BAR HARBOR – A local medical researcher has discovered a way of treating osteoporosis that is making a big splash in the scientific community and should provide women with a more successful, economic way to treat bone loss.

At the end of a two-year national study on osteoporosis, researcher Dr. Clifford Rosen has found that trial participants who took two well-known treatments in sequence showed an almost 30 percent increase in bone density.

“We’ve been looking at a way to build bone mass back,” Rosen said Wednesday afternoon from his office at the Jackson Laboratory in Bar Harbor. Rosen also works at St. Joseph Healthcare in Bangor.

According to Rosen, the study found a way to maximize the increase in bone mass with treatments.

The results of Rosen’s study are reported in today’s issue of the New England Journal of Medicine.

Osteoporosis, a disease that affects 25 million women in the United States, is characterized by a loss of calcium from bones into the bloodstream, leaving the bones brittle and easily broken. Most commonly seen in post-menopausal women, osteoporosis also can affect younger women as well as men.

Rosen and his colleagues worked with a trial group of 250 post-menopausal women in Bangor, New York, Philadelphia and Minneapolis. The women took a relatively new bone-building drug called parathyroid hormone, or PTH, for one year. The hormone was approved by the Food and Drug Administration about three years ago and works by stimulating the growth of new bone.

The women’s year on PTH was followed by a year on alendronate, which goes by the trade name Fosamax. It’s a standard drug used to fight osteoporosis that works by inhibiting the loss of calcium from bones.

Rosen published results in 2003 showing that administering PTH and Fosamax together does not increase bone density.

“We think that the PTH needs to be by itself to start stimulating new bone formation,” Rosen said. “Fosamax is preventing any bone loss that can occur after we stop the parathyroid hormone.”

Rosen sounded excited about the implications of the study’s findings.

“It’s really pretty definite evidence that this treatment regimen works,” he said. “We have finally come upon a way of really getting the most out of these drugs. … And it’s more cost-effective.”

While a year’s supply of Fosamax is about $700, PTH carries the much higher price of about $7,800 per year.

Rosen began working with PTH more than a decade ago at the Jackson Laboratory, looking at the hormone’s role in building bone in lab mice and rats. His colleagues are pleased with the final results of the study.

“Dr. Rosen’s work shows the value of translational research from working with mice at the Jackson Laboratory to clinical trials with patients,” laboratory spokesperson Joyce Peterson said Wednesday. “It also shows that the ideal of individualized medicine where each patient receives the treatment he or she needs based on their genetic makeup is really becoming a reality, and that’s very exciting.”