Public Health

Diabetes risk gene may be inherited from Neanderthals

 

A gene variant that increases the risk of diabetes in Latin Americans may have been inherited from Neanderthals, a new study has found.

The gene variant was detected in a large genome-wide association study (GWAS) of more than 8,000 Mexicans and other Latin Americans.

People who carry the higher risk version of the gene are 25 per cent more likely to have diabetes than those who do not, and people who inherited copies from both parents are 50 per cent more likely to have diabetes, researchers found.

The higher risk form of the gene – named SLC16A11 – has been found in up to half of people with recent Native American ancestry, including Latin Americans, ‘BBC News’ reported.

The variant is found in about 20 per cent of East Asians and is rare in populations from Europe and Africa.

The elevated frequency of this risk gene in Latin Americans could account for as much as 20 per cent of the populations’ increased prevalence of type 2 diabetes – the origins of which are not well understood.

“To date, genetic studies have largely used samples from people of European or Asian ancestry, which makes it possible to miss culprit genes that are altered at different frequencies in other populations,” said co-corresponding author Jose Florez, a Broad associate member, an associate professor of medicine at Harvard Medical School and an Assistant Physician in the Diabetes Unit and the Center for Human Genetic Research at the Massachusetts General Hospital.

“By expanding our search to include samples from Mexico and Latin America, we’ve found one of the strongest genetic risk factors discovered to date, which could illuminate new pathways to target with drugs and a deeper understanding of the disease,” Florez said.

In the study published in the journal Nature, researchers conducted genomic analyses, in collaboration with Svante Paabo of the Max Planck Institute for Evolutionary Anthropology, and discovered that the SLC16A11 sequence associated with risk of type 2 diabetes is found in a newly sequenced Neanderthal genome.

Source: Indian Express

New genetic clues for rheumatoid arthritis ‘cure’

An international team of researchers has found more than 40 new areas in DNA that increase the risk of rheumatoid arthritis.

The work is the largest genetic study ever carried out, involving nearly 30,000 patients.

The investigators believe new drugs could be developed to target these areas that could one day provide a cure for the disease.

The findings are published in the Journal Nature.

The research team compared the DNA of arthritis patients with those without the disease and found 42 ‘faulty’ areas that were linked with the disease. The hope is that drugs can be developed to compensate for these faults.

The lead researcher Professor Robert Plenge of Harvard Medical School found that one of these areas produced a weakness that was treated by an existing drug that was developed by trial and error, rather than specifically made to correct the genetic problem.

This finding, he says, shows such discoveries could be used to design new drugs.

“What this offers in the future is an opportunity to use genetics to discover new medicines for complex diseases like rheumatoid arthritis to treat or even cure the disease,” he said.

Complex diseases
Some have argued identifying genetic weak areas for complex diseases – known as single nucleotide polymorphisms (SNPs) – is not useful. There is little or no evidence, they argue, that “silencing the SNPs” with drugs will relieve any symptoms.

But Dr Plenge says the fact that he has found an established drug that treats the symptoms that arise from a particular SNP for rheumatoid arthritis validates this genetic approach.

“It offers tremendous potential. This approach could be used to identify drug targets for complex diseases, nut just rheumatoid arthritis, but diabetes, Alzheimer’s and coronary heart disease”

Fast track
The study also found SNPs in the rheumatoid arthritis patients that also occur in patients with types of blood cancer.

According to Prof Jane Worthington, director of the centre for genetics in Manchester, this observation suggests that drugs that are being used to treat the cancer could be effective against rheumatoid arthritis and so should be fast tracked into clinical trials.

“There are already therapies that have been designed in the cancer field that might open up new opportunities for retargeting drugs,” she told BBC News.

“It might allow us a straightforward way to add therapies we have to treat patients with rheumatoid arthritis”.

Source: escience

Diabetes patients unaware of vision loss

Diabetes commonly causes DME, which is a thickening of the eye’s retina. That change can be detected in an eye exam that includes dilation of the pupils. Left untreated, DME is likely to cause progressive vision loss.

