Excessive blood glucose levels for a prolonged period have detrimental effects on blood vessels.
This can be classified into microvascular (small vessels) and macrovascular (large vessels) complications.
Glycemic control dictates the severity of the microvascular complications but has a less consistent effect on macrovascular complications.
Microvascular complications include:
- Kidney disease (Nephropathy)
- Blindness (retinopathy)
- Amputations (the end result of Neuropathy)
These final outcomes are influenced by lipid abnormalities, blood pressure, obesity and age.
Diabetic retinopathy is the most specific and prevalent complication, which is one of the leading causes of blindness worldwide. Periodic complete dilated retinal examinations are paramount in the management of this disease.
Cataracts (lens opacification), Glaucoma (increased intra eye pressures) and fluctuating refractive errors are commonly associated with retinopathy.
Diabetic Nephropathy is characterised by persistent proteinuria (protein leakage in the urine) followed by deterioration in the renal filtration efficiency characterised by raised serum creatinine, culminating in end-stage kidney disease.
Elevated blood pressure, low haemoglobin, mineral bone disease and fluctuating blood glucose accompanies Nephropathy. Spot urine albumin creatinine ratio long with serum creatinine measurement are assessed as needed by treating health care professionals.
Diabetic Neuropathy is the least specific but might be presenting complication in the majority of the patients.
Its manifestations include foot pain, sudomotor dysfunction (deranged sweating and motor function) leading to foot ulcers and amputations.
General foot care principles like daily feet inspection, treating calluses and nail care are vital.
Autonomic Neuropathy can cause erectile dysfunction, constipation, postural hypotension, hypoglycaemia unawareness and urinary retention/incontinence.
Macrovascular complications include:
- Coronary artery disease (heart attacks)
- Brain strokes
- Peripheral vascular disease.
Elevated blood glucose levels have less correlation with their severity and other risk factors like hypertension, smoking, obesity and lipid abnormalities may play a major role in their causation.
Coronary heart disease (CHD) is the most common cause of mortality in patients with diabetes. Diabetes is being considered as coronary heart disease equivalent in many centres.
- Effective management of new onset diabetes for prolonged periods has showed improvement in prevalence of CHD.
- However, intensive treatment of advanced diabetes yielded mixed results and is discouraged by experts.
- Recently, oral hypoglycemic drugs like SGLT2 Inhibitors and GLP-1 agonists have garnered attention for their cardio-protective effects.
Strokes are broadly divided into Ischemic (onsite clots occluding flow in the blood vessel), Embolic (clots dislodged from distant artery or heart occluding the vessel) and Hemorrhagic (vessel wall rupture resulting in blood leakage) types.
- They generally present with speech difficulties, weakness of upper and lower extremities and deviation of angle of mouth.
- Neurological compromise depends on the degree of hindrance to the blood supply for specific regions of the brain. Full recovery typically takes many months in severe cases.
Peripheral vascular disease (PVD) in addition to neuropathy is one of the leading causes of non-traumatic lower limb amputations globally.
Non joint related lower extremity pain, Rest pain, Intermittent claudication (pain in the calves and thigh region on exertion) and blackening of toes (gangrene) are usual presenting symptoms.
Diabetic foot ulcers and osteomyelitis (infection of bones) are well known conditions associated with PVD, thereby increasing long-term morbidity.
Skin and joint related disorders like limited joint mobility, shin spots, frozen shoulder and carpal tunnel syndrome are not uncommon.
Last but not least, periodontal disease (teeth and gums) is prevalent in patients.