Clinical Briefs

By Louis Kuritzky, MD

Alendronate for Osteoporosis

The bisphosphonates alendronate (ALE) and risedronate are the most commonly used pharmacologic agents for the treatment and prevention of osteoporosis (OSPS). Bisphosphonates have been shown to reduce fracture rates and improve bone mass, but previous studies have been limited to windows of observation no longer than 5 years. Because patients may be receiving bisphosphonates for decades, longer-term studies are of great value.

The study population reported by Bone and colleagues included women (n = 247) from an original study group of 994 who were randomized to a placebo- controlled 3-year study of ALE. At the conclusion of that study, women were invited to extend treatment with ALE 5 or 10 mg/d for an additional 2-7 years. Some of the women who had been originally assigned to ALE ware given placebo, which also allowed determination of whether bone accrual effects would recede upon discontinuation of treatment.

Both ALE doses provided increases in bone density over 10 years, maximally in the lumbar spine (13.7% increase) and least in the femoral neck (5.4% increase). The nonvertebral fracture rate during the years 6-10 of the study was similar to that seen in the first 3 years, in which there were approximately 20% fewer fractures in the ALE group. Bone markers indicated that ALE benefits gradually diminished upon discontinuation. ALE is well tolerated and maintains efficacy with long-term administration.

Bone HG, et al. N Engl J Med. 2004;350:1189-1199.

Exercise Training in Patients Chronic Heart Failure

In the not-too-distant past, clinicians were apprehensive about exercise for patients with chronic heart failure (CHF). Evolution of knowledge about optimizing treatment in CHF has recognized that exercise may indeed provide symptomatic benefits. The effect of exercise upon mortality has not been examined, or study populations have been too small to derive meaningful data. By meta-analysis, data from 9 studies (n = 801) provides a sturdier picture of the impact of exercise upon mortality.

In the studies used to comprise the meta-analysis group, exercise programs attained peak oxygen consumption intensity ranging from 50-80%, by means of cycling, walking, or other aerobic activities. All programs provided supervised activity, ranging from 30-60 minutes per day on multiple days per week. Followup was up to approximately 2 years. To ensure that effects were related to exercise, and not changes in pharmacotherapy, drug regimens were examined. No changes in ACE inhibitors, beta blockers, or antialdosterone agents occurred during exercise study periods.

Exercise provided a favorable 35% risk reduction in mortality and 28% reduction in the combined end point of death or hospitalization. The optimum intensity, duration, method, and frequency of exercise remain unknown, but clinicians should be encouraged that aerobic exercise may be life-prolonging in patients with CHF.

ExTraMATCH Collaborative. BMJ USA 2004;4:109-112.

Cardiovascular Prognosis of "Masked Hypertension"

There is consistent agreement that ambulatory blood pressure monitoring (ABPM) provides a better indicator of ultimate cardiovascular risk than office blood pressure (OBP). Because measurement of BP at home (HBP) often frees the patient from stressors which could lead to spuriously elevated BP (white coat HTN), we are sometimes aided by such measurements in directing treatment. Unfortunately, trial data based upon HBP measurement is sparse.

The Self Measurement of BP at Home in the Elderly study followed almost 5,000 participants for 3 years. Subjects had BP measured in the office after a 5-minute rest. At home, patients measured BP 3 times each morning and evening.

During followup, 205 deaths occurred (85 cardiovascular). HBP was predictive of cardiovascular events in men and women, for both systolic and diastolic BP. There was a small group of individuals (9% of total group) whose BP was elevated on HBP measurement, but not in the office. These individuals also reflected an increased cardiovascular risk.

Bobrie and associates conclude that HBP measurement is a better prognostically than office BP. Indeed, they have identified a heretofore little-described population known as masked hypertension’, who have elevated blood pressures at home despite normal office BP.

Bobrie G, et al. JAMA. 2004;291: 1342-1349.

Dr. Kuritzky, Clinical Assistant Professor, University of Florida, Gainesville, is Associate Editor of Internal Medicine Alert.