Detemir presents mixed blessing for type 2 diabetes
Samuel Ashfield/Science Photo Library
Insulin treatment: practice should not change in response to the
study’s findings, the editorial authors argue |
Basal insulin detemir is less effective at reducing the HbA1c of patients with poorly controlled type 2 diabetes than twice-daily biphasic or thrice-daily meal-time (prandial) insulin regimens but it is associated with less weight gain and fewer hypoglycaemic episodes, according to a New
England Journal of Medicine study, recently published
online (21 September 2007).
Investigators looked at 708 patients with a suboptimal HbA1c (between
7 and 10 per cent) who were receiving the highest tolerated doses of
both metformin and a sulfonyl-urea drug for type 2 diabetes. They were
randomised to receive, open label, one of the three insulin regimens
in addition to the oral therapy.
The authors — reporting first-year results of a three-year multi-centre
trial — showed that mean HbA1c measurements were similar
for patients receiving biphasic insulin (7.3 per cent) and prandial insulin
(7.2 per
cent), but higher for those receiving basal insulin (7.6 per cent; P<0.001
for both comparisons).
The median rate of hypoglycaemic episodes (of grade 2 severity or greater)
was higher in the prandial group than in the biphasic group (P=0.002)
and higher in the biphasic group than in the basal group (P=0.01). Weight
gain was less for patients receiving basal insulin detemir compared with
either the prandial or biphasic insulin group (P<0.001 for
both comparisons).
New England Journal of Medicine editors Graham McMahon and Robert Dluhy describe
the year 1 results as disappointing: “Only a minority
of patients achieved the target goal [HbA1c of 6.5 per cent
or less]: 17 per cent of those in the biphasic group, 24 per cent in
the prandial
group and 8 per cent in the basal group.”
They say the study indicates clearly that prandial and biphasic insulin
regimens are suboptimal choices for beginning insulin in such patients,
due to “an unnecessarily high risk of hypoglycaemia”. They
also suggest that continued administration of sulfonylureas as insulin
is added, as in the current study, exposes patients to additional hypoglycaemic
risk without additional benefit.
They add: “The lower-than-expected effectiveness of detemir in
the study may be attributable to the pharmacokinetics of this type of
[basal] insulin — its half-life is dose dependent and shorter than
that of glargine.”
Dr McMahon and Dr Dluhy suggest that the study should not prompt changes
in practice. “The best approach is to continue metformin and add
a basal insulin,” they say. “Sulfonylureas are not synergistic
with insulin and should generally be stopped.” |
The
Pharmaceutical Journal
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