Howard Stern’s on-air sidekick Artie Lange has been hospitalized in New Jersey for unspecified reasons. “I can confirm that Artie is in the hospital,” a statement from his rep said. “Artie has chosen to keep all information on this matter between him and his doctor. There will be no further comment.” The 42-year-old comedian, who has struggled with substance abuse issues in the past, has not appeared on Stern’s Sirius XM satellite-radio show for several weeks and has canceled a number of recent stand-up comedy engagements.