People with Type 2 diabetes who have obstructive sleep apnoea[1] (OSA) are more at risk of losing their sight due to severe retinopathy[2], as well as foot problems and possible amputation because of neuropathy[3], according to new research.

Researchers from the University of Birmingham[4][5] looked at 231 people with Type 2 diabetes of whom 149 had OSA, a sleep disorder caused by disturbed breathing. They found there were twice as many people with severe retinopathy (48 per cent) in the group with OSA compared to the group without OSA (20 per cent). Retinopathy is the leading cause of blindness in the UK’s working-age population.

In a separate study, the researchers found that OSA was also linked to neuropathy. They looked at 230 people with Type 2 diabetes of whom 148 had OSA. They found that 60 per cent of the group with OSA had neuropathy compared to 22 per cent in the group without OSA.

Dr Iain Frame, Director of Research at Diabetes UK, said: “We already know that there is a high prevalence of OSA in people with Type 2 diabetes. However, this is the first time that the link between OSA and retinopathy and neuropathy in people with Type 2 diabetes has been examined. This research suggests that if someone with Type 2 diabetes also has this sleeping disorder they are more at risk of developing these serious complications compared to someone with the condition who does not have OSA.

“As being overweight is a risk factor for both OSA and Type 2 diabetes, this is yet another reason to highlight the importance of good weight management through a healthy diet and regular physical activity. In people with Type 2 diabetes, the increasing severity of OSA is associated with poorer blood glucose control and the treatment of sleep disorders (in this case by losing weight) has the potential to improve diabetes control and energy levels.”

In both studies, the association between OSA and the two diabetes complications in people with Type 2 diabetes was independent of age, gender, ethnicity, blood pressure, blood glucose levels, smoking and cholesterol.

Dr Abd Tahrani, who led the research, said: “Our work highlights several important issues. Our results emphasised what is already known – that OSA is very common in patients with Type 2 diabetes, much higher than OSA prevalence in the general population. Furthermore, our results suggest that OSA is not an innocent bystander in patients with Type 2 diabetes and might contribute to morbidities associated with this condition. Whether OSA treatment has any impact on these complications will need to be determined”

There are around 3.3 million people with Type 2 diabetes in the UK including an estimated 850,000 people who have the condition and are not aware of it. In the UK, it is estimated that around four in 100 middle-aged men and two in 100 middle-aged women have OSA.

Notes

1. Obstructive sleep apnoea(OSA) is a condition that causes interrupted breathing during sleep. The onset of OSA is most common in people aged 35 to 54 years old, although it can affect people of all ages, including children. The condition often goes undiagnosed. Only one in four people with obstructive sleep apnoea are diagnosed with the condition.

2. Neuropathy is nerve damage and a long term complication of diabetes.Neuropathy can lead to foot ulcers and slow-healing wounds which, if they become infected, can result in amputation.

3. Obstructive sleep apnoea and sight threatening retinopathy: A novel association in patients with Type 2 diabetes A A Tahrani1,2, A Ali3, S Begum3, P Galsworthy2,4, H Wharton2,4, D Banerjee3, S Taheri1,2, A H Barnett1,2, M J Stevens1,2, P M Dodson2,4 1Centre of Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK 2Department of Diabetes and Endocrinology, Birmingham Heartlands Hospital, Birmingham, UK 3The Biomedical Unit, Birmingham Heartlands Hospital, Birmingham, UK 4Heart of England Diabetic Retinopathy Screening Centre of Excellence, Birmingham Heartlands Hospital, Birmingham, UK. P158, Diabetic Medicine: Abstracts of the Diabetes UK Annual Professional Conference (30 March to 1 April 2011), Volume 28, supplement 1. Published by Wiley-Blackwell. Both studies were presented at the Diabetes UK Annual Professional Conference 2011.

4. Obstructive sleep apnoea is independently associated with peripheral neuropathy in patients with Type 2 diabetes A Tahrani1,2, A Ali3, S Begum3, K Dubb1, S Mughal3, M Piya1,2, B Jose3, D Banerjee3, S Taheri1,2, AH Barnett1,2, MJ Stevens1,2. P114, Diabetic Medicine: Abstracts of the Diabetes UK Annual Professional Conference (30 March to 1 April 2011), Volume 28, supplement 1. Published by Wiley-Blackwell.

5. Diabetes UK is the leading charity for over 3.5 million people in the UK with diabetes In 2011, Diabetes UK aims to spend over £6 million on diabetes research to investigate the causes and prevention of diabetes, to improve care and treatment of diabetes and ultimately to work towards a cure. For more information visit www.diabetes.org.uk. In the UK, there are currently 2.8 million people diagnosed with diabetes and it is estimated that 850,000 people have Type 2 diabetes but do not know it.

6. Type 2 diabetes develops when the body can still make some insulin, but not enough, or when the insulin that is produced does not work properly (known as insulin resistance). Insulin acts as a key unlocking the cells, so if there is not enough insulin, or it is not working properly, the cells are only partially unlocked (or not at all) and glucose builds up in the blood. Type 2 diabetes accounts for between 85 and 95 per cent of all people with diabetes, usually affects people over 40 (over 25 in people from South Asian and Black backgrounds) and is treated with a healthy diet and increased physical activity. In addition to this, medication and/or insulin is often required. In most cases the condition is linked with being overweight and can go undetected for up to ten years meaning around 50 per cent of people show signs of complications by the time they are diagnosed.

7. Type 1 diabetes develops when insulin-producing cells in the pancreas are destroyed. This type of diabetes usually appears before the age of 40 and is the least common of the two main types and accounts for around 10 per cent of all people with diabetes. Type 1 diabetes cannot be prevented, it is not known why it develops and it is not connected with being overweight. People with Type 1 diabetes have to take insulin either via a pump or by injections several times a day to stay alive.

Source: Diabetes UK