Links for Wednesday, September 5, 2018: docs are nervous about weight loss meds, risky low-carb diets, why I'm not a pediatrician, and continuity of care is good

Why don't more docs prescribe weight loss medications?

Speculation: 1) cost (and by extension, prior authorization requests); 2) residual fear from fen-phen, as one of the docs interviewed alluded to. We can surely put this to bed, since the current crop of meds has been on the market much longer than fen-phen had been when its harm was revealed; 3) nihilism. Five percent weight loss is meaningful from a medical perspective, but unless the doc is consciously, prospectively measuring outcomes like blood pressure, lipids, and fasting sugars, it won't knock her socks off. Patients won't be thanking her for getting them ready for bikini season; and 4) the old Risk Evaluation and Mitigation Strategy (REMS) for Qsymia was such a PIA that it scarred some docs to prescribing these meds.

Can we stick a fork in low-carbohydrate diets? (Ba Dum Tss)

What's a 32% increase in mortality among friends? Investigators (in a study that, to my knowledge, has not yet been published, so caveat emptor) found an association between the lowest quartiles of carbohydrate intake and death:

NHANES data. Model 1 is unadjusted for other risk factors. Model 2 is adjusted. These are ugly, ugly numbers. 

NHANES data. Model 1 is unadjusted for other risk factors. Model 2 is adjusted. These are ugly, ugly numbers. 

Remember: we can't draw causality from this. There is some chance that people who are sick and more likely to die from heart disease, cancer, or stroke are more likely to adopt low-carbohydrate diets. But it doesn't seem likely. The people at highest risk in this study were those over age 55 and "non-obese."

Reason # 1,001 I'm not a pediatrician:

Can. Not. Do. It.

Special shout-out to the 100 cell phone text alerts during the video. 

If lack of continuity is a mark against telemedicine, then it's a mark against the hospitalist model in general

Are triathlons dangerous?

First things first: I've never done a triathlon. I swim like a St. Bernard. But I've done a lot of endurance bike racing, and I've been at more than one event with a death, the most recent the 2017 Dirty Kanza. So I was interested that in the latest Annals of Internal Medicine, investigators looked into a sudden death database to identify 135 race-related deaths and cardiac arrests in American triathlons between 1985 and 2016. Interestingly, right at two-thirds of deaths and arrests happened in the swim part of races, which usually comes first, before the bike and run. The editorialists spend a lot of energy trying to link swimming to some special form of stress from cold water or other factors that might be extra-dangerous. But to me, the swimming link seems consistent with the finding that in autopsies, about half of subjects had cardiovascular abnormalities, most often old-fashioned atherosclerotic disease. Swimming caught most of these people simply because it was the first event. Had running or cycling come first, I suspect one of them might have been the death leader. I'm not convinced by their observation that most marathoners die toward the end of races; anyone who's seen the scrum at the beginning of a triathlon knows that it's inherently different than the often walking pace seen at the start of a marathon: 

From http://www.zwemza.com/?p=5515, triathletes tempting fate. 

From http://www.zwemza.com/?p=5515, triathletes tempting fate. 

85% of victims were male, but I'm not sure the significance of that number, since >60% of participants (at least in pro Ironman races) are male:

From https://www.outsideonline.com/1964906/fight-gender-equality-ironman

From https://www.outsideonline.com/1964906/fight-gender-equality-ironman

And if you look at total Ironman competitors, the distribution of sex comes much closer to the death/cardiac arrest statistics:

kona-gender-breakdown-chart.jpg

But sex aside, we're forced to see that cardiac arrest and death are not rare among triathletes. Between 2006 and 2016, their incidence was 1.74 per 100,000 participants in the study. The risk of death increased with increasing age, unsurprisingly. Don't let this dissuade you from being more active. The benefits of physical activity far, far outweigh the risks in almost everyone. If you're inactive now and thinking of becoming active, or if you're active now and thinking of doing really hard-core things like triathlon, consider taking the American College of Sports Medicine's new-ish algorithm to your doctor and talking it over before you hit it really hard:

Original.00005768-201511000-00028.FF2.jpeg

We don't know how really weird stuff like performance enhancing drugs effects this. My suspicion is that it's not good.