How does insulin deficiency occur ?

Explanation

(i) In the case of Type I insulin dependent diabetes, the `beta`-cells of the pancreas get destroyed.
(ii) This results in deficiency of insulin produced by the pancreas, since `beta`-cells produce insulin.
(iii)) In the case of non-insulin dependent diabetes mellitus, insulin production by the pancreas is normal but its action is impaired.
(iv) Thus in both cases, deficiency of insulin is observed.