Degeneration of the retina in people with diabetes, known as diabetic retinopathy – which is often caused by DME – is the leading cause of blindness in the U.S., Bressler and his colleagues write in the journal JAMA Opthalmology.

Many U.S. medical authorities recommend annual eye checks for diabetics to monitor early signs of vision problems, but many people with diabetes do not get the proper type or frequency of eye care

The survey data Bressler’s team used included patient questionnaires and physical examinations, so people with vision loss could be identified even if they themselves were unaware of the changes in their sight.

The researchers considered a subset of 800 people from the survey who reported having diabetes, which affects 25.8 million people in the U.S., according to the Centers for Disease Control and Prevention.

Of the 800 self-reported diabetics, the physical exam confirmed that 238 had diabetic retinopathy without DME and 48 had DME.

Some 60 percent of those with DME said they had undergone an eye exam with pupil dilation within the past year. But only 45 percent said their doctor told them about the changes in their eyes.

Physician and patient behavior seem not to have changed in recent years, despite wonderful new achievements in potential treatments for diabetic eye problems, Dr. Lee Jampol told Reuters Health.

A professor of ophthalmology who studies diabetes and vision at Northwestern University in Chicago, Jampol was not involved with the new estimate.

“This study is very important as it shows that many diabetics are not aware of potential or actual real risk to their eyesight from diabetic retinopathy,” Jampol said.

Physicians and patients need to be more aware of the vision risks involved in diabetes and insist on yearly visits to the ophthalmologist, he said.

Treatment for DMA “typically involves injections of biologics into the middle cavity of the eye that in most cases cause resolution of the swelling with prevention of vision loss in about 90 to 95 percent of cases, and improvement in vision in about 50 percent of cases when the edema involves the center of the retina and is causing vision impairment,” Bressler said.

Patients tend to need about nine injections in the first year with a couple of additional shots over the next two years, and may require laser surgery as well, which can cause the price to vary quite a bit, he said.

“Everyone with diabetes should be referred to an appropriate health care provider who can evaluate the retina for DME or diabetic retinopathy, even in the absence of symptoms, periodically, so that complications which can be treated to prevent vision impairment and blindness can be done,” Bressler said.

Source:

Hong Kong confirms first death from H7N9 bird flu

 

An 80-year-old man infected with the H7N9 bird flu virus has died in Hong Kong, the government said on Thursday, in the first such death in the city after the virus surfaced in early December.

The man, the second person in Hong Kong to be diagnosed with the virus strain, lived in the southern Chinese city of Shenzhen and had eaten poultry there, media reported.

The H7N9 strain was first reported in humans in February in mainland China, and has infected at least 139 people in China, Taiwan and Hong Kong, killing more than 40.

Experts say there is no evidence of any easy or sustained human-to-human transmission of H7N9, and so far all people who came into contact with the man had tested negative for the strain, authorities said.

Source: Reuters

National Cancer Institute to be set up in Haryana

National-Cancer-Institute222The Union Cabinet on Thursday approved setting up of a Rs 2000-crore National Cancer Institute (NCI), which will be housed in an upcoming campus of the All India Institute of Medical Sciences at Jhajjar, Haryana.

To be completed by 2018, the NCI seeks to plug the gap in offering cancer treatment facilities in the public sector including specialised tertiary care.

Cancer has emerged as a major public health concern in India, where every year 11 lakhs new cases are diagnosed with a mortality of 5.5 lakhs per year.

In 2013, an estimated 10,86,783 new cancer cases were reported and the numbers are slated to rise to 1148692 in 2015 — a jump of over 5.5 per cent in two years. Tobacco remains the most prominent disease causing factor.

The data, collated by the Indian Council of Medical Research, however, is not exhaustive as it does not have inputs from 25 regional cancer centres and populous states like Bihar and Utttar Pradesh.

Males have higher occurrence of cancers of lung, mouth, oesophagus and stomach. Cancers of tongue, rectum, liver, lung, prostate, brain, non-Hodgkin’s lymphoma and a type of leukaemia have shown statistically significant increase. Cancers of uterine cervix and gall bladder too is fairly common.

