Considering a mortgage refinance, particularly the 125% equity line of credit refinance? In addition to your credit score, potential lenders will look at your debt to income ratio and other factors to determine the lines of credit they are willing to extend to you and the interest rate that their offer will cost you. Most banks link their credit card interest rates to the prime lending rate as set by the Federal Reserve Bank. Because your refinance cash out increases your debt to income ratio, some credit card lenders will increase their interest rates to reflect their higher risk.