The author may not have much in life, but he does at least have his pride. Utterly destitute, and almost permanently on the brink of starvation, this struggling writer is kept alive by his burning sense of pride. It's not surprising, then, that he should care about it so much.
Yet ironically, his desperate hunger is a symptom of that pride. There's really no need for the narrator to be in this situation; if he would only make a concerted effort to find gainful employment, then at least he'd be able to keep body and soul together.
But he doesn't. Why? Because he's too proud. The narrator sees himself as an artist, a man set apart from a society he so utterly despises. His pride may allow him to maintain his integrity as a man and as an artist, but it also blinds him to reality. He seems to believe that one day he will be showered with reverence, praise, and money as the author of articles of revolutionary philosophy. With pride comes delusion.
This man's pride has a dual nature; as well as being too proud to seek gainful employment, he's also too proud to admit that his poverty and hunger is a result of his own pride. So his pride and his hunger go round in circles. It's nothing more than a disease of which his constant hunger is a symptom.