I would use this general rule to address your husband's situation. To do this, you may have to mix insulins to get a better custom regimen to meet your husband's needs. This is especially true if his sugars are high in the afternoon but satisfactory prior to lunch. My own take on the commercially available insulin mixtures is that they are convenient but, you would not sacrifice efficacy for convenience in most situations, especially if you have no problems being able to mix the insulin components required. The fatigue you are describing may be from high sugars, low sugars, or large swings in the sugars.
More monitoring is required to identify the particular pattern occurring.
Finally, I feel now is probably a good time to learn carbohydrate counting . It is the single best means of matching insulin to the meal being eaten. It works well when is refined. Comments and Feedback . Privacy statement .