Even skinnier old people with low muscle mass are at greater risk of type 2 (insulin resistant) diabetes. The risks do not just come from fat.
Sarcopenia — low skeletal muscle mass and strength — is often found in obese people and older adults; it has been hypothesized that sarcopenia puts individuals at risk for developing Type 2 diabetes.
To gauge the effect of sarcopenia on insulin resistance (the root cause of Type 2 diabetes) and blood glucose levels in both obese and non-obese people, UCLA researchers performed a cross-sectional analysis of data on 14,528 people from the National Health and Nutrition Examination Survey III.
They found that sarcopenia was associated with insulin resistance in both obese and non-obese individuals. It was also associated with high blood-sugar levels in obese people but not in thin people. These associations were stronger in people under age 60, in whom sarcopenia was associated with high levels of blood sugar in both obese and thin people, and with diabetes in obese individuals.
Dieting to be thin is on its own not enough to stave off diabetes. It is also important to be fit and, in particular, to have good muscle mass and strength.
I think arrows of causation on this one might be complex. Does the muscle loss directly contribute to the type II diabetes? Or do problems with the vascular system cause the muscle loss and the diabetes as well? Or does the vascular system first become unresponsive to insulin and does this then reduce food supplies to muscles, leading to sarcopenia? See my recent posts Aging Blood Vessels Cause Muscle Loss and Insulin Resisant Arteries Accelerate Atherosclerosis. The problem with teasing out the mechanisms of causation is that failing subsystems get into a vicious cycle of causing each other to fail even worse.
You can read the full paper for free at Plos One.
Sarcopenia was associated with insulin resistance in non-obese (HOMA IR ratio 1.39, 95% confidence interval (CI) 1.26 to 1.52) and obese individuals (HOMA-IR ratio 1.16, 95% CI 1.12 to 1.18). Sarcopenia was associated with dysglycemia in obese individuals (HbA1C ratio 1.021, 95% CI 1.011 to 1.043) but not in non-obese individuals. Associations were stronger in those under 60 years of age. We acknowledge that the cross-sectional study design limits our ability to draw causal inferences.
What I'd like to know: Does resistance weight training reverse the development of insulin resistant diabetes? Could weight training combined with dietary change reverse the disease development and restore muscle mass in old people?
| Share | | Randall Parker, 2010 May 27 10:00 PM Aging Mechanisms |
http://www.ncbi.nlm.nih.gov/pubmed/12351469
Plus, there are tons of anecdotal stories about people getting off metformin, and even insulin, on HIT or paleo diet forums.
Strength training increases insulin action in healthy 50- to 65-yr-old men.
Duh.
Insulin lowers blood glucose in large part by stimulating muscle to take up glucose and make it into glycogen.
This is a very active process, that is, sugar doesn't just diffuse across the muscle cell membrane.
Less muscle and less toning of the muscle means the muscle will be less likely to take up glucose. And, always being "full" of glycogen, (you are always eating), the muscle cells will not take up much glucose. Why bother?
It is clear. Lift weights moderately, (especially work those really big leg muscles!), and skip a few meals to drain the glycogen out of your muscles (takes 24 hours of fasting they say), and your muscles will become nice glucose sinks.
We all have our genetic blueprint, and it contains a design for our bodies based on a particular load of muscle mass. For some this spec is relatively low. For me, thanks to my sheepherding Scottish ancestors, I'm genetically designed to carry a fairly high load of muscle mass. Unlike our ancestors, modern people have become mostly sedentary. For those of us with higher muscle mass specs, it is easier to fall below our design window for muscle mass, and we fight obesity and diabetes (along with other conditions) as a result. The "cure" for both conditions is to increase muscle mass back up to within our genetic design spec.
Randall,
You bet the two in combo would do the trick!
And the beauty of weight lifting is that one only need do it once or twice a week for 20 minutes a session.
http://www.ncbi.nlm.nih.gov/pubmed/11676593
But it's not the muscle mass per se as it is the ability to utilize/uptake glucose caused in large part by eating too many carbohydrates a la the USRDA food pyramid.
The single most effective solution to T2 diabetes is eating like a cave person. T2D would essentially vanish if people ate meat, fish, eggs, fowl, leafy/cruciferous vegetables and a piece of fruit now and again. Ditch the grains/tubers entirely. Dr. Richard Feinman and others at the Nutrition and Metabolism Society are attempting to lead the AHA, ADA, ADtA and others in this direction. You should interview Dr. Feinman for a blog post on this issue. Email me if you need his info.