Shadowing a Diabetes Doctor, or, You are what your hormones decide you are – May 24, 2012

I had the opportunity to shadow a veteran endocrinologist for 4.5 hours Thursday morning.  It was a fascinating experience to see the treatment of actual diabetic patients instead of staring at diabetes data trends on a CRT computer screen.

The physician, who has been an endocrinologist for nearly 30 years, estimated that his practice consisted of 60:40 diabetes / thyroid patients.

Most diabetic patients we saw were older (>50) and had excess belly fat (possibly an indication of metabolic syndrome, i.e. insulin resistance).  And the greater the age and body fat, the greater the complications of their diabetes (which makes me quake with fear at the future health of children and adolescents with type II diabetes).  Most appeared to have circulation issues that led to swelling in the feet, discoloration, and/or dry skin around the ankles.  Circulation issues can disturb immune function which can lead to amputation: this latter problem was very scarily portrayed in HBO’s “Weight of the Nation” in which an older man required a leg amputation due to his uncontrolled diabetes.  The physician informed me that uncontrolled diabetes is the leading cause of amputation in the nation.  One very obese patient had venous insufficiency (which I assume is related to long-term, possibly poorly controlled diabetes but I cannot be certain).

Ultimately, the complications resulting from long-term diabetes are vast and severe and one causative factor appears to be the long-term accumulation of AGEs in the vascular system (advanced glycated end products, i.e. proteins and other molecules with bound glucose, due to chronically abnormally elevated blood glucose and high fructose consumption).  These glycated molecules bind together and clog/disrupt blood flow and, for capilaries, can cause hemorrhaging (which can lead to blindness in severe diabetic retinopathy, now the leading cause of blindness in working age Americans).

The accumulated damage to the vascular system can impede blood flow, oxygen distribution, and lead to nerve damage (diabetic neuropathy), which is why many diabetic patients we saw Thursday had their feet tested for nerve sensation with what is basically a 10 gauge fishing line.

All in all, diabetes is a frightening disease and prevalence, especially of type II diabetes, is reaching tremendous levels (~25 million adults, ~8.3% of population, with another 79 million people estimated to have prediabetes).  The US population prevalence has increased hugely over the past 50 years in conjunction with increases in obesity (most diabetes being type II, likely due to the effects of insulin resistance).

We also saw a handful of patients with thyroid issues, including 3 women with low thyroid levels related to thyroid surgery and 2 men for low testosterone levels.  Both of these conditions appeared to cause weight gain which supports the hypothesis that obesity may be a hormonal disorder.

One women complained of being unable to lose weight after significant dieting for three months despite subsisting primarily on yogurt, carrots, and eggs and minimizing calories.  Another man stopped his testosterone therapy and reported substantial weight regain (similar to Vince Vaughn and cigarettes, suggesting that hormones are driving weight loss/gain in various ways).  I am unsure how thyroid hormones affect weight other than affecting metabolic rate (which might simply be a downstream effect of hormonal action) but sex hormones are known to reduce fat levels by acting on enzymes on the fat tissue (estrogen and testosterone downregulate LPL enzymes on fat tissue which should limit triglyceride stores in fat cells).  Testosterone pellets are now gaining greater acceptance as positive results emerge and FDA approval has occurred.  One patient was offered this therapy and said he preferred it as the testosterone gel was ineffective and risky around children as the hormone can be transferred between patient and child and absorbed through the skin.

All in all, the day was a fascinating glimpse of the massive effect that hormones have upon the human body and mind.  Most individuals would claim that they have control over the state of their health.   They can control their weight, their mood, their energy levels, etc. etc. by simply acting from free will.  However, the fact that hormones have such a strong hold over the biological processes of our body severely weakens this belief.  If your hormones drive you to fatten, become hyperactive, stay awake, etc., then that is what you will do.

Therefore, because human health and even  behavior are driven by hormones than the understanding and control of our hormonal system, through the field of endocrinology, is all the more important.

Shadowing a Sleep Doctor- The Scourge of Sleep Apnea May 9, 2012

In a recent video, Dr. Robert Lustig, of UCSF Medical School, called obesity “the gift that keeps on giving.”  He was referring to the metabolic effects that “diabesity” in the mother have upon the fetus (aka; epigenetic affect, interuterine effect, metabolic memory of the child, etc.).  We know that obesity in many people is likely a condition of insulin resistance and that this insulin resistance may cause a host of metabolic problems linked to obesity: hyperinsulemia and eventually type 2 diabetes, hypertension and stroke, dislipidemia (low HDL, high triglycerides, high small-dense LDL) and inflammation (hyperglycemia, AGE production, and C-reactive protein) leading to heart disease, cancer (many tumors associated with breast and colon, to name a few, feed off of elevated insulin, insulin-like growth factor, and glucose to increase replicative rate and risk of metastasis), Alzheimer’s (Type III diabetes or “brain diabetes”), gout (high uric acid buildup in blood stream), etc.

Now there’s another “gift” of obesity: sleep apnea.  There now appears to be an epidemic of sleep apnea among the obese.

I shadowed a wonderful physician on Wednesday May 9th for 5 hours who has transitioned from pulmonology work to running a sleep clinic full-time due to the huge business now found in sleep apnea.  He estimated that around 95% of his practice is devoted to sleep apnea while around 70% of these cases are either overweight or obese.

