Diagnostic Limitations of Applying a Human Portable Blood Glucose Meter to the Detection of Hypoglycemia in Pregnant Ewes

Pregnant ewes are susceptible to hypoglycemia and ketosis; therefore, monitoring glycemic status is extremely important. Portable blood glucose meters (PBGM) can assist in quickly and conveniently identifying glycemic disturbances in this species, provided that they meet criteria demonstrating their analytical accuracy. This study evaluated the performance of a human PBGM (Accu-Chek Performa®, Roche Diagnostics, Basel, Switzerland), for glycemic evaluation of 34 pregnant ewes at 90 and 120 pregnancy days in comparison with glycemia determination by a reference method (RM). The device showed a high positive correlation (r = 0.71, 95%CI = 0.57 – 0.82, P < 0.0001) with the RM; however, 96.6% of the PBGM results (58.5 ± 9.82 mg/dL) were higher (P < 0.0001) than those obtained in the laboratory (48.6 ± 9.31 mg/dL). The PBGM tested was considered analytically inaccurate according to ISO 15197:2013 which states when glucose is <100 mg/dL, 95% of its measurements should not differ by more than 15 mg/dL from the RM value, while 1/3 of the PBGM results read up this limit. Hypoglycemia (< 50 mg/dL) was documented in 60.29% of samples measured by the RM, but only 17.64% read below 50 mg/dL in the PBGM. Due to these limitations, Accu-Check Performa® results should be interpreted cautiously in pregnant sheep suspected of hypoglycemia.