Do lenders care more about how many accounts you have, or the total of your credit limits on those accounts?

I am wondering if DECREASING my credit limit on a couple of credit cards would be helpful if and when we try to get a home loan, or is it simply the number of credit cards that matter? It seems that I have heard somewhere about the debt to income ration and that somehow ithe maximums that you can borrow can work against you even if you do not come anywhere near using those amounts. Thanks for any help on this!