Why does excess body fat cause sleep apnea, i.e. make people awaken at night (“sleep” = at night; “apnea” = to awaken)?

It’s hypothesized that a person’s excess body fat forces their airway closed at night which can cause some individuals to awaken as much as 100 times an hour throughout the night (that’s 800 times during a normal 8 hour night of sleep).  This constant awakening stresses their system (can exacerbate CVD, diabetes, acid reflux) and leaves many people exhausted the next day despite the impression, at least in the patient, that they got a full night’s sleep.

The physician explained it to a patient whose obstructive sleep apnea was causing them to awaken 60 times an hour, or, once-a-minute:  “Imagine if I snuck into your room and strangled you once a minute.  When you wake up, I’m gone.  But I’ll be back 59 seconds later and do the same thing again, and again, and again…hundreds of times a night.  Thousands of times a week.”

Scary stuff.  But accurate.

Not only does sleep apnea place an individual at increased risk of motor vehicle accident, crashing a plane (some pilots suffer from the condition), falling asleep at the job, missing cherished play time with their kids, etc., it also may either generate or exacerbate the conditions of CVD, hypertension, acid reflux, and diabetes.

The stress response causes the body to release adrenaline, which causes the body to dump fatty acids and blood sugar into the system (exacerbating diabetes), raises blood pressure (which worsens hypertension and may eventually lead to stroke), exacerbates acid relux, ie. GERD, by causing the esophageal sphincter to relax and allow stomach acid to enter the esophagus, and all of these conditions likely stress the heart, setting up the individual for increased risk of a heart attack (many obese people also have CHD or CVD…).

A 2005 US Dept. of HHS, AHRQ systematic review estimated that between 2-4 percent of middle-aged adults have sleep apnea.  Given the increased awareness and diagnosis of sleep apnea, and increasing prevalence of obesity in adults, it’s likely that the actual current prevalence may be higher.

CPAP machines (“continuous positive airway pressure”) are given to patients with sleep apnea to keep their airway open and prevent the occurence of sleep apnea.  Modern CPAP machines monitor the time of use, number of SA events, etc. among patients and it does, at least in patients at this clinic, appear that CPAP works very well to prevent the occurrence of SA.

There are side-effects of CPAP, though they’re minor (drying of the throat being the main one).  Still, if patients use the machine faithfully every night, SA diminishes to such an extent that many patients enter the “normal range” of waking 5 or less times and hour.

However, many patients fail to use the machine faithfully.  Like so many aspects of preventative medicine, it is up the patient to use the drug or treatment continuously, day in and day out, for the patient to be spared either disease incidence or disease progression.

Patient adherence is another discussion but, CPAP adherence in SA sufferers appears to help these patients tremendously.  Many see full cessation of SA symptoms and are able to get a full, healthy night of sleep for the first time in, for many sufferers, DECADES.

Treating SA means increased high-quality, REM sleep, which means a happier, healthier, and less accident-prone wakening life for these patients.  Kudos to the doctors who treat this condition and kudos to the marvels of modern medical technology.

However, if the majority of obstructive sleep apnea (and even central sleep apnea- occurring mainly in CVD patients) is due to excess body fat, then most of the SA disease burden in the American adult population could be prevented by not allowing these individuals to become obese in the first place.

This means altering the food environment to make it less “obesegenic” – which is another conversation.  Please see my “Diabesity” page for more information.

Did HBO get it Backwards? Is Obesity a Cause of Metabolic Mischief or an Effect? Or Both?

HBO’s “The Weight of the Nation” docuseries airing last night and tonight pushes the message that obesity, excess body fat, causes a host of metabolic diseases (diabetes, stroke, CVD, cancer, Alzheimer’s, sleep apnea, etc.).   And that if we can just lose b/w 5-10% of our body weight, this will fix the dislipidemia (low HDL, high triglycerides, high sd-LDL), hypertension, hyperinsulemia, etc. and put us back on the pathway to health.

But what if they got it backwards?  What if, for many obese people with these metabolic diseases (most falling starting with a precursor condition called “the metabolic syndrome”), the obesity itself is simply an effect of the metabolic disorder (insulin resistance) that causes all of these related metabolic diseases?  And, the subsequent 5-10% of body fat lost is an indicator of improving metabolic health, not a cause of it?

Is obesity a symptom of metabolic derangement or a cause of it?  Is it both an effect and a cause (like sleep apnea)?  Does the insulin resistance condition drive metabolic syndrome (central obesity, hyperglycemia, hyperinsulemia, hypertension, high trigly., etc.) and then the condition of central obesity release harmful hormones that cause the insulin resistance to be exacerbated, as HBO implies?

I’m not sure.  It’s an important topic though because, if obesity is largely an effect, than focusing on obesity only may distract from the important fact that many lean people suffer from insulin resistance (and therefore, are at high risk for diabetes, stroke, and CVD) as well.

Fat seems to be a strong symptom of metabolic derangement, but it’s not the only symptom.  Maybe the entire population should be screened by being given a HA1C test to gauge average insulin levels (over a 3 month period) to check for insulin resistance?