Does staying up late make you fat?

Lack of sleep makes you crabby.

But can staying up late make you fat? Or diabetic? Or increase heart disease risk?

Can forcing your body to ignore its evolutionarily-programmed day-night/sleep-wakefulness cycle also distort health, even when sleep is adequate?

Yet another study adds to the growing clinical literature documenting the lack of sleep, or, in this case, the "violation" of circadian rhythms that occurs with unpredictable or shifting sleep patterns.

In this small study of 10 men and women, forcing them to sleep on an unnatural 28-hour per "day" schedule, causing a dyssynchrony with natural day-night cycles, yielded increased glucose (blood sugar) levels, poor response to insulin, increased blood pressure. It also led to a decrease in leptin levels, a phenomenon that can trigger increased appetite.

Such circadian misalignment was meant to recreate the distorted day-night cycles of shift workers, a group that is unusually prone to diabetes and heart disease. This study further confirms that there are indeed unhealthy physiologic consequences of defying normal day-night sleep cycles.

This study suggests that, not only is sufficient sleep important for health, but the predictability and concordance with normal circadian cycles is also important.

Add to this previous studies demonstrating an association with sleep deprivation and low HDL/high triglycerides (Kaneita Y, et al 2008) and increased likelihood of having a positive heart scan (coronary calcium) score (King CR et al 2008), and it is increasingly clear that sleep is a crucial factor for overall health. It may even be a helpful strategy to control weight.

A full report on the importance of sleep is planned for the Track Your Plaque website.

Vitamin D Project: Grassroots Health

Most Heart Scan Blog readers already know:

Your doctor has been brainwashed by the pharmaceutical industry.

Your doctor more than likely has spent the better part of his or her career in the Guantanamo Bay of healthcare, water-boarded by seductive sales representatives, enticed with promises of fame and riches, threatened with ostracism from the clubby internal halls of healthcare if--gasp!--he or she didn't subscribe to the "rule" that only drugs are good, anything else is bad.

The same FDA-approval-is-necessary-to-be-good brand of nonsense is gaining popularity among my colleagues who, having caught some mention (on the Today Show, Oprah, or similar source of medical information), hope to join the vitamin D hoopla.

People will proudly declare that they are taking a high dose of vitamin D: 50,000 units once per week.

No. They are taking a barely useful form: D2, ergocalciferol.

Studies examining the reliability of the D2 form differ:

There's the Heaney study suggesting that D2 is less effective than D3:
Vitamin D2 is much less effective than vitamin D3 in humans

Then there's the Holick study showing they are equivalent:
Vitamin D2 is as effective as vitamin D3 in maintaining circulating concentrations of 25-hydroxyvitamin D.

My experience is more in line with the Heaney study: Little or no real effect with D2.

One particularly illustrative case I witnessed was a woman who was mistakenly prescribed D2 at 50,000 units per day. She told me that she'd been taking it for a year. I fully expected to see clear-cut signs of toxicity (e.g., high blood calcium levels). Curiously, she showed no signs of toxicity. Nor did she show any vitamin D at all in her blood: 25-hydroxy D level of zero--literally zero.

I've witnessed similar phenomena several times: plenty of vitamin D2 . . . very little vitamin D in the blood.

All in all, I suppose that D2 is better than No-D at all. But you are far better off joining the ranks of the pharmaceutically challenged and go with the stuff that really works: D3.

D3, or cholecalciferol, yields confident increases in blood levels. It is inexpensive, safe, and an exact copy of the human form of vitamin D. (Of course, gelcap or drops only, NEVER tablets.)

There is absolute NO reason to take vitamin D2, the form that sometimes works, sometimes doesn't, the facsimile plant form issued by the drug industry.

Why don't stents prevent heart attack?



No study has ever documented that stents prevent future heart attack. But, in day-to-day practice, stents are frequently implanted for just this reason.

A little clarification. Stents do prevent heart attack--if the heart attack is already underway, either as an "acute myocardial infarction" or "unstable angina."

In other words, a plaque in a coronary artery can rupture just like a little volcano. Rather than spewing lava, the underlying plaque contents--fibrous tissue, inflammatory cells, cholesterol crystals, fatty material, debris--are exposed to flowing blood and trigger spasm of the artery and blood clot formation. A ruptured plaque is typically found in people who go to the emergency room with severe chest pain or have difficulty breathing.

A heart catheterization is performed, a severe (e.g., 90-100%--completely closed) is found. A stent in this situation is of clear-cut benefit.

What is not clearly beneficial is someone with no symptoms, symptoms only with physical activity that has been present for at least several months, or someone with a high heart scan score and no symptoms. In these circumstances, stent implantation does not reduce risk for future heart attack.

Why?



Take a look at this angiogram of a right coronary artery. You can seen plaque all along the artery (represented by areas that appear pinched off. There are at least 4 visible.)

Putting one 15 millimeter stent in the artery will only affect the area of artery stented. (Stents vary in length, but typically are 12-18 millimeters in length.) The right coronary artery is about 10 times or more this length. There are also two other arteries of similar length. A stent at one location will do nothing to affect the potential for rupture in any of the other plaque-laden areas.

Say a stent is implanted in the "worst" blockage in this right coronary artery, the plaque located at around 9 o'clock. What about all the other plaques? They can still rupture.

Why not put in many stents, say, 4 or 5, and stent all the visible plaques?

Two reasons: 1) Plaque you can't even see on an angiogram can still rupture, and 2) it is very costly (easily $30,000 at the very least), 3) incurs greater procedural risk, and 4) messes up the artery for future procedures, since a steel-lined artery that develops more disease in future will be more difficult to re-implant stents, bypass, or perform other procedural manipulations.

The point: Putting in stents does not reduce potential for plaque rupture in the entire artery.

What can prevent plaque rupture? That's the whole point of following an effective prevention program: prevent plaque rupture.

(Of course, this discussion cannot encompass the wide variety of potential situations that may cause your doctor to individualize your approach. Nonetheless, when advised to have an elective heart procedure, a healthy dose of skepticism and is clearly a good practice.)

Top image courtesy National Heart, Lung, and Blood Institute.