Antipsychotic medications place children and young adults at serious risk for type 2 diabetes, new research suggests.
The
retrospective cohort study of more than 43,000 individuals between the
ages of 6 and 24 years adds to mounting evidence showing that these
medications cause rapid metabolic change in young patients,
putting them at increased risk for diabetes, overweight, and obesity and
subsequent cardiovascular disease.
In this latest report,
investigators found that study participants who were prescribed
antipsychotics were significantly more likely to develop type 2 diabetes
within the first year of use compared with matched control individuals
who were not prescribed these medications.
In addition, the
researchers found there was a dose-response relationship so that the
risk increased with higher medication doses and
remained elevated for up to 1 year after the medications were
discontinued.
When the investigators assessed only participants
who were younger than 18 years, the association between antipsychotic
use and type 2 diabetes remained highly significant.
"We found a
3-fold increased risk for type 2 diabetes in the children
who were antipsychotic users when compared to a very closely matched
group of control children receiving other psychotropic drugs with a
similar psychiatric profile," principal investigator Wayne A. Ray, PhD,
professor in the Department of Health Policy at the Vanderbilt
University School of Medicine in Nashville, Tennessee, told
Medscape Medical News.
"This surprised us. Not that the risk was increased but that the magnitude was so great," he added.
Dr.
Ray added that the key take-home message for clinicians is to carefully
consider the risk/benefit of antipsychotics in this vulnerable
population.
"For conditions in which there are other therapeutic
alternatives, clinicians and parents should consider those. In some case
they may end up using the antipsychotic, but at least they have
considered the other options," he said.
The study was
published online August 21 in
JAMA Psychiatry.
A Perfect Storm
According to the investigators, antipsychotics for children and
adolescents used to be prescribed primarily to treat schizophrenia and
other psychotic disorders.
However, with the introduction of
atypical antipsychotics, the use of
this class of medication has "expanded to include bipolar disorders,
affective disorders, and symptoms related to behavior and conduct, which
now account for the majority of prescriptions."
Previous research has shown that these medications are associated with increased metabolic risks, including
weight gain, increased glucose levels, and
insulin resistance in this young patient population.
As reported by
Medscape Medical News, investigators led by Susan Andrade, ScD, from the University of Massachusetts, published a retrospective study in 2011 in
Pediatrics.
They found that use of antipsychotics increased the risk for diabetes
in a group of children and adolescents between the ages of 5 and 18
years. Out of 9636 of the participants who were taking second-generation
antipsychotics (SGAs), 57 were diagnosed with incident
diabetes.
"Although we found a potentially 4-fold increased rate
of diabetes among children exposed to SGAs, the findings were
inconsistent and depended on the comparison group and the outcome
definition," the researchers wrote at the time, adding that the small
number of cases was
a potential study limitation.
The current investigators sought to examine these
associations in a larger trial. Dr. Ray noted that the "dramatic
increase" in antipsychotic use by children and an increase in pediatric
diabetes cases has led to a possible "perfect storm" of problems.
"We
thought it was important to clarify this issue for clinicians and
for parents. And if this increased risk was really there, they needed to
take that information into account when choosing a drug," he explained.
The
investigators evaluated records from the Tennessee Medicaid program of
28,858 first-time users of antipsychotic medications and 14,429 1-for-2
matched control individuals who had recently initiated use of a
psychotropic other than an antipsychotic. All of the participants were 6
to 24 years of age between 1996 and 2007 (mean age, 14.5 years; 56%
boys).
Those who had received a previous diagnosis of diabetes,
schizophrenia, or some other condition for which antipsychotics are "the
only generally recognizable therapy" were excluded.
Antipsychotics
used included risperidone, quetiapine, aripiprazole, and olanzapine;
and the median starting dose was 67 mg of chlorpromazine equivalents.
Medications used by the control group included mood stabilizers such as
lithium, as well as antidepressants, psychostimulants, α-agonists, and
benzodiazepines.
Lowest Possible Dose, Shortest Possible Time
Results showed that 106 of the young people receiving
antipsychotics were diagnosed and treated for type 2 diabetes (mean age,
16.7 years; 63% girls). This translated into 18.9 cases per 10,000
person-years.
