Thanks for your question.

Let us go through some details of Lantus and Levemir insulins. Bothe are long acting insulin drugs. Of these, Lantus is slightly longer than Levemir. Usually, both of them are prescribed to administer once a day. In some cases, it is ordered twice a day also. Normally, they are ordered once at bed time. They will act slowly and help controlling glucose levels all day and night. At times they are even ordered along with some other rapid acting insulins also, before taking meals or along with other oral medicines.

Secondly, body can produce more glucose at night, even if you haven’t eaten before your bed time. This increase in glucose level is caused by certain factors. Your liver reacts to your glucose level drop when you don’t eat anything for a while. But your body needs energy to keep it working. Both your body and brain are energy hungry as they work throughout the night.  As your glucose level drops, liver starts producing glucose by itself. This process is more evident in people with diabetes than those without. Your body will react to stress also, during night. This is due to the release of cortical steroids which helps in healing stresses during day time. This is a part of that healing process itself. These steroids are also known culprits in increasing glucose levels. This is the cause of having high glucose levels even though you do not eat for a while, during your sleep. This can be well managed by taking some low carb snacks before you go to bed and some snacks when you wake up. This will turn off the system of making self-made glucose during night time.

Allergy to insulin is a rare phenomenon. But it can happen also. If you experience some issue, better report to the provider. Taking insulin will never cause changes to DNA structure.