Vol. 3 No. 1: Spring Equinox, 2001
Children and Endocrinology
Dr. Daniel Metzger
Endocrinology & Diabetes Unit British Columbia's Children's Hospital Vancouver, B.C.
Pediatric endocrinology is the subspecialty of pediatrics that deal with hormone-related conditions and diseases in infants, children and adolescents. Adults are often surprised to learn that children can have endocrine disorders, thinking that hormone problems are restricted to moody teens and adults with fatigue. In fact, children are subject to a number of hormone-related conditions that may be limited to the newborn period, to the growth years, or to puberty. As well, most of the hormone conditions treated by adult endocrinologists can also occur in children, although many of these are much less common in childhood.
In most pediatric endocrinology clinics, about 50% of all patients carry the diagnosis of type 1 diabetes, previously called insulin-dependent or juvenile-onset diabetes. This condition occurs in about 1 in 500 children under the age of 18 years, although it can appear at any age. Type 1 diabetes is an autoimmune condition in which the body's immune system mistakenly destroys the beta cells of the pancreas, which normally produce insulin. As a result, these children have little or no insulin to control their blood sugar. The only treatment is by administering insulin injections 2-4 times a day. As well, they must perform blood sugar testing 3-4 times a day by fingerpoke and pay careful attention to the diabetic meal plan and to their activity. It is hoped that in the future, beta-cell transplants or an "artificial pancreas" will be developed to offer affected individuals a permanent cure. In the meantime, these children live with a chronic illness that requires ongoing attention from the diabetes health care team (pediatric endocrinologists, diabetes nurse educators, nutritionists and counsellors). The Endocrinology & Diabetes Unit at British Columbia's Children's Hospital follows some 1,000 children with type 1 diabetes.
A new challenge for pediatric endocrinologists is the epidemic rise in type 2 diabetes (formerly called non-insulin-dependent or adult-onset diabetes) in adolescents. In pediatrics, this condition occurs most commonly in obese teens of non-European background. In some centers in North America, up to one-third of children diagnosed with diabetes have type 2, compared with <5% ten years ago. In British Columbia, the affected populations are primarily of East Indian and Asian background, and these youth often have affected parents or other family members.
The rise in incidence of type 2 diabetes appears to parallel the very worrisome rise in obesity and decrease in activity that have been documented in North America and in other developed countries over the past decade or so. Unfortunately, type 2 diabetes is often associated with other adverse health conditions (e.g. high blood pressure and cholesterol) which significantly add to one's cardiovascular risk. Efforts are underway by the federal and provincial governments to develop and implement programs aimed at preventing obesity and type 2 diabetes by promoting healthy eating and activity.
After diabetes, the next largest group of disorders followed by pediatric endocrinologists relates to abnormalities of growth and/or puberty. To grow normally, a child must have a normal skeleton, sufficient hormones, adequate nutrition, and emotional nurturing. Not surprisingly, a large number of health conditions can alter a child's growth, including hormonal deficiencies; "systemic conditions" of the heart, kidneys, lungs or bowels which interfere with the absorption and delivery of nutrients to the cells of the body; skeletal problems, such as forms of dwarfism, which prevent bones from growing normally; and psychosocial factors such as abuse or neglect.
Fortunately, most children with "abnormal growth" are really just experiencing a variation of normal growth patterns. For instance, children who are "late bloomers" have a normal overall growth pattern and are normal-sized adults; they just develop physically 2-3 years later than their age peers. Moreover, many children are short because their parents are short.
One needs to remember that 5% of normal children will be below the 5th percentile on a growth chart. Nonetheless, pediatric endocrinologists do diagnose a number of hormonal deficiencies that affect growth. In younger children, these can be growth hormone deficiency (which affects about 1 in 10,000 children ) and/or thyroid hormone deficiency. Growth hormone is produced by the pituitary gland at the base of the brain, which also regulates a number of other important hormones in the body.Growth hormone treatment is given as a daily injection and is extremely costly (about $20-30,000 per year ). In British Columbia, as in the rest of Canada, the provincial government relies on pediatric endocrinologists to make the diagnosis of growth hormone carefully, to prevent its misuse and overuse. To answer a frequent question we receive: no, giving growth hormone to your otherwise-normal child will not make him or her significantly taller; in any case, growth hormone has not been licensed for this purpose in Canada.
A large number of children and teens are seen in our clinics for problems related to puberty-some too early and others too late. Again, these cases are often variations of normal developmental patters, but we do see sometimes see early puberty in 2 year olds and absence of puberty in 18 year olds. One can imagine that such conditions might raise a lot of anxiety in parents and teens. Puberty-related conditions are generally treated, if necessary, with medications.
Other conditions followed in our clinic include problems related to congenital syndromes (e.g. short stature in Turner syndrome and obesity and pubertal delay in Prader-Willi syndrome); to genetic and hereditary conditions predisposing to tumors in or failure of the endocrine glands; and to a variety of other common and uncommon hormone problems (e.g. thyroid, adrenal, and parathyroid gland disorders).
Pediatric subspecialty clinics pride themselves on providing not only medical care for affected children, but also social, emotional and educational support. We work closely with our nursing, dietitian, and counselling support staff, to ensure that patients "graduating" from our program at age 18 or so leave with a good understanding of their medical condition and any implications it may have for their vocational, reproductive and social futures. Our transition process also strives to ensure that these young adults have started to become health-care consumers, able to negotiate the health care system and to advocate for their own care. We are fortunate at British Columbia's Children's Hospital to have an extended team that is devoted to these goals and which has the resources to develop educational materials which are used throughout North America.
Dr. Daniel Metzger