Friday, April 26, 2013

Good News on Aging

The daily news reports from my body largely get worse over the years. So it was a nice change to get some good news on aging from the medical front recently. This might seem a bit random and different than my usual Equipoise postings. But science writing is what I do for a living, and the challenges of aging are another keen interest of mine.

The good news included an epidemiological study which found that it's not just poor childhood nutrition that determines stature and how much people shrink in height during old age: Healthy lifestyle in later life is associated with retaining height. Another study reported on a technique for correcting near-sightedness without surgery or glasses. Completing the hat-trick was a study describing an effective non-surgical way to shrink enlarged prostates, a common curse of aging in men. [Full Lazy Journalist Disclosure: I am rehashing press releases here and have not spent time dissecting the underlying research papers. I think I've included sufficient details so anyone interested in digging in can do so. Hah! Just followed links to other publications' stories on the first story and it looks like they did the same thing...]

Preserving Stature

I'm not sure at what age one reaches maximum height. But evidently we grow up, then we grow down into old age. Wizened. Probably the best-known reason for loss of height is osteoporosis, or thinning of the bones, a condition that takes a particular toll on women after menopause.

But evidently shrinkage is just a natural body change accompanying old age, along with increasing body fat and decreasing bone density. Other conditions can exacerbate height-loss--arthritis and inflammation of the spine, along with osteoporosis, for example.

At a "Consensus Development Conference" on osteoporosis 20 years ago, leading scientists stressed that an important key to avoiding "dowager's hump," bone-thinning, and resulting fractures in  old age was building up extra-solid bones during one's youth. With hormonal changes accompanying menopause, women lose the ability to take up calcium efficiently from their diet. So getting girls to drink that extra glass of milk was crucial to preparing mineral-dense bones able to withstand some losses as calcium is leached away more quickly than it's replaced.

As it turns out, there's more to it than frequent sporting of a Got Milk? moustache in youth. The good news is that you might have some chance of slowing height loss even though you're of a certain age.

The study uncovering the new information on late-life shrinkage was based on a massive survey, "the China Health and Retirement Longitudinal Study," led by Univ. of Southern California economist John Strauss; Yaohui Zhao of the China Center for Economic Research (CCER) at Peking University; and Gonghuan Yang of the Peking Union Medical College. The ongoing survey is following 17,708 adults from age 45 onwards. As reported in the American Economic Journal Applied Economics, the study tracked height and health, but also cognitive function, memory, geographic history, socioeconomic status, education, and blood tests. They'll be collecting these data every two years.

A press release for the study quotes USC economist Geert Ridder, a co-investigator on the study: "Height has been recognized as an acceptable proxy for childhood health conditions, but there are complications there," Ridder says. "Some of adult health might be determined by childhood circumstances, but people shrink differentially, and that shrinkage is also a measure of adult health conditions."

Some of the factors that affected shrinkage included whether a person lived in an urban or rural area (rural people shrank much more); education and literacy (illiterate and less educated men and women shrank more) and "cognitive health:"
Those who had lost more height were also much more likely to perform poorly on standard tests of cognitive health such as short-term memory, ability to perform basic arithmetic and awareness of the date.
Importantly, the data show correlation, not causation, so the study does not show why declining stature is associated with declining short-term memory, for example. It may be that better-educated urban-dwellers have better health care, are better able to maintain both mental and physical health, and doing so prevents loss of height. Or perhaps factors leading to loss of height, such as arthritis following hard agricultural work may follow from early diversion away from school, the cities, and into the fields.

The study says by the time participants entered the study in their mid-40s, overall average height loss for men was 3.3 cm. For women there had been an "average overall height decrease of 3.8 cm." Completing primary school cut this loss by 27% for men and 16% for women.

The baseline CHARLS data is publicly available to researchers at The research is supported by the U.S. National Institute on Aging, the China Natural Science Foundation, the Fogarty International Center of the U.S. National Institutes of Health and the World Bank.

Braces for Aging Eyes

Before finally dispensing with vanity and getting a pair of glasses, several dear friends went through that phase -- holding their newspaper father and father away. When the print grew too tiny to read at arm's length, old-age-denial gave way to reading glasses, bifocals, or vari-focals.

A news release about research at the University of New South Wales, Sydney, offers hope for my friends in avoiding reading glasses. It says they've found a way to correct age-related decline in near vision, or presbyopia. The method involves wearing a corrective contact lens in one eye while you sleep.

