Bone mineral density as a marker of cumulative endogenous estrogen exposure: relationship to background genetic risk of psychotic disorder

Prevalence, risk factors and clinical characteristics of osteoporosis in Chinese inpatients with schizophrenia

Patients with schizophrenia have a high prevalence of developing osteoporosis and osteoporosis-related fractures. We examined the prevalence of osteoporosis and its clinical correlates in Chinese patients with schizophrenia, which is not well-studied. A total of 199 inpatients (males/females=132/67; average age: 54.5±11.1years) and 107 healthy controls (males/females=22/85; average age: 41.7±11.9years) were recruited. Bone mineral density (BMD) was measured by ultrasonography of the calcaneus. The prevalence of osteoporosis and low BMD (osteoporosis and osteopenia) was 23.1% and 65.3% for the patient group, versus 7.5% and 39.3% for the control group (both p<0.001). Further, the average BMD T-score in patients was significantly lower than in controls (p<0.05). There was gender difference in the prevalence of low BMD conditions for the patients (males: 56.1% versus females: 76.1%; p<0.01) as well as the BMD T-score (p<0.001). Several risk factors correlated with the osteoporosis classification in the patient group: older age (58.9±11.2years vs. 53.3±11.0years), lower weight (63.7±12.2kg vs. 70.4±15.2kg) and body mass index (BMI) (22.8±4.1kg/m² vs. 24.2±4.7kg/m²; all p<0.01) than those without osteoporosis. Stepwise multiple logistic regression analysis indicated that age, weight and BMI remained significantly associated with osteoporosis. In addition, correlation analysis showed significant correlations between BMD T-score and the following parameters: gender, age and drug type (clozapine versus non-clozapine) (Bonferroni corrected p's<0.05). Our results suggest a higher prevalence of osteoporosis and osteopenia in Chinese schizophrenic inpatients, with both the expected risk factors of gender and age, as well as drug type.

Lower Bone Mineral Density at the Hip and Lumbar Spine in People with Psychosis Versus Controls: a Comprehensive Review and Skeletal Site-Specific Meta-analysis

It remains unclear if differences in bone mineral density (BMD) exist at different skeletal sites between people with schizophrenia and age- and sex-matched healthy controls (HCs). Major databases were searched from inception until February 2016 for studies measuring BMD using dual-energy X-ray absorptiometry (DXA) at any skeletal site in individuals with schizophrenia. Ten studies investigating 827 people with schizophrenia (55.4 % female, 33.8 ± 9.7 years) and 1379 HCs (58.7 % female, 34.7 ± 9.1 years) were included. People with schizophrenia had significantly reduced BMD at the lumbar spine (standardised mean difference adjusted for publication bias (SMD) = -0.950 (95 % CI = -1.23 to -0.66, fail-safe number = 825) and hip (SMD = -0.534, 95 % CI = -0.876 to -0.192, fail-safe number = 186). A higher proportion of hyperprolactinaemia (β = -0.0102, p < 0.0001) and smokers (β = -0.0099, p = 0.02) moderated a larger reduced BMD at the lumbar spine. Further research is required to investigate if low bone mass and fractures can be prevented in people with schizophrenia.

Relationship between antipsychotic medication, serum prolactin levels and osteoporosis/osteoporotic fractures in patients with schizophrenia: a critical literature review

INTRODUCTION

Using an antipsychotic medication can increase prolactin (PRL) levels, causing hyperprolactinemia (HPRL). Although the occurrence of osteoporosis within the population of patients with schizophrenia has been recognized, the precise nature of the association between antipsychotic treatment, PRL, osteoporosis, and the disease itself seems to be elusive.

AREAS COVERED

The aim of this review is to critically review the literature regarding the association between osteoporosis and PRL and to summarize the available evidence with respect to the impact of PRL-elevating antipsychotics on bone mineral density (BMD) and fractures in non-elderly patients with schizophrenia.

