In biology, basal rate is the rate of continuous supply of some chemical or process. In the case of diabetes mellitus, it is a low rate of continuous insulin supply needed for such purposes as controlling cellular glucose and amino acid uptake. Together with a bolus of insulin, the basal insulin completes the total insulin needs of an insulin-dependent person. An insulin pump and wristop controller is one way to arrange for a closely controlled basal insulin rate. The slow-release insulins (e.g., Lantus and Levemir) can provide a similar effect.
In healthy individuals, basal rate is monitored by the pancreas, which provides a regular amount of insulin at all times. The body requires this flow of insulin to enable the body to utilize glucose in the blood stream, so the energy in glucose can be used to carry out bodily functions. Basal rate requirements can differ for individuals depending on the activities they will carry out on that particular day. For example, if one is not highly active on a certain day, they will have a decreased basal rate because they are not using a lot of energy. On the other hand, basal rate increases dramatically when an individual is highly active.
Basal rates often even vary from hour to hour throughout the day. For example, one’s insulin needs vary from activity to activity. Activities, such as sports, housework, shopping, gardening, tidying the house, and consuming alcohol all require a lowering in basal rate. These activities all require energy and, thus, use glucose; basal rate must decrease in order to keep glucose levels high enough to be used as fuel for the body. On the other hand, fevers, having a cold, taking a nap, taking cortisone-containing medication, and moments of excitement call for different basal rate needs. In these instances, the body has an overwhelming supply of glucose, and glucose levels need to decrease. To induce this decrease, basal rate needs to increase to increase insulin release to absorb some of the excess glucose from the blood stream.
Those with diabetes mellitus must be aware of their basal rates and regulate them accordingly. Basal rate can be raised and lowered through various methods. For example, individuals with diabetes mellitus often use an insulin pump to supply an increased amount of insulin into the blood stream. Those with diabetes also may eat carbohydrates or sugars to account for low blood sugar. However one monitors and regulates their blood sugar levels and basal rates, it is important to make changes gradually. An initial lowering in basal rate should be no more than 10% of the original. After the initial lowering point, one must note the factor by which one’s blood sugar changes. If blood sugar levels decreased, one should lower their basal rate by 20% next time. If their blood sugar levels increased, a lowering of 10% was too great, and one should not lower their basal rate at all next time. If blood sugar levels remained relatively constant, a drop in basal rate of 10% was sufficient.