Journal Club 1

The bigger picture

How we hope it works

• http://dundeeresearch.wordpress.com/– Introduction– Discussion Points– Summary

Article 1- Chocolate can lower your BP

Journal Article 1Effect of Cocoa on Blood Pressure

Ried K, Sullivan TR, Fakler P, Frank OR, Stocks NP. Effect of cocoa on blood pressure. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD008893. DOI: 10.1002/14651858.CD008893.pub2.

• Cochrane Library– Review of 20 studies• 856 participants

Selection of Trials

• ‘Randomised controlled, parallel or crossover, single-blind, double-blind or open-label trials of ≥ 14 days’

• ‘Trials were included if the control group received a placebo or a minimal dose of flavanol-containing cocoa product. Minimal dose of cocoa accepted as control is defined as products containing ≤ 10% of the dose of cocoa polyphenols given as the active intervention product.’

• “Primary outcomes – Difference in systolic and diastolic blood pressure at final follow-

up between cocoa and control group and adjusted for baseline.”

The first thing you see...

Questions

• Is 2-3mmHg change in BP likely to be solely down to the treatment?

• If yes, what dose should be used (given that the variability between doses of cocoa products ranged from 3.6g to 105g)?

• Can you even control the dose of a dietary compound?

• Is two weeks long enough to determine change in BP?

• Were the controls enough?

So what can we take from this review?

• Flavanols probably do have some effect on blood pressure– This may be useful as foods containing these

compounds are readily available e.g. dark chocolate

What can we not take from this review?

• Flavanols have a molecular basis for lowering BP

• Chocolate will lower your BP– If you eat lots and lots of chocolate...

CCT trial: Statin therapy in low-risk individuals

Lancet 2012; 380: 581–90

Trial selection

• 27 trials, 174149 participants– All randomised trials published before 06/11 and • included at least one intervention whose main effect

was to lower LDL• no other possible intended confounding

interventions/factors• at least 1000 participants and for >=2 years duration

– Investigating major vascular events, major coronary events, coronary revascularisation procedure, cancer, and cause-specific mortality

What they did with the trials

• Statistical models and risk– Participants grouped into <5%, >=5% to <10%,

>=10% to <20%, >=20% to 30%, or >30%

What they found

Points to note/Questions

• Does having previous vascular disease affect the results

• Effect on mortality• Any adverse affects?• Relative vs Absolute Risk

What can/can’t we take from this study?

• Statins are beneficial for low risk individuals as well as high risk individuals– Benefit likely outweighs any risks BUT– the benefit is rather small

• Guidelines/NHS vs the study– Should everyone be on a statin?