EXPERT OPINION

Although long-standing HPRL can have an impact on the rate of bone metabolism and, when associated with hypogonadism, may lead to decreased bone density in both female and male subjects, the relative contribution of antipsychotic-induced HPRL in bone mineral loss in patients with schizophrenia remains unclear. Methodological shortcomings of existing studies, including the lack of prospective data and the focus on measurements of BMD instead of bone turnover markers, preclude definitive conclusions regarding the relationship between PRL-raising antipsychotics and BMD loss in patients with schizophrenia. Therefore, more well conducted prospective trials of these biomarkers are necessary to establish the precise relationship between antipsychotics, PRL levels and osteoporosis/osteoporotic risk.

Spanish consensus on the risks and detection of antipsychotic drug-related hyperprolactinaemia

INTRODUCTION

Iatrogenic hyperprolactinaemia (IHPRL) has been more frequently related to some antipsychotic drugs that provoke an intense blockade of dopamine D2 receptors. There is a wide variation in clinical practice, and perhaps some more awareness between clinicians is needed. Due to the high frequency of chronic treatment in severe mental patients, careful attention is recommended on the physical risk. IHPRL symptoms could be underestimated without routine examination.

METHODOLOGY

An intense scientific literature search was performed in order to draw up a multidisciplinary consensus, including different specialists of psychiatry, endocrinology, oncology and internal medicine, and looking for a consensus about clinical risk and detection of IHPRL following evidence-based medicine criteria levels (EBM I- IV).

RESULTS

Short-term symptoms include amenorrhea, galactorrhoea, and sexual dysfunction with decrease of libido and erectile difficulties related to hypogonadism. Medium and long-term symptoms related to oestrogens are observed, including a decrease bone mass density, hypogonadism, early menopause, some types of cancer risk increase (breast and endometrial), cardiovascular risk increase, immune system disorders, lipids, and cognitive dysfunction. Prolactin level, gonadal hormones and vitamin D should be checked in all patients receiving antipsychotics at baseline although early symptoms (amenorrhea-galactorrhoea) may not be observed due to the risk of underestimating other delayed symptoms that may appear in the medium term. Routine examination of sexual dysfunction is recommended due to possible poor patient tolerance and low compliance. Special care is required in children and adolescents, as well as patients with PRL levels >50ng/ml (moderate hyperprolactinaemia). A possible prolactinoma should be investigated in patients with PRL levels >150ng/ml, with special attention to patients with breast/endometrial cancer history. Densitometry should be prescribed for males >50 years old, amenorrhea>6 months, or early menopause to avoid fracture risk.

Bone Mineral Density in Schizophrenia: An Update of Current Meta-Analysis and Literature Review Under Guideline of PRISMA

Numerous reports have discussed bone mineral density (BMD) or the risk of osteoporosis in schizophrenia, but have yielded only controversial results.We conducted an update of meta-analysis to examine the overall change in BMD in patients with schizophrenia and the effect on BMD of different antipsychotic drugs.Electronic research through platform of PubMed.The inclusion criteria were as follows: articles with relevance to comparisons of BMD in patients with schizophrenia (SCHIZ) and healthy controls (HCs), or articles discussing comparisons of BMD in SCHIZ receiving prolactin-raising (PR) and prolactin-sparing (PS) antipsychotics; articles about clinical trials.In the current meta-analysis, we used the random-effect model to pool the results from 13 studies comparing BMD in SCHIZ and in HCs, and the results from 7 studies comparing BMD in patients receiving PR and PS.Our results revealed significantly lower BMD in SCHIZ than in HCs (P < 0.001). In the meta-regression, mean age of subjects modulated the difference in BMD between patients and control subjects (P < 0.001). In addition, the BMD in SCHIZ taking PR was significantly lower than in those taking PS (P = 0.006).Our study can only point to the phenomenon that BMD in SCHIZ is lower than that in HCs, and cannot reveal any possible pathophysiology or mechanism of this phenomenon. In addition, we could not rule out the possible effect of medication on BMD based on the results of the meta-analysis of comparison of BMD in SCHIZ receiving PR and PS.The main result of our meta-analysis suggests that BMD is significantly lower in SCHIZ than in HCs. Our study emphasizes the importance of further screening for the risk of osteoporosis in young-aged schizophrenic patients, especially those taking PR, which are in high risk of fracture.

