Caffeine, which is absorbed into the system at an incredible rate, can temporarily raise blood sugar levels and make for an inaccurate FBS reading. Moreover, the chemical composition of roasted coffee beans is nearly 40 percent sugar (in the form of polysaccharides). Drinking coffee will stimulate the pancreas to excrete insulin, which balances blood sugar, and throw off your test results. http://healthyliving.msn.com/diseases/diabetes/can-i-drink-coffee-before-a-fasting-blood-test-1
Quest is a great local place to have blood work done and learn about diabetes, diabetes testing, diabetes research and more.