The actual question is not clear (what "credit"?), but to answer the title question -
Yes using debt to grow a business can increase ROE, because the debt will (presumably) be used to buy assets that will increase returns, but leave equity unchanged. So the ratio increases. It's called leverage in finance.
It can also decrease ROE if the cost of debt (interest) is greater then the additional earnings. In other words, the interest on the debt is costing you more than you are earning from the additional assets, so your return is lower with the same amount of equity. Generally, though, debt is "cheaper" than equity, so in most cases ROE is increased by taking on debt.
This is why it's important not to use any one financial ratio in a vacuum. You have to look at why the ratio changed, and look at other ratios to make sure that a company hasn't used too much leverage to increase ROE, since leverage works against you in bad times (gains and losses are multiplied).