Diabetes – Important facts and screening.

Diabetes is increasing faster than projected, yet 50–73% of affected people remain undiagnosed and only half of diagnosed patients are treated to target; every practice should therefore implement systematic screening and integrated cardio-renal-metabolic risk management.

Important facts about diabetes.

1. Diets high in carbohydrates and sedentary lifestyle are the main causes of diabetes.
2. 50% of diabetics are obese.
3. 589 million people worldwide have diabetes, and this will explode to 629 million people in 2045. This equates to 10,5% of the world’s population.
4. 54% of people globally are not aware that they have diabetes.
5. In 2024 2,4 million SA had diabetes or 7,2% of the population.
6. 90% are Type 2 and 10% Type 1.
7. In South Africa 50% are undiagnosed and the latest figure is even higher at 73%.
8. 50% of known diabetic patients are not treated to target and remain uncontrolled.
9. 80% are from low-income groups and will place a large burden on healthcare.
10. The incidence of diabetes will increase by 142% from 2024-2050.
11. South Africa has the 5^th highest incidence of diabetes in Africa.
12. Although mortality in diabetic patients has decreased, the risk of having a cardiovascular event is still twice that of a non-diabetic.
13. Diabetes remains the leading cause of death in women in South Africa since 2019.
14. Diabetes is the sixth most common cause of death in men.
15. A person with diabetes has the same risk of a cardiovascular event, myocardial infarct or stroke, than someone who has already had a cardiovascular event.
16. Once a person has had his first cardiovascular event, they are twice as likely to die. Prevent the first event.
17. Smoking doubles the chance of developing complications from diabetes. They must stop.
18. Diabetes is the last of the metabolic syndrome diseases to present. It starts with obesity → hypertension → dyslipidemia and lastly diabetes. Thus, all the components of the metabolic syndrome must be screened for and treated to target. All metabolic diseases should be screened for diabetes. Treat each individual condition to target to get the best outcome from the metabolic syndrome.
    • Hypertension controlled at 130/80mmHg.
    • Treat LDL cholesterol to target depending on the risk classification.
    • Treat obesity as a disease.
19. We all know that diabetes causes macro and microvascular disease, but do we all know about cardio-renal-metabolic syndrome?

Glycemic control is very important as measured by HbA1C

For every 1% decline in HbA1C

• 43% reduction in peripheral vascular disease and amputations.
• 37% reduction in microvascular complications.
• 21% reduction in deaths.
• 12% reduction in strokes.

Diabetes is a very important cause of heart failure.

• After age and gender, diabetes is the 3^rd most important cause of both HFpEF due to concentric LVH disease and HFrEF after a myocardial infarction. It is the most common complication of diabetes.
• There is a 2-5-fold increased risk of diabetes if diagnosed with heart failure.
• 68% of the high-risk group with normal stress testing showed LV dysfunction.
• 33% of people with diabetes will have cardiovascular disease.
• 67% of patients with heart failure also have chronic kidney disease.
• ACR is an important biomarker for the incidence of heart failure.

Diabetes and Chronic Kidney Disease

• 80% of end stage renal failure cases either have hypertension or diabetes or both.
• Diabetics are 6 times more likely to be hospitalized with chronic kidney disease and 12 times more likely to have end stage renal failure.
• Diabetes and early CKD results in 16yrs reduction in life expectancy.
• Chronic kidney disease (CKD) increases the risk of all-cause mortality:
  • No CKD               – 4,1
  • With albuminuria -17,2
  • With low eGFR    – 23.9
  • The combined presence of albuminuria and reduced eGFR is associated with the highest all-cause mortality risk, underscoring the importance of early CKD detection in people with diabetes.
• As kidney function declines, coronary artery disease and heart failure increase significantly.
• As kidney function declines episodes of hypoglycemia increase with all its associated complications.

Metabolic fatty liver disease.

• 55% of diabetics have fatty liver disease.

