Will a secured loan effect my remortgage?

Yes. If you wish to leave your secured loan on your property and you wish to remortgage then all lenders will take into consideration the amount you pay back each month and may not lend you the required amount to remortgage.
If the remortgage lender is offering a better rate than the secured loan it may be more financially viable to remrotgage and include your normal mortgage and your secured loan as well.
Also, a point to make is that the lender you are remortgaging with says you can keep the secured loan where it is they must give permission to that lender for it to be there and they will contact the secured lender to say this. This should not cause any issues though.
I would seek independent financial advice from our experts to be sure this is the correct thing to do.