(RxWiki News) Osteoporosis is often regarded as a disease of old age. But the path to osteoporosis may start much earlier in life, especially for girls who smoke or show signs of depression.
A recent study followed a group of teenage girls for several years to see if smoking habits and depressive symptoms got in the way of proper build-up of bone density.
These results showed that daily smoking and depressive symptoms could stunt as much as one year’s worth of bone-density growth.
"Talk to your teen about the dangers of smoking."
Lorah D. Dorn, PhD, from Cincinnati Children’s Hospital Medical Center and the Department of Pediatrics at the University of Cincinnati College of Medicine in Ohio, led an investigation into links between substance use, depression and bone density in teen girls.
“Bone is living tissue, which is constantly being absorbed and replaced. Osteoporosis occurs when the creation of new bone doesn’t keep up with the removal of old bone,” according to the Mayo Clinic. People with osteoporosis have greater risk for bone fracture due to weak bone structure.
“Osteoporosis is primarily evident in postmenopausal women, but its roots are traceable to periods of growth, including during adolescence,” the study authors wrote.
The researchers said that more than half of bone density is built during puberty. And several factors can get in the way of building the right amount of bone density to prevent osteoporosis after menopause.
In previous studies, depression, anxiety and smoking have been linked to lower bone density in adults.
For this study, 262 girls between 11 and 19 years of age were given medical exams once per year for three years.
During each medical exam, a dual energy x-ray was used to determine each girl’s hip and lower spine bone density.
The girls were also asked to fill out a questionnaire about depressive and anxiety symptoms and any alcohol and cigarette use.
A total of 15 percent of the girls reported daily smoking in the previous 30 days and 2 percent reported smoking on three to five days in the previous 30 days.
The researchers found that regardless of smoking status, all of the girls started adolescence with similar levels of bone density, but bone density build-up across adolescence was significantly lower as smoking frequency increased.
Girls with depressive symptoms had lower bone density in their lower spine scans, but not a lower overall bone density.
The researchers did not find any links between bone density and alcohol consumption or anxiety symptoms.
The authors said that the differences in lower spine bone density between a never smoker and a daily smoker by age 19 were as much bone density build-up that an adolescent girl could gain in one year.
Depressive symptoms were assessed with the Children’s Depression Inventory, which consists of 27 questions. Each of the 27 questions has four possible answers. The range on the depression inventory goes from 0 to 81 points.
The researchers found that for every 10 point increase in depressive symptoms, there was a decrease in lower spine bone density. The decrease was roughly similar to what a girl without depressive symptoms would gain in bone density over the course of one year.
The authors noted a limitation to this study was that the participants, on average, did not consume recommended levels of calcium or get enough exercise. Both calcium and exercise have been linked to proper bone density build-up.
“Importantly, as much bone is accrued (built-up) in the 2 years surrounding menarche (when a girl begins getting her period) as is lost in the last four decades of life,” said the authors.
“Adolescent smokers are at higher risk for less than optimal bone accrual (build-up),” they concluded.
The authors recommended further studies would be necessary to validate these results in order to make further recommendations on how to prevent reduced bone build-up in teenage girls.
This study was published in April in the Journal of Adolescent Health.
The National Institute of Drug Abuse, the National Center for Research Resources, the Bureau of Health Professionals, the Health Resources and Services Administration and the Department of Health and Human Services provided funding for this project. No conflicts of interest were found.
