...that taking a commonly prescribed “water pill” for high blood pressure (Hctz - hydrochlorothiazide) can increase the risk of developing diabetes? 

This is due to the depletion of magnesium, potassium and chromium.  A reduction in magnesium can also make blood pressure go up; the very medication used to treat high blood pressure might actually cause blood pressure to go up.  Of note, Hctz also causes CoQ-10 to drop which can also cause blood pressure to go up.