Meta-analysisindependent cross-checkabstract checked★ key study I-DIAB-112 in-depth review

Lowering blood pressure in type 2 diabetes

Blood pressure lowering in type 2 diabetes: a systematic review and meta-analysis.

Overview

Emdin CA et al.. JAMA 2015 · PMID 25668264 · DOI 10.1001/jama.2014.18574

In 40 trials with 100,354 people, each 10 mmHg lower systolic pressure reduced deaths by 13% and strokes by 27%.

Does the study support the specific claim? No · Methodological quality: high

Study explained simply

What did the researchers want to find out?: Quantify benefits of BP lowering in T2D.
How was the study done?: Meta-analysis of 40 RCTs.
How many people, animals or samples were studied?: 100,354 people.
What was actually found?: Death RR 0.87, stroke 0.73 per 10 mmHg.
How large was the observed effect?: ARR 3.16 deaths per 1000 patient-years.
What do the results mean in everyday life?: Measuring and treating blood pressure protects people with diabetes.
What are the study's limitations?: Fixed-effects model.
What does it say about Elawady's specific claim?: Contradicts 'no need to measure blood pressure'.
Do the results apply to Germany and Europe?: Applicable.
What can explicitly not be concluded from this study?: Cannot define the optimal BP target for every person.

What are the associations between BP lowering and vascular outcomes in T2D?

Study design: Meta-analysis – Systematic review and fixed-effects meta-analysis of large RCTs
Population: Participants with diabetes in BP-lowering RCTs
Country: Multinational
Period: 1966-2014
Sample size: 40 trials; 100,354 participants
Inclusion and exclusion criteria: Large RCTs, low risk of bias

Exposure / intervention: BP-lowering treatment (per 10 mmHg systolic)
Comparator: Control/less intensive
Endpoints: Mortality, CV events, CHD, stroke, HF, retinopathy, albuminuria, renal failure
Statistical methods: Fixed-effects meta-analysis; stratified

Results: Per 10 mmHg lower systolic BP: mortality RR 0.87 (0.78-0.96), ARR 3.16 per 1000 patient-years; CV events RR 0.89 (0.83-0.95); CHD 0.88 (0.80-0.98); stroke 0.73 (0.64-0.83); albuminuria 0.83 (0.79-0.87); retinopathy 0.87 (0.76-0.99). Larger benefits with baseline SBP >=140.
Absolute risks: Mortality ARR 3.16 per 1000 patient-years per 10 mmHg (reported)
Authors' conclusion: BP lowering is associated with improved mortality and clinical outcomes in T2D.

Consistent RRs with absolute risk reductions.

Treating raised BP in diabetes saves lives; this is impossible without measuring BP.

Directly applicable; same biology and clinical standards in Europe.

High-quality evidence for BP measurement and treatment.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	high
Risk of bias	low
Precision of results	high
Directness	direct
Reproducibility	replicated
Consistency with the overall evidence	consistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable