Category: Diabetes 101

A study recently published in the journal “Cancer” has discovered that therapy with the drug tamoxifen — an oral medication used in women with breast cancer — is linked to a significant increase in development of diabetes in older survivors of breast cancer.

The study was headed by Lorraine L. Lipscombe, M.D., with the Women’s College Hospital in Toronto. Dr. Lipscombe’s team studied 14,360 women over the age of 65 who had been diagnosed with early-stage breast cancer and had survived. The women had received treatment for breast cancer with tamoxifen therapy. The study used data collected from 1996 to 2006; the patients who were diagnosed with diabetes through March 31, 2008 were matched with control subjects who had not developed diabetes. The research team adjusted for other risk factors and compared the risk of developing diabetes in participants who received tamoxifen and aromatase inhibitor therapy compared to women who were not treated with those drugs.

According to the study’s findings, 10 percent of the patients received a diagnosis of diabetes over a mean follow-up of 5.2 years. Women who were currently receiving tamoxifen therapy had a significantly higher chance of developing diabetes (1.24 adjusted odds ratio) over women who were not being treated with tamoxifen. Treatment with aromatase inhibitors, on the other hand, was found not to be linked to an increased risk of developing diabetes.

“Current tamoxifen therapy is associated with an increased incidence of diabetes in older breast cancer survivors. These findings suggest that tamoxifen treatment may exacerbate an underlying risk of diabetes in susceptible women,” wrote the authors of the study.

Tamoxifen, marketedd as Nolvadex, Istubal, and Valodex in the U.S., is an orally-administered tablet that disrupts the female body’s production of estrogen, which is known to promote breast cancer in women. Tamoxifen binds to the estrogen receptor proteins, effectively blocking additional binding at the site that would cause cancerous growth. Tamoxifen is approved by the FDA for the treatment of breast cancer and other types of cancer and has been used for over 30 years in the treatment of early-stage breast cancer.

The drug has also been used to reduce the risk of breast cancer in women who are at increased risk of developing the disease. It works by blocking the effects of estrogen on breast cancer cells with estrogen receptor-positive proteins, preventing the growth of the cancerous cells. However, the medication is only useful in treating cancer cells that are specifically estrogen receptor-positive. Doctors must determine whether the tumor will respond to tamoxifen treatment before prescribing the drug.

Tamoxifen therapy is known to be associated with several serious side effects, including stroke, blood clots, uterine cancer, and cataracts. It may also cause symptoms similar to menopause such as hot flashes, irregular menstrual periods, headaches, nausea, and fatigue. Though tamoxifen therapy does cause blood clots or stroke in a small number of women, the chances of developing such complications are similar to those associated with estrogen replacement therapy.

Additional adverse side effects associated with tamoxifen therapy include an increased risk of thromboembolism and fatty liver as well as mental effects such as reduced cognition and degraded memory, though memory loss with tamoxifen therapy is not as severe as with aromatase inhibitor therapy. Tamoxifen has also been associated with reduced libido.

However, not all the side effects of tamoxifen therapy are negative; it is known to improve bone health, especially in women, by inhibiting osteoclasts and preventing osteoporosis.

Doctors and scientists have long known that people with Type 2 diabetes are at an increased risk of developing certain types of cancer. Until recently, the mechanisms behind the link between the two diseases have been unclear to medical professionals.

However, the mystery may finally be solved: researchers with the Harvard Medical School have reported that variations in levels of two different proteins are present in both diabetics and cancer patients. The findings were reported in the journal “Cell.”

The study demonstrated that mice who were engineered to have increased levels of the proteins Lin28a and Lin28b had a lower chance of developing diabetes when they were fed a high-fat diet. In contract, mice who are fed the same diet with those proteins functioning at normal levels are apt to become obese and develop Type 2 diabetes. The two proteins have also been proven to be related to an individual’s risk of developing some types of cancer, underscoring a relationship between cancer and diabetes in the activity of these two proteins.

