15-40 times greater for a person with diabetes.
Each year, 56,200 people lose their foot or leg to diabetes.
Impotence due to diabetic neuropathy or blood vessel blockage.
Impotence afflicts approximately 13% of men who have type 1 diabetes
and 8% of men who have type 2 diabetes.
Nephropathy
General principles
Persistent albuminuria in the range of 30-299 mg/24 h (microalbuminuria)
has been shown to be the earliest stage of diabetic nephropathy and
is a significant risk marker for cardiovascular disease. Patients with
microalbuminuria will likely progress to clinical albuminuria (>300
mg/24 h) and decreasing GFR over a period of years. Once clinical albuminuria
occurs, the risk for ESRD is high in type 1 diabetes and significant
in type 2 diabetes. If untreated, hypertension can hasten the progression
of renal disease. Over the past several years, a number of interventions
have been demonstrated to retard the initial development or rate of
progression of renal disease. Quantitative microalbumin testing plays
a major role in early detection.
Cardiovascular
Disease Persons with diabetes have a high rate of macrovascular
disease and those with the disease have a high mortality rate. This
complication of diabetes is thought to be due to a high level of risk
factors such as lipids and to other biological factors intrinsic to
diabetes. High lipid levels are modifiable risk factors and should be
monitored. Performing a lipid profile is the first step in good lipid
management. Evidence of cardiovascular disease, such as angina, claudication,
decreased pulses, vascular bruits, and electrocardiogram abnormalities,
requires effort to correct contributing risk factors (e.g., obesity,
smoking, hypertension, sedentary lifestyle, dyslipidemia, poorly regulated
diabetes) in addition to specific treatment of the cardiovascular problem.
Daily intake of aspirin has been shown to reduce cardiovascular events
in patients with diabetes. (For specific recommendations and further
discussion, see the American Diabetes Association's position statement
"Aspirin Therapy in Diabetes.")
Testing for Coronary Heart Disease is warranted in patients without
a prior history of CHD when the following is observed:
1) typical or atypical cardiac symptoms
2) resting electrocardiogram suggestive of ischemia or infarction
3) peripheral or carotid occlusive arterial disease
4) sedentary lifestyle, age >35 years, and plans to begin a vigorous
exercise program
5) in addition to diabetes, two or more cardiac risk factors (total
cholesterol >240 mg/dl, LDL cholesterol >160 mg/dl, or HDL cholesterol
<35 mg/dl; blood pressure >140/90 mmHg; smoking; family history of premature
CHD; positive micro-/macroalbuminuria test).
Cardiac testing might consist of exercise stress testing, stress perfusion
imaging, stress echocardiography, or catheterization. The type of testing
and need for referral to a cardiologist depend on the severity of underlying
or suspected coronary artery disease.
Dyslipidemia
General principles
Diabetes increases the risk for atherosclerotic vascular disease. This
risk is greatest in people who have other known risk factors, such as
dyslipidemia, hypertension, smoking, and obesity. Furthermore, in type
2 diabetes there is an additional increased risk for obesity and lipid
abnormalities independent of the level of glycemic control. A common
abnormal lipid pattern in such patients is an elevation of VLDL, a reduction
in HDL, and an LDL fraction that contains a greater proportion of small,
dense LDL particles. Recent studies have shown Lp(a) to be a significant
independent risk factor for assessing CHD.
Increased Risk
of Heart Disease in Diabetes
In people with diabetes:
Nearly 75%
of deaths are attributable to CHD
The risk
of CHD is increased two- to fourfold compared with nondiabetics
There is
a high 1-year mortality rate following a first MI: 44% in diabetic men,
37% in diabetic women
Cardiovascular
complications are the most common cause of health care expenditures
It is important
to reduce the risk of CHD
Click
here for more information about
Dyslipidemia and Cardiac Implications
References
Bierman EL. Arteriolscler Thromb. 1992; 12:647-656.
Carpentier A, Lewis GF. Can J Diabetes Care. 1998;22:28-38.
Miettinen H, et al. Diabetes Care. 1998;21:69-75.
