Saturday, May 29, 2010

Advanced paternal age may play a role in non-Hodgkin lymphoma etiology.

Am J Epidemiol. 2010 May 27. [Epub ahead of print]

Parents' Ages at Birth and Risk of Adult-onset Hematologic Malignancies Among Female Teachers in California.
Lu Y, Ma H, Sullivan-Halley J, Henderson KD, Chang ET, Clarke CA, Neuhausen SL, West DW, Bernstein L, Wang SS.

Although advanced parental age at one's birth has been associated with increased risk of breast and prostate cancers, few studies have examined its effect on adult-onset sporadic hematologic malignancies. The authors examined the association of parents' ages at women's births with risk of hematologic malignancies among 110,999 eligible women aged 22-84 years recruited into the prospective California Teachers Study. Between 1995 and 2007, 819 women without a family history of hematologic malignancies were diagnosed with incident lymphoma, leukemia (primarily acute myeloid leukemia), or multiple myeloma. Multivariable-adjusted Cox proportional hazards models provided estimates of relative risks and 95% confidence intervals. Paternal age was positively associated with non-Hodgkin lymphoma after adjustment for race and birth order (relative risk for age >/=40 vs. <25 years = 1.51, 95% confidence interval: 1.08, 2.13; P-trend = 0.01). Further adjustment for maternal age did not materially alter the association. By contrast, the elevated non-Hodgkin lymphoma risk associated with advanced maternal age (>/=40 years) became null when paternal age was included in the statistical model. No association was observed for acute myeloid leukemia or multiple myeloma. Advanced paternal age may play a role in non-Hodgkin lymphoma etiology. Potential etiologic mechanisms include de novo gene mutations, aberrant paternal gene imprinting, or telomere/telomerase biology.

PMID: 20507900 [PubMed - as supplied by publisher]


Friday, May 28, 2010

Male Biological Clock

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HomeMen’s Biological Clock
by justin on May 24, 2010
in Happy Daze
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There were rumours a while back that Hugh Hefner, the octogenarian founder of the Playboy empire was planning to father a child with Holly Madison (53 years his junior), the alpha female of his three live-in girlfriends. Of course that was before the jam hit the fan and all three moved out of the mansion.

But, apropos the baby – why not? Charlie Chaplin and Picasso both fathered children well into their 70s, with no ill-effects. There are even anecdotal reports in the medical press of men in their 90s becoming fathers. Everyone knows that we men can just carry on having children until very late in life, (although it’s possible that having kids just makes you feel 100 hundred years old).

Photo by: judepics
But is it all true? It seems that medical evidence is mounting that men are not immune from the ticking of the biological clock (although we often battle to hear it quite as loudly as our partners).

The first part of the problem lies with the decline in fertility of men as they age. Testosterone levels fall over time which not only makes it harder for men to hold their tummies in at the beach, but also affects sexual performance. There is also a decline in sperm count and sperm quality which means that it takes men over 45 significantly longer to produce a pregnancy than men under 25 – up to 5 times longer according to some research.

Still, it was thought that even with a decline in fertility, any genetic issues with the pregnancy or resulting child lay with the mother. This was because while a woman is born with her full quota of eggs, men manufacture sperm continually without even having to think about it, so conception between an older couple might be the meeting of a forty-year-old egg with a three-month-old sperm (the time taken to manufacture mature spermatozoa).

However, it now seems that there’s also a deterioration in the quality of the genetic material that each sperm carries. This is first seen in an increase in the number of miscarriages – three times greater where fathers are older than 35 compared to those younger than 25. The incidence of pre-eclampsia also rises with increasing paternal age.

This deterioration of genetic material is thought to arise from a number of causes. The cells which divide to produce sperm cells replicate around 23 times per year starting from puberty, so by the time a man hits 50, those cells have divided about 800 times, increasing the risk of errors.

With age, the frequency of sporadic single-gene mutations also increases four to five times for a person over 45. On top of that, the enzymes that repair faulty DNA decrease in efficiency as one gets older.

All of which means an increase in a list of medical problems now totalling about 20.

A study of data from a huge Israeli health database showed that, for example, schizophrenia is twice as likely to occur in the children of men over forty as in those in their twenties. Men over fifty lead to a three-time increase in risk.

A further study on the same database showed that autism too is six times more frequent where fathers are over forty than those under 30.

An earlier study by Dr Harry Fisch (author of the book The Male Biological Clock) concluded that parents over 40 have a six-times higher risk of having a child affected by Down Syndrome than where both are under 35. And where a woman over forty has a child affected by Down Syndrome, the genetic blame is now thought to lie 50% with the father.

