Posted on 07/24/2006 11:32:15 PM PDT by neverdem
Diabetes appears to be written into some people's genes, but with the right diet and exercise, the disease may never surface, according to a new study.
Nearly 1 in 10 U.S. adults age 20 and older have diabetes, a condition in which the body cannot properly regulate blood glucose levels, leading to organ disease and other complications. Type 2 diabetes accounts for 90% to 95% of all diabetes cases, and over the past 6 years, researchers have linked a handful of genes to the disease. Most recently a team at deCode Genetics in Reykjavik, Iceland, found that individuals with one copy of a variant of a gene called TCF7L2 were 45% more likely to develop type 2 diabetes than individuals without the variant; people with two copies of the variant were 141% more susceptible (ScienceNOW, 17 January). Still, such results have proven hard to replicate.
The new study confirms the variant's role in diabetes, although the findings came about somewhat fortuitously. In 1999, researchers based at 27 centers across the U.S. launched a clinical trial to see whether individuals prone to type 2 diabetes could reduce their chances of developing the disease by adopting a healthy lifestyle. In all, 3234 people aged 25 or older participated. All were overweight and had impaired glucose tolerance. Minorities, who are disproportionately at high risk for diabetes, made up nearly half of the volunteers. After 3 years, the team found that individuals on a low-calorie diet who walked 30 minutes a day, 5 days a week were 58% less likely to develop type 2 diabetes than individuals who maintained their current lifestyle.
Once the deCode study came out, the multicenter group decided to reanalyze its data with the TCF7L2 variant in mind. The researchers found that participants in the control group with two copies of the variant were 80% more likely to develop the disease than those without the variant. (The authors say the larger and more diverse patient sample in the trial may explain why its numbers don't match up with deCode's). In the lifestyle modification group, however, even individuals with two copies of the variant were no more likely to develop type 2 diabetes than participants without the variant, the team reports 20 July in the New England Journal of Medicine. "It's a very hopeful message," says lead author and endocrinologist Jose Florez of Massachusetts General Hospital in Boston.
Endocrinologist Robert Rizza of the Mayo Clinic in Rochester, Minnesota, welcomes the verification of the deCode study, praising the size of the multicenter trial.
TCF7L2 Polymorphisms and Progression to Diabetes in the Diabetes Prevention Program NEJM title and linked abstract
Conclusions Common variants in TCF7L2 seem to be associated with an increased risk of diabetes among persons with impaired glucose tolerance. The risk-conferring genotypes in TCF7L2 are associated with impaired beta-cell function but not with insulin resistance. (ClinicalTrials.gov number, NCT00004992 [ClinicalTrials.gov] .)
ping
i.e being fat and lazy is more likely to kill you.
wow a stunning breakthrough in medical research wonder how much the study cost taxpayers?
bump
how "low" is a low-calorie diet?
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