involves the administration of andro-
gens, usually with a progestin every 2–3
months, to suppress pituitary gonadotrophic support
for sperm production (this is analogous to the combined
female oral contraceptive pill). Data shows that sperm concen-
tration falls to below one million/ml or zero in 95% of men. This
approach is reversible within 6–12 months, and it provides
similarly effective contraception to female hormonal methods.
However, the viability of this method is undermined by the
slow speed of onset of protection (1–6 months),
the need to check sperm density given its
failure to suppress all men, and the
potential for sperm output to
rebound if treatment is inter-
rupted. Importantly, the poten-
tial side-effects to cardiovascular
health and mood require further
evaluation.
The development of an effective,
consumer-friendly male contraceptive remains challenging as
it requires strong co operation between the public and private
sectors. It is now 25 years since the first World Health Organ-
ization-sponsored trial showed comparable contraceptive effi-
cacy to female methods, yet all major pharmaceutical companies
withdrew from the area a decade ago, and show no signs of
returning, because of concerns about safety, market size,
patentability, medico-legal dimensions and the prodigious
expense of product development and registration. Small-scale
publically funded work continues in the USA, but sadly there
is no prospect of a marketable product in the foresee-
able future.
Finally, at a population
level, infertile men die younger
than fertile men. While this has only
been recently recognised, in hindsight it
makes perfect scientific sense and offers a brilliant
opportunity for intervention.
Comparisons of lifespan are compounded by many factors,
including lifestyle, genetics and psychological factors. It is for
this reason that a Danish study of lifespan in men presenting
for infertility treatment was so compelling (http://
tinyurl.com/pbmwetk). Data from semen analyses from more
than 43,000 men presenting for infertility treatment in the
greater Copenhagen region was linked to longevity via the
Danish central registers. All semen data was obtained from the
same laboratory. While undoubtedly not perfect, the selection
of this patient group normalises for several factors, including
socioeconomic standing (which is undoubtedly a key deter-
minant of life expectancy) and geographical influences.
The results of this study showed that menwith lower sperm counts
were significantly more likely
to die younger than men with high
sperm counts.
Indeed, a negative linear relationship was observed
between sperm count and life expectancy, which levelled
off above 40 million sperm per millilitre of semen. A similar
correlation was observed between sperm motility, sperm
morphology and life expectancy. Interestingly, the presence of
children in the man’s home (from his partner, for example)
was not protective against early death, suggesting that children
per sedo not help you live longer.
Across the Atlantic, a similar result was obtained in an Amer-
ican study (http://tinyurl.com/qf5mt8g) that analysed its data
in a slightly different way: the chances of death in an 8-yearfollow-up period. The researchers analysed semen profiles from
12,000 relatively young patients (<50 years) in California and
Texas, and linked it to mortality data via the National Death
Index or Social Security Death Index. The authors found that
any of low semen volume, sperm concentration and count, and
the percentage of motile sperm within an ejaculate was associ-
ated with higher risk of early death. The authors found that if
a man presented with two or more abnormal semen parameters
he had a 2.3-fold higher risk of death compared with men with
normal semen. This risk was comparable to diabetes or smoking.
But why are infertile men dying younger, and what are they
dying of? While the two studies above could not define cause
due to a paucity of events within the datasets, other studies
have reported links between male infertility and both testicularJAN/FEB 2016|| 21alex-mit/iStock