Frequency of blood glucose testing in well educated patients with diabetes mellitus type 1: How often is enough?

Aims: Self-monitored blood glucose (SMBG) and knowledge of insulin requirements are pivotal for good metabolic control in patients with diabetes mellitus type 1. However, the SMBG-frequency needed for optimal glycaemic control especially in well educated patients is unclear. Methods: In patients with type 1 diabetes treated with flexible intensified insulin therapy, we evaluated HbA1c values and the directly preceding computerised SMBG-frequencies over a 12 months period. To estimate the association between HbA1c and SMBG-frequency, we fitted a piecewise linear spline model with a change in slope at 4 SMBGs per day which is the recommended minimal SMBG-frequency at our institution. Results: A total of 150 patients were available for analysis, with a median baseline HbA1c of 7.1% (interquartile range 6.6, 7.8). In the multivariable analysis (adjusted for gender and psychological problems), each additional SMBG measurement was associated with an estimated difference in HbA1c of -0.19% (95% confidence interval (CI) -0.42, 0.05) for >4 SMBGs per day and of -0.02% (95% CI -0.10, 0.06) for >4 SMBGs per day. Conclusions: Good diabetes control can be achieved in routine diabetes care with flexible intensified insulin therapy based on continuing patients' education and with a minimum of 4 SMBGs per day. (C) 2013 Elsevier Ireland Ltd. All rights reserved.