Loan says I got 48 "Debt to income" ratio, what he talking about?

[Philip Johnson]

Hi,

I have 5 flip-to-rent properties, and i have a day job as well ... I just refinanced a property and my loan officer said I have a "high debt to income ratio of 48" What does that mean? How do I get this down? 

I am filing my 2018 taxes soon (I asked for extension).  Does it help to have as much as possible in improvements as opposed to repairs, or not claim repairs?  Is there anything else in tax filing that helps? My properties cash flow very well, $500 a property.  But, I have lots of repairs that I claim on them every year. 

Basically, what is debt to income ratio, and how do I keep getting qualified for properties?