Unexpected effect of fruit peeling

Like most PJ readers, I know the importance of hand washing before finger tip blood sampling, but my eye was recently caught by a paper in Diabetes Care about glucose monitoring after peeling fruit.

The study subjects were healthy volunteers with a normal glucose tolerance test. Capillary blood glucose samples were collected from the fingertip after peeling orange, grape or kiwi fruit, followed by no action, by washing hands with tap water or by rubbing the fingertip with an alcohol swab. Analysis with glucose monitors showed that the blood glucose levels after peeling any of the fruits followed by washing hands were similar to those in control subjects who had not handled fruit.

However, the levels after fruit peeling followed by no washing were abnormally and significantly high even when the fingertip was cleansed once or five times with an alcohol swab before blood sampling.

So, if patients report high blood glucose readings with their portable monitors, check that they have not peeled fruit. More seriously, to avoid overestimation of blood glucose, emphasise the importance of thorough hand washing before monitoring capillary blood glucose.