Key points:
50% of Americans are insulin resistant.
Insulin resistance starts in the muscle and is associated with a sedentary lifestyle.
Excess body fat adds to insulin resistance, and obesity almost always indicates that there is some level of insulin resistance, but is not the origin.
Even young, lean people can have insulin resistance, if they are sedentary.
Did you know that about 50% of Americans are insulin resistant? Yes! You read that right… FIFTY PERCENT! While I know this and have written about it several times, it always just hits me so hard every time. Maybe it’s because my life’s work has been working with people who deal with the chronic diseases that insulin resistance causes and so I see, on a daily basis, the gravity of what this means. To be honest, it truly makes my heart so heavy. Insulin resistance is a big deal and many of us are walking around with no idea we have it, even if you are good about having routine lab work at your yearly physical.
We see that long before blood glucose levels rise to the point that a problem is detected on lab work, insulin resistance sets in and it starts in the muscle cell. I find this fact very interesting as I think that so many of us would guess that it would start at the adipocyte (fat cell). I think we are conditioned to think that it is the accumulation of excess fat that makes us resistant. While yes, excess fat can add to resistance, it is not the origin.
The story starts at the muscle cell. This is a huge shift in paradigm, even for healthcare providers. We are very fat focused. We look at the excess body weight as the major problem and assume if you lose the weight, then all is corrected; BUT this is miss-guided. Our focus should be on correcting the underlying problem and this means focusing on muscle. The weight, I venture to say, is a symptom of the underlying insulin resistance and if we focus on improving muscle insulin sensitivity, weight loss will follow.
A study conducted by Peterson et al. found that even young and lean individuals can be insulin resistant. All of the participants maintained normal blood sugar levels after being given a high carbohydrate milkshake but in the insulin resistant subjects, it took much higher insulin levels to maintain the normal blood sugar, indicating there was resistance there. Another important finding from this paper was the fate of the ingested sugar. Those with insulin resistance stored significantly less (61% lower) glucose as muscle glycogen, meaning the muscle took up much less of the sugar and further, they had nearly double an increase in how much of the sugar got turned to fat in the liver (which is laying the ground work for developing metabolic syndrome, fatty liver and diabetes)! It is astonishing that these were young, lean men that no one would even think there is anything going awry. The caveat to this story is that the insulin resistant men were sedentary. Lack of exercise seems to be a MAJOR factor in determining muscle insulin resistance. More to come on this in the next post! Stay tuned!