english.prescrire.org > Spotlight > Archives : 2017 > Type 2 diabetes: intensive therapy can be harmful

Spotlight: Archives

Every month, the subjects in Prescrire’s Spotlight.

2017 : 1 | 30 | 60

Type 2 diabetes: intensive therapy can be harmful

It has been established that in patients with type 2 diabetes, intensive hypoglycaemic therapy targeting an HbA1c around 6% leads to excess cardiovascular mortality. It is best to aim for a reasonable target, around 7%.

In patients with type 2 diabetes whose HbA1c (indicating sustained hyperglycaemia) remains high under drug therapy, an HbA1c target in the range of 7 to 7.5% appears to reduce the risk of cardiovascular events.

A randomised trial compared two HbA1c target values in approximately 10 000 patients with type 2 diabetes at high risk of cardiovascular events. The trial was stopped prematurely after a follow-up of around three and a half years due to excess mortality in the "intensive therapy" group with an HbA1c of less than 6%.

In 2016, follow-up of the participants for another 4 years confirmed this initial result. Among the 8601 patients followed for 7.7 years on average cardiovascular mortality was consistently higher in the initial "intensive therapy" group.

The fact is, in patients with type 2 diabetes, there is no benefit in intensifying hypoglycaemic therapy in order to lower HbA1c to around 6%: this does not reduce the risk of cardiovascular complications – quite the opposite. It is better to opt for an HbA1c target of around 7 to 7.5%, adjusted according to the patient and the risk of hypoglycaemia.

©Prescrire 1 November 2017

"Type 2 diabetes. Don't aim for too low an HbA1c" Prescrire Int 2017; 26 (187): 273. (Pdf, subscribers only).

Download the full review.
Pdf, subscribers only

See also:

Controlling glucose levels
in type 2 diabetes: aim for
an HbA1c level of around 7%
(August 2009)

Numerous texts available
via the "Search" function using
the keyword "diabetes"