Friday, March 30, 2012

Lifestyle Affects All-Cause Mortality

What's in a name? That which we call a rose

By any other name would smell as sweet.

You like "po-tay-to" and I like "po-tah-to",
You like "to-may-to" and I like "to-mah-to";
Po-tay-to, po-tah-to, to-may-to, to-mah-to!
Let's call the whole thing off!
George & Ira Gershwin, Let's Call the Whole Thing Off

So what do the above two quotes have to do with today's study/topic? Well, I've been meaning to point out this analysis of the National Health & Nutrition Examination Survey (NHANES) published online earlier this month & in print this week in JAMA in which the authors followed 44,959 adults for 14+years and concluded that meeting more cardiovascular metrics was associated with lower risk of all-cause & cardiovascular mortality, similar to previous findings from a subset of the same study published last August.

And just what are these 7 so called cardiovascular metrics? Not smoking, being physically active, eating a healthy diet, and having normal weight, blood pressure, blood glucose & total cholesterol levels. If you ask me, the first 3 out of the 7 metrics appear to be lifestyle issues while the remaining 4 are consequences or at least partially modifiable by the first 3.

From my perspective as a lumper rather than a splitter, I'd conclude that all these studies point towards the same conclusion: lifestyle affects all-cause mortality. Let's start improving ours!

Follow @alvinblin

Thursday, March 29, 2012

Lifestyle Affects Cancer Risk

One of my sisters-in-law is fond of telling me to "Choose wisely". Unfortunately, when it comes to lifestyle, we Americans have not been making the best choices. Studies have demonstrated that a healthy lifestyle can improve all-cause mortality, diabetes risk, erectile function, and stroke risk. And despite study after study demonstrating the benefits of regular physical activity, we still succumb to our inertia.

So in an attempt to mimic Don Quixote tilting at windmills, let me point out a collaborative Annual Report to the Nation that was published yesterday by the American Cancer Society, the Centers for Disease Control & Prevention, the National Cancer Institute, and the North American Association of Central Cancer Registries. Their conclusion? After reviewing data from 1975-2008, excess weight (whether just overweight or actually obese) and insufficient physical activity (<150 minutes/week) increase one's risk of cancer and decrease quality of life for cancer survivors.

Don't become a statistic but putting your head in the proverbial sand like an ostrich and ignoring all the evidence. If you don't do something about your lifestyle, you're bound to suffer the consequences.

Follow @alvinblin

Wednesday, March 28, 2012

Don't Just Sit There, Do Something! Part 6

I do my best to point out major studies demonstrating a link between physical activity & mortality. But obviously, not enough people read my drivel and listen to my exhortations since our country is getting fatter by the minute. Depending upon who you ask, most guidelines recommend 150 minutes of moderate intensity exercise weekly or 30 minutes most days of the week. Kick it up a notch to vigorous (or high intensity) exercise and you might be able to get away with just 15 minutes 5 days/week. Studies demonstrate that even more exercise, say 300 minutes per week, increases health benefits and lowers mortality.

But think about it. 60 minutes/hour. 24 hours/day. 7 days/week. That means there are over 10,000 minutes/week (10,080 to be exact). At best, 300 minutes of exercise each week represents only 3% of our time being active (150 minutes is a more realistic 1.5%). We generally recommend sleeping 8 hours/night so that means 33% of our time is already accounted for. But what about the remaining 64%? What are we doing during the rest of our day?

In an observational study published in Archives of Internal Medicine earlier this week, the authors followed 222,497 Australians for close to 3 years. These participants, at least 45 years old, were equally divided between men & women, two-thirds of whom were either overweight or obese, yet 4 out of 5 self-reported good to excellent health. Interestingly, 1 in 4 sat at least 8 hours/day while 3 in 4 met the 150 minute/week physical activity guideline. As noted previously, sitting most of the day doesn't preclude one from meeting the minimum recommendations for exercise.

But what's scary is the conclusion: even after taking into account physical activity (remember, this was a very active group of individuals, at least compared to us Americans), the more one sits, the greater one's risk for all-cause mortality. These results are similar to study after study demonstrating that TV viewing is linked to mortality. I suspect this is because we're usually sitting when we watch TV.

Don't get me wrong. We still need to exercise. But from this new study, it would appear that what we do the rest of our waking hours is just as important in its effect on our mortality. So don't just sit there, do something! And if you don't believe this study, check out Part 5!

Follow @alvinblin

Tuesday, March 27, 2012

Chocolate vs BMI

In the past, I've been ranting and raving about eating less & exercising more in order to get healthy. But perhaps it's not so simple as calories in vs calories out. Perhaps what we eats is as important as how much we eat. For instance, would a diet of 1,500 calories daily of potato chips, ice cream & steak be truly healthy? Or would 1,500 calories of non-fried fruits & vegetables, whole grains, poly- & monounsaturated fats, and lean protein be a better choice? Yet the former diet is so much easier to consume (and fun, I might add).

Along this line of thinking, chocolate has traditionally been considered a fun food, perhaps even junk food. Certainly, until recently, chocolate was not considered a health food. And given that chocolate has been sold, at least in this country, as candy, that's not surprising. But a number of studies have linked consumption of dark chocolate, not the more common & sweeter milk chocolate, to health benefits, eg heart failure, heart disease & cardiovascular risk factors.

And in a short research letter published in the Archives of Internal Medicine earlier this week, the authors studied chocolate consumption in close to 1,000 participants of a statin study. After taking into account the usual confounders, they concluded that chocolate consumption was associated with lower BMI (body mass index) despite the fact that chocolate consumption was also associated with greater consumption of saturated fats and not associated with activity.

