Treatment of hypertensive diabetic patients

Elevated hepatic insulin extraction in essential hypertension

Insulin resistance, hyperinsulinemia, and dyslipidemia are common characteristics of patients with untreated hypertension. However, the link between the vascular and metabolic disturbances is still unclear. To provide further insights into the metabolic picture of subjects with hypertension, we evaluated insulin resistance, pancreatic secretion, and hepatic extraction of the hormone in 16 untreated patients with essential hypertension before and after 12-16 weeks of drug treatment in comparison with 16 age-, sex-, and body weight-matched normotensive control subjects. All subjects underwent an oral and a frequently sampled intravenous glucose tolerance test. Metabolic parameters were calculated by the minimal model technique. The hypertensive patients exhibited a highly reduced tissue insulin sensitivity (2.6 +/- 0.4 versus 9.6 +/- 1.9 10(4) min-1/[microunits/mL]; p < 0.001). The basal secretion rate (70 +/- 11 versus 35 +/- 5 pmol/L per minute) and the total amount of prehepatically secreted insulin (32 +/- 4 versus 16 +/- 2 nmol/L in 4 hours) were significantly increased in the hypertensive patients compared with the control subjects (p < 0.01), whereas the posthepatic insulin delivery rate was not significantly different between the two groups (4.9 +/- 0.6 versus 3.5 +/- 0.3 nmol/L in 4 hours). Hepatic insulin extraction was found to be significantly elevated in the hypertensive patients compared with control subjects (81 +/- 4% versus 69 +/- 3%, p < 0.04). Increased hepatic insulin extraction partially ameliorated B cell hypersecretion in hypertensive patients. After 12-16 weeks of drug treatment, the blood pressure was normalized, but the metabolic profile of the patients remained unchanged. We conclude that elevated insulin extraction in the liver is a specific characteristic of individuals with essential hypertension and partially compensates pancreatic B cell hypersecretion.

Effects of ACE inhibition supplementary to beta blockers and diuretics in early diabetic nephropathy

Angiotensin converting enzyme (ACE) inhibition has shown promising results in diabetic nephropathy, but long-term results on survival are not available. In a cohort of patients receiving antihypertensive treatment predominantly consisting of beta blockers in combination with diuretics, support for an improved survival has been presented. Addition of ACE inhibition to such a combination treatment may be favorable both due to the suggested renoprotective effects of ACE inhibitors and because diuretics activate the renin-angiotensin system. In 10 insulin-dependent diabetic patients with early diabetic nephropathy [urinary albumin excretion rate (UAE) less than 100o micrograms/min], who were receiving continuous therapy with metoprolol and bendroflumethiazide, a double-blind crossover study with four months addition of ramipril 5 mg (Ramace) and placebo was conducted. UAE (radioimmunoassay) and fractional albumin excretion were significantly reduced after the four months of ramipril administration [UAE: 114.1 x/divided by 1.3 (geometric mean x/divided by confidence factor] versus 174.6 x/divided by 1.2 micrograms/min, 2P less than 0.005). Renal plasma flow (clearance of 131I-hippuran) tended to increase [497 +/- 25 (mean +/- SE) vs. 464 +/- 28 ml/min/1.73 m2, 2P = 0.08], while GFR (125I-iothalamate) stayed unchanged (121 +/- 8 vs. 120 +/- 9 ml/min/1.73 m2). Mean arterial pressure during clearance studies fell moderately (95 +/- 3 vs. 101 +/- 1 mm Hg, 2P less than 0.05) and renal resistance was decreased (2P less than 0.03). ACE activity was suppressed in all patients. Twenty-four-hour ambulatory blood pressure measurements were not significantly different after the two periods (daytime averages: 91 +/- 2 vs. 93 +/- 2, nighttime 80 +/- 2 vs. 84 +/- 3 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin resistance and hypertension

The author has reviewed the development of the concept that insulin resistance is related not only to the hypertensive state but potentially to the initiation and maintenance of high blood pressure. Potential sequelae of insulin resistance and hyperinsulinemia, as they apply to atherogenesis, are also discussed. The impact of present antihypertensive pharmacologic therapy on insulin resistance is addressed, as are future directions in pharmacologic and nonpharmacologic management of hypertension. In addition, the author speculates on possible mechanisms leading to insulin resistance in hypertension.

Drug therapy for the hypertensive diabetic patient: implications for the diabetes educator

A variety of side effects associated with the use of antihypertensive medications may occur in any patient with diabetes mellitus. Also, some antihypertensive agents produce symptoms that would be insignificant to the nondiabetic patient but may be life-threatening to the patient with diabetes mellitus. Therefore, it is imperative to instruct patients to be aware of any changes they may notice after starting an antihypertensive medication or changing their antihypertensive drug regimen. With this increased awareness and an increase in glucose monitoring (when necessary), the patient is prepared to recognize subtle changes in blood glucose levels or other conditions related to diabetes mellitus--changes that might otherwise go unnoticed. As diabetes educators, being knowledgeable about the pharmacodynamics of various antihypertensive medications, their influence on diabetes, and any risks the drugs may impose on the diabetic patient gives us a sound base to intervene with patients and prevent potentially life-threatening complications.