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 (SH), based on self-monitoring of blood glucose (SMBG).


METHODS
There were 96 adults with IDDM (mean age 35+/-8 years, duration of diabetes 16+/-10 years, HbA1 8.6+/-1.8%), 43 of whom 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 transformed, and an LBGI was computed for each patient.


RESULTS
The two patient groups did not differ with respect to HbA1, 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 classified 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, respectively (P = 0.001). The frequency of future SH was predicted by the LBGI and history of SH (R2 = 40%), while HbA1, age, duration of diabetes, and BG variability were not significant predictors.


CONCLUSIONS
LBGI provides an accurate assessment of risk of SH. In the traditional relationship history of SH-to-future SH, LBGI may be the missing link that reflects present risk. Because it is based on SMBG records automatically stored by many reflectance meters, the LBGI is an effective and clinically useful on-line indicator for SH risk.
Kovatchev
B P
BP
University of Virginia Health Sciences Center, Charlottesville, 22908, USA. bpk2u@virginia.edu
Cox
D J
DJ
Gonder-Frederick
L A
LA
Young-Hyman
D
D
Schlundt
D
D
Clarke
W
W
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D015190:Blood Glucose Self-Monitoring / Q000706:statistics & numerical data; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007003:Hypoglycemia / Q000209:etiology*; D007328:Insulin / Q000097:blood; D008297:Male; D012044:Regression Analysis; D012307:Risk Factors
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin