He had several episodes of hyperglycemia requiring large doses of insulin.
 He had high blood sugar levels
(ROOT (S (NP (PRP He)) (VP (VBD had) (NP (NP (NP (JJ several) (NNS episodes)) (PP (IN of) (NP (NN hyperglycemia)))) (VP (VBG requiring) (NP (NP (JJ large) (NNS doses)) (PP (IN of) (NP (NN insulin))))))) (. .)))
(ROOT (S (NP (PRP He)) (VP (VBD had) (NP (JJ high) (NN blood) (NN sugar) (NNS levels)))))
( He ( ( had ( ( ( several episodes ) ( of hyperglycemia ) ) ( requiring ( ( large doses ) ( of insulin ) ) ) ) ) . ) )
( He ( had ( high ( blood ( sugar levels ) ) ) ) )