1.
Prebiotics may reduce serum concentrations of C-reactive protein and ghrelin in overweight and obese adults: a systematic review and meta-analysis.
da Silva Borges, D, Fernandes, R, Thives Mello, A, da Silva Fontoura, E, Soares Dos Santos, AR, Santos de Moraes Trindade, EB
Nutrition reviews. 2020;(3):235-248
Abstract
CONTEXT Biochemical markers correlate positively with the development and severity of obesity, depression, and anxiety, and can be modulated by changes in intestinal microbiota composition. OBJECTIVE A systematic review and meta-analysis was conducted to determine the effects of prebiotics or synbiotics on blood biomarkers of obesity, depression, and anxiety (including: ACTH [adrenocorticotropic hormone], cortisol, leptin, ghrelin, TSH [thyroid-stimulating hormone], PTH [parathyroid hormone], vitamin D, BDNF [brain-derived neurotrophic factor], and PCR [polymerase chain reaction]) in individuals with overweight or obesity. DATA SOURCES MEDLINE, Web of Science, Scopus, and CENTRAL databases were searched, along with the reference lists of included articles. Authors were contacted for unpublished data. STUDY SELECTION RCT in individuals with overweight or obesity, supplemented with prebiotics or synbiotics, assessing any of the outcomes of interest. DATA EXTRACTION Data were extracted independently by three researchers. RESULTS Thirteen studies were identified up to March 7, 2018. Regarding outcomes, 1 study assessed leptin, 4 studies assessed ghrelin, and 10 studies assessed CRP (C-reactive protein). Meta-analysis showed reduction in serum concentrations of ghrelin (-37.17 pg/mL; 95%CI = -69.62, -4.73; P = 0.025) and CRP (SMD [standardized mean difference] = -0.31; 95%CI = -0.58, -0.04; P = 0.027) after supplementation of inulin-type fructans. CONCLUSIONS Prebiotics may help regulate blood concentrations of ghrelin and CRP in overweight or obese individuals.
2.
Meta-analysis of ghrelin alterations in schizophrenia: Effects of olanzapine.
Goetz, RL, Miller, BJ
Schizophrenia research. 2019;:21-26
Abstract
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.