Without medical intervention, the Emperor of Japan is at risk of developing osteoporosis due to a drop in bone density likely due to hormone therapy he is taking to combat prostate cancer, Imperial Household Agency officials said Monday.

A regular health checkup conducted by the agency in January showed that the Emperor is at risk of developing bone-thinning osteoporosis if no measures are taken.

The Emperor, 74, underwent surgery to remove a cancerous prostate gland in January 2003. Since July 2004, he has been receiving hormone injections once a month to suppress the cancer’s growth.

Thanks to the treatment, the Emperor’s prostate-specific antigen reading–a cancer index that indicates the existence of cancerous cells in the body–remains stable, the officials said.

However, the health checkup at Tokyo University Hospital on Jan. 26 showed that the Emperor’s bone density has fallen to a level close to osteoporosis, the officials said.

Experts say that thinning bones are one of the side effects from hormone therapy used to treat prostate cancer.

Hormone therapy is one of the major treatments for prostate cancer, which grows due to the effect of male hormones. To reduce hormonal activities, injections are given once a month, or once every three months, in addition to daily medicines.

To maintain bone density, it it necessary for individuals to take exercise to help put adequate pressure on the bones, and to ingest calcium. The Emperor will exercise and review his dietary habits under the supervision of instructors, the officials said.

According to the Imperial Household Agency, the Emperor attended about 200 events over the past year, including ceremonies and press conferences, and met about 70 foreign guests. He also signed and sealed documents for the Cabinet on almost 1,000 occasions.

As the Emperor has to conduct occasional religious services in addition to the above-mentioned duties, the agency has been considering reducing his official burdens, the officials said.

(Feb. 26, 2008), from Japan Today.