Both weight gain and weight loss were linked to an increased risk of fracture in postmenopausal women.

Researchers looked at the link between postmenopausal change in body weight and incidence of fracture as well as how this phenomenon was influenced by intentional and unintentional weight changes, the British Medical Journal reported.

To make their findings the researchers looked at 120,000 healthy postmenopausal women who were taking part in the Women's Health Initiative Observational Study and Clincial Trials. The study subjects were between the ages of 50 and 79 and were followed for about 11 years.

Each year the participants were weighed and asked to report any fractures they had experienced. Their weight was classified as "stable (a change of less than 5 percent from initial weight), weight loss (a decrease of 5 percent or more since initial examination), and weight gain (an increase of 5 percent or more since initial examination)," the researchers reported.

Over the follow-up period researchers found weight gain was linked to a 10 percent increase in upper limb fractures and an 18 percent increase in lower limb fractures, but no significant increase in central body fractures. Unintentional weight loss was linked to an increased risk of spine and hip fractures, and intentional weight loss was associated with an increased risk of lower limb fractures.

This study is the first to focus on how weight changes can influence the risk of upper limb, lower limb, and central body bone fractures in postmenopausal women.  

 "[The findings] have clinical and research implications and challenge the traditional clinical paradigm of weight gain protecting against fractures," they researchers said. "Clinicians should be aware that even intentional weight loss is associated with increased rates of lower limb fractures."

The findings were published in a recent edition of the British Medical Journal.