But cancer treatment facilities in India are inadequate, compared to the World Health Organisation norms that requires one radiotherapy machine per million population. India currently has 0.41 machines per million population.

The Rs 2,035 crore institute will operate on the lines of National Cancer Institute, USA and DKFZ, Germany as a nodal center for indigenous research as well as preventive and curative aspects of cancer care.

In addition, the institute aims to conduct research on cancers that are more specific to India such as tobacco related cancers, cancer of the uterine cervix, gall bladder cancer and liver cancers.

The focus will be on understanding, analysing the cause and genesis of the above cancers.
The NCI will have 710 beds for different facilities like surgical oncology, radiation oncology, medical oncology, anaesthesia and palliative care and nuclear medicine.

It will have a tissue repository which is the first of its kind in India, according to a press statement issued at the end of the Cabinet meeting.

Besides the cancer institute, the second campus of AIIMS will also have a National Centre for Heart Diseases along with a full fledged hospital for which the Haryana government had provided 300 acres of land.

Source: Deccan herald

Breast-feeding longer than six months tied to better cognitive development

Breast-feeding’s benefits have been backed by yet another study, the latest finding kids who were breast-fed for more than six months scored the highest on cognitive, language and motor development tests as toddler.

Earlier research tied breast-feeding to better thinking and memory skills. But how it’s related to language skills and movement and coordination had been less clear.

The new study, out of Greece, doesn’t prove breast-feeding is responsible for better development, but it shows a strong association, researchers said.

Most evidence “pretty clearly shows there are significant medical benefits of breast-feeding,” Dr. Dimitri Christakis, professor of pediatrics at the University of Washington and director of the Center for Child Health, Behavior and Development at Seattle Children’s Research Institute, told Reuters Health in an email.

“I think that the evidence is now of sufficient quality that we can close the book on these benefits and focus instead on how do we succeed in promoting breast-feeding because all of the studies, including this one, that have looked at it have found a linear relationship, which is to say that the benefits accrue with each additional month that a child is breast-fed,” added Christakis, who was not involved in the study.

In the U.S., about 77 percent of new moms breast-feed their babies, according to an August study from the Centers for Disease Control and Prevention (CDC). Almost half follow the American Academy of Pediatrics’ recommendation of breast-feeding exclusively for first six months of a newborn’s life. Moms are also recommended to provide supplemental breast milk until a child is aged 1 year old or older.

The World Health Organization recommends breast-feeding even longer with complementary foods through age 2 and beyond.

But a March 2013 study found 40 percent of parents introduce solid foods too soon, before a baby turns 4 months old.

Given these rates, health officials often urge longer breast-feeding because it may protect against gastrointestinal tract infections, diabetes, respiratory infections, asthma and obesity, although one recent study did not find protections against childhood obesity. Moms have also been found to be less likely to develop breast and ovarian cancer if they breast-fed.

For the new study, Dr. Leda Chatzi from the University of Crete and her colleagues used data from a long-term study of 540 mothers and their kids.

When the babies were nine months old, researchers asked moms when they started breast-feeding and how long they breast-fed. They updated the information when the children were 18 months old. Psychologists also tested children’s cognitive abilities, language skills and motor development at 18 months.

About 89 percent of the babies were ever breast-fed. Of those, 13 percent were breast-fed for less than one month, 52 percent for between one and six months, and 35 percent for longer than six months.

Children who were breast-fed for any amount of time scored higher on the cognitive, receptive communication and fine motor portions of the test than children who weren’t breast-fed.

Scores on the cognitive, receptive and expressive communication and fine motor sections were highest among children who were breast-fed for more than six months, the researchers reported in the Journal of Epidemiology and Community Health.

For instance, on cognitive assessments with a normal score of 100, toddlers who were never breast-fed scored about a 97, on average. Kids who were breast-fed for more than six months scored a 104.

Chatzi and her colleagues expected to see more breast-feeding than they did.

