The
information in this column is intended for informational
purposes only, and does not constitute medical advice or
recommendations by the author. Please consult with your
physician before making any lifestyle or medication changes, or if you
have any other concerns regarding your health.
ERECTILE
DYSFUNCTION
& FREQUENCY OF SEX
A few years ago, I
reviewed a research paper that found a lower incidence
of prostate cancer in men who frequently engaged in sexual intercourse. The response of readers
fell, predictably,
along gender lines, with most male readers enthusiastically embracing
this
novel putative prostate cancer prevention activity, while many female
readers
took a less exuberant view of the results of this particular study. Now, a new study in the American Journal of Medicine reports on
the apparent relationship
between erectile dysfunction (ED) and frequency of sexual intercourse
among
older men.
In this Finnish public
health research study, 989 men between the ages of
55 and 75 (average age was 59.2 years) were assessed with a validated
ED
questionnaire, and were followed for an average of 5 years. The men were also
questioned about coexisting
ailments that are known to be associated with ED (among this cohort of
nearly
1,000 men, 32% had hypertension, 12% had heart disease, 7% complained
of
depression, 4% had diabetes, and 4% had a history of stroke). When ED-associated
illnesses were statistically
corrected for, the researchers were then able to assess the
relationship
between number of episodes of intercourse per week and the incidence of
ED.
In this study, men
reporting intercourse less than once per week had twice
the incidence of ED when compared to the men who reported intercourse
at least
one time per week. The
authors of this study,
therefore, concluded that more frequent sex is protective against the
development of ED.
Human sexuality is complex
both in terms of behavior and in terms of
biology. I wish
that I could fully
embrace the results of this study and its findings, but there are a
number of
weaknesses and potentially false assumptions involved in the authors’
conclusions. First
of all, this study
has not, in my view, adequately excluded the very likely probability
that the
men who had intercourse less than once per week did so because, in
fact, they already
had significant ED, and that ED was, itself, a direct cause of reduced
coital
frequency. Secondly,
this study suffers
from all of the potential weakness of survey-based public health
studies,
namely the potential for bias being introduced by the patients who
completed
the surveys, as well as, potentially, bias introduced by the people who
constructed the surveys (and by those who tabulated the data from these
surveys). On top of
these potential
biases, it is well known (both in research circles and throughout
general
society) that men are notoriously “subjective” in answering questions
related
to their sexuality and sexual performance.
As the conclusions of this study rest squarely upon the
accuracy of the
answers that these men provided on the study’s questionnaires, one has
to
question both the accuracy of the data collected and, in turn, the
conclusions
based upon such data. Likewise,
this
study did not evaluate the myriad social, economic, emotional,
physical, pharmacological,
and interpersonal factors that play such a powerful role in human
sexuality.
There may indeed be some
element of “use it or lose it” biology at work
relative to the potency status of elder men.
However, I do not think that this particular study’s data
is “potent”
enough to conclusively prove that more frequent intercourse leads to a
reduced
incidence of ED (i.e., rather than the other way around).
MUSCLE
STRENGTH &
MORTALITY IN MEN
There
are many
measures of overall health and fitness, many of them related to the
extent of
aerobic (cardiorespiratory) exercise capacity.
A new study, in the British
Medical Journal, examines muscular strength as a predictor of
mortality in
men. This study was
performed by the
Karolinksa Institute in Sweden,
the University
of Granada
in Spain,
the University
of South Carolina,
and the University
of North Texas.
In
this
prospective clinical study, nearly 9,000 men between 20 and 80 years of
age
were followed over an average of 19 years.
All study volunteers were assessed for muscle strength and
aerobic
fitness using standard exercise physiology testing.
During the very long period of follow-up, 503
of the men died, including 145 deaths due to cardiovascular causes and
199
deaths due to cancer. The
researchers
then adjusted for coexisting health factors in these men, including
age, level
of physical activity, smoking history, alcohol intake, obesity, other
medical
conditions, and a family history of cardiac and respiratory illnesses. The male volunteers were
then categorized
into three groups, proportional to their age-adjusted level of muscular
strength.
When
compared to
the men with the lowest level of muscle strength, the men with the
highest level
of muscle strength had a 29% lower risk of death due to cardiovascular
disease
and a 32% lower risk of death due to cancer.
The risk of dying due to any
cause was also reduced by 23% for the men in the group with the
greatest
muscular strength.
Even
the men who
exhibited muscle strength somewhere in between that of the men in the
lowest
and highest muscle strength groups appeared to also enjoy a lower risk
of
mortality. The risk
of death due to
cardiovascular disease in this intermediate group of men was 24% lower
than
that of the “lowest muscle strength” group, while the risk of death due
to
cancer was 28% percent lower, and the risk of death due to any cause was 28% lower.