The incidence of diabetes and its complications highlight the need for good care for these patients and as 73% are undiagnosed, screen for diabetes.

Who to screen:

1. Symptoms of diabetes – 3 Poly’s, weight loss and increased appetite. Fatigue. Male with candida balanitis. Female with vulvovaginal candidiasis. Visual problems. Recurrent skin infections or poorly healing skin lesions.
2. Anybody with other conditions of the metabolic syndrome, obesity, hypertension and dyslipidemia, HDL < 0,9mmol/l and/or Triglycerides >2,6mmol/l.
3. Obesity: 70% of SA women and 30% of men are obese with a BMI >25. Increased incidence of diabetes in men and women if BMI >27. The incidence increases exponentially once the BMI is more than 30. The chance of developing diabetes for obese women is double compared to men.
4. First degree family history of diabetes.
5. Females with gestational diabetes and hypertension in the past, miscarriages, stillbirths and large babies of more than 4,0kg.
6. Sedentary lifestyle.
7. PMOS patients. (Polyendocrine Metabolic Ovarian Syndrome.)

How to screen:

1. Random sugar >6,5mmol/l must have a fasting sugar done.
2. Fasting sugar of >5,8mmol/l must have a Glucose Tolerance Test (GTT) done.
3. HbA1C > 6,5% = Diabetes.
4. Oral Glucose Tolerance Test: Fasting sugar → 75g glucose load → 2h Glucose.
5. If the random sugar is >11.1mmol/l there is no need to do a GTT. Use the following criteria to make the diagnosis.

 You need two readings to make the diagnosis of diabetes.

First reading	Second reading	Diagnostic of diabetes
Random sugar >11.1mmol/l	Symptoms of diabetes	Yes
Random sugar >11,1mmol/l	Random sugar >11.1mmol/l	Yes
Random sugar >11.1mmol/l	Fasting sugar >7,0mmol/l	Yes
Random sugar >6,5mmol/l	HbA1C >6,5%	Yes

If still not sure about the diagnosis do a GTT

Fasting	2-hour value	Diagnosis
5,5 – 7,0	< 7.7	Normal
>7 mmol/l	<7,7	IFG – Impaired fasting glucose
>7	7,8 – 11.0	IGT – Impaired glucose tolerance
>7	≥11.1	Diabetes.

Diagnosis of Gestational Diabetes

	Fasting	1 hr after 75g glucose	2 hour after 75g glucose
Diagnostic of Gestational Diabetes	>5,1mmol/l	> 10mmol/l	>8,5mmol/l.
Level to aim in pregnancy	<5,3mmol/l	<7,8mmol/l	<6,7mmol/l

Prediabetes

IFG and IGT are both pre-diabetic conditions and will progress to diabetes within 8-10yrs. Then there is a period called latent diabetes when someone already has diabetes, but it has not been diagnosed yet. Micro and macrovascular complications can already start in the pre-diabetic period. It is thus of paramount importance that it be diagnosed in the pre-diabetic period or at least as soon as possible. If managed early and well with lifestyle, correct eating habits, loss of weight, exercise and with the use of Metformin one can reverse the condition and prevent diabetes.

Summary

The scale of undiagnosed and uncontrolled diabetes requires immediate action: promote sustainable lifestyle change, adopt a consistent risk-based screening protocol, identify pre-diabetes and diabetes earlier, and treat every cardio-renal-metabolic risk factor to target.

Resources

1. The above data is from a compilation of my previous summaries in the time that I did not acknowledge the authors. I apologize for this.

Dr. Charles Schoeman. Specialist Family Practitioner.

2. Extending access to GLP-1 receptor agonists for T2DM patients with chronic obesity.

Dr. Zaheer Byat. De Novo Medica.

3. Making sense of SGLT-2 inhibitors in daily practice 2026 Clinical update of CRM therapy.

4. Dr. Zaheer Byat. De Novo Medica.

Summarized by Dr. Charles Schoeman. Reviewed in July 2026.