“This highlights the overlap in the biology of these disorders,” says George Daley, M.D., Ph.D., a researcher who was involved with the study. Daley is also director of Stem Cell Transplantation and head of the Stem Cell Research Program at Children’s Hospital Boston. “It may be the same kinds of metabolic shifts that allow cancer cells to grow are also related to [whole-body] glucose metabolism.” Cancer and diabetes appear to both be caused by certain metabolic processes that may be signified by elevated levels of the two proteins.

“The results were startling,” says Daley. “Previously we had considered these molecules only as regulators of cell growth and cancer. But in these mice we discovered remarkable effects on sugar processing and diabetes.”

Daley commented that these findings have provided scientists with a molecular pathway related to diabetes and cancer that could be used in reducing the risk of those diseases. With new knowledge of the pathway in hand, scientists may be able to develop medications that target the processes and lower the risk of developing diabetes and cancer.

In addition, the findings of the study demonstrate that elevated blood sugar levels associated with diabetes are not the cause of higher rates of cancer, as was once hypothesized. This knowledge allows scientists to focus their research in other directions that may prove more fruitful. Researchers have already conducted many investigations on the link between high blood sugar levels and complications related to diabetes.

While diabetes is associated with an elevated risk of various types of cancer, it’s likely that the link between diabetes and pancreatic cancer is the most-researched one. Since the two diseases affect the same organ, it can be difficult to understand the causes and effects of one disease independently of the other. Other types of cancer that commonly follow diabetes include colorectal, prostate, endometrial, breast, liver, renal cell, and non-Hodgkin’s lymphoma. Previous research commonly stated that the strongest link between diabetes and cancer was probably elevated insulin levels, which cause Type 2 diabetes and which are believed to also promote growth of tumors.

While further research is required before scientists can fully understand the link between the two diseases, previous research has made it clear that diabetes typically precedes cancer, not the other way around.

A large meta-analysis of genetic data has discovered previously unknown genes related to Type 1 diabetes. The new information supplements existing knowledge about the genetic networks responsible for the complex range of processes that cause the disease. Type 1 diabetes affects 200 million people around the world; those diagnosed with the disease must use insulin injections to ensure that their blood sugar levels remain under control. The study was published in the journal “Public Library of Science Genetics,” also known as “PLoS Genetics.”

“Genome-wide association studies, as we used here, have been extremely powerful in identifying gene locations involved in the pathogenesis of complex, common diseases,” said Hakon Hakonarson, M.D., Ph.D., head of the study and director of the Center for Applied Genomics at The Children’s Hospital in Philadelphia, Pennsylvania. Dr. Hakonarson noted that the size of the study provided a large pool of data from which the team could draw conclusions. “The larger the cohort used, the more discoveries we can make, and the more we find intriguing biological pathways offering insight into causes of disease.” said Dr. Hakonarson, who collaborated with Constantine Polychronakos, M.D., the director of Pediatric Endocrinology at McGill University.

Called a “genome-wide association study” (GWAS), the study was a meta-analysis that pooled data from six large, existing databases of information about Type 1 diabetes patients. The six studies together comprised information on about 10,000 individuals with Type 1 diabetes in addition to 17,000 control subjects. Information in the databases included single nucleotide polymorphisms (SNPs — pronounced “snips”), single-base alterations in our genetic code that can tip off scientists to the mutations with which they are associated.

The SNPs themselves do not actually cause mutations; they simply appear in regions of the genetic code associated with mutations and allow for more in-depth DNA sequencing studies that can uncover the genes that do actually cause mutations. Hakonarson and his team have conducted studies over the past four years that found SNPs believed to be related to Type 1 diabetes.

Not only did the meta-analysis reinforce previous findings, but it also identified three new SNPs that are located in regions of the genetic code known to have influence on interactions between proteins, cell signaling activity, and inflammation. “Our study found SNPs that we had not expected to have any connection to type 1 diabetes,” says Hakonarson. “The strongest association among the three SNPs was in the region of the LMO7 gene on chromosome 13. We previously associated another member of the LMO gene family with the childhood cancer neuroblastoma. This gene family plays an important role in protein-protein interactions, but it would not have occurred to anyone that it may be active in type 1 diabetes. GWAS continues to turn up surprising biological associations.”

