Mechanisms
- Non enzymatic glycosylation (NEG)
- Vascular permeability – sorbitol (polyol pathyway – aldolase)
- Microvascular occlusions – affects retina, renal, nerve sheath
- Macrovascular – atherosclerosis (stroke, AMI, diabetic foot)
Diabetic retinopathy
- Cataracts/EOM palsy (oculomotor, trochlear, abducens)
- Fundus findings
- Blot haemorrhages, hard exudates, cotton wool spots, micro aneurysms, macular edema
- Sudden vision loss – vitreous haemorrhage
- Ischemia stimulates VEGF > non proliferative/proliferative
Treatment
- Depends on grading
- Ranibizumab (VEGF inhibitor), vitrectomy
Nephropathy
- Please check diabetic nephropathy and chronic glomerulonephritis for detailed information
- Thickening of glomerular basement membrane and matrix deposits in mesangium > glomerulosclerosis/renal failure
- Sequence of events – Microalbuminuria > proteinuria > Nephrotic syndrome
- Mesangial hypertrophy due to increase glomerular filtration rate (afferent/efferent dilation)
Diagnosis
- ACR <2.5 (males), <3.5 (females) , mid-stream urine
Neuropathy
- Occlusion of vasa-nevorum + Sorbitol > delayed nerve conduction
- Somatic and autonomic neuropathy
Types
- Symmetrical sensory polyneuropathy – altered pain and temperature
- Asymmetric motor neuropathy – weakness, wasting, cachexia
- Mononeuritis – CN3/6 – diplopia, sciatica, median nerve (carpal tunnel)
- Autonomic
- Vagus – postural hypotension, tachycardia
- Dysphagia, constipation, gastroparesis
- Bladder – incontinence, atonic, UTI, erectile dysfunction
- Combination of peripheral vascular disease and neuropathy following trauma