The study, reported in "Optometry and Vision Science" built on earlier studies of the corrective-lens technique, called "hyperopic orthokeratology (OK)." During the night, the OK contact lens gently reshapes the cornea, correcting presbyopia by the time you awaken and remove the lens.

The study included 16 middle-aged participants with presbyopia. They wore the rigid plastic lens in one eye each night for a week. The investigators measured participants' vision and the shape of their corneas each morning and evening during the week. From the first day, the procedure corrected close-vision for all participants -- and their close-vision was even better by the end of the week.

The researchers corrected vision in only one eye so that distance-vision would stay the same. When they checked distance-vision, they found no declines in the untreated eye. The overall result was to give participants good monocular vision for both close and distant vision.

To retain the close-vision correction, it was necessary to continue wearing the corrective lens during sleep. When participants stopped wearing the OK lens at the end of the study, their presbyopia returned within a week as the cornea relaxed back into its natural shape.

A news release on the study quotes Anthony Adams, Editor-in-Chief of Optometry and Vision Science: "This study demonstrates that OK is quite viable as a nonsurgical option for monovision that does not require wearing contact lenses during the day, although it does require 'retainer' orthokeratology contact lenses to be worn overnight." Dr Adams adds, "This possibility will certainly appeal to many people, especially since the changes in the corneal curvature of the treated eye are fully reversible."

As for me -- I'll just stick with my glasses, as, no doubt, will people whose aversion to putting things in their eyes exceeds distaste for wearing glasses.

Shrinking An Enlarged Prostate

The third study described a minimally invasive method of shrinking enlarged prostate by reducing blood supply to the gland. The pilot study subjected 14 men to "prostatic artery embolization (PAE)," a procedure that plugs up the arteries feeding the prostate. The study, the first of its kind in the United States, follows larger earlier studies of PAE in Europe.

The UK's National Health Service has a web page describing the procedure (not for the squeamish), and notes the "University Hospital Southampton has been offering a PAE service from April 2012 and is the first UK centre to perform this procedure."

A press release on the U.S. study said, "Nearly all men eventually suffer from an enlarged prostate as they age, and this treatment is almost like turning back the clock and giving them the prostate of their youth," according to Sandeep Bagla, M.D., the study's lead author and an interventional radiologist at Inova Alexandria Hospital in Virginia.

Enlargement of the prostate, or benign prostatic hyperplasia is a common problem besetting men in later years. The press release says more than half of 50-year-old men will have this proliferation of prostate cells, as will more than 80 percent of 80-year-old men. Androgens open the door to the unwelcome excess growth, which can constrict the urethral canal, blocking the flow of urine.

On the bright side--the cell proliferation is not cancerous. The bad news is that constriction of the urethral canal can cause problems, including urinary frequency, urgency, urge incontinence, and having to get up frequently during the night to pee. The hyperplasia can also cause piss problems, including long waits for urination to start; intermittent stopping and starting of flow; having to strain; and dribbling. Left untreated, symptoms may progress, according to Wikipedia, increasing the risk of urinary tract infection, bladder stones, and urine retention -- potentially leading to bladder distension and even kidney failure.

The options for treating enlarged prostate have not been great. The effectiveness of drugs can be so-so, and the drugs in use have various side effects, including decreased libido and ejaculatory or erectile dysfunction. The other option, invasive surgery to remove overgrown tissue, may leave the patient with urine leak, impotence, or other complications.

Although PAE doesn't sound like a picnic, it seems like a better option than more invasive surgery and not a bad choice for men who don't fare well with drugs for benign prostatic hyperplasia. PAE requires only local and regional anaesthetic, and patients may not need an overnight hospital stay for the procedure. Interventional radiologists perform a PAE by inserting a tiny wire and tube through an artery in the leg, then guiding the tube into the arteries of the prostate. A cloud of microscopic particles is fed into the tiny vessels, blocking off blood flow. "By temporarily blocking blood flow through the prostate artery, PAE causes the prostate to shrink, providing a larger passageway for urine," the press release says.

It gives early findings from the U.S. study, which was presented at the 38th Annual Scientific Meeting of the Society of Interventional Radiology in mid-April 13-18:
13 of 14 men (92 percent) who had PAE noticed a significant decrease in symptoms after one month. None of the men suffered any major complications, such as impotence, leaking urine or infection. Most went home the day of treatment.
Bagla is now conducting a larger clinical study of PAE, which will treat 30 men by this fall and then follow the patients for two years to check the long-term consequences of PAE.

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