The negative effects of glycaemic drugs on quality of life may outweigh the marginal benefits of reduced vascular risks in older adults, their study found.
The international team of researchers questioned the value of broad ‘treat-to-target’ guidelines for type 2 diabetes, saying that using one-size-fits-all glucose goals alone to guide treatment was a 'fundamentally flawed' approach.
They called on GPs to balance complication risk against patient quality of life when treating patients with HbA1c levels under 11.7mmol/L.
NICE advises GPs to treat patients with type 2 diabetes to a target of 7.8mmol/L unless side-effects impair quality of life. Treatment should be stepped up if blood sugars remain above 9.4mmol/L, one of the levels incentivised by the QOF.
But aggressive treatment with insulin and other anti-diabetic drugs can lead to weight gain, gastrointestinal problems and hypoglycaemia, as well as daily treatment burden such as regular insulin injections.
The study, published in the journal JAMA Internal Medicine, modelled the effects of lowering HbA1c levels for patients aged 45-75 and at varying levels of treatment intensity.
Patient experience vital
They compared the reduction of microvascular and cardiovascular complications against the likely harms to quality of life. Both were estimated using the quality-adjusted life years measurement also used by NICE to judge drugs’ effectiveness.
Researchers found that patients aged over 50 on metformin with HbA1c levels under 11.7mmol/L had only ‘modest benefits’ from more intensive treatment.
Even low levels of adverse effects resulted in overall harm from treatment. Patient experience of treatment burden had a large impact on the balance between benefit or harm.
The findings exclude patients with very high HbA1c levels, and patients with type 1 diabetes.
The authors concluded: 'We found that net treatment benefits of glycaemic treatments vary widely depending on a patient’s age at diagnosis, their pre-treatment HbA1c level, and most importantly, a patient’s view of the burden of the specific treatment being considered.
'Because of this, using HbA1c level treatment targets alone to guide patient decision making is a fundamentally flawed strategy; instead, each glycemic treatment decision should be individualized, mostly on the basis of patients’ views of the burdens of therapy, with age and initial level of glycemic control important but secondary considerations.'
'Balance risks and benefits'
Lead author Professor Sandeep of the University of Michigan Medical School said it was ‘essential’ to balance complication risks and treatment burdens in treatment decisions. ‘If you're a patient with fairly low complication risks, but are experiencing symptoms from low blood sugar, gaining weight or find frequent insulin shots to be disruptive to your daily life, then the drugs are doing more harm than good.’
Senior author Professor Rodney Hayward from the university said: ‘Current quality measures do not allow doctors and patients to make good decisions for each patient because they emphasise reaching targets instead of thinking of the risks and benefits of starting new medications based on individual circumstances and preferences.’