Adverse impact of temperature and humidity on blood glucose monitoring reliability: A pilot study

Background: The effect of temperature and humidity on the reliability of glucose monitoring systems (GMS) has not been well reported. We performed a study to determine if the effect of temperature and humidity on glucose values could be accurately predicted. Methods: Eight GMS, including meter, strips, and glucose control solution (GCS), were placed in an environmental chamber for 50 days. Failure of the environmental chamber allowed for the serendipitous observation of the effect on glucose results of a range of temperature (54-87 degrees F) and humidity (49-100%) typically experienced by patients when performing self-monitoring of blood glucose. GCS was used to generate glucose results in triplicate for each meter daily. Temperature and humidity variations were recorded, and a linear model was generated to explain the variation in glucose results. Results: Both temperature and humidity had significant effects on the reliability of nearly all GMS. The effect of temperature was greater than the effect of humidity. Conclusions: In this pilot study, GMS were unreliable at temperatures and humidity within the manufacturers' recommended limits. Such variations could result in clinically significant errors in diabetes management. Further studies are needed to confirm the potential inadequacies of GMS with multiple meters and real-time patient blood samples. Glucose meter manufacturers should develop systems. that either are less affected by climate or adjust reported values based on ambient temperature and humidity.