I think so too.
Seriously she stated in several interviews that drugs destroyed her kidneys.
https://variety.com/2016/music/obit...y-dead-prince-denise-matthews-1201706763/amp/
In 1994, Matthews’ crack cocaine addiction caused an almost-fatal renal failure, and she later said Jesus Christ appeared to her, offering a second chance at life if she left behind her persona as Vanity. After her 1997 kidney transplant, Matthews became a Christian evangelist — a story she expanded on in her self-published autobiography “Blame It on Vanity.”
She ultimately died of renal failure after contracting a different kidney element.