Did you know that there’s a link between type 1 diabetes and bone mineral density (BMD)? Like with many other processes, there’s a connection between bone remodeling and glucose metabolism, and a number of studies over the years have suggested an increased risk of osteoporosis among those with diabetes, particularly in people with type 1 diabetes diagnosed earlier in life, before you reach peak bone mass.
What is Osteoporosis?
Osteoporosis means “porous bone” and osteoporotic bones are bones that have lost density/mass and have abnormal tissue structure. With a decrease in bone density, bones may be more likely to break. A meta-analysis published in 2007 found that elderly people with type 1 diabetes had a 6.3-6.9 fold increased risk of hip fracture when compared with people without diabetes.
There are many factors involved in bone remodeling/ bone metabolism. Throughout your life, bone tissue is constantly being removed (resorption) and new bone tissue is formed (ossification). Osteoclasts are involved in bone resorption/break down, while osteoblasts help build new bone. An imbalance in this process in favor of bone resorption can lead to osteoporosis. A number of hormones including calcitonin, parathyroid hormone (PTH), vitamin D, growth hormone, and steroids along with cytokines and several growth factors are involved in this process.
Up to 90% of bone mass is acquired in women by the age of 18 and in men by the age of 20, but bone mass can keep growing into your late 20s. Women typically meet peak bone mass in their late 20s , but bone mass tends to rapidly decline after menopause.
The T1D BMD Connection
Research suggests that type 1 diabetes may affect both osteoblast function and differentiation in the bone marrow. There is also evidence that we may release less osteocalcin in an insulin deficient state. Osteocalcin is a hormone released by osteoblasts thought to be involved in bone building, which coincidentally promotes the proliferation of pancreatic beta cells and stimulates insulin release.
In some animal studies, osteoclasts have demonstrated increased bone resorption, but cell culture models have actually shown decreased osteoclast activity when grown in hyperglycemic media. Studies in humans have been mixed with regards to bone resorption, so it’s unclear as to whether osteoclast function is key to understanding the T1D BMD association. The decrease in bone mineral density associated with type 1 diabetes is thought to primarily be associated with impaired osteoblast differentiation and function.
Type 1 diabetes may also affect the bone matrix by formation of advanced glycation end products (AGEs). Glycation is a reaction between reducing sugars (ie glucose) and proteins, lipids, or nucleic acids. Hyperglycemia over time has been shown to increase glycation, resulting in the gradual build up of these advanced glycation endproducts (AGEs). Studies have suggested that formation of AGEs may competitively inhibit sites for enzymatic cross-linking and may increase osteoblast apoptosis (cell death).
Decrease your Risk
There’s still a lot to learn about type 1 diabetes and osteoporosis, but there is evidence for a number of strategies to reduce your risk of osteoporosis, including the following:
- Regular weight-bearing and resistance training: Physical activity increases physical stress on bone, which actually helps activate osteoblast activity and favors increasing bone deposition. Weight-bearing and resistance training includes running, walking, and weight lifting among other activities.
- Nutrition: We’ve all heard that Calcium builds strong bones, but vitamin D plays an important role as well. Getting adequate calcium and vitamin D in your diet are important in building and maintaining bone mass. If you don’t get a lot of sunlight, it may be a good idea to ask your provider if you may need a vitamin D supplement.
- Stop Smoking! Studies have shown a direct relationship between tobacco use and decreased bone mineral density.
- Blood Glucose control: While the research hasn’t consistently shown that better blood glucose control will lower your risk of osteoporosis, research has shown the complications associated with hyperglycemia are associated with higher fracture risk.
- Get Screened: If you have diabetes, it may be advisable to initiate osteoporosis screening methods early. If concerned, ask your doctor about a bone mineral density test (DXA).