“We were surprised by the fact that breast-feeding levels in Greece remain low, even though there is an ongoing effort by the Greek State to promote breast-feeding practices,” Chatzi told Reuters Health in an email.

“One of the reasons we see such a big drop off in the United States and elsewhere around four months is because women return to work,” Christakis said.

“The real challenge we have is with sustaining breast-feeding,” he said. “I believe very strongly that we need a public health approach to doing so because these are public health issues – improving child cognition and improving in this case as they showed a child’s physical development, benefits society as a whole and society has to support women achieving that goal.”

“We need to have baby-friendly work places that help women continue to either breast-feed or pump when they return to work,” Christakis said. “There’s that African proverb, ‘it takes a village to raise a child,'” he said. “It takes a village to breast-feed a child as well, and all sectors have to contribute.”

Source: Reuters

Flu vaccine prevented 6.6 million illnesses last year, says CDC

According to the Centre for Disease Control and Prevention (CDC), flu vaccines prevented 6.6 million illnesses and 79,000 hospitalizations last year. Health officials urge people to get flu shots to prepare for upcoming “peak” months of this flu season.

Federal health officials are urging all Americans six months and older to get the flu vaccine in preparation for this year’s flu season, after evidence showed that the vaccine protected more people against the disease last year.

Last year’s flu season was more severe than recent seasons, according to findings by the Center for Disease Control and Prevention. The season started earlier than expected, causing 381,000 people to become hospitalized and 169 children to die from the flu last year.

There is good news, however. Although the virus impacted many lives, the flu vaccine also prevented millions more from becoming ill.
“We estimate that during last year’s flu season, flu vaccination prevented 6.6 million people from getting sick with flu, 3.2 million from going to see a doctor and at least 79,000 hospitalizations,” Center for Disease Control and Prevention Director Dr. Tom Frieden said in a CNN article Thursday, calling the findings on the flu vaccine and protection “eye-opening”

Although Friden explained the importance of getting vaccinated, less than half of Americans — 40 percent—have gotten the flu shot this year. To put the findings by health officials into perspective, if 70 percent of Americans had gotten the flu vaccine last year, another 4.4 million cases of flu and 30,000 hospitalizations would have been prevented. As the flu season begins to pick up across the country, especially in some Southeastern states, Frieden and other health officials now use the data to urge people to get vaccinated.

“We know that it will increase in the coming weeks and months, but we cannot predict where and when and how severe this year’s flu season will be,” Frieden stated in an article for WebMD. “What we can predict is that the best way you can protect yourself against flu is to get a flu vaccine. “It’s not too late to get vaccinated.

CDC’s Center for Global Health Director Dr. Anne Schuchat also spoke of the importance of getting vaccinated as soon as possible, noting that flu season typically peaks between January and March. She also explained that it was particularly important for children to get the flu shot.

“Already, three children have died this year from the flu,” Shuchat said in an article for CNN. “We hate to see anyone die from the flu, but particularly children. I really urge parents to make sure their children are vaccinated.”

Source: digital journal

Report Warns Future Smoking Epidemic Among African Youth

A new report from the American Cancer Society warned that Africa will face a severe health threat from the fast-growing increase in tobacco use.  The report combines African smoking rates and cigarette consumption with population trends, and found that without aggressive intervention, the continent will experience a significant increase in smoking in the near future.

The report, “Tobacco Use in Africa: Tobacco Control through Prevention,” reveals that Africa as a region has the smallest number of smokers and smallest rate of tobacco use in the world.  About two percent of all cigarettes are consumed by smokers in Africa, but they make up about six percent of the world’s smokers.

While the numbers are small for now, Evan Blecher, a Cape Town, South Africa based senior economist for the American Cancer Society said these small numbers also provide the greatest for growth.

“That means along with it will come an increase among tobacco-related, smoking-related diseases in an environment where health systems are already significantly over-stretched because of infectious diseases like malaria and HIV,” said Blecher.

While adult smoking among both among men and women is low in Africa, he pointed out that’s not the case with youth.