"That's why this study had to be so large, in order
to detect clinically meaningful differences in the risk of type 2
diabetes, a relatively uncommon but serious condition for children and
youth," explained Dr. Ray in a release.
Still, the group of
antipsychotic users had a 3-fold increased risk of developing type 2
diabetes by the end of the study compared with the group of nonusers
(hazard ratio [HR], 3.03; 95% confidence interval [CI], 1.73 - 5.32).
And this risk was significant within the first year of follow-up (HR, 2.49; 95% CI, 1.27 - 4.88).
The
risk also increased with cumulative dose. For less than 5 grams of
chlorpromazine equivalents, the HR was 2.13; for 5 to 99 grams, the HR
was 3.42; and for 100 grams or more, the HR was 5.43.
One year
after discontinuing use of any antipsychotic, the risk for type 2
diabetes remained elevated (HR, 2.57; 95% CI, 1.34 - 4.91).
Overall
risk also remained significant when investigators only evaluated the
subgroup of children between the ages of 6 and 17 years (HR, 3.14; 95%
CI, 1.50 - 6.56).
A total of 87% of the antipsychotic users used
atypicals; and use of this medication classification was associated with
significant risk (HR,
2.89).
Risperidone, which was associated with an HR of 2.20 for
type 2 diabetes in this study, was also the most frequently prescribed
antipsychotic (n = 10,718), followed by quetiapine (n = 5807) and
olanzapine (n = 5671).
Interestingly, the difference between HRs for risperidone and aripiprazole was strongly significant (
P < .001).
Dr.
Ray noted that the results show the need for examining alternatives to
antipsychotic use. He added that this is especially important for
high-risk children, such as those who are overweight.
"Children
should be monitored carefully for metabolic effects predisposing them to
diabetes, and use of the drug should be at the lowest possible dose for
the shortest possible time," he said.
"Important, Landmark Study"
"Overall, I think this is a really important study. Some would
call it a landmark study," Dina Panagiotopoulos, MD, associate professor
of pediatrics at the University of British Columbia (BC) and
endocrinologist at the BC Children's Hospital in Vancouver, told
Medscape Medical News.
It's the largest sample size to date to look at this
question, they did very complex statistical analyses to adjust for 151
covariates, and they did very careful subgroup and sensitivity
analyses," she said.
She was also impressed that the investigators
ensured that the matched control group was as mentally and physically
ill as the study group.
"Clearly, these findings are important and clinically relevant."
Dr.
Panagiotopoulos, who was not involved with this research, was
codeveloper of the Canadian Alliance for Monitoring Effectiveness and
Safety of Antipsychotics in children (known as CAMESA) guidelines. She
and her colleagues
also published a study in 2012 that examined the link between SGAs and cardiometabolic risks in kids.
"My
only concern about this study, and it's been echoed by other local and
international colleagues, because we've had quite a bit of email
interaction about this study already, is with the way the diagnosis of
diabetes was made," she said.
She noted that the investigators
relied upon a clinical diagnosis, "using an administrator code that a
doctor would use for diabetes with use of a medication." However, most
cases were not confirmed with blood work.
"So you can't say that
there was true ascertainment of diabetes in all of those patients. But
because they used the same definition in both
groups, you can say that the relative risk has still been increased,"
said Dr. Panagiotopoulos.
Even with this limitation, she said that the analysis was important especially because the investigators were able to look at such a young age group.
"This study is adding to the body of literature suggesting that using
atypical antipsychotics in children increases diabetes risk. We cannot ignore that," she said.
"There
are some very important findings here for clinicians, emphasizing once
again that these drugs are dangerous, they should be used only for
appropriate indications, and that kids need careful monitoring."
The study was funded by a grant from the Agency for Healthcare
Research and Quality, Centers for Education and Research on
Therapeutics. The study authors and Dr. Panagiotopoulos have disclosed
no relevant financial relationships.
JAMA Psychiatry. Published online August 21, 2013.
Abstract