There were 8,042 responses to Piper Jaffray's teen survey in February and March, of which 1,707 have diabetes or a member of their household does, analyst JP McKim tells investors in a research note. The survey implies underlying continuous glucose monitoring market growth of close to 58%, says the analyst. Abbott (ABT) reported 70% Libre growth in Q1 and DexCom (DXCM) reports May 1, McKim points out. He expects "continued strong growth" from DexCom following the "robust" survey results and reiterates an Overweight rating on the shares with a $165 price target.