Some diabetes complications can be detected and treated early to prevent their progression and causing significant adverse effects on health. These complications include diabetic retinopathy, diabetic kidney disease, neuropathy, peripheral arterial disease, and metabolic-associated fatty liver disease (MAFLD).
Screening for diabetic retinopathy
Diabetic retinopathy can develop insidiously and without any symptom. Untreated, it leads to vitreal hemorrhage (bleeding) and blindness. Other complications also include swelling at the center of the retina, called diabetic macular oedema (DME).
Eye examination to look for early signs of diabetic retinopathy or DME is invaluable as it allows the diabetes care provider to monitor for retinopathy progression and administer timely treatment to prevent bleeding and blindness. Treatments with pan-retinal photocoagulation (PRP), focal photocoagulation, and vascular endothelial growth factor (VEGF) inhibitors are very effective and have been proven to reduce the risk of sight loss in people with diabetes. Without regular eye examinations, the opportunity for these treatments are often missed and patients may lose their vision if diagnosed too late.
All person with diabetes should undergo annual eye examination to screen for diabetic retinopathy and DME. Eye examination should start 5 years after diagnosis in people with type 1 diabetes, or as soon as after diagnosis in people with type 2 diabetes. More frequent eye examinations are required if the person with diabetes becomes pregnant, or if previous eye examinations are abnormal.
A normal fundus (portion of the retina that is visible on examination) (click on image to zoom).
Fundus of a patient with proliferative diabetic retinopathy (click on image to zoom).
Screening for diabetic kidney disease
Early diabetic kidney disease can be detected by testing the urine for albumin. The presence of very low levels of albumin in the urine can be normal, but at elevated levels (moderately-increased or severely-increased albuminuria), it predicts the development and progression of diabetic kidney disease, cardiovascular disease, and heart failure. Treatment for albuminuria, on the other hand, have been unequivocally shown to reduce the risks of these complications.
Albuminuria can be treated or even reversed with:
1. Improving blood pressure control
2. Improving HbA1c control
3. Treatment with ACE inhibitors or angiotensin receptor blockers
4. Treatment with SGLT-2 inhibitors and/or GLP-1 receptor agonists
5. Treatment with finerenone, a new minerolocorticoid receptor antagonist (not available yet in Malaysia)
It is important to note that a single reading of albuminuria may not be significant, as many other daily events (exercise, fever, high blood pressure, infection, etc) can transiently increase the albumin level in the urine. If albuminuria is detected, a repeat test in 3 months time is recommended to establish the diagnosis.
Some people with diabetes may develop diabetic kidney disease even without albuminuria. Hence, apart from testing for urine albumin, regular kidney function test is also warranted for all patients, typically once a year if normal. If the test is abnormal, it may need to be repeated more frequently.
Screening for diabetic foot complications
Foot complications from diabetes can be the result of nerve damage (diabetic neuropathy), peripheral arterial disease, or both. These complications include Charcot arthropathy, diabetic foot ulcer, foot gangrene, and amputations.
Diabetic foot complications can be prevented by regular foot examination for diabetic neuropathy and peripheral arterial disease. The most commonly used method to screen for diabetic neuropathy is using the monofilament, a plastic filament used to test for sensory loss that the feet and soles. This can also be used together with either a 128 Hz tuning fork or a tendon hammer to demonstrate the loss of sensation to vibration perception and the loss of ankle tendon reflexes.
The monofilament test is performed by pressing the standard 10g monofilament to the skin until it buckles for 2 seconds, and then releasing it. Inability to perceive the monofilament pressure on the skin is a sign of sensory loss due to diabetic neuropathy. The red and pink dots are the recommended sites for examination (click on image to zoom).
Peripheral arterial disease can be easily screened with a simple palpation of the foot arteries (the dorsalis pedis and tibial arteries). The ankle-brachial index test may also be used to detect abnormal pressures at these foot arteries.
People with diabetes should have their feet examined at least once a year by their diabetes care provider, and more frequent if any abnormality is detected. Patients with sensory loss or high risk of foot ulcers require foot examination at every visit. These examinations will also include inspection of the skin for skin breaks, callus, or infections, as well as the toenails for any abnormality that can lead to foot infection or gangrene.
Screening for metabolic-associated fatty liver disease
Metabolic-associated fatty liver disease (MAFLD) is being increasingly recognized as a major complication of diabetes, and is currently the most common cause of liver failure in developed countries. Various screening tests have been developed for MAFLD. The probability of having liver fibrosis due to MAFLD can also be predicted using calculations derived from blood tests for liver enzyme levels (ALT and AST) and platelet levels. These tests are increasingly offered as part of the screening process for diabetes complications.