Changes in blood flow close to subcutaneous insulin injection sites in stable and brittle diabetics

• Published in: Diabetes (New York, N.Y.) Vol. 32; no. 5; pp. 466 - 473
• Main Authors: Williams, G., Pickup, J., Clark, A., Bowcock, S., Cooke, E., Keen, H.
• Format: Journal Article
• Language: English
• Published: American Diabetes Association 01-05-1983
• ISSN: 0012-1797; 1939-327X; 0012-1797
• DOI: 10.2337/diabetes.32.5.466

Changes in blood flow close to subcutaneous insulin injection sites in stable and brittle diabetics.
G Williams ,
J Pickup ,
A Clark ,
S Bowcock ,
E Cooke and
H Keen
Abstract
Photoelectric plethysmography (PPG) was used to investigate blood flow changes close to superficial subcutaneous injection
sites. As a validation procedure, the PPG response to subcutaneous injection of a known hyperemic agent, prostaglandin E1
(10(-5) M), was shown to correlate strongly with subcutaneous blood flow changes estimated by the established technique of
133Xe washout. Changes in blood flow over the subcutaneous injection sites of insulin (Actrapid) and insulin diluent were
measured by photoelectric plethysmography in six nondiabetics and in six stable and seven brittle insulin-dependent diabetics.
In all subject groups, an acute increase in local blood flow was seen within 2 min of both insulin and diluent injections,
probably caused by injection trauma. At diluent injection sites, this acute hyperemia faded rapidly, blood flow returning
to preinjection levels within 15-20 min, and there was no further increase in blood flow in any of the subjects. Insulin injected
into the nondiabetics and stable diabetics caused a pronounced increase in local blood flow, sustained for at least 60 min
after injection. In the brittle diabetics, however, there was no prolonged local hyperemia, the response being significantly
less than that seen in both the nondiabetics and the stable diabetics. Insulin-related hyperemia close to injection (or infusion)
sites may be important in subcutaneous insulin absorption. Its near-absence in brittle diabetics may contribute to the impaired
response to subcutaneous insulin characteristic of these patients.