May 2007
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Volume 52
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Special Issue
Challenges in care
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Puberty is a period of rapid and radical physical,
psychological and social change during which
a child, in physiological terms, becomes an adult
capable of reproduction. Adolescence refers
as much to the psychosocial characteristics of
development during puberty as to the physical
changes. Adolescents with diabetes, who
need to adhere to a complex medical regimen
based around self-care throughout this period
of development, face a series of particular
and considerable challenges. In this article,
Hala Tfayli and Silva Arslanian look at the
hormonal, metabolic and behavioural changes
that impact on diabetes care during the years
of puberty, and outline strategies that could
help young people to achieve good glycaemic
control, and thus protect their health and well-
being into adulthood.
The difficulties involved in maintaining good blood glucose
control during adolescence were reflected in the findings
of the Diabetes Control and Complications Trial (DCCT). In
both the intensive and the conventional treatment groups,
adolescents had 1% higher average long-term blood glucose
levels (measured by HbA
1c
) compared with the adults, de-
spite similar therapeutic approaches – and despite receiving
higher doses of insulin (units per kg of body weight).
1
This
worsening in metabolic control is due to both physiological
and behavioural changes.
Physiological insensitivity to insulin
Studies have demonstrated that insulin levels are higher during
puberty than they are during adulthood or the years preced-
ing puberty.
2
The direct evidence of this pubertal insensitivity
to insulin became apparent only after experiments which
measured in vivo insulin sensitivity.
3,4
A decrease in insulin-stimulated glucose uptake in healthy
adolescents compared with pre-pubertal children was dem-
onstrated for the first time in the 1980s. While this effect is
exaggerated in children with type 1 diabetes,
3
in children
without diabetes, whose pancreatic beta cells function nor-
mally, puberty-related insensitivity to insulin is compensated
by an increase in insulin secretion.
4
The challenge
of adolescence:
hormonal changes
and sensitivity to insulin
Hala Tfayli and Silva Arslanian
May 2007
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Volume 52
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Special Issue
Challenges in care
29
Healthcare professionals should be aware of the evolution of
insensitivity to insulin during puberty in children with type 1
diabetes, and appropriately increase insulin doses in order to
prevent any deterioration in blood glucose control. Recently,
a large cross-sectional study of children without diabetes
found insensitivity to insulin to be lowest at age 12 to 14
years (Tanner stage 3 of puberty) in both sexes, and across
ethnic groups, returning to almost pre-pubertal levels in young
people above 16 years of age (Tanner 5).
5
The cause of insensitivity to insulin during puberty has been
under investigation. The major hormonal changes that are
associated with the onset of puberty include a two-fold in-
crease in the secretion of growth hormone and an increase
in the sex steroids that lead to the development of secondary
sexual characteristics, remarkable increase in height, and
change in body composition. Thus, both growth hormone
and sex steroids are likely hormonal candidates for inducing
insensitivity to insulin during puberty.
However, while pubertal insensitivity to insulin is transient, in
adulthood, the increasing levels of sex steroids remain elevated
and insensitivity to insulin subsides. On the other hand, the
secretion of growth hormone increases during puberty. Once
the pubertal growth spurt is completed, growth hormone levels
decline. Moreover, growth hormone is known to be an impor-
tant factor in reducing insulin sensitivity – through several effects
that are shared between insulin and growth hormone.
We now know that insulin-stimulated glucose metabolism
correlates negatively with growth hormone and/or levels of
insulin-like growth factor-1.
3,5,6
Additionally, a correlation be-
tween speed of growth and an increase in fasting serum insulin
has been reported in pubertal adolescents without diabetes.
Our studies show that the metabolic characteristics of pubertal
insensitivity to insulin are decreased glucose oxidation and
increased free fatty acid oxidation – known as the Randle cy-
cle.
6,7
Thus, increased growth hormone secretion during puberty
leads to increased breakdown of fat in fat cells (lipolysis) and
increased flux of free fatty acids. These compete with glucose
for glucose oxidation, resulting in decreased glucose uptake
and insensitivity to insulin.
The question remains as to the significance of these physiologi-
cal changes in metabolism and insulin sensitivity for children
with type 1 diabetes. Deteriorating diabetes control in ado-
lescents was thought to be merely the result of the behavioural
and psychosocial factors that are characteristic in teenage
years. However, it is now apparent that during puberty, insulin
action decreases by between 30% and 50% – an important
factor which may contribute to poor glycaemic control.
Therefore, healthcare providers working with children with type 1
diabetes should be aware that insulin requirements increase by
between 30% and 50% during puberty, and unless this is ap-
propriately addressed, a child’s blood glucose control and HbA
1c
levels will deteriorate. In our diabetes clinic, the average daily
dose of insulin in pre-pubertal children is between 0.8 and 1.0
units/kg/day, while in adolescents it is between 1.2 and 1.4
units/kg/day. The Hvidore Study Group on Childhood Diabetes,
which includes 18 countries in Europe and North America, and
Japan, revealed a sharp increase in insulin requirements during
pubertal years, particularly in girls with type 1 diabetes.
8
Behavioural and psychosocial changes
In addition to the hormonal and metabolic changes that are
characteristic of puberty, adolescence is associated with rapid
behavioural changes that may impact on diabetes control.
Adolescent behaviour typically involves challenging of author-
ity figures, non-conformity, efforts at establishing autonomy,
rebellious and pleasure-seeking behaviour, privacy, and
heightened awareness of self-image and peer pressure, and
the emergence of eating disorders in some girls.
