Interesting New Meta Analyses Out on BP and Low Carb. Response from Egg Study

In case you haven’t heard, last week the Cochrane Hypertension Group released some compelling updates on Blood pressure medications (1). But before we get to that, you may be wondering what the heck the Cochrane Collaborative is. While TheFatNurse can’t comment on all nursing schools, during TheFatNurse’s time as a wee little nursing student, one of the buzzwords was Evidence Based Practice in school. As a result, one of the organizations to help increase the use of evidence based practice is the Cochrane collaboration.

The Cochran Collaboration consists of over 28,000 volunteers in more than 100 countries that saw a need to organize the medical literature in a way that was easy to understand and evaluate. The goal is to allow evidence based practice to make its way into the healthcare setting. They go about doing this through systematic reviews of randomized control trials. So what did they findout about hypertension and blood pressure?

The Cochrane group set out to see what the literature showed about individuals with anti hypertension medications and mild hypertension (systolic of 140-159 or diastolic of 90-99) but no prior related issues involving cardiovascular diseases/events. They wanted to examine Randomized Control Trial studies that had at least 1 year duration. Specifically, the outcomes from the literature they were examining were all hypertension related such as coronary heat disease, stroke, mortality, total cardiovascular events and adverse effects from medications causing withdrawals. So what did they conclude? In the author’s own words:

In this review, existing evidence comparing the health outcomes between treated and untreated individuals are summarized. Available data from the limited number of available trials and participants showed no difference between treated and untreated individuals in heart attack, stroke, and death. About 9% of patients treated with drugs discontinued treatment due to adverse effects. Therefore, the benefits and harms of antihypertensive drug therapy in this population need to be investigated by further research.

Pretty interesting. Another new study out last week was a meta analysis on low carb diets (2). Here were the results:

A total of 23 reports, corresponding to 17 clinical investigations, were identified as meeting the pre-specified criteria. Meta-analysis carried out on data obtained in 1,141 obese patients, showed the LCD to be associated with significant decreases in body weight (−7.04 kg [95% CI −7.20/−6.88]), body mass index (−2.09 kg m−2[95% CI −2.15/−2.04]), abdominal circumference (−5.74 cm [95% CI −6.07/−5.41]), systolic blood pressure (−4.81 mm Hg [95% CI −5.33/−4.29]), diastolic blood pressure (−3.10 mm Hg [95% CI −3.45/−2.74]), plasma triglycerides (−29.71 mg dL−1[95% CI −31.99/−27.44]), fasting plasma glucose (−1.05 mg dL−1[95% CI −1.67/−0.44]), glycated haemoglobin (−0.21% [95% CI −0.24/−0.18]), plasma insulin (−2.24 micro IU mL−1[95% CI −2.65/−1.82]) and plasma C-reactive protein, as well as an increase in high-density lipoprotein cholesterol (1.73 mg dL−1[95%CI 1.44/2.01]). Low-density lipoprotein cholesterol and creatinine did not change significantly

Again, very interesting stuff. Also David Spence, the author behind the egg yolk as deadly as cigarette smoking study (as some in the media dubbed it), responded to Nutritionist Zoe Harcombe’s critique of his study in her blog’s comments. Just scroll down until you find it.  It’s a good debate between Dr. Spence and Zoe Harcombe.

Picture by Coldbourne from ClipArt. Creative Commons Attribution-Share Alike 3.0

TheFatNurse hopes this is where the future of research is heading towards where debate can occur openly and freely for people to observe and put in their analysis. What would make this better is if all studies were open to the public and not just the abstracts. For example, the two studies TheFatNurse mentioned are not accessible with TheFatNurse’s university account which means TheFatNurse and others can only rely on the abstract to see what the study is about. This is a start, but the abstract tells us nothing about the details on how the experiment was setup, potential confounding factors and other information to allow an honest critique. By having open debate, it’ll be much more productive in moving towards the truth and confirming the validity of studies whether they are for or against the existing paradigm of fat.

References:

(1) Pharmacotherapy for mild hypertension

  1. Diana Diao1,*,
  2. James M Wright2,
  3. David K Cundiff3,
  4. Francois Gueyffier4

Editorial Group: Cochrane Hypertension Group

Published Online: 15 AUG 2012

Assessed as up-to-date: 1 OCT 2011

DOI: 10.1002/14651858.CD006742.pub2

(2) Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors

  1. F. L. Santos1,
  2. S. S. Esteves2,
  3. A. da Costa Pereira3,
  4. W. S. Yancy Jr4,5,
  5. J. P. L. Nunes3,*

Article first published online: 20 AUG 2012

DOI: 10.1111/j.1467-789X.2012.01021.x

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