To evaluate the efficacy of empagliflozin administered orally once daily in postprandial glucose and 24-hour glycaemic variability compared to placebo given for 4 weeks as mono-therapy in Japanese patients with type 2 diabetes mellitus with insufficient glycaemic control on no antidiabetic treatment.

Inclusion criteria:

• Diagnosis of type 2 diabetes mellitus prior to informed consent

• Male and female patients on diet and exercise regimen for 12 weeks prior to informed consent who are:

  • drug-naïve, defined as no antidiabetic drugs for at least 12 weeks prior to informed consent or,
  • pre-treated with one oral antidiabetic drug (except sulfonylurea and thiazolidinedione); the present antidiabetic therapy has to be unchanged for at least 12 weeks prior to the informed consent. (Sulfonylurea is permitted as pre-treatment drug only if the dose is equal or less than a half of daily maximum approval dose.)

• Glycosylated haemoglobin (HbA1c) at Visit 1 (screening)

  • for patients without antidiabetic therapy : HbA1c >=7.0 to =<10.0%
  • for patients with one oral antidiabetic drug : HbA1c >=7.0 to =<9.5%

Exclusion criteria:

• Uncontrolled hyperglycaemia with a glucose level >240 mg/dL (>13.3 mmol/L)
• Impaired renal function, defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m2 (moderate and severe renal impairment, modification of diet in renal disease (MDRD) formula)
• Acute coronary syndrome, stroke or transient ischemic attack (TIA) within 12 weeks prior to informed consent
• Indication of liver disease, defined by serum levels of either alanine transaminase (ALT), aspartate transaminase (AST), or alkaline phosphatase (ALP) above 3 x upper limit of normal (ULN)

Full analysis set: all patients treated with at least 1 dose of randomised study drug, and with a baseline AUC1-4h for plasma glucose.

between the first drug intake of study medication and 7 days after last drug intake of study medication, up to 35 days