Hakonarson commented that the team would be conducted future studies intended to sequence entire regions of the genetic code which are related to the SNPs. Such a thorough sequencing would provide a better picture of specific mutations which are responsible for the processes that result in Type 1 diabetes.

SNPs have been used for a variety of functions, from predicting an individual person’s response to certain medications to risk of developing certain diseases to breeding livestock. SNPs are single-nucleotide modifications, meaning that they change a single nucleotide; for example, changing a thymine (T) nucleotide to a cytosine (C) nucleotide. Scientists hope that further research will allow SNPs to be used to discover the exact genes responsible for diseases such as diabetes and cancer.

A study recently conducted by researchers at Glasgow University in Scotland found that men develop Type 2 diabetes faster than women do in terms of weight gain. The study’s findings showed that Type 2 diabetes occurred in men at a lower body mass index (BMI) than it did in women. The research could provide the reasoning behind higher rates of diabetes among men throughout many areas of the world.

The study was headed by Professor Naveed Sattar with the Institute of Cardiovascular and Medical Sciences. According to Dr. Sattar, being obese or overweight is a significant risk factor that makes Type 2 diabetes much more likely. Additional risk factors for the disease include older age, ethnicity, and a genetic predisposition toward diabetes.

Researchers used data from 51,920 men and 43,1367 women from Scotland who had been diagnosed with diabetes. Their findings demonstrated that the mean BMI for males at the time of their diabetes diagnosis was 31.83; meanwhile, the same statistic for females was only 33.69. The difference in mean diagnosis age was more significant at younger ages.

“Previous research has indicated that middle-aged men are at a higher risk of developing diabetes than women and one possible explanation is that men have to gain less weight than women to develop the condition,” said Dr. Sattar. “In other words, men appear to be at higher risk for diabetes,” he continued.

According to Dr. Sattar, human physiology could be partly to blame for the younger age at which men are diagnosed with diabetes. A man carries body fat around the stomach and liver; this distribution could be responsible for men developing diabetes earlier in life than women.

Chronically elevated blood glucose levels, which disrupt the body’s ability to regulate sugar in various parts of the body, cause the development of Type 2 diabetes. The disease is associated with excess stores of fat in certain organs, such as the liver and muscles.

According to the Centers for Disease Control and Prevention, 16 million Americans have diabetes; 55 percent of them are women. Women comprise 58.4 percent of Type 1 diabetics. However, they only comprise 47 percent of individuals with Type 2 diabetes. While more women have Type 1 diabetes, slightly more men have Type 2 diabetes.

Both forms of diabetes still have a significant impact on women’s health. Gestational diabetes — a glucose intolerance first diagnosed during pregnancy — affects about 2-5 percent of all pregnancies. Nearly twice as many women receive a diagnosis of nonketotic hyperosmolar coma than men, and women are diagnosed with hypoglycemia about 1.5 times more than men are. Women are also diagnosed with vision loss due to diabetes more than men in the 40-59 age range, the 60-69 range, the 70-79 range, and the 80 and above range. Doctors hypothesize that women may be diagnosed with vision loss more frequently because their diabetes has a long duration, there may be a smaller percentage of blind men registering as such, and because men’s shorter life spans could result in death before severe vision loss.

Dr. Sattar works in the metabolic medicine group at the BHF Glasgow Cardiovascular Centre, which works to uncover new information about the causes of diabetes and vascular disease as well as the complications associated with those illnesses. The group has conducted physiological studies to determine the cause of diabetes and aims to discover new treatments for the disease.

A recent study suggests that significant accumulation of calcium buildup in coronary arteries could be a signal of an impending heart attack in individuals who have metabolic syndrome and diabetes.

The study analyzed data from 6,600 people age 25 to 84; it was conducted by the UC Irvine Heart Disease Prevention Program.

The findings of the study showed that while 16% of the participants had been diagnosed with diabetes — mostly Type 2 diabetes — an additional 25% of the patients had metabolic syndrome, a series of disorders that is often a precursor to diabetes and heart disease.

