Type 2 diabetes and its misdiagnosis

According to a recent international study published in September, people of African descent may mistakenly be given the all-clear from a widely used type 2 diabetes test called HbA1c. This as scientists found 42 new genetic variants that could influence a person’s HbA1c readings which could affect the diagnosis of diabetes. This week Moneybags looks into the diagnosing of diabetes specifically in South Africa.

For many this test is being used as the sole means to diagnose diabetes, and this is where the concern presents.

What is type 2 diabetes?

Diabetes South Africa (DSA) explains: “Type 2 diabetes is caused when the insulin, which the pancreas produces, is either not enough or does not work properly. Approximately 85 – 90% of all people with diabetes are type 2, and many people who have this condition are undiagnosed.”

Type 2’s are typically over 40, overweight and do not exercise. Type 2 diabetes may be treated successfully without medication.

“Often loss of weight alone will reduce glucose levels. Eating patterns and exercise play important roles in management. Tablets may be prescribed to help improve control, however, many type 2’s will eventually use insulin,” adds DSA.

The organisation importantly adds that although type 2 is, in itself, not life threatening, in many ways it is more dangerous than type 1, as its onset is gradual and hard to detect. High blood glucose levels over a long period of time can cause serious damage to the delicate parts of the body and lead to blindness, heart attack\stroke, kidney failure, impotence and amputation.

The Science behind the misdiagnosis 

“Recent World Health Organisation recommendations cite HbA1c as a method for the diagnosis of diabetes, in addition to more conventional methods of testing blood sugar in a fasted state or after an oral glucose challenge. There is substantial debate about the use of HbA1c for diagnosis as there are known ethnic variations in the relationship between HbA1c and blood sugar, and the majority of studies to date have been done in populations of European origin. [This] study gives us a genetic explanation for why we should continue to be cautious about a wholesale shift to HbA1c for diagnosing diabetes,” University of Witwatersrand endocrinologist, Alisha Wade, told Business Day.

Further concern stems from the fact that according to The South African Society for Endocrinology, Metabolism and Diabetes’ guidelines, HbA1c is recommended for the diagnosing of type 2 diabetes in the case of there being no haemoglobin discrepancies. The issue however presents in that screening for these discrepancies is hardly done in South Africa.

The science behind this finding indicates that a variation of the G6PD gene which is responsible for encoding of an enzyme that is linked to the survival of a red blood cell tends to decrease HbA1c levels regardless of the blood glucose levels. According to the report 11% of African Americans carried copies of this variation.

“There is no such thing as ‘mild’ diabetes. Diabetes is always serious. If it is left untreated or is not well managed, the high levels of blood glucose associated with diabetes can slowly damage both the fine nerves and the small and large blood vessels in the body, resulting in a variety of complications.
These include heart disease, blindness, amputation, kidney disease and erectile dysfunction or impotence. The good news is that with careful management, these complications can be delayed and even prevented, but early diagnosis is very important. You need to know what the symptoms of diabetes are and whether you are at risk,” states Diabetes South Africa.

On a larger scale on 28 June 2017, nine international experts, including economist Jeffrey Sachs and nutritionist and writer, Marion Nestle, launched a petition through a column in the prestigious French newspaper Le Monde calling for urgent international action to tackle the scourge of diabetes in Africa, reports the International Diabetes Federation (IDF).

“The epidemic of diabetes is increasing inexorably on the continent, under the combined effects of rapid urbanisation, modification of eating habits, increase in life expectancy and environmental changes. Despite the gravity of the situation, less than 2% of all global health funding is dedicated to this major public health challenge. An international movement is urgently needed to raise awareness of an epidemic that has been overlooked for too long, and more importantly to support and give hope to people with diabetes, mostly disadvantaged, who lack access to care and appropriate treatment,” the IDF further adds.