 A total of seven study visits will be scheduled: at screening, at weeks -4, -2, 0, 4, 6, 12 and 24 week follow-up. During each visit, an endocrinologist will make the physical and metabolic assessment. Safety and tolerability data will be collected at screening and throughout the study, and includes incidence of serious and non serious adverse events AEs in linagliptin arms and standard arms. Clinical laboratory data, vital signs, and 12-lead electrocardiogram parameters at each visit, will be collected. The causal relationships between study drugs and AEs will be evaluated by the investigators at site. All drug-related AEs occurring during the study will be followed up until relieved or judged to be no longer clinically significant. Changes in body weight from baseline until week 12 will also be assessed. Hypoglycaemic event intensity will be defined as symptoms of hypoglycemia accompanied by a fingerstick glucose value of 50 mgdl. 