Hypertension and Diabetes
Hypertension is a common finding in the diabetic patient. In Type 1 diabetes (IDDM)
hypertension usually develops after renal impairment. The hypertension subsequently
accelerates the decrease in renal function. Type 2 diabetes (NIDDM), the adult and
most common type of diabetes, is associated with obesity. In fact, obesity is involved
in the pathogenesis of Type 2 diabetes. The alarming increase in diabetes worldwide
coincides with the increased prevalence of obesity.
This combination of diabetes and hypertension is lethal to the cardiovascular system.
Strokes, myocardial infarctions, heart failure, and renal failure are all increased
in the diabetic patient with hypertension. However, the benefits of treatment are
even greater than the benefits of treatment of the non-diabetic hypertensive patient.
All studies have emphasized this greater benefit. It appears that the higher the
risk the greater the benefit from treatment of hypertension. The benefit is also
related to the degree of hypertension control. In the United Kingdom Prospective
Diabetes Study (UKPDS) 1"tight" but still not optimal control of blood
pressure (mean 144/82 mmHg) compared with usual treatment (154/87 mmHg) resulted
in a 24% reduction in any diabetic complication and a 32% reduction in deaths related
to diabetes, primarily myocardial infarctions and strokes. Patients who also had
good glucose control had even fewer complications.
The Sixth Report of the Joint National Committee on Detection, Evaluation and Treatment
of High Blood Pressure (JNC VI) set 130/85 mmHg as the treatment goal for hypertensive
diabetic patients and as low as 125/75 mmHg for patients with renal insufficiency
with proteinuria greater than 1 gram/24 hours. The treatment goal should begin with
lifestyle changes, particularly weight reduction in Type 2 diabetes. Weight loss
can improve glucose, lipid and blood pressure control. The presence of diabetes,
a major risk factor, demands the institution of drug therapy.
Which drug should be started? This is not easy to answer, but one principle to remember
is that control of blood pressure is the critical goal and this usually requires
two to three drugs. In patients with diabetic nephropathy an ACE inhibitor should
be one of the drugs. In patients with angina or a recent myocardial infarction b
-blockers should be used. The concern over hypoglycemia with the use of b -blockers
has been grossly exaggerated. b -blockers have clearly been shown to save lives
post myocardial infarction.
Usually, the management of the hypertensive diabetic patient involves a three-prong
The middle-aged or older diabetic patient is assumed to have underlying coronary
heart disease. The dyslipidemia should be vigorously treated to reduce the LDL cholesterol
below 100 mg/dl. Glycemic control can also improve abnormal lipid levels, especially
- control of blood pressure
- control of glucose and
- control of lipids.
This vigorous treatment of the hypertensive diabetic patient can yield gratifying
results in lowering cardiovascular complications, but it is expensive and beyond
the reach of many developing countries. However, even small decreases in blood pressure
can reduce complications, so do something!
An action that can have a profound long-term effect on the cardiovascular disease
rate in a country is PREVENTION: PREVENTION OF OBESITY,
the central risk factor that links hypertension – diabetes – dyslipidemia.
The key to success is to control obesity at an early age.
Patrick J. Mulrow, M.D.
- UK Prospective Diabetes Study (UKPDS) Group. Tight blood pressure control and risk
of macrovascular and microvascular complications in type 2 diabetes. UKPDS 38. BMJ
317: 703-713, 1998.
World Hypertension League