“Our study points out that there’s a wide range in risk for cardiovascular consequences seen in persons with metabolic syndrome and diabetes and that screening of coronary calcium by heart scans – and, to a lesser extent, carotid arteries by ultrasound – may be helpful in picking out those most vulnerable,” says Nathan Wong, a professor of medicine at UC Irvine and director of the Heart Disease Prevention Program. Dr. Wong was also senior author on the study.

“Our findings also suggest that individuals with significantly high levels of coronary calcium or carotid wall thickness should receive more aggressive monitoring and treatment for any associated risk factors,” said Dr. Shaista Malik, co-author on the study and a cardiologist at UC Irvine.

The buildup up plaque in the arteries is called atherosclerosis. Such arterial plaque is composed of a variety of substances, including calcium, cholesterol, fat, and other materials found in the bloodstream. In patients with atherosclerosis, plaque hardens over time and causes a narrowing of the arteries that restricts the flow of blood to the organs and elsewhere throughout the body. As plaque buildup can develop in any artery in the human body, it can cause different negative effects depending on which artery is restricted.

The most common effect of calcium buildup in the arteries is coronary heart disease (CHD), the number one killer of adults in the United States. The buildup of plaque in the coronary arteries causes CHD; the narrowing of the arteries means that the heart receives less blood, and increases the likelihood of blood clots forming in the arteries, which can completely block blood flow through an artery. Such blockage of blood flow in the coronary arteries can cause angina — pain in the chest — or even heart attacks.

Some other complications that can arise from the buildup of arterial calcium include carotid artery disease, peripheral arterial disease, and chronic kidney disease.

Atherosclerosis is known to cause heart attacks, strokes, and death. While the exact cause of the buildup is unknown, risk factors such as a lack of exercise, smoking, poor diet, and a family history of heart disease can contribute to the development of atherosclerosis.

Arterial calcium buildup has been previously studied in the Multi-Ethnic Study of Atherosclerosis (MESA), which was funded by the National Heart, Lung, and Blood Institute division of the National Institutes of Health. Previous studies had shown that buildup of arterial calcium was associated with a greater risk of heart disease in Caucasians, but the MESA study conducted in 2007 showed that the same was true of other ethnic groups, including African Americans, Hispanics, and Chinese.

The MESA study analyzed data from 6,814 individuals, both men and women, who had no history of heart disease from coronary calcium. The study followed those individuals for 3.5 years on average.

A recent review of past research has confirmed that individuals with diabetes are at an increased risk of developing colon cancer. However, scientists aren’t sure why the connection exists or what can be done to lower the risk. The findings were reported in the American Journal of Gastroenterology.

Researchers analyzed the results from 14 international studies, finding that on average, individuals with diabetes were 38% more likely to develop colon cancer than those who did not have diabetes.

In addition, diabetic men involved in the study showed a 20% increase in risk of colon cancer over non-diabetic men. However, the results of the study did not prove that diabetes is directly related to the development of colon cancer.

The findings were produced through observational studies, which demonstrated that diabetics were more likely to be diagnosed with colon cancer than non-diabetics. Researchers adjusted for confounding factors such as age, obesity, and smoking in most of the studies, yet the connection between diabetes and cancer remained.

“I think we can make the statement that diabetes is consistently associated with colorectal cancer,” said Dr. Edward Giovannucci, with the Harvard School of Public Health. Dr. Giovannucci was not one of the researchers involved with the study.

“The cause-and-effect aspect is a bit difficult to consider since diabetes is such a complex disease,” continued Dr. Giovannucci. While he believes that the results do likely show a direct connection between diabetes and colon cancer, it’s still uncertain what factor connects the two diseases.

One theory hypothesizes that hormonal imbalances caused by diabetes could be responsible for the growth of cancer cells. Diabetics have elevated levels of the hormone insulin as well as insulin-like growth factors, which are both responsible for the growth of cells. This growth may include cancer cells.

According to Dr. Hiroki Yuhara, head of the study conducted at the University of California Berkeley, patients with diabetes are not currently advised to receive colon cancer screening more often than patients without diabetes. Yuhara says that it’s unclear whether doctors will begin recommending more frequent colon cancer screenings for diabetics.

Most individuals are advised to begin colon cancer tests at the age of 50. Such tests may include sigmoidoscopies, colonoscopies, or tests that check for the presence of blood in the stool. Individuals with risk factors for colon cancer, such as inflammatory bowel disease or family history of the disease, are advised to begin screening earlier in life. Currently, diabetes is not considered cause for recommendation of earlier screenings.

There is also evidence that the link between diabetes and colon cancer may not be as strong as once thought. Last year, researchers at the American Cancer Society published a study which found that among 184,000 older American men, diabetes was associated with a 25% increase in the risk of colon cancer. However, according to the researchers on the study, the risk was modest and was not as severe as previous studies had suggested.

It was also discovered that the link between the two diseases did not exist in women. The ACS researchers thought that the findings of the study could point to improved diabetes control, among women in particular. Better control of blood sugar would lead to reduced insulin levels, which would limit the factor that may be the link between diabetes and colon cancer.

A research team at the John G. Rangos Sr. Research Center at Children’s Hospital of Pittsburgh of UPMC and the University of Pittsburgh School of Medicine has discovered a molecular pathway responsible for regulating management of insulin in the liver as well as the production of new glucose. The team published their findings in the American Diabetes Association’s journal “Diabetes.”

The liver typically stores excess blood glucose as glycogen and releases that energy during periods of fasting, such as sleeping, to ensure that blood sugar levels remain within the proper range. According to H. Henry Dong, Ph.D., head of the study and associate professor of Pediatrics at the Pitt School of Medicine, in individuals with diabetes the liver continues producing glucose even when the patient is supplemented with insulin treatments.

“Scientists have been trying to find the factors that contribute to this liver overproduction of glucose for decades,” says Dr. Dong. “If we can control that pathway, we should be able to help reduce the abnormally high blood sugar levels seen in patients with diabetes.”

Dr. Dong’s research team has been investigating the Forkhead box family of proteins, also known as FOX. This particular study was focused on the protein FOX06. When mice took too much FOX06, they developed symptoms of metabolic syndrome, a series of complications such as elevated blood glucose, increased insulin levels, and impaired glucose tolerance that typically precedes diabetes. Similarly, mice who produced lower levels of FOX06 displayed very low levels of blood glucose when fasting.

“In a normal animal, a glucose injection causes blood sugar level to rise initially and then it goes back to normal range within two hours,” said Dr. Dong. “In animals that made too much FOX06, blood sugar after a glucose injection doesn’t normalize within two hours. They have lost the ability to regulate the level while the liver keeps making unneeded glucose.” The protein appeared to affect the animals’ ability to respond to elevated blood glucose levels properly by using insulin to shuttle it away from the bloodstream.

The research team also conducted tests on human liver cells that confirmed the effects of FOX06 on glucose production.

“These findings strongly suggest that FOX06 has potential to be developed as a therapeutic target,” said Dr. Dong. “If we can inhibit its activity, we can possibly slow the liver’s production of glucose in patients with diabetes and better control blood sugar levels.”

The study received funding from the National Institutes of Health. Co-authors on the study included lead author Dae Hyun Kim, Ph.D., as well as researchers from the Pedatrics and Pathology departments of the University of Pittsburgh.

The University of Pittsburgh is one of the leading academic centers for biomedical research in the U.S., consistently placing in the top 10 recipients for funding from the National Institutes of Health since 1997. The school system’s progress in research and development is primarily headed by the School of Medicine and its affiliates.

The Forkhead box (FOX) family of proteins is a series of transcription factors that play a role in the expression of certain genes related to cell growth, differentiation, longevity, and proliferation. Also known as the winged helix, the family is named after the forkhead box, a sequence of amino acids that form a motif which binds to genetic material (DNA).

A large United States-backed study recently discovered that lowering blood glucose levels in older individuals with diabetes was helpful in preserving brain volume in the patients but did not help in mitigating the effects of memory loss. The findings were published in the journal “Lancet Neurology.”

