Adiponectin, leptin and resistin levels in first-episode, drug-naïve patients with psychosis before and after short-term antipsychotic treatment

OBJECTIVE

There is increasing evidence that adiponectin, resistin and leptin may be implicated in the pathophysiology of neuropsychiatric disorders, including schizophrenia. The results of the studies so far remain controversial. Our aim was to compare serum adiponectin, leptin and resistin levels between drug-naïve, first -episode patients with psychosis and healthy controls and in the same group of patients after six weeks of antipsychotic treatment.

METHODS

Forty first-episode patients with psychosis and 40 matched controls were included in the study. Serum levels of adiponectin, resistin and leptin were measured by enzyme linked immunosorbent assay (ELISA) in both groups. In the patient group, the same adipokines were also measured six weeks after the initiation of antipsychotic treatment.

RESULTS

Log-transformed serum levels of adiponectin (mean difference = 1.68, 95% confidence interval [CI] = 1.30 to 2.06, U = 157, p < 0.0001), resistin (0.48, 95% CI = 0.36 to 0.59, t = 8.00, p < 0.0001) and leptin (0.66, 95% CI = 0.52 to 0.80, U = 160, p < 0.0001) were significantly higher to the patient group compared to controls. Leptin levels were significantly decreased in the patient group six weeks after the initiation of antipsychotic treatment (mean change = -0.40, 95% CI = -0.59 to -0.21, W = 666; p < 0.0001) while those of adiponectin and resistin levels did not change significantly.

CONCLUSION

In our study we found higher levels of adiponectin, leptin and resistin in drug-naïve, first-episode patients with normal Body Mass Index (BMI) compared to controls. After six weeks of antipsychotic treatment, there was no change in adiponectin and resistin levels, while leptin levels were reduced compared to baseline.

Changes in the cytokine profile in first-episode, drug-naïve patients with psychosis after short-term antipsychotic treatment

An increasing body of evidence suggests that antipsychotic medication can cause immunological changes that could be attributed to the amelioration of psychotic symptoms or the metabolic side effects of the drugs. So far, the results of the studies remain controversial. Our aim was to compare the levels of interleukin (IL) IL-2, IL-6 and transforming growth factor-β2 (TGF-β2) in drug-naïve, first-episode patients with psychosis before and after six weeks of antipsychotic medication. Thirty-nine first-episode patients with psychosis were enrolled in the study. Serum levels of IL-2, IL-6 and TGF-β2 were measured by enzyme linked immunosorbent assay (ELISA) before and six weeks after the initiation of antipsychotics. In addition, clinical psychopathology was assessed using Positive and Negative Syndrome Scale (PANSS) before and after treatment. Serum levels of IL-2 were significantly increased six weeks after the initiation of antipsychotic treatment (p <0.001) while TGF-β2 levels were decreased (p <0.001). IL-6 levels were overall increased (p <0.004), but this occurred in a non-linear way. These findings, although preliminary, provide further evidence that antipsychotic treatment in patients with psychosis may be correlated with immunological changes but further research is needed.

Elevated levels of Insulin-like Growth Factor-1 (IGF-1) in drug-naïve patients with psychosis

Insulin-like growth factor 1 (IGF-1) plays an important role in neurogenesis and synaptogenesis and may be implicated in schizophrenia, although data so far have been inconclusive. The aim of our study was to compare levels of IGF-1 in drug-naïve patients with a first episode of schizophrenia and related disorders with matched healthy controls. Forty drug naïve first-episode patients with schizophrenia and related disorders and forty healthy subjects matched for age, gender, body mass index (BMI) and smoking status were enrolled in the study. Serum levels of IGF-1 for each sample were measured in duplicate by the enzyme-linked immunosorbent assay (ELISA) method using human IGF-1. The median IGF-1 levels were significantly higher in drug-naive patients with psychosis compared to healthy controls (109.66ng/ml vs. 86.96ng/ml, respectively p=0.039). Multiple regression analysis revealed that differences in serum IGF-1 values were independent of glucose metabolism (fasting glucose, fasting insulin, insulin resistance) and cortisol. These results show that IGF-1 may be implicated in the pathophysiology of psychosis but confirmation is needed from other studies.

Prolactin levels in drug-naïve patients with schizophrenia and other psychotic disorders

OBJECTIVE

Hyperprolactinaemia as a side effect of dopamine receptor blockers is common in patients with schizophrenia and other psychotic disorders and may lead to amenorrhoea, galactorrhoea, hypogonadism, subfertility and osteoporosis. The aim of our study was to determine whether hyperprolactinaemia occurs also in patients with schizophrenia and other psychotic disorders prior to any antipsychotic treatment.

METHODS

Serum prolactin, thyroid-stimulating hormone (TSH), triiodothyronine (T3), free tetraiodothyronine (FT4) and cortisol levels were measured in 40 newly diagnosed, drug naïve, patients with schizophrenia and other psychotic disorders and in 40 age and gender matched healthy subjects.

RESULTS

The median prolactin value was 12.5 ng/ml (range: 2-38 ng/ml) for patients and 8.6 ng/ml (range: 4-17.6 ng/ml) for healthy subjects (p = 0.011). Patients had lower levels of T3 compared to healthy controls (mean: 1.08 ng/ml, SD: 0.16 vs. 1.18 ng/ml, 0.18, respectively; p = 0.008). Serum TSH, FT4 and cortisol levels were similar between the two groups. Multiple regression analysis revealed that the difference in serum prolactin values was independent of thyroid function (TSH, FT4, T3) and serum cortisol levels.

CONCLUSIONS

A higher serum prolactin level was found in drug naïve, newly diagnosed patients with schizophrenia and other psychotic disorders compared to healthy controls, prior to starting any antipsychotic treatment.

Cytokine profile in drug-naïve, first episode patients with psychosis

OBJECTIVE

An increasing body of evidence suggests that immunological changes may play a role in schizophrenia but the results of the studies are controversial and little is known about the presence of those changes at the onset of the disease. Our aim is to compare the levels of interleukin (IL) IL-2, IL-6, IL-10, IL-17 and transforming growth factor -β2 (TGF-β2) between drug-naïve-first episode patients with psychosis and healthy controls matched for age, sex, BMI and smoking.

METHODS

Thirty-nine drug-naïve-first episode patients with psychosis and 39 healthy individuals (control group) were enrolled in the study. Serum levels of IL-2, IL-6, IL-10, IL-17 and TGF-β2 were measured by enzyme linked immunosorbent assay (ELISA).

RESULTS

Serum IL-2 and IL-6 levels were significantly higher in the drug-naïve patients with psychosis group (p<0.022 and p<0.002 respectively) compared to healthy controls. No differences were found between the two groups in the levels of IL-10, IL-17. The levels of TGF-β2 did not differ significantly between the two groups.

CONCLUSION

The serum levels of IL-2 and IL-6 are increased in first episode drug-naïve patients with psychosis compared to healthy controls. An inflammatory response mediated by IL-2 and IL-6 may play a role in schizophrenia.