After a 3-week wash-in period , eligible patients aged 18 to 80 years with a hemoglobin A1c ( HbA1c ) level of 5.5 % to 9.5 % ( 37-80 mmol/mol ) were randomized to compare either 4 - vs 8-mm PNs or 4 - vs 12.7-mm PNs , using each of the 2 assigned PNs for 12 weeks in random order .