Metabolic factors that can affect the action of insulin
Usually, the level of circulating blood glucose is kept tightly regulated by an appropriate response by the β cells of the pancreas to produce insulin.
In diabetes, there can often be a mismatch between administered insulin and blood glucose levels. There can also be problems with administered insulin action in diabetes if there are liver or kidney problems.
If present, there can be a reduced capacity for gluconeogenesis which can reduce the amount of active glucose available for insulin to work with. Insulin dose reduction may be needed in this situation. This is also because liver impairment can reduce the metabolism of injected insulin, so it remains metabolically active for longer.
Figure: human chest with liver highlighted
If kidney function is reduced below a certain threshold, its ability to contribute to insulin metabolism and clearance is also reduced. This can result in the action of insulin being prolonged.
Figure: human chest with kidneys highlighted
Patients who need to take steroids for any reason may also see a rise in blood glucose levels, with or without diabetes.
Steroids raise sugar levels by making the body more resistant to the effects of both natural and injected insulin. Quinine has also been reported to lower glucose levels though the mechanism is not fully understood.
© University of Southampton 2017