“We found that African children smoke at comparable levels, and sometimes even higher than other developing regions of the world, particularly Asia.  What’s driving this is unclear, but it must be because of significantly more aggressive tactics from the tobacco industry itself.  But, also it’s in an environment where children aren’t protected from advertising, marketing… in the way that they are in places like the United States,” explained Blecher.

In addition he said,–that while smoking rates are lower in Africa than other regions, it doesn’t mean there is no variation in smoking patterns within the continent.

“On the one hand, we’ve got a lot of countries with really low smoking prevalence, like Ghana for instance, or Nigeria,” said Blecher. “And that’s compared to countries of very high smoking prevalence like South Africa or Mauritius, which have prevalence more similar to what we see in the developed world.

“But, what we do know is that smoking is declining in those markets like South Africa and Mauritius, and increasing in markets like Ghana and Nigeria.

“These other markets which have smaller smoking prevalence are more concerning to us because these are places with much larger populations, which creates a situation where we expect both the number of smokers and smoking prevalence to increase dramatically over the next generation or two,” explained the senior economist.

Blecher attributes the decline in smoking in countries such as South Africa and Mauritius to very strict tobacco control policies like advertising bans, smoke free areas, and very aggressive tax policies.

“Tax policies are critically important in environments where incomes are growing rapidly, because as incomes grow, everything becomes cheaper and more affordable, including cigarettes.  So you need for tax policies to be able to ensure that tobacco products are not becoming more affordable.  So in a country like South Africa where we’ve seen tax rates increase dramatically over the last 20 years–we’ve also seen smoking prevalence plummet.  Twenty years ago, 33 percent of South African adults smoked, and nowadays only 20 percent of them smoke.  It’s a result of deliberate action, rather than luck,” said Blecher.

There is a broader movement in Africa towards comprehensive tobacco control policies like advertising bans and smoke free areas, be said, but these efforts are not enough.

“Tax policy is something that hasn’t really been pursued by African governments with respect to tobacco, partly because the tax systems aren’t as developed as they are in places like South Africa and Mauritius.  So the technical capacity to implement, enforce and administer tax policies is just not where it needs to be at the moment,” stated Blecher.

In addition, he said more needs to be done to educate Africans on the dangers of smoking.  While most Americans are aware of the risk of disease and even death caused by smoking, the idea that smoking is harmful is mostly not known in Africa, especially in rural areas.

As more African countries pursue tobacco control policies, Blecher said people will become more knowledgeable about the harmful effects of smoking. It is not by accident that people in the United States are aware of the dangers of smoking, it is through deliberate action, he said.

Source: Voice Of America

 

Tongue controller for the paralyzed offers greater independence

In an advance that promises to improve the lives of the more than 250,000 people in the United States who are paralyzed from the neck down, researchers announced on Wednesday that they have developed a wireless device that operates specially rigged chairs by means of a tiny titanium barbell pierced through the tongue.

Merely by moving their tongues left or right across their mouths, essentially using it as a joystick, paralyzed patients have been able to move their motorized wheelchairs, as well as computer cursors. Tapping tongue against cheek, quickly or slowly, controls the chair’s speed.

The advance “is more than just a wheelchair control,” said Jason Disanto, 39, who has been paralyzed from the neck down since a 2009 diving accident and tested the device. “It’s an independence system.”

The innovation is especially meaningful for the most seriously paralyzed. Tetraplegics cannot use a joystick to operate their wheelchairs, as people with less severe paralysis can, and in many cases cannot even use voice commands: their voices are often so weak that recognition systems work poorly or not at all.

Even more advanced assistive technologies fall short. Brain-computer interfaces (BCIs), which translate brain waves from the scalp into electrical signals that move a motorized wheelchair or computer cursor, require intense concentration, have slow response times and are vulnerable to electronic interference. The implantable versions are more reliable but can damage brain tissue.

The most popular technology for operating a motorized wheelchair, called sip-and-puff devices and based on inhaling or exhaling into a tube, offers only four commands – forward, back, left and right—and is also slow and cumbersome.

