Diabetes is a condition in sugar levels in the blood are too high. Blindness is one of the most debilitating and common complications of diabetes. Gestational diabetes is a form of diabetes which is first picked up in pregnancy, and which resolves after pregnancy. Women with gestational diabetes are at high risk of later developing long-term diabetes. Gestational diabetes may also carry a significant risk of long-term eye complications associated with the development of diabetes after pregnancy. There is a national eye screening program for people living with long-term diabetes to detect these complications early. This program has been shown to slow the worsening of the disease and/or partially reverse sight problems. This screening program does not include women who have had gestational diabetes (unless they subsequently develop diabetes). Using the Clinical Practice Research Datalink, we aim to compare the long-term risk of diabetic eye disease in women with diabetes who’ve previously had gestational diabetes with the risk in those who never had gestational diabetes. If women with a past of gestational diabetes have a higher risk of diabetic eye problems, it suggests we should perhaps be screening them from the point at which they are found to have gestational diabetes, not just from the point from which they later develop diabetes. In doing this research we would aim to provide evidence that may change national guidelines to prevent a relatively young group of women from developing debilitating eyesight problems.
Diabetic retinopathy (DR) is one of the leading causes of visual impairment in people of working age in Great Britain; its early detection is key to reversing its progression. There is evidence that, by the time of diagnosis of diabetes, some patients already have DR. In pilot data from a Northwest London dataset, gestational diabetes (GDM) conferred an 18.8% risk of DR within the decade post-partum (c.f. in a cohort of pregnant women without any form of diabetes over the same time-period, this rate was 2.5%). The question is: is GDM a flag for an increased risk of DR, and should we be screening for DR following GDM even before diabetes is formally diagnosed on blood tests? We thus aim to explore the extent to which a past of GDM is a risk factor for DR amongst women living with diabetes. We will compare the risk of developing DR in women with diabetes to the present day. We will perform a multivariate analysis (e.g Cox proportional hazard regression) taking into account demographic and clinical characteristics (for example those with concurrent hypertension, or of particular ethnic groups) to examine their effect on the development of DR. We will use Hospital Episode Statistics (HES) data to ensure as many cases of GDM and DR are captured as possible. The practice-level Index of Multiple Deprivation record will be used to determine the impact of this co-variate on our outcomes. Office of National Statistics death registration will help to interpret the length of longitudinal follow-up data. This study may provide evidence that clinical studies comparing the risk of DR after GDM with that of DR after incident diabetes should be performed, the result of which could change national guidelines to include women with GDM in the eye screening program.
Primary outcome:
• new diagnosis of any diabetic retinopathy
Secondary outcomes:
• new diagnosis of referrable diabetic retinopathy
Frederick Wai Keung Tam - Chief Investigator - Imperial College London
Gabrielle Goldet - Corresponding Applicant - Imperial College London
- Collaborator -
Mark Cunningham - Collaborator - Imperial College London
HES Accident and Emergency;HES Admitted Patient Care;ONS Death Registration Data;Practice Level Index of Multiple Deprivation