Page 17 - Glucose Monitoring Devices

12 CHAPTER 1 Introduction to SMBG

medications may affect glucose control, the aim of the meta-analysis by Mannucci
et al. [90] was to assess the effect of SMBG on HbA1c in noninsulin-treated T2D
considering these potential confounders. SMBG in comparison with no SMBG
led to a small reduction (0.17%) in HbA1c. However, when SMBG data were
used to adjust medical treatment, a greater reduction in HbA1c levels was observed
(0.3%). In the randomized controlled trials comparing structured and unstructured
SMBG, in which structured SMBG was also coupled with adjustment of medica-
tions, the difference in HbA1c reduction between groups was 0.27% in favor of
structured SMBG. Another review [91] took a look at SMBG in T2D without inten-
sive insulin treatment to establish whether SMBG improves glycemic control. The
review included 24 randomized controlled trials and 5454 people with T2D not using
intensive insulin regimens. Studies, where people were using basal-bolus insulin
injections, were excluded, although four studies included people on less intensive
insulin treatment. This meta-analysis showed a small benefit of SMBG for HbA1c
reduction in a short term (0.31% lower HbA1c at 12 weeks and 0.34% lower at
24 weeks), with the greatest benefit seen in those with poor glycemic control.
However, the benefit of SMBG did not last beyond 6 months; at a 1-year follow-
up, there was no difference between the groups.

Guidelines for SMBG
For people living with diabetes, medical guidelines recommend SMBG at varying
frequencies, depending on the type of diabetes, antihyperglycemic therapy and
adequacy of glycemic control. In addition, the frequency and timing of SMBG
should be individualized to a person’s specific needs and goals. Daily SMBG is
essential in insulin-treated individuals, providing the means to assess the progress
of treatment and avoid hypoglycemia. For individuals on intensive insulin regimens,
the ADA recommends performing SMBG before meals and snacks, at bedtime,
occasionally postprandially, before exercise, when they suspect low blood glucose,
after treating low blood glucose until they are normoglycemic and before critical
tasks such as driving. Consequently, testing may be required 6e10 times per day
to optimize intensive control [92]. Similarly, to optimize intensive diabetes manage-
ment in children, adolescents, and young adults aged <25 years, the International
Society for Pediatric and Adolescent Diabetes recommends self-monitoring of
glucose at least 6e10 times a day: before meals and snacks, 2e3 h after food intake,
during the action profiles of insulin, with vigorous exercise, at bedtime, during the
night and on awakening, during intercurrent illness, to confirm hypoglycemia and
monitor recovery, before driving a car or operating hazardous machinery. In addi-
tion, frequent and regular reviewing of results and pattern recognition is necessary
to make appropriate treatment adjustments [93].
As pregnancy complicated by either gestational diabetes mellitus or preexisting
T1D or T2D is associated with risks to maternal and fetal complications, maternal
glycemic targets are stricter to maintain glucose control throughout pregnancy as