Middle-aged African American Man With Diabetes and Hypertension

A 57-year-old African American man comes to your office because he isconcerned about his blood pressure (BP). When it was measured at a healthfair a month earlier, it was 157/96 mm Hg; a week later at a clinic it was162/97 mm Hg. Now his resting BP is 166/101 mm Hg.HISTORY
The patient has non-insulin-dependent type 2 diabetes mellitus, whichhas been reasonably well controlled with diet and exercise.LABORATORY RESULTS
Fasting blood glucose level is 142 mg/dL. Creatinine level is 1.1 mg/dL.In addition to diet and exercise, which antihypertensive regimenwould you prescribe?A. Thiazide diuretic alone.B. β-Blocker alone.C. Angiotensin-converting enzyme (ACE) inhibitor alone.D. Thiazide diuretic and ACE inhibitor.E. β-Blocker and thiazide diuretic.F. Dihydropyridine calcium channel blocker alone.CORRECT ANSWER: D
Hypertension continues to be one of the most commonmedical conditions in the United States. It affects about 1in 4 Americans and is even more prevalent among AfricanAmericans.¹ Hypertension is an important risk factorfor a variety of serious diseases and conditions, includingstroke, renal failure, myocardial infarction, and dementia.²The primary and secondary morbidity associatedwith hypertension is related to the degree of BP elevationand its duration. In the Seventh Report of the Joint NationalCommittee onPrevention, Detection,Evaluation,and Treatmentof HighBlood Pressure(JNC 7), the newsystolic BP goalfor patients withdiabetes is lessthan 130 mm Hgand the new diastolicgoal is lessthan 80 mm Hg.³These are morestringent thanthe previousgoals of 140 mmHg (systolic) and90 mm Hg (diastolic).In addition,the guidelinesrecommend earlier use of multiple agents; furthermore,they state that in patients with diabetes andhypertension, 2 or more agents are usually needed toachieve goal BP.³This patient's BP is at or above the levels of 160 mmHg systolic and 100 mm Hg diastolic, at which all wouldagree treatment with both lifestyle modifications (for example,maintenance of ideal body weight, aerobic physicalactivity, smoking cessation, and dietary modification) andpharmacologic therapy is required.⁴A variety of effective antihypertensive agents are nowavailable. ACE inhibitors, β-blockers, calcium channelblockers, and angiotensin receptor blockers (ARBs) haveall been shown to lower the risk of cardiovascular diseaseand stroke in patients with diabetes. However, of thesedrug classes, only ACE inhibitors and ARBs have alsobeen shown to delay the progression of diabetic nephropathy.Thus, this patient has a compelling indication for useof an ACE inhibitor--or an ARB if ACE inhibitors are not tolerated.Because this patient has diabetes, he will likely needdual therapy to control his hypertension. Thus, the optimaldrug regimen is not ACE inhibitor monotherapy(choice C); rather, it is combination therapy with an ACEinhibitor and a thiazide diuretic (choice D).Treatment with a β-blocker alone (choice B) is unlikelyto adequately control BP. Moreover, a β-blockermay mask the symptoms of hypoglycemia. One of the importantmediators of glucose metabolism--besides insulinand glucagons--is epinephrine. Epinephrine helps preventhypoglycemia by stimulating glycogenolysis and gluconeogenesisand by inhibiting insulin secretion. However,epinephrine can also trigger symptoms of early CNSlevelhypoglycemia; it can cause diaphoresis and anxiety.Thus, there is at least a theoretical risk with β-blockadethat the symptoms of hypoglycemia will be masked. Forthis reason, these are not first-line agents for patients withboth diabetes and hypertension.Calcium channel blockers (choice F) have also beenshown to be effective in the treatment of hypertensionand in prevention of cardiac disease and stroke--althoughthey are no more effective than any other class of agents.Thiazide diuretics (choice A) are another good class of antihypertensiveagents and are probably underused. However,neither of these agents alone is likely to achieve adequateBP control in this patient.Use of a thiazide diuretic and a β-blocker (choice E)was the first-line dual therapy recommended in previousguidelines. However, because this man has diabetes,he needs an ACE inhibitor or an ARB to help delay progressionof diabetic nephropathy. In addition, as mentionedabove, a β-blocker poses the risk of masking hypoglycemia.

References:

REFERENCES:

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Wing LM, Reid CM, Ryan P, et al. A comparison of outcomes with angiotensinconvertingenzyme inhibitors and diuretics for hypertension in the elderly.

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Major outcomes in high-risk hypertensive patients randomized to angiotensinconvertingenzyme inhibitor or calcium channel blocker vs diuretic: the Antihypertensiveand Lipid Lowering Treatment to Prevent Heart Attack Trial(ALLHAT).

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The Seventh Report of the Joint National Committee on Prevention, Detection,Evaluation, and Treatment of High Blood Pressure: the JNC 7 report.

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August P. Initial treatment of hypertension.

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2003;348:610-617.