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In people with type 2 diabetes, intensive treatment that aims to lower blood sugar levels reduces nonfatal heart attacks and doesn’t increase deaths

Seidu S, Achana FA, Gray LJ, et al. Effects of glucose-lowering and multifactorial interventions on cardiovascular and mortality outcomes: a meta-analysis of randomized control trials. Diabet Med. 2016;33:280-9.

Review question

In people with type 2 diabetes, does intensive drug treatment that aims to lower blood sugar levels affect risks for death, heart attack, or stroke?

Background

Type 2 diabetes is a disease that increases blood sugar levels. High blood sugar levels over a long period of time can increase your risk of getting heart disease or having a heart attack or stroke. Some people with type 2 diabetes can control their blood sugar levels through exercise and diet. Many people will also need to use drugs to help manage their diabetes. Intensive treatment, which often includes higher drug doses or more than one drug, may better control blood sugar levels in some people. We need to know whether intensive treatment lowers risks for death, heart disease, or stroke.

The research

19 studies (randomized controlled trials) that were published up to May 2015.

The studies included 84,460 adults with type 2 diabetes. People were, on average, 52 to 69 years of age. 29% to 100% were men.

Studies compared an intensive treatment with a control group (placebo, standard care, or a less-intensive treatment). Most studies assessed intensive treatment that only aimed to lower blood sugar levels. Some studies assessed a multicomponent intensive treatment regimen that aimed to control blood pressure or cholesterol as well as blood sugar levels.

What the researchers found

Compared with control, intensive drug treatment to lower blood sugar levels (with or without treatment to lower blood pressure or cholesterol levels):

  • reduced nonfatal heart attacks; and
  • did not increase or decrease nonfatal strokes, death from heart or circulation problems, or death from any cause.

Compared with control, multicomponent intensive treatments that aimed to lower blood pressure or cholesterol as well as blood sugar levels reduced nonfatal strokes.

Conclusion

In people with type 2 diabetes, intensive drug treatment to lower blood sugar levels reduced heart attacks; when combined with treatments to lower blood pressure and cholesterol, stroke was reduced as well.

Intensive treatment* vs control (placebo, standard care, or a less-intensive treatment) to lower blood sugar levels in people with type 2 diabetes

Outcomes

Number of trials and people

Rate of events with intensive drug treatment

Rate of events with control

Effect of intensive drug treatment

Nonfatal heart attack

16 trials (79,595 people)

Not reported

Not reported

Fewer people had a nonfatal heart attack (relative risk reduction of 11%; could be as low as 4% or as high as 17%)

Nonfatal stroke

14 trials (78,568 people)

Not reported

Not reported

No difference in effect†

Death from heart or circulation problems

18 trials (83,938 people)

4.6%

4.6%

No difference in effect

Death from any cause

18 trials (84,266 people)

8.1%

8.1%

No difference in effect

*Most studies assessed intensive drug treatment that aimed to lower only blood sugar levels. Some studies assessed intensive treatment with multiple components that aimed to control blood pressure or cholesterol levels as well as blood sugar levels. Results for both types of treatment were similar unless noted otherwise.

†People who also received intensive treatment for high blood pressure and high cholesterol had fewer strokes than those who received a control treatment.




Glossary

Control group
A group that receives either no treatment or a standard treatment.
Placebo
A harmless, inactive, and simulated treatment.
Randomized controlled trials
Studies where people are assigned to one of the treatments purely by chance.

Related Web Resources

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  • What should I eat? Types of fat

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    There are three main types of fat: unsaturated, saturated and trans fat. Unsaturated fats can help improve cholesterol levels and lower inflammation and are found in olive oil, avocados, nuts, seeds and fish. Trans fats are common in fast foods, and can increase your risk of heart disease, stroke, diabetes and other chronic conditions.
  • Medication for type 2 diabetes

    Informed Health Online
    Talk to your doctor about diabetes medications. Consider your treatment goals, age, weight, health conditions and other medications when deciding if a drug is right for you.
DISCLAIMER These summaries are provided for informational purposes only. They are not a substitute for advice from your own health care professional. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the McMaster Optimal Aging Portal (info@mcmasteroptimalaging.org).

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