Wednesday, November 30, 2016
A new study published in Diabetologia (the journal of the European Association for the Study of Diabetes [EASD]) suggests that a 'Sit Less' intervention ? breaking sitting with standing and light-intensity walking ? may be an alternative to structured exercise to promote blood sugar control in patients with type 2 diabetes, giving improved 24-hour glucose levels and improved insulin sensitivity.
The use of moderate to vigorous exercise is one of the cornerstones of prevention and treatment of type 2 diabetes, with current physical activity guidelines recommending a performance of at least 150 min per week of exercise at these intensities. Despite the proven effectiveness of such a regime, however, over 90% of the healthy population does not adhere to the guidelines. Non-compliance is likely to be even higher in those with type 2 diabetes, in which related comorbidities such as muscle weakness and peripheral neuropathy can be a barrier to physical exercise. An alternative approach is needed.
This study considered the possible benefits of a 'Sit Less' programme, replacing sitting time with standing and light-intensity walking, in comparison to the use of a conventional structured exercise regimen of the same energy expenditure. It was conducted by Bernard Duvivier, Department of Human Biology and Movement Science, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Netherlands, and colleagues.
The study involved 19 adults (13 men and 6 women) with type 2 diabetes, with a mean disease duration of 6 years, a mean HbA1c of 6.7% and a mean fasting plasma glucose of 7.88 mmol/l during screening. Their mean age was 63 years and the mean BMI was 30.5 kg/m2 (just within the definition of obese). A total of 14 participants were using glucose-lowering diabetes drugs and 13 were using lipid-lowering drugs (most often statins).
The participants followed three activity regimens - 'Sitting', 'Exercise' and 'Sit Less' - each lasting 4 days. During the sitting regimen participants were restricted to 1 hour/day of walking and 1 hour/day standing, with the remaining 14 hours spent sitting. During the exercise regimen approximately 1 hour/day of sitting time was replaced by supervised cycling on an ergometer at the research centre, in 20 minute bouts separated by 5 minutes rest. In the sit less regimen, 5 hours/day sitting were replaced by 2 hours walking and 3 hours standing, with participants encouraged to break up their sitting time every 30 minutes with small bouts of walking and standing throughout the day. The exercise and sit less regimens were designed to have comparable energy expenditure for each participant. The order of the regimens was randomised, and 10 days of usual lifestyle was maintained as a 'wash-out' period before and between regimens.
Diet was controlled with use of the participants' normal diet, supplemented during the last 36 hours of each regimen by the provision of pre-packed meals based on their energy requirements for each regimen. Glucose levels were measured continuously using a subcutaneous glucose monitor and also via the collection of blood glucose samples four times daily. The use of light-intensity walking was diarised and verified using advanced accelerometry (which monitors motion via multiple parameters). 24-hour glucose levels were analysed during the last 24 hours of each four-day regimen. On the day after each regimen, between 08.30 and 09.30 hours, after an overnight fast, blood was collected for glucose, insulin and lipid measurements.
The data were analysed to provide: 24 hour glucose concentration; incremental AUC for glucose (incremental area under the curve - a summary measure of glucose usage - the increase above fasting level over 24 hours); duration of hyperglycaemia; an average glucose concentration for each 30 minutes to indicate any bouts of hypoglycaemia; an estimate of insulin sensitivity; fasting triacylglycerol levels and non-esterified fatty acid (NEFA) levels.
The study found that the use of the sit less regimen led to significant improvements in insulin sensitivity, mean 24-hour glucose levels, 24-hour glucose excursions, durations of hyperglycaemia and fasting triacylglycerol levels, compared with sitting. Whilst positive effects for most variables (other than 24-hour glucose) were also found in the traditional exercise regimen, these were generally less potent than the improvements found for the sit less group. In addition, glucose level reductions, which can lead to hypoglycaemia and render some diabetic patients reluctant to perform structured exercise, were found to be less for the sit less regimen.
