Increased proinsulin levels as an early indicator of B-cell dysfunction in non-diabetic twins of Type 1 (insulin-dependent) diabetic patients

✍ Scribed by D. A. Heaton; B. A. Millward; I. P. Gray; Y. Tun; C. N. Hales; D. A. Pyke; R. D. G. Leslie

• Publisher: Springer
• Year: 1988
• Tongue: English
• Weight: 317 KB
• Volume: 31
• Category: Article
• ISSN: 0012-186X
• DOI: 10.1007/bf00276853

✦ Synopsis

Glucose tolerance and insulin secretion were studied in two groups of non-diabetic identical twins of recently-diagnosed Type 1 (insulin-dependent) diabetic patients: (1) a group of 5 twins with islet cell antibodies, and (2) a group of 6 twins without. Despite similar fasting glucose, insulin and C-peptide concentrations both groups of twins had significantly higher fasting proinsulin concentrations than the control group (p less than 0.05). The twins with complement-fixing islet cell antibodies had reduced glucose tolerance and clearance, whilst the twins without islet cell antibodies did not. Neither group of twins showed any abnormality in insulin, C-peptide or proinsulin response to oral or intravenous glucose. We conclude that increased fasting proinsulin levels precede abnormalities of insulin secretion, and are an early indication of minor B-cell damage in these twins irrespective of their risk of developing diabetes.