Bone May Play Role in Diabetes
I found this article on MedPage Today of interest: “Bone May Play Role in Diabetes.” While the implications for treatment of diabetes is interesting, there also seem to be implications there about obesity and its effects and treatment.
Bone is more than an inert repository for calcium and in fact may be an endocrine organ, a researcher suggested here at the American Association of Clinical Endocrinologists meeting.
Bone may secrete blood-borne proteins that influence the function of other body organ systems at a distance from the bone compartment, according to Clifford Rosen, MD, director of clinical and translational research at Maine Medical Center in Portland.
This is yet another piece of the huge puzzle that is our body — how it works and how it regulates itself.
“We now know there are three bone-specific proteins that are just made in bone,” Rosen said. These proteins are:
- Fibroblast growth factor 23 (FGF-23), which works to control homeostasis of phosphorus and vitamin D
- Sclerostin, which is produced by osteocytes in the bone and shuts down bone formation.
- Osteocalcin, which influences blood sugar levels and fat deposition
“The fact that osteocalcin can help diabetics actually is consistent with the idea that exercise improves insulin sensitivity,” Rosen said. “Besides the obvious benefit of exercise to muscle, there may be a skeletal component to it as well,” Rosen said. “As we exercise, we remodel our skeleton more frequently; we release osteocalcin from our bone and it has an effect on fat cells.”
We already know that weight-bearing exercises strengthen bones, so I’m wondering if the “As we exercise, we remodel our skeleton more frequently“ refers to that relationship. And by doing those exercises, are we also having some kind of an effect on our fat cells? This is intriguing.
Rosen’s own work has shed light on the dynamic process of bone remodeling.
He and his colleagues have shown that bone loss is increased in cold temperatures, but not because of low vitamin D. In mice experiments, they found that insulin-like growth factor-1 (IGF-1) may be involved.
“Mice exposed to cold temperatures tend to lose bone very quickly. We’re trying to understand if that environmental factor is influenced through the brain via sympathetic nervous system impulses, and if so, maybe that is part and parcel of why people in northern latitudes have a higher rate of bone osteoporosis,” Rosen explained.
Cold temperatures also stimulate brown adipose tissue, or brown fat, which burns energy. But why does that lead to negative bone changes?
But one problem seems to be that fat people and the elderly don’t have enough brown fat, so the body tries to compensate by making more brown fat in other areas of the body, which has a negative effect on bone. So, it seems to me that if you’re fat, live in a cold climate, and you want your bones to stay strong, then it wouldn’t hurt to add weight-bearing exercises to your exercise regimen. That is, if this hypothesis is true.
I wonder if that type of exercise regimen would also help convert white fat to brown fat?
Rosen said that there’s still some skepticism in the medical field about bone being an organ like the heart or kidney. His future research involves investigating the relationship between stem cells and bone cells.
He has already shown that a connection exists in a preclinical experiment. Two groups of mice were fed the same amount of food and water for 12 weeks. One group of mice, however were on a vibrating table, which simulated a kind of low-impact exercise.
The hypothesis was that through the low-impact exercise the stem cells would become bone rather than fat. In fact, they found that the vibrating mice had fewer fat cells and more bone density.
Okay, I want a vibrating bed and a vibrating computer chair — then when I’m sleeping and doing my chair aerobics I’ll be getting the same benefits as those mice: fewer fat cells and denser bones. That’s assuming that what applies to mice also applies to people (and how many times have we seen that that just isn’t the case?).
Regarding low-impact exercise for people, Mayo Clinic researchers showed that a raised desk outfitted with a treadmill that allowed people to walk less than 1 mph while they worked burned an extra 100 calories per hour, which could translate into losing nearly 60 lbs a year.
Yeah, well, I think the doctor who responded to this article had the best answer to to this last paragraph of the article:
It is simply not true that if, for example, one cuts down 100 calories a day that one will drop 60 or whatever pounds over time. One will not lose any weight at all. The body autoregulates calorie intake and energy expenditure to a remarkable degree that is largely out of conscious awareness.
Can I have him for my doctor? He gets it that it’s not just calories in/calories out!!!!