Previously it has been noted that a sedentary (inactive) lifestyle is associated with an increased risk of type 2 diabetes, and that regular interruption of sitting using small bouts of walking may be beneficial to insulin action and glucose control. This study, however, is the first to consider the effects of a sit less regimen for people with type 2 diabetes in free-living conditions. The outcome of the study fits the emerging picture that breaking up sedentary behaviour by light-intensity activities may be a potent way to help improve blood glucose control.
The authors suggest that sustained compliance with exercise programmes, especially by individuals with type 2 diabetes, is at best mediocre. Strategies to reduce sitting time are generally considered to be less demanding than structured exercise programmes and hence are more likely to have long-term compliance. The authors say that their findings "provide indications favouring the implementation of interventions targeting the breaking-up of sitting time over interventions involving structured exercise". As the volume of activities in this proof-of-concept study was high (an additional 2 hours walking and 3 hours standing during the sit less regimen in comparison to the other regimens), the authors suggest "that future long-term studies are needed to determine the volume of light-intensity activity that is feasible in daily life".
Monday, April 18, 2016
Friday, April 15, 2016
Thursday, April 7, 2016
While controlling blood pressure, blood sugar and LDL-cholesterol levels reduces the risk of cardiovascular disease in people with diabetes, only 7 percent of diabetic participants in three major heart studies had recommended levels of these three factors, according to research from the Heart Disease Prevention Program at the University of California, Irvine School of Medicine.
The findings illustrate the need for persons with diabetes to better manage their blood pressure, blood sugar and LDL-cholesterol levels, which are prime indicators of future cardiovascular disease. The diabetic participants surveyed in the UCI review were enrolled in the three heart studies between the late '80s and early 2000s, when treatment was not as good as it is now. Still, more recent data show that only 25 percent of Americans with diabetes achieve all three of these targets.
The good news is that those in the heart studies who did control all three factors had a 62 percent lower risk of developing cardiovascular disease, according to Nathan D. Wong, lead author of the UCI report, which appears online in Diabetes Care.
"But we have done a dismal job nationally at getting most of our patients with diabetes controlled for even just these three measures," said Wong, director of the Heart Disease Prevention Program and a cardiology professor at UCI.
"Since cardiovascular diseases - including coronary heart disease, stroke and heart failure - are leading causes of death for people with diabetes, these findings underscore the value of achieving target or lower levels of these modifiable risk factors," he added.
Wong and colleagues studied 2,018 adults (57 percent female) with diabetes mellitus but without known cardiovascular diseases who participated in the Atherosclerosis Risk in Communities Study, the Multi-Ethnic Study of Atherosclerosis or the Jackson Heart Study. Fifty-five percent were African American, 30 percent white, 11 percent Hispanic and 4 percent Asian/Pacific Islander.
The researchers compared measurements of the three key factors to American Diabetes Association guidelines that were in effect at the time - blood pressure under 130/80 mmHg, LDL (or bad) cholesterol less than 100 mg/dL and blood HbA1c (glycated hemoglobin) under 7 percent. Forty-one percent of the study group were on target in one of the three categories; 27 percent had achieved two of the benchmarks; but only 7 percent met the recommended scores in all three.
Study participants' control of individual and composite factors was also examined in relation to the occurrence of new cardiovascular events (including heart attacks, coronary deaths, strokes, heart failure, percutaneous interventions and bypass surgeries) over an average follow-up of 11 years.
Wong said that proper management of any one factor translated to a 36 percent lower risk, proper management of any two factors was linked to a 52 percent lower risk, and proper management of all three factors correlated to a 62 percent lower risk of cardiovascular events compared to those without any factors controlled.
Blood pressure management appeared to benefit African Americans and women more than other ethnic groups or men; however, the converse was true for LDL control.
"Our analysis of three large U.S. cohorts including persons in whom diabetes has been diagnosed shows those who were at target levels for HbA1c, blood pressure and LDL to have substantially lower risks for cardiovascular disease than persons with diabetes who were not at target levels for such factors," Wong said. "These findings emphasize the importance of composite control of these modifiable risk factors to better address the cardiovascular disease risks seen in persons with diabetes, the need for the development of healthcare strategies to better ensure such management, and the need for studies to evaluate and eliminate barriers to risk factor control in persons with diabetes."
