Biology Reference
In-Depth Information
0.6
LBGI<2.5
1.5
2.5 to 5
5.8
LBGI>5
0
1
2
3
4
5
6
FIGURE 5-11.
Correlation of the LBGI with the number of severe hypoglycemic episodes in the subsequent six
months. The individuals with the lowest LBGI suffered the fewest episodes of SH.
within three months of the LBGI calculation with those who reported
SH during months 4 through 6, but not within the first 3 months.
The LBGI of the first subgroup was significantly higher—6.4 versus 3.5
(p
0.005). At the same time, the two subgroups reported similar
numbers of SH episodes within the last year—9.6 and 7.6 (p
¼
0.5), and
did not differ in HbA
1c
, age, or duration of diabetes. This suggests that
high-risk status indicates the likelihood of an SH event sooner rather
than later.
¼
As a result of this and other similar studies, it is now known that about
130 SMBG readings, spread over 4 to 5 weeks, are sufficient to permit the
calculation of an accurate LBGI. This index has been shown to be
reliable, internally and across studies, and to be a significant predictor of
future SH. It can be used separately or in combination with other
variables to create more complex models with higher levels of
sophistication. In addition, the computation of a patient's LBGI is quite
uncomplicated, which encourages its clinical and research use. We
anticipate that the calculation of a person's LBGI could be incorporated
directly into future SMBG devices. A patient's LBGI exceeding a critical
value could then be used to provide an immediate alert for an increased
risk for SH.
Our last comment raises a serious ethical question. Let's assume that in a
clinical trial a researcher records a dangerously high LBGI value. What
should the researcher do? During the studies described above, two fatal
automobile accidents occurred where the driver's loss of control was
attributed to hypoglycemia. The values of the LBGI for these two people
(shown in Figure 5-12) indicate a continuous increase of the LBGI during
the three months preceding the accidents. Should researchers in this
situation contact the participant to convey a concern or issue a warning?
