Hypertensive patients with diabetes are at particularly high risk for cardiovascular events. More aggressive treatment of hypertension in these patients prevents progressive nephropathy, myocardial infarction, and stroke. Treatment recommendations suggest a target of < 130/80 mm Hg. Because of their beneficial effects in diabetic nephropathy, ACE inhibitors (and ARBs in intolerant patients) should be part of the initial treatment regimen.
However, most diabetics require combinations of three to five agents to achieve these goals, usually including a diuretic and a calcium channel blocker or β-blocker. In addition to rigorous blood pressure control, treatment of persons with diabetes should include aggressive treatment of other risk factors and early intervention for coronary disease and left ventricular dysfunction.
Hypertension is present in 40% of patients with a glomerular filtration rate (GFR) of 60-90 mL/min, and 75% of patients with a GFR < 30 mL/min. Many factors play a role in the hypertension of renal failure, including volume; the renin-angiotensin system; renal artery disease; activation of the sympathetic nervous system; and increased arterial stiffness and changes in vasoactive mediators, such as prostaglandins, endothelin, and parathyroid hormone. ACE inhibitors and ARBs have been shown to delay progression of renal impairment in persons with type 1 and type 2 diabetes, respectively. It is also likely that inhibition of the renin-angiotensin system protects renal function in nondiabetic renal disease associated with significant proteinuria.
As discussed above, hypertension should be treated until blood pressure reaches < 130/80 mm Hg in patients with chronic kidney disease. There is a lack of definitive data to show that tighter blood pressure control slows the decline of GFR in persons with hypertensive chronic kidney disease without high-grade proteinuria. However, since all patients with chronic kidney disease are at high risk for cardiovascular damage, treatment of blood pressure to the < 130/80 mm Hg target is appropriate, and interruption of the renin-angiotensin system would seem a reasonable approach. Furthermore, it has recently been demonstrated that ACE inhibitors remain protective and safe in renal disease associated with significant proteinuria and creatinine as high as 5 mg/dL. It should be noted that such treatment would likely result in acute worsening of renal function in patients with significant renal artery stenosis, so renal function and electrolytes should be monitored carefully after introduction of ACE inhibitors.
Substantial evidence indicates that blacks are not only more likely to become hypertensive and more susceptible to the cardiovascular complications of hypertension - they also respond differently to many antihypertensive medications. This may reflect genetic differences in the cause of hypertension or the subsequent responses to it, differences in occurrence of comorbid conditions such as diabetes or obesity, or environmental factors such as diet, activity, stress, or access to health care services. In any case, as in all persons with hypertension, a multifaceted program of education and lifestyle modification is warranted. Because it appears that ACE inhibitors and ARBs - in the absence of concomitant diuretics - are less effective in blacks than in whites, initial therapy should generally be a diuretic or a diuretic combination, with the use of additional agents as discussed above. Some experts have recommended a goal blood pressure of 130/80 mm Hg for blacks at high risk for cardiovascular events as well as those with diabetes.
Because the goal is to reduce cardiovascular morbidity and mortality, attention must be paid to the management of other risk factors. Elevated LDL cholesterol should be aggressively treated (see above), and patients should be urged to stop smoking, exercise regularly, and lose weight.
Once blood pressure is controlled on a well-tolerated regimen, follow-up visits can be infrequent and laboratory testing limited to tests appropriate for the patient and the medications used. Yearly monitoring of blood lipids is recommended, and an electrocardiogram should be repeated at 2- to 4-year intervals depending on whether initial abnormalities are present, the presence of coronary risk factors, and age.
Patients who have had excellent blood pressure control for several years, especially if they have lost weight and initiated favorable lifestyle modifications, should be considered for “step-down” of therapy to determine whether lower doses or discontinuation of medications are feasible.
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