The diagnosis for treatment of diabetes received a major boost following the results of the recent study conducted by a group of investigators from four top academic and research institutions. The investigators came from the South African Medical Research Council SAMRC, Cape Peninsula University of Technology, Stellenbosch University and the US National Institute of Health. This is the first detailed study ever to involve an African population.
The outcomes have demonstrated for the first time in an African population that the combined use of glycated haemoglobin (HbA1c) and glycated albumin (GA) to diagnose dysglycem has potent effect on diabetes. Dysglycemia is the combination of diabetes mellitus and pre-diabetes.
Diabetes mellitus is a common condition characterised by chronic elevation of blood sugar. It is growing at a fast rate globally particularly in sub-Saharan countries (SSA). According to the International Diabetes Federation (IDF) it is estimated that the number of people with the condition increased by 134% from 24 million in 2021 to 55 million by 2045. The IDF shared the percentage increases of the number of people with diabetes and identified following five countries as top on the list in the SSA.
- South Africa (4.2 million)
- Nigeria (3.6 million)
- Tanzania (2.9 million)
- Ethiopia (1.9 million), and
- Democratic Republic of Congo (1.9 million)
Low detection rates
According to the study, diabetes in SSA is further characterised by the low detection rates, with about 54% of SSA people with diabetes being unaware of their condition; against 44.7% at the global level. The low diabetes detection rate in Africa is attributed to a number of factors. These include the lack of screening programmes, the low prioritisation of large segments of the population (young adults and non-obese people) for diabetes screening where programmes are available, and the lack of accurate and practical diagnostic approaches.
Limited adoption in Africa
The investigators used data for nearly 1 300 adults of mixed-ancestry South African residing in Cape Town to examine the ability of the HbA1c and GA in combination to diagnose diabetes or dysglycemia. HbA1c and GA are both tests used to monitor blood sugar control in response to treatment in people with diabetes. Investigators observed that these have also been proposed for diabetes diagnosis, although not yet widely adopted in the African settings due to their variable performance.
Said Professor Andre Pascal Kengne: “In mixed-ancestry South African, HbA1c and GA levels varied in opposite directions with increasing levels of adiposity as measured by the body mass index (BMI). As a consequence, combining the two tests improved the detection of dysglycemia above and beyond the achievements of each test taken separately, and this improvement was observed across all levels of BMI.” Professor Kengne is the lead author of the publication, and Director of the Non-Communicable Diseases Research Unit (NCDRU) at the SAMRC.
Added another academic who took part in the study: “These findings in mixed-ancestry South Africans are in line with results from our previous studies in African-born Blacks living in America, which have shown that combining HbA1c and GA improves dysglycemia diagnosis, particularly in individuals who are non-obese,” said Dr. Anne E. Sumner, senior author on the paper and Senior Investigator based in Bethesda, Maryland, USA.
For the current study, investigators obtained data from the Cape Town Vascular and Metabolic Health (VMH) project, which is an extension of the Bellville South research programme initiated in Cape Town in 2008. “These new findings are a very useful addition to our efforts to improve the understanding, prevention, detection and control of common cardio-metabolic diseases in mixed-ancestry South Africans and other African populations over the last two decades”, said Professor Tandi E Matsha, co-lead author of the paper.
The investigators noted that screening of populations for common chronic and infectious conditions such as HIV infection is already taking place across Africa using minimally invasive blood sample collection. They said the addition of HbA1c and GA to these programmes provides an opportunity to co-screen people for dysglycemia.
*The study was published in eClinicalMedicine, a Journal of The Lancet group, with the title “Combining HbA1c and glycated albumin improves detection of dysglycemia in mix-ancestry South Africans”; and is fully accessible here: https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(22)00173-0/fulltext