Acute Complications of Insulin deficiency

ACUTE COMPLICATIONS OF INSULIN DEFICIENCY

Patients with type 1 diabetes present when progressive β-cell

destruction has crossed a threshold at which adequate insulin

secretion and normal blood glucose levels can no longer be

sustained. Above a certain level, high glucose levels may be toxic

to the remaining β cells, so that profound insulin deficiency rapidly

ensues, causing the metabolic sequelae shown above.

Hyperglycaemia leads to glycosuria and dehydration, causing

fatigue, polyuria, nocturia, thirst and polydipsia, susceptibility to

urinary and genital tract infections, and later tachycardia and

hypotension. Unrestrained lipolysis and proteolysis result in weight loss. Ketoacidosis occurs when generation of ketones

exceeds the capacity for their metabolism. Elevated blood

H+ ions drive K+ out of the intracellular compartment, while

secondary hyperaldosteronism encourages urinary loss of K+.

Thus patients usually present with a short history (typically a few

weeks) of hyperglycaemic symptoms (thirst, polyuria, nocturia

and fatigue), infections and weight loss, and may have developed

ketoacidosis