Saturday, August 14, 2010

The Latest Low-Carb vs. Low-Fat Diet Study is Available Online for FREE!

The much talked about low-fat/low-carb diet comparison study published this month in the Annals of Internal Medicine can be found online for free.  As far as I know, it's not supposed to be free as several bloggers have stated that they had to purchase the full text version.  I've asked Stargazey at Low-Carb for You to confirm if this version is the same as the one she purchased.  She hasn't gotten back to me yet, but it sure appears to be a valid copy.  Here it is if you want to take a look at it:  Weight and Metabolic Outcomes After 2 Years on a Low-Carbohydrate Versus Low-Fat Diet.  Click on "Original Version (PDF)".  Here's a direct link to the PDF if for some reason the first link doesn't work:

Happy Reading!

Tuesday, August 10, 2010

Nurse Claims She Was Reprimanded for Not Readily Giving Ice Cream to Diabetic Patient

Wow, I hope this story isn't true.

To give some background: for the last few years, there has been a big push by hospital administrators for staff to think of patients more like customers and to provide customer service along with health care. This goes beyond simply being polite and courteous; it entails ideas borrowed from the hospitality industry such as leaving a fancy note card in a patient's room after performing a service like drawing blood stating "Your phlebotomist today was Susan. I hope I exceeded your expectations and provided you with excellent care. Thank you for choosing City Hospital". The hospital will then give out questionnaires asking patients to rate their customer service experience and the hospital will use the results (if they're good of course) in advertising. I think they may even be required to report the results to some kind of governing body, but I could be wrong on that.

I was surfing the internet yesterday and happened upon a thread at titled Customer Service ... Yay or Nay?  In it, a nurse described a situation in which she was reprimanded by her superior for not providing good customer service because she was trying to discourage a diabetic patient from eating ice cream.  In her own words:

"I agree with everything said. I have worked in many aspects and in many settings of healthcare for 35 years. Most recently I've been an LPN for the last 12 years and I have found that the "customers" have finally completely burned me out. I am supposed to renew my license in the next 5 days and quite frankly I don't want to. If I am going to give people what they want with a smile instead of what they need with understanding and caring, then I'll flip burgers. I have ALWAYS greeted my patients (yes patients) with a smile, a caring hand on the shoulder if they allow and carefully explained what, why, and how. Lately I leave a bedside with confidence that while not pleased with their situation, they are comfortable with it. An hour later I'm being called into the charge nurse's office being chewed out for being mean and/or rude to the patient and/or the family! I did my nursing duty, I brought them that extra helping of ice cream with a teaching that this may not be their best choice for a diabetic and perhaps they would do better with the apple slices or sugar free cake I also brought along. But how rude of me to suggest such things! The "client" knows what is best for them, I'm told. I have seen nurses lose their jobs for consistently doing their job in just this way. I believe in doing everything and anything within the confines of the healthcare process to make a patient happy and comfortable but this customer satisfaction has come to a place where healthcare is no longer part of the process."
OK, maybe I'm just tired and not thinking straight, but isn't a nurse supposed to discourage a diabetic patient from eating a bunch of sugar?  She's not a waitress in a restaurant trying to ensure herself a hefty tip, she's a healthcare professional trying to see to her patient's best interest.  The patient may get annoyed but so what?  "I'm here to save your ass, not kiss it" is an old nursing adage.  Too bad this particular hospital's administrators seemed to have forgotten it.

Friday, August 6, 2010

Fat Fails First?

In my previous blog post, I explained what initially made me skeptical of the idea that insulin resistance develops first in the liver and skeletal muscles and last in fat tissue. Now I'd like to argue the opposite: that insulin resistance develops first in fat tissue and this leads, over time, to less insulin sensitivity in liver and muscle cells eventually resulting in the development of the metabolic syndrome.

Consider the fact that people with congenital generalized lipodystrophy, in whom fat cells are lacking from birth, typically develop components of the metabolic syndrome such as insulin resistance, non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes at a much earlier age and in more severe forms than do obese humans. This is believed to happen because a dearth of fat cells causes the body to have no "safe" place for excess fatty acids to be stored, and people with lipodystrophy tend to generate excess fatty acids because they cannot make much leptin, a major adipose-derived satiety hormone, and hence have a strong drive to eat. Some of the excess fatty acids will end up being stored in the liver and muscles as well as in other non-adipose tissues (aka lipotoxicity) resulting in decreased insulin sensitivity in these organs and the metabolic syndrome.

Obese humans, on the other hand, are not lacking fat cells so they can, and do, store a lot of excess fatty acids in their fat cells. I'm sure we've all known overweight or obese individuals who possess good health with no obvious signs of the metabolic syndrome - normal blood pressure, normal blood sugar, normal lipid profile, etc. These individuals will often bring these things up when a friend or family member urges them to lose weight - "All my blood tests are good and I'm not on any medication; my doctor says I'm healthy so I feel no urgent need to lose weight." And they may be able to go their entire lives without a hint of the metabolic syndrome if their fat cells maintain their insulin sensitivity. If they don't, these corpulent individuals will become, in essence, like a person with congenital generalized lipodystrophy: unable to store excess fatty acids in adipose tissue which will lead to lipotoxicity and metabolic syndrome. Unfortunately, the majority of obese individuals will develop metabolic problems related to their weight at some point in their lives.

It has been shown that many people's free fatty acid blood levels are elevated years before a diagnosis of type 2 diabetes (which is based solely on some measure of high blood sugar). In other words, blood sugar can remain within normal limits while fatty acid levels are soaring. Knowing that the inhibitory effects of insulin are the more physiologically important, this indicates that adipose tissue becomes resistant to insulin (resulting in increased free fatty acids via unrestrained fat cell lipolysis) before the liver does (resulting in increased blood sugar via unrestrained hepatic glucose production). 

It's also important to note that a class of diabetes drugs called thiazolidinediones (TZDs) lowers blood sugar primarily by increasing fatty acid uptake and storage in fat cells. By taking excess fatty acids out of the circulation, the liver becomes less affected by lipotoxicity and regains its sensitivity to insulin. Hepatic glucose production is restrained by insulin in a more normal fashion and blood glucose concentrations fall. 

Further, it has been demonstrated that serum free fatty acids are the main source of liver triglycerides in people with NAFLD; therefore, fat cell insulin resistance to lipolysis is likely a major contributor to fat accumulation in the liver.

Using the above information, the following scenario makes sense to me:

Chronic caloric surplus (possibly caused by a diet high in sugar and fat along with a sedentary lifestyle) causes fat tissue to expand to sequester toxic fatty acids that would otherwise damage organs. When fat tissue can no longer expand, it becomes resistant to insulin. This leads to increased fat cell lipolysis and elevated free fatty acids which leads to "ectopic" fat deposits in the liver and muscles. The liver and muscles then become resistant to insulin. This leads to increased hepatic glucose production with substrate partially supplied by amino acids coming from skeletal muscle because of increased proteolysis. The increase in blood sugar results in stimulation of insulin secretion from the pancreas. We now have chronic hyperinsulinemia and hyperglycemia - these conditions are associated with and possibly cause many of the problems linked with the metabolic syndrome like hypertension, coronary artery disease, kidney disease etc.

To be continued...