Wednesday, March 23, 2016
Friday, March 11, 2016
Friday, March 4, 2016
Wednesday, March 2, 2016
Monday, February 29, 2016
NIH-funded clinical trial shows Eylea, Avastin, and Lucentis perform similarly when vision loss is mild.
“This rigorous trial confirms that Eylea, Avastin, and Lucentis are all effective treatments for diabetic macular edema,” said NEI Director Paul A. Sieving, M.D., Ph.D. “Eye care providers and patients can have confidence in all three drugs.”
Eylea, Avastin, and Lucentis are all widely used to treat DME, a consequence of diabetes that can cause blurring of central vision due to the leakage of fluid from abnormal blood vessels in the retina. The macula is the area of the retina used when looking straight ahead. The drugs are injected into the eye and work by inhibiting vascular endothelial growth factor (VEGF), a substance that can promote abnormal blood vessel growth and leakage. Although the drugs have a similar mode of action, they differ significantly in cost. Based on Medicare allowable charges, the per-injection costs of each drug at the doses used in this study were about $1850 for Eylea, about $60 for Avastin, and about $1200 for Lucentis.
DRCR.net investigators enrolled 660 people with DME at 89 clinical trial sites across the United States. When the study began, participants on average were 61 years old with 17 years of type 1 or type 2 diabetes. Only people with a visual acuity of 20/32 or worse were eligible to participate (to see clearly, a person with 20/32 vision would have to be 20 feet away from an object that a person with normal vision could see clearly at 32 feet). At enrollment, about half the participants had 20/32 to 20/40 vision. The other half had 20/50 or worse vision. In many states, a corrected visual acuity of 20/40 or better in at least one eye is required for a driver’s license that allows both day- and nighttime driving.
Each participant was assigned randomly to receive Eylea (2.0 milligrams/0.05 milliliter), Avastin (1.25 mg/0.05 mL), or Lucentis (0.3 mg/0.05 mL). Participants were evaluated monthly during the first year and every 4-16 weeks during the second year. Most participants received monthly injections during the first six months. Thereafter, participants received additional injections of assigned study drug until DME resolved or stabilized with no further vision improvement. Subsequently, injections were resumed if DME worsened. Additionally, laser treatment was given if DME persisted without continual improvement after six months of injections. Laser treatment alone was the standard treatment for DME until widespread adoption of anti-VEGF drugs a few years ago.
Among participants with 20/40 or better vision at the trial’s start, all three drugs improved vision similarly on an eye chart. On average, participants’ vision improved from 20/40 vision to 20/25.
Among participants with 20/50 or worse vision at the trial’s start, visual acuity on average improved substantially in all three groups. At two years, Eylea participants were able to read about 3.5 additional lines on an eye chart; Lucentis participants were able to read about three additional lines, and Avastin participants improved about 2.5 lines, compared with visual acuity before treatment. Eylea outperformed Avastin at the one- and two-year time points. While Eylea outperformed Lucentis at the one-year time point, by the two-year time point gains in visual acuity were statistically no different. At the end of the trial, average visual acuity was 20/32 to 20/40 among participants in all three groups.
“The results of the DRCR Network’s comparison of Eylea, Avastin, and Lucentis will help doctors and their patients with diabetic macular edema choose the most appropriate therapy,” said John A. Wells, M.D., the lead author of the study and a retinal specialist at the Palmetto Retina Center, Columbia, South Carolina. “The study suggests there is little advantage of choosing Eylea or Lucentis over Avastin when a patient’s loss of visual acuity from macular edema is mild, meaning a visual acuity of 20/40 or better. However, patients with 20/50 or worse vision loss may benefit from Eylea, which over the course of the two-year study outperformed Lucentis and Avastin.”
