South Africa’s diabetes crisis calls for people at risk to be identified earlier

Source: The Conversation – Africa (2)

Diabetes is the leading cause of death in South Africa. But many people with the condition don’t know they have it. The International Federation of Diabetes has estimated that 60% to 70% of people with diabetes remain undiagnosed.

One reason is that the disease often develops without significant symptoms. There are two main types of diabetes which develop in different ways. Type 2 diabetes is the most common and develops when the cells become less responsive to insulin.

Insulin is a hormone that is produced by the pancreas. It plays a vital role in controlling the amount of sugar (glucose) in our blood. The food we eat is broken down into glucose, which enters the bloodstream and provides the body with energy.

However, glucose needs help to move from the blood into the body’s cells where it can be used for fuel. Insulin acts as a key which unlocks the cells and allows the glucose to enter and provide the fuel needed for organs and tissues to function. When there is more glucose than needed, the insulin can direct the excess to the liver for storage and later use.

Diabetes develops when this system does not work properly.

One of the biggest dangers of diabetes is that people can live with high glucose levels for many years without any symptoms. During this time the excess glucose can damage blood vessels throughout the body. This, in turn, can lead to blurred vision and nerve, heart and kidney damage.

This is why it is important to detect diabetes early. Treatment and lifestyle changes can be introduced to reduce the risk of life-threatening complications.

But many communities don’t have easy access to routine screening or healthcare. Even when routine screening is available, it is often inconsistent and only performed on individuals who already have complications. Point-of-care, finger-prick tests are not uniformly available at health facilities and the quality of testing is not maintained.

Our research at the SAMRC/CPUT Cardiometabolic Health Research Unit aims to study ways of identifying people living with diabetes before they develop complications. Over the years, we have developed expertise in identifying early biological indicators of diabetes. We’ve recognised pitfalls in current tests which are not always appropriate for all populations.

To address this gap we recently investigated simple screening tools which could be used in community clinics that do not have access to laboratories. Our study found that simple measurements, such as waist circumference, could be used to identify those at risk of developing diabetes.

This is important because South Africa must move beyond a symptom driven approach to diabetes detection, and towards risk-based screening.

The challenges with testing

There are four tests used to diagnose diabetes in South Africa. These are the oral glucose tolerance test (OGTT), fasting glucose, random glucose and glycated haemoglobin (HbA1c). Each of these has advantages and challenges.

The OGTT can identify patients at an early stage of the disease. But it is time consuming and requires patients to fast overnight. Before the test, glucose levels must be tested and then patients ingest 75g of glucose. Patients wait two hours for the second glucose sample to be taken. By comparing the two glucose levels doctors can see how the body handled the concentrated glucose intake. This is the gold standard test. But practically it is difficult to implement in primary healthcare settings.

The random blood glucose test does not need fasting, it only requires a blood sample. But it is influenced by food intake, which is difficult to control and can lead to unreliable results. The fasting blood glucose requires an overnight fast and tests must often be repeated as results can be variable. There are many point-of-care glucose tests which people can use at home to monitor glucose levels but these too can give false results if done incorrectly.

Tests for glycated haemoglobin (known as HbA1c) measure the average blood sugar levels over the past two to three months by determining how much excess sugar is stuck to the haemoglobin in the red blood cell. It does not require fasting and could be used to identify people with pre-diabetes as it measures how the body has handled glucose intake over time. Internationally, it has been recommended that a person has diabetes if more than 6.5% of their haemoglobin has blood sugar attached. However, our earlier research has shown that this level may miss early diabetic risk in mixed ancestry communities and that a level of 6.1% would be more appropriate. This has been supported by more recent research which proposed that 6.1% is far more appropriate for early detection and to screen those who remain undiagnosed.

There’s another snag with this test. HbA1c can be tested using point-of-care instruments. But these are not consistently used in South Africa. The test is expensive, and usually performed in laboratories. It is not widely available in public clinics. HbA1c results can also be affected by many conditions such as iron deficiency anaemia, chronic kidney disease or when the lifespan of a red cell is lower than normal.

This means that the test is not equally reliable across different population groups, particularly in Africa. In response to these limitations, the National Department of Health suggested in 2017 that the HbA1c should not be used as the primary diagnostic test unless evidence-based population studies have been conducted.

Our unit’s previous research supports this and recommends that HbA1c in combination with other tests such as glycated albumin may improve the early detection of diabetes.

One of our goals is to identify simple measurements which can be used in community clinics to identify risk of diabetes before the development of complications.

Recent research conducted in our laboratory has identified waist circumference, waist to height ratio and excess abdominal fat to be closely associated with insulin resistance and a higher risk of type 2 diabetes. This simple measurement could be included in routine community health screening. It would allow those with increased waist circumference together with other risk factors such as high blood pressure and family history to be referred for further glucose testing.

Waist circumference cannot diagnose diabetes, but can be valuable in identifying those at risk, and with simple lifestyle changes and exercise this could be reversed.

What needs to be done

South Africa’s diabetes crisis requires a multi-pronged approach.

Simple, inexpensive tests and screening tools are required to detect undiagnosed people living with diabetes in South Africa. Research must identify these tests, and provide evidence that they work and can be used effectively.

The country needs strong public health campaigns, simple and accessible screening programmes and improved access to diagnostic testing and treatment.

This requires commitment from policymakers, citizens, healthcare workers and researchers.

Glenda Mary Davison receives funding from the South African Medical Research Council (SAMRC) and the South African National Research Foundation (NRF) NEDBANK SARChi Chair (Grant number: 115450).

Saarah FG Davids and Shanel Raghubeer do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

Original source: https://analysis1.mil-osi.com/2026/11/13/south-africas-diabetes-crisis-calls-for-people-at-risk-to-be-identified-earlier/