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

Showing HDL The O Face

Actually it’s more like “OMG my chest hurts so bad!” instead of the above clip from Office Space, but…some people do get symptoms of Acute Coronary Syndrome (ACS) from doing “O Face” type “activities.” What is TheFatNurse reffering to? A new study showing some associations between Apolipoprotein O levels and ACS.

Apo O is a novel lipoprotein found in mostly HDL and researchers are still trying to figure out its role in the body. In the meantime, the new study found associations of increased Apo O levels and people with ACS compared to normal subjects. This was found independent of other lipid markers. So what does this mean? It’s too soon to tell, but this study can be useful for generating further hypothesizes. Perhaps it can be a cardiac marker in the future? Apo O will certainly be something interesting to follow as the research on it continues.

Regardless, this was probably the first study TheFatNurse read that made TheFatNurse extremely hungry…I mean look at this sentence!

ApoO was measured by the sandwich dot-blot technique with recombinant apoO as a protein standard.

Yes TheFatNurse knows they are not talking about food but it makes TheFAtNurse think of:

Filtering studies in the media

So you may have heard about the latest study on eggs and heart disease. The one where CNN and NYdailynews write:

Is eating egg yolks as bad as smoking?

CNN

Like Hollandaise sauce? Too bad — for your heart and blood vessels. Yolks are packed with cholesterol, causing blood-vessel-clogging plaque buildup, just like smoking does.

NYdailynews

Ironically, TheFatNurse saw these articles in the morning when TheFatNurse was chowing down on some eggs. What a way to wake up! Sadly, the article is not  free for view and TheFatNurse’s university account doesn’t have a subscription to it! TheFatNurse isn’t going to plop down 31 dollars for this study – after all 31 dollars can get you 240 eggs at Costco! Even more Ironic…240 eggs per year is about how many eggs the people in the highest egg group ate in the study…CONSPIRACY!?

Anyways, the study looked at carotid plaque buildup and divided the subjects into five groups based on how many eggs they ate via food surveys. They then found an association between egg consumption and plaque buildup. Scary? Not eggactly (hehe), because there are problems galore with the study itself and the way the media is interpreting it. Of course anytime the media represents a study this runs through TheFatNurse’s head:

f

In anycase  Zoe Harcombe has already done a pretty good critique of the study (she has the full study) which you can check out. Like any critique, once you look at how a study is setup, designed, calculated, and interpreted it is quite simple to spot things that are fishy.

Seinfeld Falls For The Old Fat Hypothesis

TheFatNurse recently jogged down memory lane in the 90’s with a few episodes of Seinfeld. You can only imagine TheFatNurse’s delight when an episode about low fat yogurt plopped onto the screen – CAPTURES THE PERSPECTIVE OF FAT SO WELL IN THE FATNURSE’S CHILDHOOD!

Photo by Alan Light; CC 2.0

While the belief that fat is evil still persists today, it was much much worse in the 1990s and this seinfeld episode captures it perfectly:

http://yadayadayadaecon.com/clip/46/

The episode shows Seinfeld and Elaine ecstatic about a new yogurt shop serving non fat yogurt. Both characters can’t believe there is no fat and proceed to gobble down cups and cups only to be shocked when they end up packing on the pounds. It’s revealed that the non fat yogurt actually has some fat in it which is what’s causing the weight gain. Mayor Rudy Giuliani even weighs in on the evils of fat in the non fat yogurt.

TheFatNurse is pretty sure the characters were getting fat not from over indulging in just fat, but also sugar. Even if the yogurt was 100% fat free, the characters would still have gained weight from eating so much yogurt with sugar under the belief that its ok because there is no fat. Look at the nonfat yogurt from Costco: 52 grams of sugar!

It’s a sad reminder of how TheFatNurse grew thinking fat consumption worked. This paradigm that eating fat makes one fat and eating sugar is ok was also shared by a lot of TheFatNurse’s friends growing up. In fact, TheFatNurse even remembers having an old friend who use to indulge in sherbert and yogurt while TheFatNurse ate full fat ice cream because TheFatNurse’s friend didn’t want to get fat…well guess what happened to her?

SHE’S DEAD

…dead emotionally to TheFatNurse that is. Cause we had a falling out but otherwise her health is probably ok.

Anyways, on a related note, a new study (observational study) came out from the Journal of American Board of Family Medicine showing the dangers of obesity may be against what society believes using data from 2000-2006. It’s not the obesity that is causing mortality but the diseases that are associated with it like diabetes and hypertension.

Regarding severe obesity, as in the relatively fewer prior studies examining this category separately,1519 this study found it to be associated with significantly increased mortality risk without adjusting for diabetes or hypertension. However, severe obesity was no longer significantly associated with mortality after adjusting for these conditions, something not examined in the prior studies. Considered in the context of prior studies, these findings suggest that the mortality risk of above-normal BMI, at least in the short term, may be lower in the current era than in the past.

…suggest that efforts to reduce mortality among the overweight and obese might be targeted most productively at individuals with coexisting diabetes, hypertension, or both.

Nice that the study reminds readers that generating conclusions from an observational study is not the same as RCTs!

Given the observational nature of the current analyses, these notions represent hypotheses to be tested in randomized controlled trials.