The number of injections participants needed was about the same for all three treatment groups. Eylea, Avastin, and Lucentis participants on average required nine injections in the first year of the study and five in the second year.
The need for laser treatment varied among the three treatment groups. By two years, 41 percent of participants in the Eylea group received laser treatment to treat their macular edema, compared with 64 percent of participants in the Avastin group and 52 percent in the Lucentis group.
The risk of heart attack, stroke, or death from a cardiovascular condition or an unknown cause by end of the trial was higher among participants in the Lucentis group. Twelve percent of Lucentis participants had at least one event, compared with five percent of participants in the Eylea group and eight percent of participants in the Avastin group. This difference in cardiovascular rates has not been seen across all other studies, and therefore may be due to chance. Continued assessment of these serious cardiovascular events and their association with these drugs is important in future studies. Cardiovascular events such as heart attack and stroke are common complications of diabetes. The occurrence of eye complications, such as eye infections and inflammation, was similar for all three drugs.
Results of the study were published online today in Ophthalmology, the journal of the American Academy of Ophthalmology. Eylea and Lucentis were provided by drug manufacturers Regeneron and Genentech, respectively. Additional research funding for this study was provided by the National Institute of Diabetes and Digestive and Kidney Diseases, also a part of NIH.
“This important study would not have happened without funding from the National Institutes of Health and the cooperation of two competing companies,” said Adam R. Glassman, M.S., principal investigator of the DRCR.Net Coordinating Center at the Jaeb Center for Health Research.
Friday, February 26, 2016
Wednesday, February 24, 2016
There is some good news for people with eye complications from diabetes. A network of researchers supported by the National Eye Institute (NEI) found that the drug Lucentis (ranibizumab) can be highly effective for treating proliferative diabetic retinopathy, an eye disease that can occur as a complication of diabetes. The researchers, part of the Diabetic Retinopathy Clinical Research Network, say this is the first major advance in therapy in 40 years.
Diabetic retinopathy is the leading cause of vision loss and blindness among working-age Americans. An advanced stage, called proliferative diabetic retinopathy, occurs when abnormal blood vessels grow near the retina, the light-sensitive tissue at the back of the eye. These new vessels can leak blood, which can obscure vision and damage the retina. Lucentis is one of several drugs called VEGF inhibitors that can block this process.
In the new study, Lucentis was compared to scatter laser therapy (or panretinal photocoagulation), which has been the standard treatment for proliferative diabetic retinopathy since the 1970s. Although laser therapy is effective in improving central vision, it can cause decreased night and side vision. The study found that Lucentis produced more improvement in central vision and little change in side vision when compared to laser therapy.
An injection into the eye might sound scary, but it's one of the most common procedures performed by ophthalmologists. VEGF inhibitors have been used for several years to treat diabetic macular edema, a swelling of the retina that can occur as blood leaks around it. The new study suggests that VEGF drugs may even help prevent macular edema. Study participants who were treated with Lucentis were less likely to develop macular edema than those treated with laser therapy.
As better treatments for diabetic retinopathy emerge, it's important to remember that an early diagnosis is the first step to getting treatment and saving your sight. If you have diabetes, you should get a comprehensive dilated eye exam at least once a year. Diabetic retinopathy often has no symptoms in its early stages. But an eye care professional can detect it before symptoms occur. And with early detection and appropriate treatment, the risk of severe vision loss from the disease can be reduced by 95 percent.
"Only about half of all people with diabetes get an annual comprehensive dilated eye exam, which is essential for detecting diabetic eye disease early, when it is most treatable," said NEI Director Paul A. Sieving, M.D., Ph.D.
Keeping diabetes under control is also key to preventing vision loss. If you have diabetes, NEI's National Eye Health Education Program recommends these important steps to keep your health on TRACK:
• Take your medications as prescribed by your doctor.
• Reach and maintain a healthy weight.
• Add physical activity to your daily routine.
• Control your ABC's -- A1C, blood pressure, and cholesterol levels.
• Kick the smoking habit.