Non-islet-cell tumours which induce hypoglycaemia are rare. Insulin-like growth factor-II (IGF-II) produced by some tumours is thought to be responsible for the hypoglycaemia and other systemic effects, despite normal or even low serum IGF-II levels. We studied a 44-year-old woman presenting with symptomatic hypoglycaemia associated with a large intraabdominal haemangiopericytoma. The serum IGF-II level was 455 μg/l when measured after acid-ethanol extraction (normal range (NR) 450–750 μg/l) and 1063 μg/l after acid chromatography (normal human serum pool 1068 μg/l). Levels of fasting plasma insulin, C-peptide, glucose and serum IGF-I levels were low before the operation (< 2 mU/l (NR <2-14), 0·23 nmol/l (NR 0-4-1-2), 3-1 mmol/l, (NR 3-7-5-9) and 002 U/ml respectively). After tumour removal, the symptoms resolved rapidly and the patient made a full recovery. Secretion of both insulin and growth hormone was suppressed before the operation in response to a 75 g glucose meal and to an infusion of 100 μg GH-releasing hormone (GHRH) respectively in comparison with studies after the operation. Serum IGF-II levels 6 weeks and 12 weeks after the operation fell to 385 μg/1 (777 μg/1; acid chromatography) and 280 μg/1 (647 μg/1; acid chromatography) and serum IGF-I levels increased to 0-35 U/ml and 0-26 U/ml. Serum before the operation and tumour extract contained chiefly a large molecular weight precursor IGF-II (molecular weight 15 000–20 000) which disappeared from the serum after the operation. The IGF-binding proteins (IGFBP-1, IGFBP-2, IGFBP-3 and IGFBP-4) were examined. The preoperation fasting serum IGFBP-1 level was lower than expected (31 μg/l (NR 20–70 μg/l)) and similar to levels at 6 weeks after the operation (33 μg/l). This was surprising given the differences in plasma insulin levels before and after the operation (< 2 mU/l versus 13 mU/l). Using Western ligand blotting techniques, serum IGFBP-3 levels were found to be low and IGFBP-2 appeared to be the dominant IGFBP before the operation. Serum IGFBP-3 levels after the operation fell further. This further decrease appeared, in part, to be due to the presence of a cation-dependent IGFBP-3-specific protease which has previously only been described in late pregnancy.
We conclude that in this subject, despite normal serum IGF-II levels, the hypoglycaemia and systemic effects on insulin and GH secretion were due to increased bioavailability of a circulating tumour-produced precursor form of IGF-II. This increased bioavailability appears to be due to alterations in the circulating levels and perhaps affinities of the IGFBPs.
Journal of Endocrinology (1991) 131, 303–311
Journal of Endocrinology is committed to supporting researchers in demonstrating the impact of their articles published in the journal.
The two types of article metrics we measure are (i) more traditional full-text views and pdf downloads, and (ii) Altmetric data, which shows the wider impact of articles in a range of non-traditional sources, such as social media.
More information is on the Reasons to publish page.
| Sept 2018 onwards | Past Year | Past 30 Days | |
|---|---|---|---|
| Full Text Views | 3 | 0 | 0 |
| PDF Downloads | 2 | 0 | 0 |
Online ISSN: 1479-6805
Print ISSN: 0022-0795
Strengthening biomedical communities
to advance science and health
CONTACT US
Bioscientifica Ltd | Starling House | 1600 Bristol Parkway North | Bristol BS34 8YU | UK
Bioscientifica Ltd | Registered in England no 3190519
