Perfomance Issue while making multiple calls to share point list items from ASP.NET page

In our ASP.NET web application, in a button click event, the following activities are performed.

1. Making 5 database calls (Stored procedures are optimized)
2. 8 different calls (can’t be grouped) to update/check SharePoint list items. 2 calls to create list items.

We are facing performance problem in this event because of these much activities. It is taking 40 to 60 seconds to complete the operation. We have found that the calls to SharePoint list items are time consuming. Unfortunately we can make the SharePoint calls as a batch.

Any idea to improve the performance?