Difference Between Osteopenia and Osteoporosis

To understand the two medical conditions osteopenia and osteoporosis, let us look a little more closely at the words themselves. Much like other medical terms, the words that describe the various conditions of the bone all begin with the prefix 'osteo-'. 'Osteo-' originated from the Greek word 'osteon', meaning 'bone'. Whenever the term '-penia' is a part of any medical term, it means deficiency or low level of something; for example, leukopenia means a condition wherein the white blood cell count of an individual is lower than normal. Finally, the term '-porosis' refers to the presence of pores.

Now that you have understood the meaning of the words, let us look at the terms as a medical condition. Osteopenia refers to a condition in which the mineral density of the bones is lower than normal. The average bone mineral density of a healthy adult human being is 1500kg/m³; hence bone density lower than this is osteopenia. Osteoporosis, on the other hand, refers to a condition wherein the bones are internally weak, brittle and more prone to fractures due to reduced bone mineral density, a deteriorating bone structure and altered profile of bone proteins in terms of type and amount of proteins.

Osteopenia vs. Osteoporosis

Osteopenia and osteoporosis are the two most common diseases of the skeletal system. Osteoporosis affects more than 50% of Americans, with more than 80% of them being women. Though a less severe condition, osteopenia has been recognized by the WHO as one of the precursors to osteoporosis. A medical condition affecting more than half of the population of a country is something very serious indeed! Here is a comparative account of osteopenia vs. osteoporosis. But before we begin with it, let us take a look at what is the connection between calcium and bone density, as calcium deficiency is one of the major causes for a majority of bone-related medical conditions.

Calcium and Bones - What is the Connect?

One of the primary functions of bones in the human body is the storage of minerals such as calcium and phosphorus. The chunk of the bone tissue (known as osseous tissue) is made of salts of calcium, including calcium phosphate and calcium hydroxyapatite. When the bones are formed in the fetus, the bone tissue is first synthesized in the unmineralized form. It is then mineralized into calcium and phosphorus salts. Hence, a major chunk of the mass of bones is made of calcium compounds. Now imagine there being less than normal calcium level in the body - wouldn't it affect the strength of bones? This is why one of the primary causes of osteopenia as well as osteoporosis is calcium deficiency.