Participants

This is a long-term observational cohort study focusing on patients with diabetes and their household members. Diabetes patients will be followed up to monitor risk factors related to poor glycaemic control and the development of diabetic complications. Household family members will be followed up for risk factors associated with the development of diabetes, while the unrelated non-diabetic cohort will be observed to identify factors influencing health outcomes and the risk of complications.

As a comparator to the family member group, a separate cohort who are non-diabetic and not family members of the diabetic patients but reside in Seremban will be recruited (hereby referred to as the “unrelated non-diabetic cohort”). This cohort will follow the same schedule for follow-up as described above. This cohort will permit assessment of magnitude of genetic risk for diabetes and to determine excess risk that diabetes brings for the other outcomes

Participants, including diabetes patients, their household family members, and the unrelated non-diabetic cohort, will be recruited over a three-year period (2023–2025). Each participant will be followed up within the subsequent three-year periods:

1. First follow-up: 2026–2028 (3 years)
2. Second follow-up: 2029–2031 (3 years)
3. Third follow-up: 2032–2035 (3 years)
4. Fourth follow-up: 2036–2037 (3 years)

This is an open cohort study, where all diabetes patients registered under the National Diabetes Registry (NDR) and followed up at below listed Kk will be invited to participate.

1. Klinik Kesihatan Seremban (KKS)
2. Klinik Kesihatan Seremban 2
3. Klinik Kesihatan Ampangan
4. Klinik Kesihatan Senawang
5. Klinik Kesihatan Sikamat
6. Klinik Kesihatan Desa Rhu
7. Klinik Kesihatan Sendayan
8. Klinik Kesihatan Rantau

Household family members of these index diabetes patients will also be invited to join the cohort. Additionally, adult unrelated individuals residing in Seremban, who are not known to have diabetes, will be invited to participate.

1. Adult Malaysians (age ≥ 18 years) with doctor-diagnosed type 2 diabetes (Index patients) registered under the National Diabetes Registry (NDR) who are still being followed up at KKS and 7 government health clinics under Seremban District Health Office (PKD Seremban) which includes:
1. Klinik Kesihatan Seremban 2
2. Klinik Kesihatan Ampangan
3. Klinik Kesihatan Senawang
4. Klinik Kesihatan Sikamat
5. Klinik Kesihatan Desa Rhu
6. Klinik Kesihatan Sendayan
7. Klinik Kesihatan Rantau
2. Adult household family members (e.g., spouse, sibling, children, grandchildren) (age ≥ 18 years) of the index patients. A household consists of individuals who usually live together and make common provisions for food and other essentials for living (as defined by the Department of Statistics Malaysia). Household members who are below the age of 18 will be invited to participate in the study when they reach the age of 18 years old.
3. Adult unrelated individuals not known to have diabetes (not related to the index patient) aged ≥ 18 years old living in Seremban.
4. Able to provide written informed consent.

1. Individual’s age <18 years
2. Individuals diagnosed with type 1 diabetes
3. Family members who do not live together or who do not make common provisions for food and other essentials for living with the index patients
4. Individuals who reside outside Seremban.
5. Individuals who do not or are unable to provide informed consent.

1. This study will recruit a total of 9,770 participants, comprising 3,650 diabetes patients, 4,600 household family members, and 1,520 unrelated non-diabetic individuals.

Klinik Kesihatan Seremban (KKS) - the main primary care health clinic in Negeri Sembilan.
Negeri Sembilan has the highest diabetes prevalence in the country at 33.2%, and the population demographic is closely resembling the Malaysian population (in term of racial distribution, socio-economic status, etc).

Each subject will be followed-up for at least 12 years after enrolment. Recruitment will be started in 2023 and continued throughout the study with every 3-years follow-up for at least 12 years.