9
This process
of maturation both affects and is affected by the presence of
a chronic illness like diabetes.
Adolescents with a chronic disease have generally been
found to be at increased risk for depression, anxiety, and low
self-esteem. In a number of studies, adolescents with type 1
diabetes have been found to suffer from anxiety and depres-
sion.
10
The prevalence of depression in young people with
diabetes is reported to be two- to three-fold higher compared
with their peers without diabetes. The combination of depres-
sion and diabetes in children and especially adolescents has
serious consequences, including increased rates of suicide
or suicidal tendencies, making diabetes management and
self-care extremely difficult.
Lifestyle, diet, and exercise habits also tend to change dur-
ing puberty. The Health and Behaviours in Teenagers Study
May 2007
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Volume 52
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Special Issue
Challenges in care
30
Hala Tfayli and Silva Arslanian
Hala Tfayli is Fellow of the Division of Pediatric Endocrinology,
Metabolism and Diabetes Mellitus at the Children’s Hospital of
Pittsburgh, University of Pittsburgh School of Medicine, USA.
Silva Arslanian is Director of the Division of Weight Management and
Wellness, and Professor in the Division of Pediatric Endocrinology,
Metabolism and Diabetes Mellitus at the Children’s Hospital of
Pittsburgh, University of Pittsburgh School of Medicine, USA.
References
1 Diabetes Control and Complications Trial Research Group. Effect of
intensive diabetes treatment on the development and progression of long-
term complications in adolescents with insulin-dependent diabetes mellitus:
Diabetes Control and Complications Trial. J Pediatr 1994; 125: 177-88.
2 Smith CP, Williams AJK, Thomas JM, et al. The pattern of basal and
stimulated insulin responses to intravenous glucose in first degree relatives
of type 1 (insulin-dependent) diabetic children and unrelated adults aged
5 to 50 years. Diabetologia 1988; 31: 430-4.
3 Amiel SA, Sherwin RS, Simonson DC, et al. Impaired insulin
action in puberty. A contributing factor to poor glycemic control in
adolescents with diabetes. N Engl J Med 1986; 315: 215-9.
4 Caprio S, Plewe G, Diamond M, et al. Increased Insulin Secretion in
puberty: A compensatory response to reductions in insulin sensitivity.
J Pediatr 1989; 114: 963-7.
5 Moran A, Jacobs DR Jr, Steinberger J, et al. Association between the
insulin resistance of puberty and the insulin-like growth factor-I/growth
hormone axis. J Clin Endocrinol Metab 2002; 87: 4817-20.
6 Arslanian SA, Kalhan SC. Correlations between fatty acid and glucose
metabolism. Potential explanation of insulin resistance of puberty.
Diabetes 1994; 43: 908-14.
7 Hannon TS, Janosky J, Arslanian SA. Longitudinal study of physiologic insulin
resistance and metabolic changes of puberty. Pediatr Res 2006; 60: 759-63.
8 Mortensen HB, Robertson KJ, Aanstoot HJ, et al. Insulin management and
metabolic control of type 1 diabetes mellitus in childhood and adolescence
in 18 countries. Hvidore Study Group on Childhood Diabetes.
Diabet Med 1998; 15: 752-9.
9 Hamilton J, Daneman D. Deteriorating diabetes control during
adolescence: physiological or psychological? J Pediatr Endocrinol
Metab 2002; 15: 115-26.
10 Dantzer C, Swendsen J, Maurice-Tison S, Salamon R. Anxiety and
depression in Juvenile diabetes: A critical review. Clin Psychol Rev
2003; 23: 787-800.
(HABITS), a school-based study in the UK, evaluated the as-
sociation between puberty, smoking, food, and exercise. In
both boys and girls, being more pubertally advanced was
associated with a higher likelihood of smoking. In boys,
puberty was linked to a less healthy diet, but higher levels
of exercise; in girls, there was little association with either
diet or exercise. Such findings constitute important barriers
to achieving adequate blood glucose control.
Responding to the changes in puberty
Since the results of the DCCT were published in 1993, it has
become widely accepted that good blood glucose control
delays the onset and slows the progression of diabetes eye
damage, nerve damage, and kidney disease. In order to
maintain optimal glycaemic control, health professionals who
provide care to children with diabetes during puberty should
tailor therapy to counterbalance behavioural changes and
physiological reductions in insulin sensitivity.
Children who are going through puberty require increased
daily insulin. Diabetes outcomes are linked to the degree of
adherence to medical regimens, blood glucose monitoring,
and meal plans. Involving adolescents in decision making
regarding the insulin regimen that best suits their daily sched-
ules, meal plans, and exercise and sleep habits is potentially
beneficial. Gradual transition of the responsibility to self-care
from the parent(s) to the child is important.
A continued role for parents in providing collaborative sup-
port is associated with optimal health outcomes. Parents can
also help prevent depressive symptoms by providing support
and guidance, and encouraging positive coping strategies.
Routine assessment and interventions to treat depression
among adolescents with diabetes is strongly recommended;
screening for anxiety and eating disorders may be necessary
in certain situations.
Conclusions
In summary, the turbulent adolescent years are character-
ized by important hormonal, metabolic and psychological
changes which impact on the management of type 1 diabetes.
It is imperative that the healthcare team is aware of these
changes. The decline in insulin sensitivity requires appropriate
readjustment of insulin doses in order to prevent deteriora-
tion in blood glucose control. Psychosocial changes must be
monitored in order to identify any depressive symptoms or
behavioural problems, and provide supportive therapy and
appropriate referral.
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