INFLUENCE OF SIMULATED ALTITUDE ORE THE PERFORMANCE OF 5 BLOOD-GLUCOSE METERS

OBJECTIVE - To determine the reliability of five blood glucose meters (BGMs) at various simulated altitudes using a hypobaric chamber. RESEA RCH DESIGN AND METHODS - Blood glucose levels (ranged from 2.5 to 26.3 mmol/l, according to the reference method) were measured in 18 venous blood samples by each BGM at 200, 1,000, and every 500 m up to 4,000 m in a hypobaric chamber, where temperature and humidity were held con stant. RESULTS - Four BGMs underestimated and one overestimated blood glucose concentration while barometric pressure decreased. The average percent error varied in relation to simulated altitude from 0.26 +/- 4.8% (SD) at 200 m to - 28.9 +/- 4.5% at 4,000 m (Glucometer 3; P < 0. 05), from 28.4 +/- 5.7 to 49.3 +/- 5.9% (Accu-Chek Easy; P < 0.05), fr om -10.5 +/- 2.6 to 19.8 +/- 4.3% (Tracer; P < 0.05), from -5.5 +/- 2. 6 to -11.2 +/- 3.0% (Reflolux; NS), and from 17.8 +/- 4.3 to 14.8 +/- 3.6% (One Touch; NS). The most accurate seemed to be the Reflolux, exc ept for high brood glucose levels at simulated high altitudes. The One Touch II showed a good agreement, whatever the barometric pressure an d the range of blood glucose concentrations. The highest underestimati on was seen with the Glucometer 3. CONCLUSIONS - Except for the Accu-C hek Easy low barometric pressure underestimated the BGM results in com parison with measurements taken at simulated low altitudes. The lack o f accuracy and consistency of performance >2,000 m should be known by diabetic patients practicing sports activities, such as trekking or sk iing at high altitudes.