And the list goes on, with various studies linking advanced paternal age to disorders such as dwarfism, progeria (an extremely rare accelerated aging disease), skeletal disorders, congenital heart defects, certain types of cancer and even reduced scores in nonverbal IQ tests.

All of which helps explain why the cutoff age for sperm donors in The States is set at 40. So that’s another paying hobby limited to the youth – smacks of ageism, doesn’t it?

And yet more and more couples are leaving it later to have children for any number of reasons. Many want to feel like they’ve experienced something of a life and a career before the little tyrants arrive. Some prefer to wait until they’re in a more financially stable phase of their lives before committing. Maybe its just that there are more frogs to kiss nowadays in search of princes. Or even that the kiss-per-frog ratio has risen.

And really, what’s the downside? You may be more likely to spend time in casualty with a back problem from flinging your toddler around and there’s the danger of injuring yourself by tripping over your Zimmer frame when playing cricket with the young ‘uns.

Having kids later probably means that you’re going to have a bit less energy for them, but then again, that depends on how well you’ve looked after yourself in getting to where you are. Also, a decrease in the time available to spend with children can be offset to a certain degree by an increase in the quality of the time spent.

Many parents are finding that they’re having children later without even planning it that way – life often gets in the way of our plans. Then when one’s finally ready to make this life-altering commitment it takes a little while to get everything ready to even start trying (especially when you discover that the whole house has to be remodelled before you can even start).

And then it doesn’t just happen right away, and where there are miscarriages, recovery, both physical and emotional, takes time before you can start again.

All of which means an upswing in the number of parents who battle to remember where they left the children a few minutes before.

Then again, children of older parents should be more independent when they grow up, if only because they’re used to being able to easily outpace their pursuers.

From a selfish point of view, having kids later means that you’ll have someone around who is able to intuitively figure out how to use the new DVD player that has been standing unused because you can’t work out what the instruction manual is trying to tell you.

Also, you don’t resent the loss of your social life to the same degree as those that have their children while they are young (the parents, not the children) – you’re giving up a whole lot less when your idea of a good time is staying in with a good book and listening to Smooth Classics.

And when you’re lucky enough to have your mid-life crisis with small children you’re much less likely to embarrass yourself by running off and buying a convertible or any motorcycle that comes with tassles hanging from the handlebars.

The bottom line? Don’t leave it too late. While it is physiologically possible for a man to produce heirs at a very late stage of life, the risks do rise along the way.

And Hef? I think that at his age, he’s just perfected the art of saying ‘Yes Dear’ without really listening to what anyone is actually saying.

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Tags: fathers, old dads, senior fathers


Saturday, May 15, 2010

We conclude that the trend of delaying fatherhood in men undergoing IVF or ICSI treatment is detrimental to sperm quality

J Androl. 2010 May 13. [Epub ahead of print]

Semen Quality Decline among Men below 60 years of age Undergoing IVF or ICSI Treatment.
Hammiche F, Laven J, Boxmeer J, Dohle G, Steegers E, Steegers-Theunissen R.

Due to changes in the society, couples in Western countries are increasingly delaying reproduction. This is accompanied by unhealthy lifestyles that may not only be detrimental to general health but also for reproductive capacity. It is well-known that maternal age has detrimental effects on fertility; the paternal influence on this outcome is largely unknown. This study aims to investigate associations between a paternal age below 60 years of age, lifestyles and sperm quality. In a periconceptional prospective cohort study we included two hundred twenty-seven men undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment. Age at sperm collection, lifestyles, cause of subfertility, ethnicity, sperm DNA fragmentation index (DFI), as marker of sperm DNA damage) and sperm parameters were determined. Linear regression analyses showed a positive association between a rising age from 26 to 59 years and DFI (P
PMID: 20467050 [PubMed - as supplied by publisher]


ANDROLOG SUMMARY: Risks to Offspring Associated with Advanced Paternal Age.

J Androl. 2010 May 13. [Epub ahead of print]

ANDROLOG SUMMARY: Risks to Offspring Associated with Advanced Paternal Age.
Bhandari A, Sandlow J, Brannigan RE.

The exact degree to which advanced paternal age imparts increased risk to offspring as a variety of disorders varies and is not entirely well defined. The following string of Androlog entries summarizes a discussion by several colleagues pondering how best to advise couples regarding the risks of advanced paternal age.

PMID: 20467047 [PubMed - as supplied by publisher]