TY - JOUR
T1 - Meta-analysis of ghrelin alterations in schizophrenia
T2 - Effects of olanzapine
AU - Goetz, Ryan L.
AU - Miller, Brian J.
N1 - Funding Information:
Dr. Miller has nothing to disclose for the work under consideration. In the past 12 months, Dr. Miller received research support from the National Institute of Mental Health, NARSAD, the Stanley Medical Research Institute, and Augusta University, and Honoraria from Psychiatric Times.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/4
Y1 - 2019/4
N2 - Objective: Schizophrenia is associated with an increased prevalence of the metabolic syndrome. Patients receiving antipsychotic medications, including olanzapine, are at further risk. Ghrelin is an appetite-stimulating peptide hormone, although whether blood levels are altered by antipsychotic treatment, remains unclear. We performed a systematic review and meta-analysis comparing blood ghrelin levels in patients with schizophrenia before and after treatment with olanzapine. Method: Two authors independently searched major electronic databases from inception until February 2018 for studies measuring blood ghrelin levels among patients with schizophrenia before and after olanzapine therapy. Random effects meta-analysis calculating standardized mean difference (SMD)and 95% confidence intervals (CI)and meta-regression analyses were performed. Results: Six studies met the inclusion criteria. Across these studies, there were 111 patients with schizophrenia (mean age 40, 85% male, baseline BMI 22, and endpoint BMI 23). Olanzapine treatment (mean [standard deviation]duration = 12.3 [7.6]weeks)was associated with a significant decrease in blood ghrelin levels with a medium effect size (SMD = −0.48, 95% CI −0.88 to −0.08, p = 0.018). Age, sex, baseline BMI, geography, olanzapine dose and duration, year of publication, study quality, inpatient status, and antipsychotic washout did not moderate this association. Conclusion: Our results suggest that in patients with schizophrenia, olanzapine therapy is associated with decreased blood ghrelin levels, a paradoxical phenomenon known to occur in obesity. Future studies should investigate the contribution of dietary factors (e.g., caloric intake)and physical activity to this association, as well as the effects of other antipsychotics on ghrelin levels.
AB - Objective: Schizophrenia is associated with an increased prevalence of the metabolic syndrome. Patients receiving antipsychotic medications, including olanzapine, are at further risk. Ghrelin is an appetite-stimulating peptide hormone, although whether blood levels are altered by antipsychotic treatment, remains unclear. We performed a systematic review and meta-analysis comparing blood ghrelin levels in patients with schizophrenia before and after treatment with olanzapine. Method: Two authors independently searched major electronic databases from inception until February 2018 for studies measuring blood ghrelin levels among patients with schizophrenia before and after olanzapine therapy. Random effects meta-analysis calculating standardized mean difference (SMD)and 95% confidence intervals (CI)and meta-regression analyses were performed. Results: Six studies met the inclusion criteria. Across these studies, there were 111 patients with schizophrenia (mean age 40, 85% male, baseline BMI 22, and endpoint BMI 23). Olanzapine treatment (mean [standard deviation]duration = 12.3 [7.6]weeks)was associated with a significant decrease in blood ghrelin levels with a medium effect size (SMD = −0.48, 95% CI −0.88 to −0.08, p = 0.018). Age, sex, baseline BMI, geography, olanzapine dose and duration, year of publication, study quality, inpatient status, and antipsychotic washout did not moderate this association. Conclusion: Our results suggest that in patients with schizophrenia, olanzapine therapy is associated with decreased blood ghrelin levels, a paradoxical phenomenon known to occur in obesity. Future studies should investigate the contribution of dietary factors (e.g., caloric intake)and physical activity to this association, as well as the effects of other antipsychotics on ghrelin levels.
KW - Ghrelin
KW - Meta-analysis
KW - Metabolism
KW - Obesity
KW - Olanzapine
KW - Schizophrenia
UR - http://www.scopus.com/inward/record.url?scp=85057618837&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85057618837&partnerID=8YFLogxK
U2 - 10.1016/j.schres.2018.11.036
DO - 10.1016/j.schres.2018.11.036
M3 - Review article
C2 - 30528312
AN - SCOPUS:85057618837
SN - 0920-9964
VL - 206
SP - 21
EP - 26
JO - Schizophrenia Research
JF - Schizophrenia Research
ER -