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  This is Journal Watch, a medical-literature
survey produced by the Massachusetts Medical
Society.
  Twice a week, our physician-editors summarize
important new clinical research from a group
of 25 journals. Twice a month, the summaries
get compiled into newsletter form and mailed
to subscribers.
  If you'd like to subscribe to the newsletter,
which costs $US79 a year, please call
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(49) 30 335 8006.
  To comment via e-mail, please contact us at
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  Contents copyright 1994, Mass. Medical Society.



Journal Watch Summaries for August 23, 1994



SLEEP DISTURBANCES IN OBESE PATIENTS.
  Arch Intern Med 1994 Aug 8; 154:1705-11.


PREVENTING HIV TRANSMISSION WITH CONDOMS.
  N Engl J Med 1994 Aug 11; 331:341-6.


LYME DISEASE DOESN'T IMPAIR COGNITIVE FUNCTION IN
KIDS.
  Pediatrics 1994 Aug; 94:185-9.


DO CASE MANAGERS REDUCE READMISSIONS?.
  Arch Intern Med 1994 Aug 8; 154:1721-9.


THE BENEFITS OF DIETARY CHANGE AND SMOKING CESSATION.
  Arch Intern Med 1994 Aug 8; 154:1697-1704.


ASSESSING CARDIOLOGY'S FUTURE.
  J Am Coll Cardiol 1994 Aug; 24:275-328.


CAN GENE THERAPY PREVENT VASCULAR RESTENOSIS?.
  Science 1994 Aug 5; 265:781-4.



SLEEP DISTURBANCES IN OBESE PATIENTS.
   An increasing number of Americans are overweight and
obesity is a known risk factor for sleep apnea. This study
compared sleep disturbances of obese patients (50 men, 200
women) referred for weight management with 128 controls
matched for age and sex.
   Most obese patients were severely or morbidly overweight
and none had presented with sleep-related complaints. Staff,
students, and friends of staff served as controls. None of
the controls had sleep apneic activity during sleep testing.
In contrast, 40 percent of obese men and 3 percent of obese
women had sleep apnea that required intervention. Other
sleep disturbances (e.g., number of awakenings) were also
much more frequent among the obese patients. The severity of
snoring (based on frequency and loudness), sleep attacks,
and self-reported nocturnal breathing cessation were the
best clinical predictors of sleep apnea in obese patients.
   Comment: The actual incidence of sleep disturbances and
apnea cannot be determined from this study because it
involved referred patients, but the large number of obese
men with apnea warranting intervention illustrates the
importance of considering this diagnosis in this population.
--CD Mulrow.
   Citation: Vgontzas A; et al. Sleep apnea and sleep disruption in obese
patients. Arch Intern Med 1994 Aug 8; 154:1705-11.

PREVENTING HIV TRANSMISSION WITH CONDOMS.
   How well do condoms prevent heterosexual transmission
of HIV? To find out, this European prospective study
followed 256 sexually active heterosexual couples, each with
one HIV-infected partner.
  The couples were counseled about safe sex and the HIV-
negative partners were interviewed and tested for HIV every
six months. None of the uninfected partners reported other
HIV risk factors such as injection drug use. About two
thirds of the HIV-positive partners were men and about 10
percent had AIDS.
  During a median follow-up of 22 months, 124 couples (48%)
reported using condoms every time they had intercourse; none
of the HIV-negative partners in these couples seroconverted.
In contrast, there were 12 seroconversions among the 121
couples who reported that they inconsistently or never used
condoms. (The remaining 11 couples refused to answer
questions about sexual behavior). The risk of transmission
was enhanced if the HIV-positive partner had advanced
disease or the HIV-negative partner reported genital
infections. Transmission risk was lower if the couple
practiced withdrawal before ejaculation. The rate of
transmission did not differ by the sex of the infected
partner.
  Comment: Although it is unlikely that a larger study with
longer follow-up would find the rate of HIV transmission
among condom users to be zero, this report provides
reassuring evidence that condoms are highly effective. The
sobering news is that half the couples did not use condoms
consistently despite ongoing counseling. --AS Brett.
   Citation: De Vincenzi I; et al. A longitudinal study of human
immunodeficiency virus transmission by heterosexual partners. N Engl J Med
1994 Aug 11; 331:341-6.

LYME DISEASE DOESN'T IMPAIR COGNITIVE FUNCTION IN
KIDS.
   Nervous system involvement is common in Lyme disease
(LD), and previous studies suggest that LD can eventually
cause cognitive impairment. This pediatric study says "it
ain't so."
   The authors studied 41 children (6 to 17 years old) who
were treated for LD at a children's hospital in a Lyme-
endemic area, and compared them with two control groups: 23
healthy siblings closest in age to the patients and 14
children with non-Lyme arthritis. The children with LD had
become ill an average of two years earlier and had a range
of clinical findings, including CNS involvement in 9 and
arthritis in 22. Extensive neuropsychologic testing,
including tests of general intelligence, information
processing, and memory, found no differences among the three
groups. Academic achievement was comparable before and after
the onset of LD.
   Comment: This study is more credible than previous
investigations because of its superior design: it was
prospective, controlled, and blinded and used formal
cognitive testing. I would have been more convinced by the
findings if more of the children with LD had presented with
neurologic involvement. It is also important to note that
all children were adequately treated for LD, and the two-
year gap between disease onset and testing may have been too
short for all cognitive impairment to surface.
--RA Dershewitz.
   Citation: Adams WV; et al. Cognitive effects of Lyme disease in children.
Pediatrics 1994 Aug; 94:185-9.

DO CASE MANAGERS REDUCE READMISSIONS?.
   Descriptive studies suggest that nearly ten percent of
hospital readmissions are preventable. This trial evaluated
whether nurse case managers reduce readmission rates.
   Researchers randomized 668 patients over age 44 years who
were discharged from a Veterans Affairs general medicine
inpatient service to receive usual primary care follow-up or
follow-up with case managers. Using educational materials,
routine telephone calls, and regularly scheduled general
medicine visits, case managers educated patients about their
diseases, facilitated access, identified unmet needs and
alternative sources of care, and helped coordinate overall
care.
   After one year, patients with case managers had 15
percent more clinic visits but not a significant reduction
in readmissions or total readmission days when compared with
controls. About 49 percent of patients in both groups were readmitted.
   Comment: This study found that case managers did not
reduce readmissions. A reasonable approach for future
studies evaluating case managers is to target high-risk
patients with very high readmission rates and measure more
comprehensive outcomes such as functional status and overall
costs. --CD Mulrow.
   Citation: Fitzgerald J; et al. A case manager intervention to reduce
admissions. Arch Intern Med 1994 Aug 8; 154:1721-9.

THE BENEFITS OF DIETARY CHANGE AND SMOKING CESSATION.
   Health promotion programs that involve behavior
change, such as diet modification and smoking cessation, are
often recommended for reducing coronary disease, but what
are the expected benefits of each strategy? This study used
a computer model to estimate the impact on life expectancy
of  reduced-cholesterol diet or smoking cessation.
   The distribution of coronary risk factors such as blood
pressure, glucose intolerance, cholesterol, and smoking
status were derived from the Canadian Health Survey. The
predicted change in cholesterol was based on a diet with
cholesterol intake of 240 to 300 mg/day and 8 to 10 percent
of calories from fat; the model assumed that, on average,
such diets would reduce serum cholesterol 17 to 29 mg/dl in
men and 5 to 21 mg/dl in women. Smoking cessation assumed
that all smokers became nonsmokers.
   The maximal increase in life expectancy from dietary
modification was 0.4 year for men and 0.16 year for women.
The maximal increase in life expectancy from smoking
cessation was 4.43 years for men and 3.68 years for women.
The greatest dietary benefits were estimated in men who were
assumed to start dieting at ages 30 to 59. The benefits of
smoking cessation were fairly consistent regardless of age
and sex.
  Comment: Although these results are based on estimates
from a computer model and not the actual efficacy of
specific programs, they do highlight the need to continue to
focus on cigarette smoking as a public health priority.
--CD Mulrow.
   Citation: Grover S; et al. Life expectancy following dietary modification
or smoking cessation. Arch Intern Med 1994 Aug 8; 154:1697-1704.

ASSESSING CARDIOLOGY'S FUTURE.
   Increasing financial pressures on health care have led
many professional groups to attempt predictions of future
personnel needs. Six task forces convened by the American
College of Cardiology met last November to evaluate the
outlook for cardiology.
   The most striking conclusion was that there seems to be
"an abundance of interventional cardiologists" and that
training should emphasize other aspects of cardiovascular
care, including noninvasive and preventive cardiology. Other
task forces concluded that, despite large numbers of
cardiologists at some centers, poor and lower-class rural
and urban populations are often underserved. If these
populations are "brought into the mainstream of cardiac
care," it's projected that the need for pediatric
cardiologists will increase, as the latter are in
undersupply relative to adult cardiologists.
   Other major challenges for cardiology include improving
the training of generalists in cardiovascular medicine,
decreasing the number of training positions without
adversely affecting the quality of training, and integrating
cardiologists more effectively into networks of care in
partnership with nonphysician providers.
   Comment: Changes in the health care system are likely to
limit and even reduce the number of cardiologists, but such
is the case for many other specialties. The conclusions of
these task forces are in many ways generalizable to other
fields. --TH Lee.
   Citation: 25th Bethesda Conference. Future personnel needs for
cardiovascular health care.
November 15 to 16, 1993. J Am Coll Cardiol 1994 Aug; 24:275-328.

CAN GENE THERAPY PREVENT VASCULAR RESTENOSIS?.
   A top gene-therapy team at the University of Michigan
reports using gene therapy to reduce the proliferation of
vascular smooth muscle cells that causes arterial narrowing.
   The researchers, led by Gary and Elizabeth Nabel,
deliberately injured the endothelium of the ileofemoral
artery in pigs (a good animal model for vascular disease) to
induce smooth-muscle-cell proliferation. They then inserted
a special double-balloon catheter that stopped blood flow
and allowed prolonged therapeutic infusions into the space
between the two balloons. First, they infused adenoviruses
that contained a herpesvirus gene for thymidine kinase (tk)
and infected the smooth muscle cells in the area. They then
infused ganciclovir, a drug that stops proliferation of
cells that contain the tk gene.
   Smooth-muscle-cell proliferation was indeed prevented in
the animals receiving these infusions, but not in control
animals. No damage to nonproliferating cells adjacent to the
lesion was observed, and none was expected, since the
treatment affects only dividing cells.
   Comment: There are several caveats to this potentially
important study. A peripheral artery was used, not a
coronary artery. Healthy endothelium was deliberately
injured: this was not a model of atherosclerosis. Finally,
the technique required blockage of blood flow for 20
minutes. The efficacy and feasibility of this approach in
human coronary atherosclerosis are therefore unknown.
--AL Komaroff.
   Citation: Ohno T; et al. Gene therapy for vascular smooth muscle cell
proliferation after arterial injury. Science 1994 Aug 5; 265:781-4.