The SOUth London Diabetes (SOUL-D) Study
The SOUth London Diabetes (SOUL-D) Study is a prospective cohort study of the association between depression and diabetes outcomes in people with newly diagnosed type 2 diabetes. It recently completed its two year follow-up
NIHR programme grant `Non-Pharmacological Approaches to Improving Diabetes Outcomes'
The aim of this study is to examine a range of biological, psychological and social factors in a group of people who have just been diagnosed withT2DM to determine their independent impact, and their interactions, on biomedical targets, quality of life, psychological functioning and economic consequences at 1 and 2 years. In addition, to study whether screening for depression improves the course and outcome for depression and for diabetes, and to identify the characteristics of those most at risk for depression and for poor diabetes control.
One thousand eight hundred and five adults, three-quarters of those eligible, participated in the study, recruited from 96 GP practices in the London Boroughs of Lambeth, Southwark and Lewisham. Half the participants were of non-White ethnicity, and most of these (40% of the total) were of Black African or Caribbean background, reflecting their higher risk of diabetes (Winkley, Thomas et al. 2013). A positive score on a screening questionnaire for depression was recorded by just under 15% of participants, of whom just under half were found to have clinical depression on diagnostic interview (Twist, Stahl et al., 2013). The information provided by the participants will help us better understand the interactions between depression and diabetes outcomes; explore the impact of Black ethnicity on diabetes presentation and course and investigate other factors that influence outcomes in people with type 2 diabetes, with a view to developing more personalised treatments and services.
Additional studies conducted in the SOUL-D study:
1. Uptake of structured education in people with newly diagnosed type 2 diabetes (T2DM)
The uptake of group education in people with T2DM is known to be very low. Dr Kirsty Winkley, our research manager who is also a diabetes nurse, was awarded an NIHR post doctoral fellowship to investigate why this is the case. To date she has published 2 journal articles and both of which used data from SOUL-D participants. The first was a qualitative interview study with 30 SOUL-D participants who had not attended the structured education course offered in the local area. Reasons given for not attending were split into 3 main themes:
i. lack of information or perceived benefit of the programme (e.g. not being informed about the course by their health professional, or its benefits explained); ii. Unmet personal preferences (e.g. parking, timing, caring for others); and iii. shame and stigma of diabetes (e.g. such as not wishing to tell others of diabetes diagnosis) (Winkley, Evwierhoma et al. 2015).The second publication was a prospective analysis of the SOUL-D cohort to determine the association between individual factors and general practice factors and attendance at structured education. This demonstrated that only 22% of the SOUL-D cohort had attended education within the first 2 years since diagnosis and factors associated with attending included being female, not smoking and having better glycaemic control at baseline. General practice factors such as achievement of primary care targets for glycaemic control were also positively associated with attendance (Winkley, Stahl et al. 2015).
2. Use of HbA1c > 48 mmol/mol to diagnose diabetes
Most people in SOUL-D were diagnosed with diabetes before the new diagnostic criterion of having a glycated haemoglobin value of 48 mmol/mol (6/5%) or more was introduced locally. Examing the data from this group showed that an HbA1c taken at diagnosis fell below this value in about one-fifth of participants. Although those people who had an HbA1c value below the new diagnostic value were older and more likely to be of white ethnicity than the SOUL-0D cohort as a whole, there were no major differences in the prevalence of diabetes complications (Azim, Marwood et al., 2015)
3. Markers of inflammation in people with newly-diagnosed type 2 diabetes
Type 2 diabetes is increasingly recognised as a state of chronic inflammation with elevated levels of markers for inflammatory processes found in the ciurculation. In a study part funded by the European Foundation for the Study of Diabetes (EFSD) using data from the SOUL-D participants, we found some of these markers to be circulating in even higher concentrations in those participants who scored positive for depression at entry into the study (Laake, Stahl et al, 2015). A synergy between two pro-inflammatory states (diabetes and depression) may contribute to the reported higher prevalence of diabetes complications in those patients who are also depressed. In a pilot investigation, use of incretin based therapies for glycaemic control was associated with reduced symptoms of depression independent of markers of diabetes control but associated with a change in highly sensitive C reactive protein, a marker of inflammation (Moulton, Pickup et Al, 2015)
The SOUL-D Team:
Prof Stephanie Amiel - Principal Investigator
Prof Khalida Ismail - Co-investigator
Kirsty Winkley - Trial Manager
Linda East - Data Manager
Winkley, K., S. M. Thomas, et al. (2013). "The clinical characteristics at diagnosis of type 2 diabetes in a multi-ethnic population: the South London Diabetes cohort (SOUL-D)." Diabetologia 56(6): 1272-1281.
Twist K, Stahl D, Amiel SA, Thomas S, Winkley K, Ismail K. Comparison of depressive symptoms in type 2 diabetes using a two-stage survey design. Psychosom Med. 2013;75:791-7.
Winkley K, Evwierhoma C, Amiel SA, Lempp HK, Ismail K, Forbes A. Patient explanations for non-attendance at structured diabetes education sessions for newly diagnosed Type 2 diabetes: A qualitative study. Diabetic Medicine 2015; 32(1): 120-128.
Winkley K, Stahl D, Chamley M, Stopford R, Boughdady M, Thomas S, Amiel SA, Forbes A, Ismail K. . Low attendance at structured education for people with newly diagnosed type 2 diabetes: General practice characteristics and individual patient factors predict uptake. Patient Education and Counseling. 2015: 99(1): 101-107.
Laake JP, Stahl D, Amiel SA, Petrak F, Sherwood RA, Pickup JC, Ismail K. The association between depressive symptoms and systemic inflammation in people with type 2 diabetes: findings from the South London Diabetes Study. Diabetes Care. 2014;37:2186-92
Moulton CD, Pickup JC, Amiel SA, Winkley K, Ismail K. Investigating incretin-based therapies as a novel treatment for depression in type 2 diabetes: Findings from the South London Diabetes (SOUL-D) Study. Prim Care Diabetes. 2015 Jun 29. pii: S1751-9918(15)00088-1.