Growth & Puberty
The information on this page represents the recommended standard of care for Duchenne muscular dystrophy. Most of the care recommendations also apply to Becker muscular dystrophy, but at older ages. Most, but not all, people with Duchenne are males—but the care recommendations apply to both males and females with Duchenne.
If you don’t understand any of the medical terms and concepts, ask your healthcare providers. Take notes and ask questions during your clinical visits.
Facts to Remember
- Chronic daily steroids can cause delays in vertical growth (height) and puberty.
- Growth (heights, lengths) should be measured every 6 months.
- Puberty should be evaluated each year after age 9 years old.
- If growth declines to the third percentile (3%), or is less than 4 cm (1.5 inches) per year, a referral to an endocrinologist is needed.
- If there are no signs of puberty by age 14, a referral to an endocrinologist is needed.
- Growth hormone, at this time, is only recommended for people who are found to have a growth hormone deficiency.
Common Growth and Puberty Issues
People with Duchenne are not usually born with endocrine (hormone) issues. Endocrine issues may happen in Duchenne if a person is on steroids for a long time. When steroids are taken every day over a long period, they change the way our body’s natural hormones are made and work.
The body’s endocrine system is made up of glands that produce hormones. Hormones are chemical messengers. Examples are growth hormone (the chemical messenger that tells your body when to start and stop growing) and testosterone (the male hormone that messages your body to begin puberty). Hormones are important for all body functions including growth, weight, puberty, and bones.
Some people are unable to produce appropriate amounts of growth hormone. This is called “growth hormone deficiency” and can lead to short stature. Most people with Duchenne do not have growth hormone deficiency, but experience growth delay as a result of long term chronic steroid use. Steroids can alter levels of the hormone testosterone, that can lead to delayed pubertal development. If puberty has not started by age 14 years, your primary care provider or neuromuscular team may recommend that you see a pediatric endocrinologist. Endocrinologists can help address concerns related to growth and/or pubertal delay.
Growth & Puberty Surveillance
Short stature and delayed puberty may be distressing and should be discussed. Additionally, testosterone deficiency may worsen bone health in older males, so it is important to monitor. You and your doctor should follow your growth and pubertal development closely.
Height and/or length and weight should be measured every 6 months and should be tracked on a growth chart. If you have not grown 4 cm (1.5 inches) in a year, are in the the 3% for your age (or less), or if you have fallen off the normal growth curve, you should be referred to an endocrinologist for evaluation. Pubertal status should be checked every 6 months starting at 9 years of age, and you should be referred to an endocrinologist if there is no sign of pubertal development by age 14.
Growth hormone deficiency
Delayed vertical growth may, or may not, cause distress in people living with Duchenne who are taking chronic daily steroids. Growth should be evaluated every six months, using standing height when appropriate, and a consistent measure of length (either arm span, segmental lengths, or ulnar lengths). Growth should be plotted on a growth curve at each visit. If growth begins to decrease (causing you to fall off the growth curve), if you are only taller than 3% or fewer of their peers, or if growth is less than 4 cm (1.5 inches) in a year, a referral to an endocrinologist for evaluation is necessary.
Some people with Duchenne may be found to be growth hormone deficient. If so, they may be prescribed growth hormone to treat the short stature associated with growth hormone deficiency. The risks and benefits of growth hormone should be discussed before starting this therapy. Growth hormone has not been recommended in Duchenne for patients who are not found to be growth hormone deficient.
Not going through puberty with your peers can be extremely distressing, and should be addressed. An endocrinology evaluation is warranted for males who have not started puberty by age 14. Testosterone is the male hormone that messages the body to begin pubertal changes. If testosterone levels are found to be low, testosterone replacement therapy may be recommended. Testosterone therapy might be provided in the form of injections (often preferred, as the dose is able to be more closely regulated), patches, or gels. Testosterone replacement therapy is recommended to start at low doses and increase slowly (mimicking the body’s natural testosterone production) over several years. Testosterone, and the process of going through puberty, is important for physical health (including bone health), as well as for emotional and psychosocial health.