Clinical Briefs-By Louis Kuritzky, MD
Microalbuminuria as a Marker of Preclinical Diastolic Dysfunction in Never-Treated Essential Hypertensives
Normal urinary albumin excretion does not exceed 30 mg/24 h. Microalbuminuria (MAU), defined as 30-300 mg/24 h albumin excretion, is seen in hypertensive and diabetic patients and has been shown to reflect, in addition to propensity for decline in renal function, cardiovascular risk. For instance, MAU is associated with greater incidence of left ventricular hypertrophy (LVH) and LV systolic dysfunction (SDF). LV diastolic dysfunction (DDF) is considered one of the earliest detectable myocardial derangements attributed to hypertension, antedating SDF, but studies have not previously been done relating MAU to DDF in never-treated hypertensives.
This study included never-treated hypertensives (n = 87) that were divided into MAU+ (= 30-300 mg/d albuminuria) and MAU- (= normal albumin excretion) categories, and evaluated for DDF. Diastolic function, as measured by peak LV lengthening rate, was found in MAU+ patients 3 times as often as MAU- patients (67.8% vs 22%).
Grandi and colleagues conclude that in addition to the acknowledged association between MAU+ and other cardiovascular risk, MAU+ is associated with impairment of diastolic ventricular function in asymptomatic hypertensive patients.
Grandi AM, et al. Am J Hypertens. 2001;14:644-648.
Smoking Cessation and the Course of Major Depression: A Follow-Up Study
It has been previously noted that persons attending smoking-cessation clinics have a statistically greater frequency of past episodes of depression than nonsmoking comparators. Additionally, previous depression is linked with smoking recidivism.
The issue of new episodes of major depression attendant to smoking cessation efforts has been little examined. Glassman and colleagues examined 100 smokers with a previous history of major depression who participated in a smoking cessation trial for 2 months. Sertraline was the active agent used to assist smoking cessation (placebo controlled). Patients were not taking antidepressant medications during the 6- month observation period after smoking cessation intervention.
Comparing persons who successfully stopped smoking with those who continued to smoke, the frequency of major depression was 5 times as likely among abstinent persons (31% vs 6%). Interestingly, among abstinent smokers, those who had used placebo were twice as likely to suffer subsequent depression than the group who received active pharmacotherapy (43% vs 19%). Glassman et al conclude that smoking cessation is associated with an elevated risk of recurrence of depression; nicotine may have some effect that alters vulnerability to depression. The evenly distributed frequency of depressive episodes throughout the 6 months postcessation observation period argues against a "sertraline halo" effect.
Glassman AH, et al. Lancet. 2001;357: 1929-1932.
Prophylaxis with Single-Dose Doxycycline for the Prevention of Lyme Disease After an Ixodes Scapularis Tick Bite
Though lyme disease may be prevented by vaccination, the cost and need for multiple doses are substantial obstacles to implementation, in addition to imperfect protective effects. To test the applicability of using single-dose pharmacotherapy (200 mg doxycycline PO) in persons who have recently suffered a tick bite from Ixodes scapularis, Nadelman and colleagues performed a placebo-controlled trial (n = 482) among persons who had removed a tick within 72 hours of attachment. Subjects underwent physical examination, blood cultures, and Borrelia burgdorferi antibody tests at baseline, 3 weeks, and 6 weeks.
Erythema migrans was infrequent, but doxycycline did statistically significantly reduce its occurrence (0.4% vs 3.2%). In regard to the primary end point of the trial (development of erythema migrans), the overall efficacy of doxycycline was 87%.
Nadelman et al conclude that when given within 72 hours of a recognized tick bite, a single dose of 200 mg of doxycycline is highly effective in preventing development of Lyme disease.
Nadelman RB, et al. N Engl J Med. 2001;345:79-84.