No link between diabetic retinopathy and cognitive impairment

Research by the Florence Nightingale School of Nursing and Midwifery, King’s College London, has revealed that contrary to previous research findings, there is no link between progressive retinopathy and cognitive impairment in people with diabetes. The study, which was funded by King’s College Hospital Research and Development Initiative Grant, found that there was more cognitive impairment in people with no or mild retinopathy compared with those who have more advanced retinopathy.

Dr Roxanne Crosby-Nwaobi, Lead Researcher, said:

“These findings are significant because previous work in this area has suggested a linear relationship between severity of diabetic retinopathy and cognitive impairment. As our study contradicts this finding, severity of diabetic retinopathy cannot be used as a marker of cognitive impairment. Our study, therefore, indicates the need for further research into the early detection of cognitive impairment in people with diabetes.”

Diabetic retinopathy is one of the most established complications of diabetes and is the leading cause of blindness in the under 65s. While the mechanism for retinopathy in diabetes is well understood, less is known about why people with diabetes have a higher prevalence of cognitive impairment and dementia. The study, which included nearly 400 men and women with type 2 diabetes, aimed to test whether there were common causes for both conditions.

Professor Angus Forbes, Chair in Diabetes Nursing at the School, said:

“Our study confirmed previous research findings that the prevalence of cognitive impairment and dementia is high in the diabetes population. We found that 10% of our research participants had undiagnosed dementia, and 50% had significant cognitive impairment.

“However, the fact that we found no link between those who had significant retinopathy and those who had more advanced cognitive impairment suggests that the two have different causes.”

Dr Sobha Sivaprasad, Medical Retinal Consultant at King’s College Hospital, and Principal Investigator and grant holder of the project, said:

“This is the largest study on a multiethnic population to date examining the relationship between retinopathy and cognitive impairment in diabetic patients. The findings are significant, especially since they contradict earlier studies. However, it is now very important that more studies are undertaken into the causes of cognitive dysfunction so that we can develop strategies to support patients. This is becoming increasingly urgent since there is a rising prevalence of diabetes, which is likely to lead to many more people with cognitive impairment and dementia.”

The study, entitled The relationship between diabetic retinopathy and cognitive impairment, was published in Diabetes Care in April 2013.

For more information or interview opportunities contact:

Allie Johnstone

Communications Officer

Florence Nightingale School of Nursing & Midwifery, King’s College London

T: 020 7848 3062

E: allie.johnstone@kcl.ac.uk