A large cross-sectional study has found that children and adolescents who take medication for attention-deficit hyperactivity disorder (ADHD) show decreased bone density.

Researchers believe the finding should prompt physicians to address risk, and enact preventative strategies to avoid long-term consequences of low-bone density among children receiving medications for ADHD.

Study results were presented at the 2016 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS).

“This is an important step in understanding a medication class, that is used with increasing frequency, and its effect on children who are at a critical time for building their bones,” said senior study author Jessica Rivera, M.D., an orthopaedic surgeon with the U.S. Army Institute of Surgical Research.

The discovery is important as the U.S. Centers for Disease Control and Prevention (CDC) estimates 6.4 million children were diagnosed with ADHD through 2011. In addition, the CDC says that parents reported 3.5 million children and teenagers taking medications to treat ADHD, a 28 percent increase from 2007 – 2011.

In the new study, researchers identified 5,315 pediatric patients in the CDC’s National Health and Nutrition Examination Survey (NHANES) and compared children who reported taking ADHD medications with survey participants not on these medications.

Researchers discovered that children on ADHD medication had lower bone mineral density in the femur, femoral neck, and lumbar spine.

Approximately 25 percent of survey participants on ADHD medication met criteria for osteopenia — a condition characterized by lower than normal peak bone density. This incidence of osteopenia was significantly higher compared to participants not on medication.

A definite link has not been established between osteopenia in childhood and osteoporosis later in life, which increases the risk of brittle and porous bones, and ultimately, fracture risk, explains Dr. Rivera.

However, low-bone density in children theoretically could have long-term implications and lead to poor bone health in adulthood because childhood and adolescence is when growing bones accrue mass and strength.

Medications used by patients in the study were: methylphenidate (Ritalin), dexmethylphenidate (Focalin), dextroamphetamine (Dexedrine), atomoxetine (Strattera), and lisdexamfetamine (Vyvanse).

These medications can cause gastrointestinal problems such as decreased appetite and stomach upset, which may result in poor nutrition and reduced calcium intake. The drugs also may diminish bone density because they alter the sympathetic nervous system, which plays an important role in bone remodeling, or regeneration.

The findings are important because most skeletal growth occurs by ages 18-20. As a result, physicians should realize the potential threat that ADHD medications pose to maturing bones and consider nutritional counseling and other preventative measures, explains Dr. Rivera.

Source: American Academy of Orthopaedic Surgeons/EurekAlert 

一個大型的橫向比較研究發現,服食專注力不足及過度活躍(ADHD)藥物的兒童及青少年,骨質密度有下降的趨勢。

研究人員相信,此發現將促使醫學界應對使用ADHD藥物的風險,並制定預防方法,以避免ADHD藥物對兒童造成骨質密度低的長遠後果。

這項研究結果是於2016年美國骨科醫師學會(AAOS)的年會上發表的。

美國陸軍外科研究所高級研究人員兼矯形外科醫生里維拉博士指︰「ADHD藥物的使用越來越頻繁,這項發現為我們進一步了解這些藥物邁開了重要的一步,它讓我們更了解藥物對處於骨骼成長關鍵期的兒童構成的影響。」

這項發現很重要,因爲美國疾病控制及預防中心(CDC)預計,到了2011年,將有640萬兒童被確診患有ADHD。此外,CDC表示,根據家長提供的數據,350萬兒童和青少年有服用藥物治療ADHD,人數在2007 至 2011年間增加了百分之二十八。

在這項新研究,研究人員通過CDC的美國健康與營養調查(NHANES)),確定了5315名兒科患者,並就服用了和沒有服用ADHD藥物的兒童進行比較。

研究人員發現,服用ADHD藥物的兒童,股骨、股骨頸和腰椎的骨礦密度較低。

調查中,大約有百分之二十五服用ADHD藥物的兒童達到骨質缺乏症的水平,即是說他們的骨質密度低於正常巔峰骨骼密度。 與不服用藥物的兒童相比,他們的骨質缺乏症比例明顯較高。

里維拉博士又指,兒時有骨質缺乏症和年長後有骨質疏鬆症,兩者之間沒有明確的關聯。後者會增加骨骼變脆及骨孔變大的機會,最終引致骨折的風險。

然而,理論上,兒時骨質密度低的確可能引致長遠影響,令長大後骨骼健康狀況不佳,因為兒童和青春期是骨骼增密增強的時間。

研究中患者使用的藥物是:哌甲酯(利他林),右哌甲酯(Focalin),右旋安非他明(Dexedrine),阿托西汀(斯德瑞)和地塞米松(Vyvanse)。

這些藥物有機會引致胃部及腸道問題,如食慾降低和胃部不適,進而可能導致營養不良和鈣攝取量下降。 另外,藥物也可能減少骨質密度,因為藥物會令交感神經系統出現變化,而交感神經系統對骨貿的重塑或再生起着重要作用。

這項研究的發現非常重要,因爲18-20歲正是骨骼發展最重要的時期。里維拉博士解釋指,有見及此,醫學界應認識到ADHD藥物對骨骼成長的潛在威脅,並應考慮採用營養諮詢及其他預防措施。

資料來源︰美國骨科醫師學會 (American Academy of Orthopaedic Surgeons/EurekAlert)