Now this cross-sectional study doesn't give you free permission to change your diet to 1,500 calories daily of chocolate candy, but it does make us reconsider whether what we eat is as important as how much we eat. Anyone want to volunteer to be a research subject in future chocolate studies?

Follow @alvinblin

Bariatric Surgery vs Medication to Treat Obese Patients w/Diabetes

Traditionally, treating patients w/diabetes was the domain & purview of the medical physician, at least once insulin was discovered. Over the years, we've changed our demographics such that type 2 diabetes, as typified by insulin resistance associated w/obesity, has become much more commonplace at a younger age, than the original type 1 diabetes, which is due to pancreatic failure.

However, given the increasing prevalence of obesity (and diabetes), I would daresay that medicine is fighting a losing battle despite all the pharmaceutical options available to us, a veritable treasure trove compared to the simple sulfonylureas taught during my days of training. And given our prodigious predilection to prove the veracity of Newton's First Law of Physics, inertia, it's not surprising that very few persons are able to increase their level of physical activity to such a degree that they can match the results of those competing in NBC's The Biggest Loser TV show.

This prelude leads up to a dramatic (at least for me) announcement made yesterday at the American College of Cardiology meeting in which 2 studies published online first in the New England Journal of Medicine demonstrated the efficacy of surgery over medicine in treating diabetes in obese patients.

In the first study, the authors randomized 150 patients (two-thirds women avg 49yo w/BMI 36kg/m2 & HgbA1c 9.2%) to either intensive medical therapy alone or intensive medical therapy plus either Roux-en-Y gastric bypass or sleeve gastrectomy. All operations were performed by just one surgeon. At the end of a year, only 1 in 10 randomized to intensive medical therapy alone was able to bring his/her HgbA1c below 6% compared to 2 in 5 who underwent some form of gastric surgery. Weight loss was also greater after both surgeries compared to those who did not have surgery. Most notably, medication use decreased after both surgeries but increased in those randomized to intense medical therapy.

In the second study, the authors randomized 60 patients (50% women avg 43yo w/BMI 45kg/m2 & HgbA1c 8.65%) to either conventional medical therapy, laparoscopic Roux-en-Y gastric bypass or open biliopancreatic diversion. Two surgical teams, each specializing in a particular procedure, were used to perform the operations. At the end of two years, 75-95% of those who underwent surgery had achieved diabetic remission compared to no one randomized to conventional medical therapy. Furthermore, HgbA1c dropped down to 7.69% in the conventional medical therapy group compared to 6.35% in the Roux-en-Y gastric bypass group and 4.95% in the biliopancreatic diversion group.

Surprised? Well, I sure was! But on the other hand, if I had remembered to read an article in the January 23, 2008 issue of JAMA, I would have read that a 2 year unblinded study of 60 obese patients w/T2DM randomized to either conventional medical therapy or laparoscopic adjustable gastric banding found that three out of four who underwent surgery achieved diabetic remission compared to just one in eight randomized to conventional medical therapy.

Furthermore, a systematic review & meta-analysis published in the January 2009 issue of American Journal of Medicine came to a similar conclusion: bariatric surgery appears to achieve diabetic remission for at least two years post-op, with greater success being associated with greater weight loss.

Unfortunately, we're still too early in this paradigm shift from medical management to surgical treatment of diabetes in obese patients. The results thus far are clear: bariatric surgery is effective, at least in the short-term. The bigger question is whether the results will hold up in the long run. Even more importantly, can surgeons in the community w/less procedural volume replicate these same results? Only time will tell . . .

Follow @alvinblin

Monday, March 26, 2012

Estrogen vs Breast Cancer in Postmenopausal Hysterectomized Women

When you look at the design of the Women's Health Initiative (WHI) involving women who have an intact uterus and those who've undergone hysterectomy, it's striking that everyone in both arms was randomized to conjugated equine estrogen (CEE) or a placebo, regardless of uterine status, while only those with an intact uterus were given medroxyprogesterone acetate (MPA) in conjunction w/CEE and placebo in conjunction w/placebo.

In that case, let's assign the variable A to CEE and variable B to MPA. In other words, the two arms of WHI then become trials of A+B vs placebo (intact uterus) and A vs placebo (post-hysterectomy). At that point, you can then look at the two arms together as A+B vs A. In which case, it's always seemed strange to me that when A+B (CEE +MPA) was associated with negative outcomes but A alone (CEE) was not, we lumped both regimens together and threw the baby out with the bath water.

They say time heals old wounds. More data has been analyzed & reanalyzed since the first announcement of WHI. In this latest analysis published early online almost 3 weeks ago in Lancet, the authors continued to follow for close to 12yrs 10,739 post-menopausal hysterectomized women 50-79yo at the start of the trial. They concluded that, compared to placebo, those randomized to 6yrs of CEE alone had a lower risk of breast cancer. In fact, fewer women died from breast cancer when randomized to CEE than compared to those randomized to placebo.

Yet when you look at the parallel CEE+MPA arm (A+B), you find an increase risk of breast cancer & mortality. So while the authors conclude that differences in hormone therapy may account for the different results, I can't help but wonder why they can't come out and state that MPA may not be as safe as we've been led to think. After all, the effects of MPA are quite different from that of bio-identical progesterone, sold as FDA approved Prometrium. In the meantime, while I can't recommend CEE alone to prevent breast cancer, certainly one can feel more comfortable & safe about taking it during menopause.