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We conclude that in patients with type 1 diabetes, autonomic neuropathy further reduces counterregulatory catecholamine responses. Since this should increase the risk for severe hypoglycemia, one might consider safer therapeutic goals in these patients.

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In order to examine the physiological variation in blood pressure and heart rate that occurs during normal activities in patients with diabetes, 24-h profiles were constructed from continuous ambulatory recordings. Isometric and dynamic tests were also performed. The patients were subdivided into 25 uncomplicated cases, 11 with peripheral neuropathy and 6 with autonomic neuropathy. These were compared with a 'control' group of 22 normal subjects. Abnormal 24-h blood pressure profiles were found particularly in the patients with autonomic neuropathy. This group had attenuation or reversal of the usual diurnal rhythm, blood pressure often rising during the night and falling in the early morning. Diurnal heart rate variation was reduced in all three groups of patients. Blood pressure responses to both forms of exercise were also significantly reduced in the autonomic neuropathy group (maximum change in systolic blood pressure during isometric exercise was 10 +/- 4 mmHg vs 36 +/- 3 mmHg in the control group, p less than 0.003). Patients with peripheral neuropathy also had some impairment of exercise-induced blood pressure changes, but to a lesser degree.

In clinical islet transplantation to patients with type 1 diabetes mellitus, the number of isolated and purified islet has been identified as a key determinant for functional success of the islet graft. With improved isolation methods based on the original procedure published by Ricordi et al. yield and function of isolated islets were considerably enhanced. However, there is still a large variance in the number, purity, viability and secretory capacity of islets isolated from brain-dead human donor pancreata, significantly hampering utilization of human islet preparations derived from a single donor for one diabetic recipient. The reasons for the limited success in islet isolation and purification have not been clarified in detail yet. Recent studies have indicated, that donor preconditions, and a number of technical factors during organ procurement and the islet isolation process itself are critical to successful islet isolation. This study aimed at identifying distinct morphological and histopathological characteristics of the donor pancreas as determinants for the outcome of human islet isolation and purification.