Lifestyle and Metformin the way forward in Diabetes Prevention
The concern expressed by Heneghan et al that drug therapy to
prevent diabetes may not be as attractive as it first appears, maybe
justified as far as rosiglitazone, but not for metformin which is
effective,safe and cheap.
While the 31% reduction in new cases of diabetes in the Diabetes
Prevention Programme (DPP) with metformin, appears unimpressive in
comparison to the lifestyle groups 58%; in certain subgroups metformin was
more impressive. Reductions of incidence of diabetes in the young (under
45) was 44% and the obese (BMI >35) was 53% (lifestyle 48% and 51%
respectively). It would be interesting to see an analysis of the "young
and obese", considering it is in this group much of the concern about the
It should be remembered that the subjects in the DPP were highly
selected, to be appropriate for a trial of intensive lifestyle
modification. For instance smoking prevalence was only 7%. We are unlikely
to see the same gains from lifestyle intervetion in the real world.
While Heneghan et al points out, rosiglitazone was associated with
a non-significant 37% increase in cardiovascular end-points in the DREAM
study; metformin appears safe. The UKPDS showed a 36% reduction for
all-cause mortality, and 42% for diabetes-related death with metformin in
the obese (BMI above 25.6) .
Regarding cost, lifestyle intervention in the DPP cost $2,780/ person
over 3years. The drug treatment cost with 8mg rosiglitazone/day (as per
DREAM)for 3years, would be nearly £2000, but metformin 850mg twice
daily (as per DPP), would cost less than £40. Furthermore cost
effectiveness analyasis of the UKPDS showed overall cost savings from
reduced hospital costs with metformin.
While the UKPDS is considered a diabetes study, entry criteria was a
fasting glycaemia above 6.0mmol/l, or what we now consider as impaired
fasting glycaemia. We should be prepared to follow the clear evidence base
and prescribe metformin to any overwieght patient with abnormal fasting
glucose, after 3month of lifestyle advice.
1. Heneghan, C., M. Thompson, and R. Perera, Prevention of diabetes
10.1136/bmj.38996.709340.BE, in BMJ. 2006. p. 764-765.
2. Diabetes Prevention Program Research Group. Reduction in the
incidence of type 2 diabetes with lifestyle intervention or metformin. N
Engl J Med 2002;346: 393-403
3. DREAM (diabetes reduction assessment with ramipril and
rosiglitazone medication) Trial Investigators; Gerstein HC, Yusuf S, Bosch
J, Pogue J, Sheridan P, Dinccag N, et al. Effect of rosiglitazone on the
frequency of diabetes in patients with impaired glucose tolerance or
impaired fasting glucose: a randomised controlled trial. Lancet 2006;368:
4.UK Prospective Diabetes Study Lancet 1998 sept12 352(9131):854-65
Competing interests: No competing interests