WASHINGTON, April 9 — The use of shock waves to pulverize kidney stones into sand-like material significantly increases the risk for diabetes and high blood pressure later in life, according to the longest follow-up study of the popular therapy. In the study, which is to be published on Monday from the Mayo Clinic, patients who underwent the pulverizing procedure, known as lithotripsy, developed diabetes at almost four times the rate of those whose kidney stones were treated by other methods. The lithotripsy group also developed high blood pressure about 50 percent more often than a group treated by other methods,...