Way faster, way more agency

Engineer Maysam Ghovanloo of the Georgia Institute of Technology in Atlanta thought he could do better. About five years ago he and his colleagues began developing the tongue-based system. An early version used magnets glued to the tongue, but they fell off. Dr Anne Laumann of the Feinberg School of Medicine at Northwestern University, a co-author of the new paper, had an idea: use piercing to anchor the magnets in place.

The device they came up with is a small magnetic barbell, which creates a magnetic field in the mouth. When users flick their tongues, it alters that field. The change is picked up by four small sensors on a headset with twin extensions curving around the cheeks, and relayed wirelessly to a smart phone, computer or iPod. The software translates the signals and sends them to a powered wheelchair or computer.

For the new study, published in Science Translational Medicine, Ghovanloo and his team tested the tongue system on 11 tetraplegia patients from rehabilitation centers in Chicago and Atlanta and 23 able-bodied volunteers who already wore tongue jewelry.

After just 30 minutes of training, everyone was able to move a computer cursor, clicking on targets on a laptop screen, playing video games and dialing phone numbers. Accuracy and speed improved with practice, even though subjects used the system only one day a week. After six weeks the tetraplegics were, on average, three times faster with the tongue system than with sip-and-puff, which six of the 11 (including Disanto) had been using. It was equally accurate.

Using only tongue movements, the volunteers also navigated a powered wheelchair through a 50-meter-long course with 13 turns, 24 obstacles and occasional alarms signaling “Stop! Emergency!” Here, too, on average the 11 tetraplegics drove the course three times faster with the tongue system than with sip-and-puff, and just as accurately.

“The learning was very, very fast,” Ghovanloo said. “There was a huge improvement in performance from the first session to the second.”

To Disanto, an electrical engineer, the appeal of the system is aesthetic as well as functional.

“With all the equipment that’s in my face” with the sip-and-puff system, “people saw that and not me,” he said.

The tongue system is a vast improvement, but he encouraged the researchers to go even further, and they have: they are developing a version that dispenses with the headset and instead fits inside the mouth, like a retainer.

The tongue system’s ability to operate numerous devices also promises more agency, Disanto said. He currently uses a voice-recognition system and a “head mouse” (an optical sensor that translates head movements into cursor movements) to use his computer, “but this is going to allow people like me to use one system instead of multiple ones,” he said. “I’ll be able to drive my wheelchair and connect to my computer seamlessly, and eventually connect to home devices, using it to work lights, curtains, TV and heat. I’ll be more independent.”

Those home systems already exist, with many smartphones offering apps that control home appliances, lights and heating-and-cooling systems.

“This is another example of how the field of rehab engineering and assistive devices is continuously evolving and benefiting from incorporating the emerging new technologies,” said Dr Daofen Chen, program director at the National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health.

The researchers plan to test the tongue system “using Atlanta as our laboratory,” said Joy Bruce, manager of spinal cord injury at the Shepherd Center, a rehab center in Atlanta where the study was conducted. “We’ll see if patients can use it to navigate in the community – taking the bus, going to work and doing other things they haven’t been able to.”

Ghovanloo’s startup company, Bionic Sciences, is working with Georgia Tech to commercialize the barbell device. The $1 million he got from the 2009 economic stimulus bill is gone, and government science funding has plummeted, so Georgia Tech is setting up a website and planning to use social media to raise money. If Ghovanloo gets the funds, he hopes to test the system in the streets of Atlanta next year

Source: GMA News

Link Between Diabetes and Osteoporosis

What is the link between diabetes (both type 1 and type 2) and bone mineral density/osteoporosis in postmenopausal women?

Ashraf Kardousha, MD

Adult women with type 1 diabetes have relatively decreased bone mass, increased fracture risk, and delayed fracture healing compared with healthy women without diabetes. In addition, researchers have show that the biomechanical integrity of diabetic bone may be impaired. However, patients with type 2 diabetes usually do not have a decreased bone mass and, in fact, may be relatively protected from osteoporosis.

