Osteoporosis - often called brittle bone disease - is not confined to the elderly. Younger people are also at risk if they smoke or are underweight, notes Jutta Semler, a physician from Berlin who co-chairs the Bone Health Board, a German non-profit organization.

One way to diagnose osteoporosis is by measuring a person's bone mineral density (BMD), the German medical journal Aerzte Zeitung quoted Semler as saying.

She says risk factors for the disease also included the use of certain medications, such as anti-epileptics, a family history of osteoporosis or fractures such as those of the femoral neck, and certain diseases such as rheumatologic disorders, type 1 diabetes and renal insufficiency.

People with a low BMD should protect their "bone health", Semler advises. That means refraining from smoking, drinking alcohol in moderation and getting regular exercise to boost muscular strength and coordination.