Almost one in four Sri Lankan adults (23%) had diabetes, and another one in three (31%) had high blood sugar levels according to a large national survey done in 2019 by researchers from several Sri Lankan universities, the Medical Research Institute (MRI) in Colombo, and the Institute for Health Policy (IHP).

According to IHP, the survey is the first national survey of diabetes in Sri Lanka that used the gold standard method of an oral glucose tolerance test to diagnose diabetes.

The study also found that almost two in five Sri Lankans with diabetes (38%) have not been diagnosed. The study results were published this week in the London-based British Medical Journal Open Diabetes Research and Care.

The study uses data from the first wave survey of the Sri Lanka Health and Ageing Study (SLHAS), which is a long-term national study managed by the Universities of Colombo, Peradeniya, Ruhuna and Rajarata, and IHP, and approved by the Ministry of Health. The SLHAS recruited over six thousand adults from three hundred communities across Sri Lanka during the course of 2019 to track their health over time.

Participants in the study gave a fasting glucose blood sample, and most also agreed to take the oral glucose tolerance test which requires a second blood sample after taking a sugar drink. These blood samples were then tested by Dr Renuka Jayatissa at her laboratory in the MRI in Colombo. The researchers used the results to estimate how many Sri Lankans have diabetes, and how diabetes varies across people.

The study found that diabetes is more common in Sri Lankans who are overweight, and those who are better-off or living in more developed areas of the country, and that rates are highest in Western Province, Jaffna, and some other parts of the Northern and Eastern Provinces. In the Colombo district, the researchers estimate that as many as one in three adults (34%) have diabetes.

“These findings indicate that Sri Lanka has the highest rate of diabetes in Asia, and in fact one of the highest in the world, since there are only a few countries—some small Pacific Islands and places like Egypt and the Gulf states—with higher rates,” said Dr Ravi Rannan-Eliya, lead investigator for the study and Executive Director of IHP.

The study findings show that diabetes develops at lower body weights in Sri Lankans than in Europeans, with one in five Sri Lankans (21%) of normal body weight having diabetes. “This is something we as Sri Lankans all need to be aware of—we are much more at risk of developing diabetes than people in rich countries, so keeping our weight down and eating a healthier diet as much as possible is even more important,” Dr. Rannan-Eliya added.

Although it is difficult to reverse diabetes once it develops, being diagnosed early and getting treatment can help minimize many of the bad health outcomes, such as heart and kidney disease. The study findings indicate that more than one million Sri Lankans do not know they have diabetes, and it underlines the importance of everyone getting tested on a regular basis.

“Whatever we do, we cannot prevent millions of Sri Lankans from developing diabetes in the next few decades. That’s a reality our health system is going to have to deal with for many years to come. At a time when many diabetes patients are struggling to obtain their medicines, this really underlines the importance of raising taxes in the long-term to properly fund the Ministry of Health medicines budget so that everyone can have access to the needed treatment,” commented Dr Rannan-Eliya.

The SLHAS survey of diabetes was funded by the Swiss National Science Foundation and IHP’s Public Interest Research Fund.