Health for life

Research funded by the National Institutes of Health and the Howard Hughes Medical Institute, and appearing in this months online issue of Nature Medicine, has shed light on why women in one study who took Avandia (rosiglitazone) had decreased bone density. (See our post from earlier this year: Questions Surrounding Avandia and its Effect on Bone.)

Bone is not the static organ many people think. Its constantly being ormed. Cells called osteoclasts break down bone while cells called osteoblasts lay down new bone.

These researchers found that mice given the PPAR-gamma agonist Avandia (Avandia is a thiazolidinedione, a class of insulin-sensitizing drugs under which Actos also falls) had increased activity of their osteoclasts, leading researchers to speculate:

"These findings have potential clinical implications, as they suggest that long-term rosiglitazone usage in the treatment of type 2 diabetes and insulin resistance may cause osteoporosis, owing to a combination of decreased bone formation and increased bone resorption."

If more studies support this link, it may necessitate screening patients for osteoporosis before starting or continuing them on these drugs.
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Nature Medicine abstract:
PPAR-gamma Regulates osteoclastogenesis in Mice

News summaries:
Diabetes Drug Link To Weak Bones
Diabetes Drug May Increase Bone Thinning

A gender-bending chemical found in food packaging is linked to breathing problems in young babies, researchers have found.
A study showed pregnant mothers with the highest levels of bisphenol A in  their bodies were twice as likely to have babies who suffer from wheezing in their first six months.
Wheezing in babies can be a symptom of lung damage, asthma, bronchitis, allergies or an infection.
Bisphenol A, or BPA, which is used to harden plastics, is one of the world’s most widely manufactured chemicals and can be found in dozens of everyday items including baby bottles, CD cases and food and drink packaging.


If you use water bottles or plastic of any kind (#3, #7, etc), conventionally packed products of any kind or cans and insulated cartons of any kind, chances are you have been exposed to BPA.

Human studies have found BPA in many tissues and fluids, including urine, blood, breast milk, the amniotic fluid of pregnant women and the antral fluid of mature follicles. A national survey conducted by the federal Centers for Disease Control and Prevention in 2003-2004 found BPA in 93 percent of the 2,517 people (age 6 and up) who were tested.
Because the chemical mimics oestrogen, many scientists believe it interferes with the way hormones are processed by the body.

Previous research from North Carolina State University and the National Institute of Environmental Health Sciences (NIEHS) showed significant reproductive health effects in rats that have been exposed to bisphenol-A (BPA) at levels equivalent to or below the dose that has been thought not to produce any adverse effects.
Although several animal  studies have shown it to be safe, others have linked Bisphenol A to breast cancer, liver damage, obesity, diabetes and fertility problems.
The latest U.S. study looked  at the BPA levels of 367 pregnant women, with researchers at  Penn State College of Medicine measuring levels of the chemical in expectant mothers in the 16th and 26th week of pregnancy. 
They found 99 per cent of women had measurable levels of the chemical in their bodies – and those with the highest levels in their 16th week were twice as likely to have babies who wheezed at six months old than women with the lowest levels.
However, the study also found that high concentrations of BPA at 26 weeks and at birth were not connected to the condition.
Some experts suggest exposure to hormone-disrupting chemicals causes the most harm during a crucial window of development early on in pregnancy, and believe women of child-bearing age should avoid products containing BPA.
Elizabeth Salter-Green, director of the Chemicals, Health and Environment Monitoring Trust, said: ‘This new research adds further weight to the  need to reduce our exposure to this chemical, particularly  pregnant women.
It is the foetus developing in utero that is most vulnerable to BPA exposures.’
Last year Denmark became the first country in the EU to ban BPA in packaging for food and drink aimed at under-threes, while the EU itself voted to ban it from baby bottles  last year. Canada and three  U.S. states have also introduced restrictions.
Adam J. Spanier, lead author of the study, which was presented at a conference in the U.S. yesterday, called for more research into BPA

Researchers from New England found that men who slept either less than 6 hours, or greater than 8 hours, increased their risk for type 2 diabetes. That risk remained after adjustments were made for age, hypertension, smoking status, self-rated health status, education, and waist circumference.

These results suggest that even though you have a handle on your weight, blood pressure and smoking, you may still court a diagnosis of diabetes if your sleep is consistently short-changed, or over-indulged.

The study included 1564, primarily white men, aged 40 to 70, who were enrolled in the Massachusetts Male Aging Study (MMAS), and who did not have diabetes at baseline. The men were followed for up to 15 years. Similar, although less marked results were found in women who partook in the Nurses Health Study.

The study appears in the March 2006 issue of Diabetes Care.

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For the MMAS study:
Sleep Duration as a Risk Factor for the Development of Type 2 Diabetes

For a summary of the MMAS study:
Diabetes Risk Raised By Too Much Or Too Little Sleep

For the Nurses Health Study:
A Prospective Study of Self-Reported Sleep Duration and Incident Diabetes in Women