The Influence of Vitamin D on Atypical Antipsychotic-induced Weight Gain

Specific Aim: We predict that the patients with schizophrenia, who gain weight with
antipsychotic treatment, are vitamin D-deficient compared to the patients who do not gain
weight. We will examine circulating levels of serum 25(OH)D, mRNA transcripts and protein
expression of vitamin D receptor (VDR) and the enzymes, CYP24A and CYP27B, in the white
blood cells of the subjects and correlate with BMI and the blood levels of leptin and
adiponectin.

Experimental Approach:

Recruitment of Patients: Subjects will be recruited from the psychiatry clinics of
Alegent-Creighton Clinics where the PI is working on a full-time basis. Dr. Selvaraj, the PI
of this project, provides psychiatric care annually to an average of 300 patients with
schizophrenia and bipolar disorder. In addition, other psychiatrists in the same clinic also
see patients with schizophrenia. Thus, there is an ample population available for this
study. The patients will be recruited based on the inclusion and exclusion criteria, as
shown in Figure 1. Patients with schizophrenia who are on the atypical antipsychotic,
quetiapine, will be recruited. The underlying major mechanism of action of this
anti-psychotic medication is to block both dopamine (D2 and D4) and serotonin (5-HT2A and
5-HT2c) receptors (24). Also, this antipsychotic medication has been shown to increase
weight in the patients. According to the data, mean increase in weight after 8-10 weeks on
anti-psychotics is about 12.2 lbs with quetiapine (24). In most cases, increase in weight
reaches to a plateau within 8-10 weeks (24). Therefore, we will recruit age-matched patients
who have been taking quetiapine 100mg or more for at least 12 weeks. There is no
relationship in weight gain and the severity of psychosis or the dose of the anti-psychotic
drug. During the first episode, most of these patients are in their 20s and 30s. The
patients will be divided into two experimental groups: (i) "Weight gain" and (ii) "No weight
gain". In the weight gain group, we will recruit those patients who have gained 10% increase
from the baseline weight. In the no weight group, we will recruit patients who have lost
weight, did not gain weight or have gained weight <5% over the baseline weight. The baseline
weight data and other information will be obtained from the electronic health record through
the EPICS system, upon recruitment in the study.

The human research protocol with the Informed Consent and HIPPA forms has been approved by
the Institutional Review Board of Creighton University.

Statistical Analysis: The association between weight gain and vitamin D deficiency will be
analyzed using 2x2 contingency tables and tests for independence. The three most common
tests for independence are the likelihood ratio test (LRT), the Pearson's chi-square
statistic, and Fisher's exact test. Both Pearson's chi-square and Fisher's exact test will
be used to analyze the data. If the expected number of counts in any one cell is less than
five (5), only Fisher's exact test will be reported. The purpose of this pilot is to
estimate/confirm a reasonable confidence interval for the true odds ratio and reference
proportion to design a larger scale study. We believe we can reasonably recruit between 30
and 40 patients. Should we recruit a total of 40 patients, we believe we can achieve a
minimum detectable odds ratio of 9 (with desired power of 0.80 and significance level of
0.05) with reference proportion of 0.35. This initial analysis was based on a preliminary
study where 35% of schizophrenic patients gained weight on atypical antipsychotic drugs.
Since there is no follow up of these patients, but the collection of the blood and clinical
data only at one time point, the question of potential drop-outs or the follow-ups does not
arise.

Age-matched subjects of both sex and all ethnicities will participate in this study.
Potential subjects will be approached by treating clinicians (inpatient or outpatient) for
possible participation; or potential study participants may respond to advertisements in the
form of IRB approved flyers that will be distributed at area hospitals and medical clinics.
Patients who indicate interest in the study will be asked to sign an informed consent to
allow research personnel to review clinical records and speak with the PI or other treating
physician about appropriateness for protocol participation. In the Alegent-Creighton clinics
we have sufficient number of minority patients, including African-Americans, Hispanics and
women. No children will be recruited in this study.

Experimental Protocol: Upon the recruitment of the subjects in this study, the following
information will be collected for each of the 40 patients: (i) Demographic data, including
age, sex, ethnicity, duration of the illness and the medication regimen and (ii)
Anthropometry data, including height, weight, BMI, blood pressure, pulse rate. The following
psychiatric rating scale will be used as a diagnostic measure.

The MINI International Neuropsychiatric Interview (M.I.N.I.), a well known psychiatric
diagnostic interview protocol, will be administered at baseline before collecting the blood
sample. The M.I.N.I. includes items that assess the hallmark symptoms of the exclusionary
psychotic depression, other psychotic disorders, bipolar disorder, eating disorder and
substance dependence. We will use these modules only to help exclude patients with the
prescribed diagnoses.

Following the MINI protocol, 40 ml venous blood, in a fasting state, will be collected in
three separate vacutainer EDTA tubes. One tube of 10 ml will be sent to the Clinical
Pathology Laboratories for the measurement of complete blood count, complete metabolic
panel, fasting lipid profile for the measurement of triglycerides, high density
lipoproteins, low density lipoproteins, very low-density lipoproteins. The complete blood
count and complete metabolic panel will be done to rule out infection or any other
co-morbidity. Another 10 ml tube will be sent to Clinical Pathology lab for the measurement
of serum 25-hydroxy D levels. The third tube with 20 ml blood will be used for isolating
buffy coat to measure protein and mRNA expression of vitamin D receptor (VDR), CYP24A1 and
CYP27B1, and for separating serum to measure leptin and adiponectin levels. This latter part
will be done in the research laboratory of the PI using the following procedures.

Inclusion Criteria:

- • Men and women with a DSM-IV clinical diagnosis of Schizophrenia, Schizoaffective or
Bipolar disorder

- 21 to 65 years of age; male and female

- A willingness and ability to provide signed informed consent

- The subject should have been on quetiapine 100 mg or more for more than 12
weeks.

Exclusion Criteria:

1. Pregnant women

2. Subjects considered at high suicide risk based on the MINI Suicidality Module (> 17
points)

3. Unstable general medical condition or serious illness (e.g. death or hospitalization
is anticipated within one year), poor kidney function or liver function (defined as
laboratory values ≥ three times the upper limit of the normal), and seizure disorders
except for childhood seizure disorders

4. Concurrent therapy with certain psychotropics is permitted, provided that the
medication and dose have been stable for the past 90 days

5. Patients on concomitant treatment with clozapine and olanzapine are not permitted.

6. Patients on immunosuppressant medications or any orexigenic or anorexigenic drug

7. Patients on concomitant treatment with amphetamines and/ or methylphenidate

8. History of hypothyroidism or thyroxine therapy

9. Patients with a known condition or undergoing therapeutic measures that affects
weight, including but not limited to: eating disorder, type I diabetes,
hyperthyroidism, thyroxine therapy, Topamax therapy, and infectious diseases, such as
HIV, hepatitis B, and hepatitis C

10. Active supplementation of vitamin D within the last 3 months