The ACCORD study has previously shown that aggressive treatment of diabetics in regulating blood sugar levels to be as close to normal as possible does not produce significant positive benefits. The study was stopped in 2008 when it was discovered that patients who received intensive blood glucose-regulating treatment were at a higher risk of death than were patients who received standard treatment.

Researchers recently shifted focus to study the effects on memory of aggressive diabetes management in 3,000 patients age 55 to 80 who had high blood glucose levels and were at high risk of heart disease.

Individuals over 70 with Type 2 diabetes are twice as likely to develop memory problems as those without the disease. Physicians hypothesized that increased blood sugar levels were the culprit, and reducing blood glucose to a normal level would mitigate the chances of memory loss in older Type 2 diabetics.

“We know that people with type 2 diabetes have a much higher risk of dementia and memory loss than people without diabetes,” said Dr. Jeff Williamson, of the Wake Forest Baptist Medical Center in North Carolina. Williamson also participated in the study on diabetes and memory loss. “What we didn’t know was, if you intensively control blood sugar levels in people who have had a history of trouble controlling them, does the added cost and effort to control blood sugar result in a slowed rate of memory loss?”

The group of 3,000 was split into two groups according to the type of treatment they received. One group received typical treatment for diabetics, intended to lower hemoglobin A1c levels from over 7.5% to between 7% and 7.9%. The other group received a more aggressive treatment which sought to reduce hemoglobin A1c levels to that of non-diabetics, about 6%.

Forty months after the beginning of the study, the patients who received aggressive treatment showed significantly more brain volume; however, they did not demonstrate any improvements in memory.

According to Dr. Williamson, it’s unclear whether the increase in brain volume will provide some benefits to the patients later on in their lives. However, since the intensive treatment is associated with increased risk of death and heart disease, the more aggressive treatment is not recommended.

Dr. Williamson says that instead of focusing on reducing hemoglobin A1c levels drastically, diabetics should focus on diet, exercise, and meeting their typical blood sugar requirements rather than spending extra time and energy to reach the hemoglobin A1c levels of non-diabetics.

He also commented that the results demonstrate that individuals who are at risk for diabetes should take steps to improve their health, since medication will not always provide the answer. “For those folks who are gaining weight and living a sedentary lifestyle, this is a warning that medicine is not going to rescue you,” he said.

The majority of the 366 million people worldwide with diabetes have Type 2 diabetes, sometimes called adult onset diabetes. Caused by poor diet, lack of exercise, and linked to obesity, diabetes requires individuals to manage blood sugar levels and can lead to a variety of complications, from loss of vision to nerve damage and heart disease.

Diabetics looking to network with other patients online have a variety of options, including the availability of a doctor to answer questions, who reviews the material posted on the website, and which companies are allowed advertising space on the website.

A recent study of 15 social networking sites for diabetics discovered that the sites use a variety of approaches in terms of funding and the participation of site administrators and doctors in the discussion. The study was reported in the journal “Archives of Internal Medicine.”

“The most interesting thing is that there is so much variability between sites,” said Dr. William Shrank, with Brigham and Women’s Hospital in Boston. The study was headed by Dr. Shrank. “Patients really need to know what their options are when picking sites where they’re going to participate.”

The sites involved in the study allow diabetes patients to communicate with other patients, such as posting questions and responses and interacting on message boards. The sites ranged in size from 3,000 to more than 300,000 members.

While most of the sites do not have doctors available to answer questions or offer feedback, website administrators usually monitor message boards to ensure that the information presented is accurate.

Of the 15 sites studied in the investigation, twelve run advertisements from companies that manufacture diabetes medications, devices such as insulin pumps, or other products. Most of the sites are funded by those advertisements, whether partially or fully. Some sites, such as www.tudiabetes.org and www.diabetes.org (run by the American Diabetes Association), rely on volunteer donations or support from advocacy and research foundations.

David Edelman, the co-founder of Diabetes Daily (www.diabetesdaily.com), says that members on his site are only required to give minimal identifying information so that they do not feel their privacy is at risk. The site boasts about 65,000 registered members.

