Page 136 - Glucose Monitoring Devices

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Glucose monitoring

The American Diabetes Association defines typical hypoglycemia symptoms
accompanied by a measured plasma glucose concentration of 3.9 mmol/L
( 70 mg/dL) as documented symptomatic hypoglycemia. Recurrence of hypogly-
cemia is known to increase the risk of hypoglycemia unawareness and severe
hypoglycemia, both linked with increased morbidity and mortality [12,13]. Severe
hypoglycemia is a medical emergency where individuals are dependent on treat-
ment from a third party. Delayed treatment can often result in immediate morbidity
from seizure, coma, and even death.

Time in range and glucose variability
Hyperglycemia and severe hypoglycemia are established complications linked to
short-term (within day) glucose variation, longitudinal lability in fasting plasma
glucose, and HbA1c [14,15]. Despite evidence associating glycemic variability
with high levels of oxidative stress and endothelial dysfunction [16,17], studies
have been conflicting in attempts to establish glucose variability as a modifiable
vascular risk factor. Long-term glucose variability in T1DM and T2DM has been
shown to be associated with increased microvascular risk [18e21], and although
supported in the early DCCT studies, subsequent data analyses failed to affirm
this association [22,23]. Other studies have linked longitudinal and short-term
glucose variability with increased cardiovascular risk outcomes [24,25]. However,
longer and more robust trials are needed to clarify the benefit of reduced glucose
variability on clinical outcomes.

Glucose monitoring
Limitations of SMBG
An association between frequent glucose monitoring and improved glycemic control
is well established in the literature and becomes increasingly evident when nontest-
ing individuals self-monitor glucose at least 3e4 times a day [26e29]. The UK Na-
tional Institute for Health and Care Excellence (NICE) and the American Diabetes
Association (ADA) encourage individuals on multiple daily insulin injections (MDI)
to monitor blood glucose levels at least four times a day to achieve target glycemic
control [30,31]. Unfortunately, compliance using conventional glucose meters
remains a challenge and is often hindered by the inconvenience and pain associated
with multiple daily fingerprick tests [32]. Compliance rates as low as 40% have been
reported in T1DM populations with up to one-third of individuals being unaware of
the recommended SMBG guidelines [28,33]. Lack of time and forgetfulness have
been cited as explanations for low SMBG compliance, particularly in younger,
recently diagnosed, and individuals in full-time employment [33]. These findings
highlight psychosocial barriers hindering SMBG compliance and remind us of the
importance of structured education and appropriate psychological support to harness
the full potential of glucose monitoring technology.