Upon
further
analysis of their data, the authors of this study found that the
association
between muscular strength and a reduced risk of death due to cancer, or
due to
“all causes,” remained even when adjusting for the level of
cardiorespiratory
(aerobic) fitness. However,
among those
patients with poor cardiorespiratory fitness, increased muscular
strength was
less protective against death due to cardiovascular disease.
In
summary,
increasing levels of muscular strength appear to be protective against
death
due to “all causes,” cardiovascular diseases (e.g., heart attack and
stroke),
and cancer. Even
among patients with
poor cardiorespiratory fitness levels, increased levels of muscular
strength
still offered some protection against death due to various causes. Given the strong
interrelationship between
muscular fitness, on the one hand, and overall health and fitness, on
the other
hand, it is not entirely clear if muscular strength is, by itself, a
major
contributor to the reduced death rates observed among “muscularly fit”
men in
this study (i.e., rather than muscular strength being only one of
several
interrelated health factors that, together, reduce the risk of
mortality). However,
the authors of this study did adjust
their statistical calculations in an effort to correct for health
factors
unrelated to muscular strength, and they still found that muscular
strength, by
itself, reduced mortality rates. So,
I’ll see you at the gym soon, in the weight training section….
CRYOABLATION
FOR PROSTATE
CANCER
New
approaches to
the treatment of prostate cancer are being investigated, in addition to
existing surgical and non-surgical treatments.
Cryoablation is a technique that uses probes, inserted
into the prostate
gland, to freeze both the cancer and the surrounding normal prostate
gland. Although
there is currently no
data available from prospective, randomized clinical trials comparing
cryoablation with standard therapies, there is a growing body of
clinical data
looking at the benefits and risks of cryoablation versus other more
established
therapies.
A
new study in
the journal Urology reviews the
cumulative data, thus far, from an online data registry (the “COLD
Registry,”
or “Cryo Online Data Registry”) encompassing 1,198 patients who have
undergone
whole prostate gland cryoablation for prostate cancer.
The institutions participating in this study
included the Cleveland Clinic, the M.D.
Anderson Cancer
Center, Columbia
University,
the University
of Calgary
in Canada,
and the International Society of
Cryosurgery in Trieste,
Italy.
The
patients included in this study were grouped according to tumor-related
risk
factors into low, intermediate, and high risk groups.
The average age of these men was
approximately 70 years, and the average length of follow-up, to date,
has been
2 years (136 of the patients have been followed for at least 5 years).
Following
whole gland prostate cryoablation, 77% of the patients were deemed to
be free
of detectable prostate cancer 5 years following treatment. When broken down into
separate prognostic
risk groups, 85% of the low-risk group appeared to be disease-free at 5
years,
73% of the intermediate-risk group appeared free of disease at 5 years,
and 75%
of the high-risk group was clinically without evidence of recurrent
prostate
cancer at 5 years (using a different scoring system, 62% of the
high-risk
patients were clinically free of disease at 5 years).
Recurrence
rates confirmed by re-biopsy ranged from 15 to 38%, depending upon the
clinical
indications used to recommend re-biopsy (38% of the re-biopsies
performed for
rising prostate antigen, or PSA, levels in the blood were positive for
residual
or recurrent prostate cancer within the prostate gland).
Complications
associated with whole prostate gland cryoablation included breakdown
(fistula)
of the adjacent rectal wall (0.4%), incontinence of urine (5%), and
impotence
(91% of patients were impotent without the use of erectile dysfunction
drugs or
devices, and 75% were impotent despite using medications or devices).
Although
a longer follow-up of the entire group of these patients may reveal
very
different trends, the findings of this study, thus far, compares rather
favorably with other methods of prostate cancer treatment in terms of
efficacy
and complications. However,
as in other
clinical studies of whole prostate gland cryoablation, the incidence of
impotence following cryoablation appears to be significantly higher
when
compared to radiation therapy or nerve-sparing prostate surgery, while
the
incidence of incontinence of urine appears to be much lower for
cryoablation
when compared to other therapies.
Although
this particular study offers very useful information, we will have to
wait for
the results of randomized prospective clinical trials that perform
head-to-head
comparisons between cryotherapy and other conventional prostate cancer
therapies before cryoablation can be accepted as an equivalent (at
least)
therapy when compared to more established treatments.
A small randomized prospective clinical trial
in Canada,
which compared cryoablation with radiation therapy for localized
prostate
cancer, completed enrollment of all of its patients in April of 2007. It will be at least
another 5 years before
mature data is reported from this trial.
If that data is favorable, then cryotherapy may become
accepted
mainstream treatment for at least some prostate cancer patients. Until then, whole gland
cryoablation should
be considered an experimental treatment, and should be limited to
properly
accredited clinical research trials, in my view.
Disclaimer:
As always, my advice to readers is to seek the advice of your physician
before making any significant changes in
medications, diet, or level of physical activity.
