Expert: John Locke - 8/9/2007

Question
Hi Christen,
It appears laughter can change the genetic expression that leads to type 2 diabetes, at least that's what I read into the conclusion of the medical report below.  However, I'm a layman.  Any help with interpreting what the report's conclusion is saying would be gratefully received.  Thanks!
Regards,
Usuff

http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSear...

Answer
Thanks for using AllExperts, Usuff. The conclusion here actually suggests that laughter causes gene changes that make Type II diabetes less severe. One of the most serious complications of diabetes is peripheral neuropathy, damage to nerve tissue in the tissue of extremities (like fingers and toes). This damage is caused by at least four mechanisms that we're currently aware of; one of these is related to the control of the microvasculature, where oxygen is delivered directly to the tissues.

Prorenin, the substance described in the abstract, is the precursor of renin, a chemical that normally helps the body save water but can cause blood vessel constriction if too active. An overactive renin system is a common, worrisome complication of diabetes; too much prorenin (and thus too much renin) leads to the microvasculature closing up. Less blood is delivered to the tissues and nerves, which die as a result: peripheral neuropathy.

Laughter, apparently, causes the blood levels of prorenin in diabetic patients to drop: that should lead to the opposite of the disease process described above. Additionally, the receptor for prorenin was up-regulated by laughter therapy (more receptors were available in cells to respond to prorenin; this means that prorenin receptors are able to work normally with less prorenin in the bloodstream, bringing the whole system closer to the healthy level--note that no change in gene expression occurred in the healthy test subjects).

This is not the first incidence of laughter therapy having a positive effect on diabetes-related complications. Other studies have found that laughter therapy moderates blood glucose levels, and that laughter therapy moderates levels of other renin-related compounds that contribute to peripheral neuropathy.