Diabetes developments – by Simon O’Neill
In a regular blog series, Simon O’Neill, Diabetes UK’s Director of Health Intelligence and Professional Liaison, rounds up the latest diabetes news.
This week Simon looks at updates on research.
Eyes not on the prize
2Although about 80% of eligible people attend for regular retinal screening, the “Incentives in Diabetic Eye Assessment by Screening (IDEAS)” study targeted a “hard-to-reach” group with very low attendance rates to see whether financial incentives would improve the uptake.
1051 people were included in the study who had been invited to attend a retinal screening appointment in the previous 24 months but had not attended. Participants were aged 16 or over and lived in the Kensington, Chelsea, and Westminster boroughs of London. The socioeconomic status of participants was recorded.
The study tested two different incentive schemes against a standard invitation letter. These were either a fixed incentive, where a standard invitation letter was sent containing a voucher redeemable for £10 cash if the patient attended, or an invitation letter plus a voucher for a lottery, with a one in 100 chance of winning £1000 if screening were attended.
Attendance rates were very low in all groups. In the control group, 7.82% of people attended, but interestingly, in the combined incentive groups, only 4.38% attended, which was 44% lower, showing that incentives do not appear to be effective at promoting attendance and may even deter attendance. Even in groups who had medium and high levels of deprivation, there was no benefit in offering either type of incentive, particularly not the lottery incentive where only 3.29% of people attended.
The findings came as something of a surprise as such financial incentives have been effectively used to change other health behaviors, such as improving medication adherence or to encourage breast and cervical cancer screening.
People who did attend explained that they had not attended previously because of organisational problems (60%); practical/logistical reasons (20%); or they did not think they needed to attend (20%). The study authors suggest that because these people had not attended eye screening for a long time or had never attended in many instances, there might have been an underlying mistrust or fear of the screening service and that being offered money to do something of which you are already distrustful can simply reinforce negative feelings.
Diabetes leading to more sight loss worldwide
The Global Burden of Disease Study has shown that diabetes led to a worldwide increase in vision loss of nearly a third and visual impairment of nearly two-thirds from 1990 to 2010. This increase was seen in all world regions except for higher-income regions of Asia Pacific, Australasia, Western Europe, and North America, which experienced a slight decrease in diagnoses.
Diabetic retinopathy was responsible for 1 in every 39 cases of blindness in 2010, a 27% increase compared with 1990, and 1 in every 52 cases of visual impairment, an increase of 64% over the same period.
The researchers stated that the total number of people worldwide with new cases of blindness caused by diabetic retinopathy increased to nearly 834,000 and the number of people with new cases of visual impairment increased to 3.7 million.
This means that diabetic retinopathy is now the fifth leading cause of global blindness and global moderate and severe visual impairment, with 34.2 million people with diabetic retinopathy-related blindness and 191 million with diabetic retinopathy-related visual impairment.
This is not surprising with the global growth in diabetes, especially in developing countries who may not be able to offer routine retinal screening. Countries with retinal screening programmes have seen a decrease in both blindness and visual impairment as we know that early detection and treatment of retinopathy can reduce the risk of blindness by 95%.
Should we screen young people for retinopathy?
In the UK all children over the age of 12 with diabetes are enrolled in the National Retinal Screening Programmes for, currently, annual review. However, a review of evidence from the Type 1 diabetes Exchange Registry, published in October, questions the benefit of screening for diabetic retinopathy in this younger age group.
The authors surveyed 12,535 people in the Registry, all of whom were under 21 years of age and not pregnant, with a mean age of 12 years, diabetes duration of 5 years, and an average HbA1c of 8.6%.
Participants (or their parents) were asked “Have you ever received treatment for diabetic retinopathy (change in the retina of the eye due to diabetes), such as with laser, injections into or around the eye, or vitrectomy surgery?”
Only 0.36% (45) respondents reported having received retinopathy treatment. But interestingly, when ophthalmologist reports or medical records were checked, none had a record of having actually received treatment for diabetic retinopathy.
The authors therefore suggest that retinopathy requiring any form of treatment is extremely rare in children enrolled in this Registry and propose that the findings indicate that screening all youth with T1D solely on the basis of age and diabetes duration may not be justified. They propose that future studies may show that other risk factors, such as microalbuminurea or hypertension, may prove to be better markers of who should be screened.