Both site members and forum moderators are responsible for ensuring that advertisements such as product pitches are removed from the message boards. Additionally, treatments that have not yet received approval cannot be mentioned by name anywhere on the website. Edelman says that the advertisements that do run on the website are only for “legitimate” products. He also noted that receiving sponsorship from a particular company or organization would not make for an “ideal model.” The site receives funding from a variety of sources, such as drug manufacturers and non-profit organizations.

Advertisements are the only commercial interests that Edelman allows on the site. “We have these rules and our values: you can’t give medical advice, you can’t have financial self-interest, you can’t promote your book. We want to try to get commercial influence out of the community,” said Edelman.

Dr. Shrank noted that backing by pharmaceutical companies “may be great,” but he noted that product promotion has been a concern in the past.

Shrank hopes that the research will show patients and doctors that there is a wide range of social networking options available to diabetics and help them choose sites to participate in by displaying the value of such sites. However, he stressed that the study’s intent was not to recommend any particular site over another. The perfect site for each patient will depend on what he or she wants from the experience, says Shrank. “Some patients may feel comfortable in a setting where there is no health professional oversight. Some patients may really want a health professional to answer questions.”

A study published in the September 26 issue of the journal “Archives of Internal Medicine” has demonstrated that diabetics are healthier when they visit their doctors frequently. The patients involved with the study who saw their primary care physicians once every 1 to 2 weeks had a better chance of achieving their clinical goals than patients who saw their doctors less frequently.

Despite the negative implications of elevated levels of LDL cholesterol, blood pressure, and hemoglobin A1c, most diabetics do not meet their target levels for those factors, which are known to be associated with various complications resulting from diabetes. Hemoglobin A1a (or HbA1c) is a test of a diabetic individual’s blood sugar level over an extended period of time — usually six to eight weeks. Normal hemoglobin A1c levels in non-diabetics are between 4 and 6 percent; for most diabetics, the target is 7%.

While there are no established guidelines for how often diabetics should visit their physicians, it is believed that those who interact more frequently with their doctors are quicker to gain control of hemoglobin levels, blood pressure, and LDL cholesterol.

The retrospective cohort study was headed by Fritha Morrisson MPH, with the Division of Endocrinology at Brigham and Women’s Hospital in Boston, Massachusetts. Morrisson’s research team analyzed data 2000 and 2009 for 26,496 patients who had been diagnosed with diabetes. All of the patients had elevated blood pressure, LDL cholesterol, and/or hemoglobin A1c levels; researchers looked for a correlation between frequency of the patients’ visits to their health care providers with the period of time that it took to attain proper control of the three factors.

The patients were divided into groups according to the frequency of visits to their physicians. Patients who were not taking insulin who visited their doctors every 1 to 2 weeks displayed a median time of 4.4 months to attain hemoglobin A1c levels of less than 7%; patients not taking insulin who saw their physicians once every 3 to 6 months showed a median time of 24.9 months to achieve control of those factors. In patients taking insulin, the difference was 10.1 months for the patients who saw their physicians more frequently compared to 52.8 months for patients who recorded less frequent doctor visits.

A multivariate analysis showed that for every doubling of the time between visits with the physician, median time to reaching the target hemoglobin A1c levels increased: patients not taking insulin displayed a 35% increase while patients taking insulin displayed a 17% increase. Blood pressure and LDL cholesterol also showed similar increases as the length of time between doctor visits grew larger.

According to Allan H. Goroll, M.D., MACP, with the Massachusetts General Hospital and Harvard Medical School, the study did have limitations. The retrospective nature of the study was not optimal; a randomized, prospective study would have provided more accurate results. Since the study is retrospective, according to Dr. Goroll, there is no information available about the nature of the doctor visits or the events that triggered changes in patient behavior.

“Understanding how best to deliver… care and change patient behavior, especially in primary care settings, is going to be as important as knowing what care to prescribe,” says Dr. Goroll.

The study was sponsored with grants from the Diabetes Action Research and Education Foundation, the Agency for Healthcare Research and Quality, and the National Library of Medicine. The study’s authors did not disclose any financial interests.