Half of women's bone accumulation takes place during these early years, researchers say
TUESDAY, Dec. 4 (HealthDay News) -- Teen girls who smoke may be at greater risk for osteoporosis, according to a new study that found girls who smoke build up less bone during this critical growth period in their lives.
In osteoporosis, bones lose mineral density and become brittle. People with the condition -- which is much more common in women than men -- are susceptible to fractures.
"As much bone is accrued in the two years surrounding a girl's first menstrual cycle as is lost in the last four decades of life," said principal investigator, Lorah Dorn, director of research in the division of adolescent medicine at Cincinnati Children's Hospital Medical Center, in a center news release.
The researchers examined how smoking, depression, anxiety and alcohol affected the buildup of bone among 262 girls ranging in age from 11 to 19 years old.
Over the course of three years, the girls underwent clinical exams and had their total body bone mineral content and bone mineral density measured. The girls were also asked if they had any symptoms of depression or anxiety, and reported how often they smoked or used alcohol.
Although all the girls had about the same bone mass at the age of 13, regardless of how much they smoked, those who smoked frequently were found to have a lower rate of lumbar spine and total hip bone mineral density by age 19 than girls who smoked less.
More significant symptoms of depression were also associated with lower bone mineral density in the lumbar spine among girls in all age groups. Meanwhile, alcohol had no affect girls' bone mineral density.
"To our knowledge this is the first longitudinal study to test and demonstrate that smoking by girls, as well as symptoms of depression, have a negative impact on bone accrual during adolescence," Dorn said.
However, larger studies incorporating other races (the study included black and white girls) and geographic areas are needed, the researchers said, adding that the girls involved in their study consumed less calcium and got less physical activity than what is recommended in national guidelines.
"Osteoporosis is a costly health problem affecting an estimated 10 million Americans, with an additional 34 million considered at risk," Dorn noted.
The study was published Dec. 4 in the Journal of Adolescent Health.
The study found a link between smoking and lower bone density in teen girsl; it did not prove a cause-and-effect relationship.
Visit the U.S. Centers for Disease Control and Prevention to learn more about youth and tobacco use (http://www.cdc.gov/tobacco/data_statistics/fact_sheets/youth_data/tobacco_use/index.htm ).
SOURCE: Cincinnati Children's Hospital Medical Center, news release, Dec. 4, 2012