Januvia® is licensed to improve glycaemic control for people with type 2 diabetes (T2DM). The Summary of Product Characteristics (SPC) states that the dose of Januvia® is 100mg once daily (using tablets for oral ingestion). For research participants with moderate kidney disease (CrCl < 50 ml/min or eGFR < 50 ml/min/1.73m2), the Summary of Product Characteristics (SPC) states that the dose of Januvia® is 50mg once daily (using tablets for oral ingestion). In keeping with this all participants with an eGFR < 50ml/min/1.73m2 who are due to receive Januvia® will receive 50mg once daily.