The Diabetic Cohort (DC) was set up to study the determinants of complications in individuals with type 2 diabetes and examine the role of genetic, physiological and lifestyle factors in the development of complications in these individuals.
Inclusion criteria were adult Singaporeans and permanent residents (aged 21 years and above) with physician-diagnosed type 2 diabetes. Individuals with mental illness, clinically-obvious non-diabetic kidney disease (such as polycystic kidney disease), type 1 diabetes or diabetes mellitus resulting from endocrinopathies were excluded.
Data has been collected at 3 different timepoints: baseline, 2004 to 2010 (DC_T1); first follow-up, 2010 to 2016 (DC_T2); and second follow-up, 2016 to 2021 (DC_T3).
DC_T1 (2004 to 2010)
DC is a prospective cohort consisting of 14,100 adults with type 2 diabetes enrolled from multiple public sector polyclinics and re-structured hospitals during the period of 2004 to 2010. Participants were recruited from Clementi, Toa Payoh, Choa Chu Kang, Jurong, Yishun and Pasir Ris Polyclinics, Tan Tock Seng Hospital, National University Hospital, Changi General Hospital, and Alexandra Hospital in Singapore.
Detailed cohort information has been described in Luo M et al. Cohort profile: the Singapore diabetic cohort study. BMJ Open 2020;10:e036443.
| Study | IRB Approval Ref No | Principal Investigator | Documents |
| DC_T1 | NUS 03-017 | Prof Rob van Dam | Participant information sheet and consent form |
| DC_T1 | NUS 06-128 | Prof Rob van Dam | Participant information sheet and consent form |
DC_T2 (2010 to 2016)
410 participants of the DC were selected for a pilot follow-up in 2010 to study the associations between the glycaemic index of their diet with glycaemic control and risk factors for cardiovascular disease. Following the pilot, the first wave of in-person follow-up with the cohort participants began in 2012 and ended in 2016. A total of 4,300 DC participants were followed up using the same recruitment and data collection protocol as MEC1_T2.
| Study | IRB Approval Ref No | Principal Investigator | Documents |
| DC_T2 (pilot) | NUS 10-314 | Prof Rob van Dam | Participant information sheet and consent form |
| DC_T2 | NUS 12-140 | Prof Rob van Dam | Participant information sheet and consent form |
DC_T3 (2016 to 2021)
A second wave of in-person follow-up of the DC started in 2016 and was completed in 2021. A total of 2,700 participants were revisited in DC_T3.
| Study | IRB Approval Ref No | Principal Investigator | Documents |
| DC_T3 | NUS LB-16-125 | Dr Xueling Sim | Participant information sheet Consent form |
Summary of data collected across all timepoints of DC
The data dictionaries, data collection forms (DCF), and categories of variables collected across all timepoints of DC are provided below.
| Source | Section | DC_T1 Data Dictionary Main DCF |
DC_T2 Data Dictionary Pilot DCF Main DCF |
DC_T3 Data Dictionary Main DCF Online survey and telephone interview |
| Questionnaire | Socio-demographic characteristics | x | x | x |
| Questionnaire | Smoking | x | x | x |
| Questionnaire | Alcohol consumption | x | x | |
| Questionnaire | Dietary assessment | x | ||
| Questionnaire | Physical activity | x | x | |
| Questionnaire | Personal medical history | x | x | x |
| Questionnaire | Family medical history | x | x | x |
| Questionnaire | Medical information | x | x | |
| Questionnaire | Mental health | x | ||
| Questionnaire | Cognition | x | x | |
| Questionnaire | Wellbeing | x | x | |
| Questionnaire | Social and family | x | x | |
| Questionnaire | Sleep | o | x | |
| Questionnaire | Healthcare expenditure | o | ||
| Questionnaire | Health behaviour | x | x | |
| Physical examination | Anthropometry | x | x | x |
| Physical examination | Body composition and bone mineral density | o | ||
| Physical examination | Eye health | x | ||
| Physical examination | Cardiovascular health | x | x | |
| Physical examination | Peripheral neuropathy | x | x | |
| Physical examination | Physical fitness | x | x | |
| Physical examination | Pulmonary health | x | ||
| Physical examination | Urine biomarkers | x | x | x |
| Physical examination | Blood biomarkers (core) | x | x | |
| Physical examination | Blood biomarkers (others) | x | x | x |
| Omics | Omics | * | ||
| Medical linkage | NHGP | x | ||
| Medical linkage | Case notes | x |
o Performed only in the pilot DC_T2 study
* Performed in a subset of participants
Updated on 26 March 2024