ASSESSMENT OF RISK FOR SEVERE HYPOGLYCEMIA AMONG ADULTS WITH IDDM - VALIDATION OF THE LOW BLOOD-GLUCOSE INDEX

OBJECTIVE - To evaluate the clinical/research utility of the low blood glucose index (LBGI), a measure of the risk of severe hypoglycemia (S H), based on self-monitoring of blood glucose (SMBG). RESEARCH DESIGN AND METHODS - There were 96 adults with IDDM (mean age 35 +/- 8 years, duration of diabetes 16 +/- 10 years, HbA(1) 8.6 +/- 1.8%), 43 of who m had a recent history of SH (53 did not), who used memory meters for 135 +/- 53 SMBG readings over a month, and then for the next 6 months recorded occurrence of SH. The SMBG data were mathematically transform ed, and an LBGI was computed for each patient. RESULTS - The two patie nt groups did not differ with respect to HbA(1), insulin units per day , average blood glucose (BG) and BG variability Patients with history of SH demonstrated a higher LBGI (P < 0.0005) and a trend to be older with longer diabetes duration. Analysis of odds for future SH classifi ed patients into low- (LBGI <2.5), moderate- (LBGI 2.5-5), and high- ( LBGI >5) risk groups. Over the following 6 months low-, moderate-, and high-risk patients reported 0.4, 2.3, and 5.2 SH episodes, respective ly (P = 0.001). The frequency of future SH was predicted by the LBGI a nd history of SH (R-2 = 40%), while HbA(1), age, duration of diabetes, and BG variability were not significant predictors. CONCLUSIONS - LBG I provides an accurate assessment of risk of SH. In the traditional re lationship history of SH-to-future SH, LBGI may be the missing link th at reflects present risk. Because it is based on SMBG records automati cally stored by many reflectance meters, the LBGI is an effective and clinically useful on-line indicator for SH risk.