Diabetes In Sindhi Families In Nagpur (DISFIN)

At each Participant Recruitment Center:

1. We announced the dates of recruitment locally through pamphlet distribution, personal conversations, emails and a study website to the residents of the study areas. When the participants came in for the study, they were first administered the informed consent form.

2. Upon receiving such consent a Field Research Officer (FRO) appointed specifically for the study collected the demographic data and conduct anthropometric measurements. All the data has been directly input into a cloud-based database through tablet computers made available to the FROs for the purpose of the study.

3. A trained nurse then measured the blood pressure of the participant as follows: These measurements were conducted using a random-zero sphygmomanometer on the left arm. To account for the potential variability in the blood pressure measurements, we measured the blood pressure thrice with 5-minute intervals but use the average of the last two readings as the phenotypic trait value. Appearance of the first Korotkov sound and disappearance of the fifth Korotkov sound was considered as the systolic and diastolic blood pressures, respectively.

4. Thereafter the participant were under electrocardiographic evaluation. The examination was conducted by a trained ECG technician using a portable ECG machine with limb leads, chest leads and augmented leads. The signal recordings were digitized and stored as digital signal files. Novacode software was used to quantitatively measure important phenotypic traits from the ECG signals.

5. The participant then proceeded to measurement of random blood glucose using a glucometer and disposable test strip. The results are shared with the participant as well as entered directly into the cloud-based database.

6. Then the participant were given a urine sample collection cup. The urine sample was used to estimate urine sugar and microalbuminuria.

7. The participant were then given an appointment for fasting blood studies.

8. On the day of the appointment, a trained laboratory technician appointed for the purpose of the study drew 10 ml of venous blood from the ante-cubital vein. This blood sample will be used for lipid profile studies (total and free serum cholesterol, serum triglycerides, high-density lipoproteins, low-density lipoproteins, very low-density lipoproteins and apolipoproteins), fasting plasma glucose, serum cotinine (to corroborate the history of smoking), serum creatinine (to quantify urinary dilution), serum C peptide (to distinguish between type 1 and type 2 diabetes), plasma insulin and serum HbA1c (glycated hemoglobin).

9. To maximize participation for the fasting blood studies, we sent text reminders to participants before the date of appointment. If the participant cannot make it on the day of appointment then we again sent text and/or telephonic reminders to them for a revised appointment date. We did this for a total of three times before the reminders can be stopped.

10. If the participants were diagnosed with any medical condition during the examination then they were duly referred to expert medical help outside of the DISFIN study. If the participant was newly diagnosed as a case of T2D during study the participant was referred to expert diabetologist in the city for further medical care.

11. Lastly, we provided a nominal time compensation for each participant who completed all the study procedures.