RESEARCH - Older men and women have similar refracture risks

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Older Men and Women Have Similar Refracture Risks

By Judith Groch, Senior Writer, MedPage Today

Reviewed by Zalman S. Agus, MD; Emeritus Professor at the

University of Pennsylvania School of Medicine.

January 23, 2007

SYDNEY, Australia, Jan 23 -- After an initial low-trauma

fracture from a simple fall, both older men and women are equally likely to

have a subsequent significant fracture, found researchers here.

Nevertheless, they pointed out, less than 30% of women and 10%

of men with a prior fracture are treated for osteoporosis to help lower this

risk.

The reduced risk of an initial fracture associated with male sex

was lost once a single low-trauma fracture occurred, reported Jaqueline

Center, Ph.D., of the University of New South Wales, and colleagues, in the

Jan. 24-31 issue of the Journal of the American Medical Association.

For men, the absolute risk of a subsequent fracture was similar

to that of women and equivalent to or greater than the initial fracture risk

of a woman 10 years older, they found. Women had nearly twice the risk of a

subsequent re-fracture while men had more three times the re-fracture risk.

Their calculations of the absolute risk of refracture in both

women and men came from an ongoing prospective cohort study (Osteoporosis

Dubbo Epidemiology Study) of 2,245 community-dwelling women and 1,760 men,

60 or older, living in the city of Dubbo, 240 miles northwest of Sydney. The

participants were followed up from July 1989 through April 2005.

Only low-trauma fractures caused by a fall from a standing

height or less were included in the original analysis. Individuals with

skull fractures or underlying disease that could predispose to a

pathological fracture were excluded. Median follow-up from initial fracture

to subsequent fracture, death, or the end of the study was 3.25 years among

women and 2.13 years among men.

There were 905 women (mean age 78) and 337 men (mean age 77)

with an initial fracture, of whom 253 women and 71 men had a subsequent

fracture. The initial fracture risk increased with age and, as expected, was

higher in women than in men.

Women had nearly twice the risk of a subsequent fracture (RR

1.95 (95% confidence interval [CI], 1.70-2.25), while men had 3.5 times the

refracture risk (RR 3.47, CI 2.68-4.48). Although the initial fracture may

have been minor, the subsequent fracture was a hip or other major break, the

researchers said.

In terms of person-years, women and men, ages 60 to 69, had

absolute refracture rates of 36/1,000 person-years (CI, 26-48/1000) and

37/1,000 person years (CI, 23-59/1000), respectively.

As a result, the absolute risk of a subsequent fracture was

similar in women and men and at least as great as the initial fracture risk

for a woman 10 years older, the researchers said.

The increase in the absolute fracture risk remained for up to 10

years, by which time 40% to 60% of surviving women and men experienced a

subsequent fracture. The majority of the fractures occurred in the first

five years after the initial fracture, and up to 10 years if the individual

was still alive and had not experienced a subsequent fracture, the

researchers said.

The researchers calculated that a 60-year-old woman with an

initial fracture had an absolute refracture risk comparable to or greater

than an initial fracture risk of a 70- to 79-year-old woman.

For men, the absolute risk of a subsequent fracture was similar

to that of women and equivalent to or greater than the initial fracture risk

of a woman 10 years older.

For example, a 60- to 69-year-old man's absolute refracture risk

was equivalent to or greater than a 70- to 79-year-old woman's initial

fracture risk and similar to the initial risk of a man at least 20 years

older, the researchers said.

Thus, the investigators said, men no longer enjoyed their

reduced risk of an initial fracture once a single low-trauma fracture

occurred.

All initial fracture locations apart from rib (men) and ankle

(women) resulted in increased subsequent fracture risk, with the highest

risks following initial hip fractures (RR, 9.97; CI, 1.38-71.98) and

clinical vertebral fractures in younger men (RR, 15.12, CI, 6.06-37.69).

In multivariate analyses, bone mineral density in the femoral

neck, age, and smoking were predictors of subsequent fracture in women and

bone mineral density in the femoral neck, physical activity, and calcium

intake were predictors in men.

Among the study's limitations mentioned by the authors is that

the population was almost 99% white, and the results therefore may not hold

for other racial and ethnic groups.

Vertebral fractures were those that came to clinical attention,

so the results may not be the same for morphometric vertebral fractures.

Furthermore, it was not possible to examine individual fracture types for

each age group, and peripheral fractures were analyzed together in upper or

lower limbs or major or minor groupings. Thus, they said, individual

fracture types may signal greater or lesser refracture risks.

Also, the investigators said, there were few individuals alive

without refracture available for follow-up of more than 10 years.

Summing up, Dr. Center's team wrote, " The critical clinical

relevance of these findings is that and incident low-trauma fracture is a

signal for increased risk of all types of subsequent osteoporotic fractures,

particularly in the next five to 10 years? "

Thus, virtually all low-trauma fractures indicate the clinical

need for fracture-preventive therapy, and given the early peak of

refracture, such preventive treatment should not be delayed. " The lack of

consideration of osteoporosis and treatment initiatives by the medical

profession and the public, particularly in relation to men, should be the

focus of education initiatives, " the investigators concluded.

http://www.medpagetoday.com/Endocrinology/Osteoporosis/tb/4911

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