Although further studies are needed to confirm these results, at least they might give some reassurance to parents in the UK who may find their children moving to biennial screening in future (if they currently have no signs of any retinopathy).
Autoimmunity and Type 1 diabetes
It has long been recognized that people with Type 1 diabetes (an autoimmune disease) are also more likely to be diagnosed with other autoimmune conditions, most commonly problems with the thyroid.
A new study, using data from the Type 1 diabetes Exchange Registry, has highlighted the scale of this problem. Reviewing data on 25,759 people with Type 1 diabetes, the study has determined the prevalence and factors that may predict association with other autoimmune diseases.
27% of the study sample had a diagnosis of at least one other autoimmune disease. Most people only had one additional diagnosis (20%) but 5% had two other conditions and around 1% had three, four or five.
Risk factors for additional autoimmune conditions were older age, being female and white non-Hispanic race/ethnicity. At least one additional autoimmune disease was also common in participants who were Hispanic/Latino (21%), black non-Hispanic (12%) and other races (21%). Other conditions were also more likely to occur the longer people had had Type 1 diabetes and if they were diagnosed later in life.
Thyroid diseases were the most frequently diagnosed additional autoimmune diseases (20%); hypothyroidism or Hashimoto’s disease were most common (96% of all thyroid diseases), and hyperthyroidism or Graves’ disease were less common (8% of all thyroid diseases).
Rheumatoid arthritis (< 1%), vitiligo (< 1%) and Addison’s disease (< 1%) were less common. Women and girls also had the highest prevalence of systemic lupus erythematosus (93%), scleroderma (91%), coeliac disease (57%) and Addison’s disease (53%).
The researchers stressed the need for diabetes teams to be particularly alert to any indicators of other autoimmune conditions, particularly thyroid problems, and particularly in older people with a longer duration of Type 1 diabetes.
Glycaemic Index Not So Indicative
A new study has shown that the Glycemic Index (GI) may not be quite as black and white as has previously been thought. GI was created to show how fast blood glucose levels rise after eating a specific type of food, to help people with diabetes control their blood sugar levels better. It has long been understood that it is only an indication because when foods are combined (as they are in most meals we eat) the GI of each ingredient will be altered by the other foods in that meal.
However, this study has demonstrated that the GI value of the same foods can also vary widely and may be an unreliable indicator of blood glucose response. The study looked at 63 healthy adults after eating the same amount of white bread on three different occasions over a 12 week period. Rather than showing similar responses each time, the study actually found that GI values varied on average by 20% among individuals and 25% between different people in the study.
This means that if someone ate the same amount of the same food on three different occasions, rather than seeing a similar blood glucose response each time, they could see a markedly different response. There would be an even greater difference between individuals. This would certainly explain why sometimes one’s blood glucose can defy all logic and respond in a totally unexpected way.
The authors suggest that, based on these findings, using GI isn’t particularly practical for food labelling or in dietary guidelines at the individual level.
Exercise Is Good For You
Several studies have provided more evidence that exercise is important in diabetes.
In one study, researchers found that simply telling people with Type 2 diabetes to “take a short walk right after meals” may be one of the best exercise prescriptions you can give. Results from the randomized crossover study showed that post meal blood glucose levels dropped 12%, on average, when people with Type 2 diabetes walked for 10 minutes after three daily meals, compared with walking for 30 minutes at any time of day, with the biggest effect coming from a 22% glycaemic drop in the three hours post evening meal. Interestingly, people also walked for longer when they walked after meals, although the researchers aren’t sure why.
The second study, a meta-analysis of 23 cohort studies in 1.2 million non-diabetic individuals from the United States, Asia, Australia, and Europe, showed that those who achieved a 11.25 metabolic equivalent of task (MET) hours/week of moderate activity (the 150 minutes/week currently recommended) had a 26% reduction in the risk of developing Type 2 diabetes. Those who achieved 60 MET hours/week, however, reduced their risk of developing diabetes by more than 50%.
In a third review of more than 180 studies, researchers suggest that people with diabetes should move more than previously advised. This is a rather different approach to most guidance suggesting that there is a benefit in doing three or more minutes of light activity every 30 minutes during prolonged periods of sitting, such as working on a computer or watching TV. Such activities could include overhead arm stretches, walking in place, leg lifts or extensions, desk chair swivels, torso twists and side lunges.