A gene variant that is linked to an increase in the risk of Alzheimer's disease also predicts which people with diabetes are most likely to suffer neuropathy. In diabetes, impaired circulation may cause neuropathy in the lower limbs - that is, peripheral nerve damage leading to pain and numbness. In severe cases, amputation may even be necessary. Researchers at Duke University in the US have now identified a gene variant which makes people more likely to suffer from peripheral neuropathy if they have diabetes.
The gene variant is APOE4, which has also been implicated in increased risk for Alzheimer's disease. In the current study, 187 people with diabetes were found to have more severe peripheral neuropathy, if they had the APOE4 variant, compared to those with other variants of APOE. It was as if these patients had had diabetes for 15 years longer, say the researchers. It's not clear how APOE4 is linked with peripheral neuropathy, however. It may be that it somehow blocks the circulation in the lower limb or impairs the secretion of the growth factors which the peripheral nerves need to be healthy.