Early onset of diabetes, in particular, is associated with reduced bone density, and patients with type 1 diabetes show evidence of low bone mass following adolescence. This finding may explain the higher incidence of hip fracture reported for postmenopausal women with type 1 diabetes. The osteopenia associated with diabetes appears to be associated with a decreased bone turnover associated with impaired osteoblastic maturation and function. This is reflected in a decrease in serum markers of bone formation, such as osteocalcin. Bone resorption and formation are usually tightly coupled, but this has not been well studied in patients with diabetes. The few available studies suggest that the rate of bone resorption in diabetes is normal and therefore elevated relative to the decreased rate of bone formation. Evidence that there are significant alterations in serum parathyroid hormone levels or function is lacking. Boullion and colleagues[3] showed reduced serum levels of insulin-like growth factor 1 (IGF-1), osteocalcin, and bone-specific alkaline phosphatase in adolescents with type 1 diabetes, but not all markers were reduced in adults. Studies in diabetic animals show that there is enhanced apoptosis of osteoblastic cells and, although there is sufficient production of immature mesenchymal tissue, there is failure to adequately express genes that regulate osteoblast differentiation.

In contrast to findings in type 1 diabetes, patients with type 2 diabetes do not have low bone mass and may be relatively protected from osteoporosis. It is not known whether adolescents with type 2 diabetes will demonstrate a low bone mass. However, it is hypothesized that this is unlikely since most of these children are also obese. Our own studies in type 2 diabetes show that, while bone turnover is suppressed in patients in poor glycemic control, bone metabolism returns to normal with normalization of glycemia. Recent studies suggest that a negative correlation may exist between levels of osteocalcin and glycemic control. It is not clear if hyperglycemia per se is responsible or if the associated absolute or relative insulin deficiency might be involved. Bone cells have receptors for both insulin and IGF-1, and in vitro insulin has been shown to increase proliferation and function of osteoblasts. In animals, insulin deficiency suppresses osteoblastic activity. Levels of IGF-1 tend to be low in patients with poorly controlled diabetes mellitus and improve with improving glycemic control. A correlation between IGF-1 and osteocalcin levels has been shown for both type 1 and type 2 patients, and IGF-1 has been shown to stimulate osteoblastic differentiation, maturation, and function.

The difference in bone loss between the 2 forms of diabetes is often attributed to the degree of adiposity. Increased body weight has been associated with an increased bone mass in both normal and diabetic individuals, and may account for the relative protection seen in patients with type 2 disease. In addition to the mechanical effects of increased weight bearing, many women who are obese and relatively insulin-resistant have elevated levels of androgens, which may contribute to bone maintenance. In addition, it is not clear whether bone cells are insulin-resistant, similar to other tissues in type 2 diabetes. If not, then high circulating insulin levels could be expected to increase osteoblast function and have a beneficial effect on bone mass. It has been suggested that hyperinsulinemia may be partially responsible for the association of both diabetes and obesity with a higher BMD in women. It should be noted that there is some evidence of higher fracture risk in type 2 patients despite normal bone mass. Other factors, such as neuropathy and impaired vision, may contribute to the increased fracture risk.

Type 1 diabetes does appear to be a significant risk factor for osteoporosis. Currently, we recommend that patients with type 1 diabetes be monitored more carefully than persons without diabetes or those with type 2 disease, and should be encouraged to consume a diet high in both calcium (at least 1200 mg/day) and vitamin D (400-600 IU/day). It appears that intensive insulin therapy and a stable body weight in patients with type 1 diabetes is important in preventing bone loss. Patients with diabetes and osteopenia or osteoporosis have successfully been treated with bisphosphonates, with similar bone density results as patients without diabetes. Due to impaired osteoblast function, patients with diabetes might be expected to benefit more from bone anabolic (rather than anti-resorptive) medications, but this has yet to be demonstrated in a clinical trial.

For patients with type 2 diabetes who are in good metabolic control, prevention and treatment of osteoporosis can be approached in a manner similar to patients without diabetes as outlined in the National Osteoporosis Foundation (NOF 2003) physician guidelines.

Source: Med Scape