Bone Mineral Density as a Marker of Cumulative Estrogen Exposure in Psychotic Disorder: A 3 Year Follow-Up Study

Altered estrogen-induced neuroprotection has been implicated in the etiology of psychotic disorders. Using bone mineral density as a marker of lifetime estrogen exposure, a longitudinal family study was conducted to discriminate between etiological mechanisms and secondary effects of disease and treatment. Dual X-ray absorptiometry scans were acquired twice, with an interval of 3 years, in 30 patients with psychotic disorder (male (M)/female (F): 24/6, mean age of 32 years at second measurement), 44 non-psychotic siblings of patients with a psychotic disorder (M/F: 26/18, mean age 32) and 27 controls (M/F: 7/20, mean age 35). Total bone mineral density, Z-scores and T-scores were measured in the lumbar spine and proximal femur. Associations between group and bone mineral density changes were investigated with multilevel random regression analyses. The effect of prolactin-raising antipsychotic medication was evaluated. (Increased risk of) psychotic disorder was not associated with disproportionate bone mineral density loss over a three year period. Instead, femoral bone mineral density measures appeared to decrease less in the patient versus control comparison (total BMD: B = 0.026, 95% CI 0.002 to 0.050, p = 0.037; Z-score: B = 0.224, 95% CI 0.035 to 0.412, p = 0.020; and T-score: B = 0.193, 95% CI 0.003 to 0.382, p = 0.046). Current or past use of a prolactin-raising antipsychotic medication was not associated with bone mineral density changes. In this small longitudinal study, there was no evidence of ongoing estrogen deficiency in psychotic disorder as there was no excessive loss of bone mineral density over a 3-year period in patients using antipsychotic medication.

A meta-analysis of prevalence estimates and moderators of low bone mass in people with schizophrenia

OBJECTIVE

To assess the prevalence and moderators of low bone mass, osteopenia and osteoporosis in schizophrenia patients.

METHOD

Major electronic databases were searched from inception till December 2013 for studies reporting the prevalence of low bone mass (osteopenia + osteoporosis = primary outcome), osteopenia or osteoporosis in schizophrenia patients. Two independent authors completed methodological appraisal and extracted data. A random effects meta-analysis was utilized.

RESULTS

Nineteen studies were included (n = 3038 with schizophrenia; 59.2% male; age 24.5-58.9 years). The overall prevalence of low bone mass was 51.7% (95% CI = 43.1-60.3%); 40.0% (CI = 34.7-45.4%) had osteopenia and 13.2% (CI = 7.8-21.6%) had osteoporosis. Compared with controls, schizophrenia patients had significantly increased risk of low bone mass (OR = 1.9, CI = 1.30-2.77, P < 0.001, n = 1872) and osteoporosis (OR = 2.86, CI = 1.27-6.42, P = 0.01, n = 1824), but not osteopenia (OR = 1.33, CI = 0.934-1.90, P = 0.1, n = 1862). In an exploratory regression analysis, older age (P = 0.004) moderated low bone mass, while older age (P < 0.0001) and male sex (P < 0.0001) moderated osteoporosis. The subgroup analyses demonstrated high heterogeneity, but low bone mass was less prevalent in North America (35.5%, CI = 26.6-45.2%) than Europe (53.6%, CI = 38.0-68.5%) and Asia (58.4%, CI = 48.4-67.7%), and in mixed in-/out-patients (32.9%, CI = 49.6-70.1%) vs. in-patients (60.3%, CI = 49.6-70.1%).

CONCLUSION

Reduced bone mass (especially osteoporosis) is significantly more common in people with schizophrenia than controls.

Testing the estrogen hypothesis of schizophrenia: associations between cumulative estrogen exposure and cerebral structural measures

BACKGROUND

Bone mineral density (BMD), as an indicator of cumulative estrogen exposure, may be reduced in female patients with psychotic disorder (van der Leeuw et al., 2013), possibly reflecting reduced cerebral exposure to estrogen and alterations in neuroprotective effects. To the degree that BMD is a marker of cumulative (endogenous) estrogen exposure, we hypothesized that BMD would be positively associated with cerebral gray and white matter indices.

METHODS

Dual X-ray absorptiometry (DEXA) and magnetic resonance (MRI) scans were acquired in fourteen female patients diagnosed with a psychotic disorder. BMD was expressed in total BMD (g/cm(2)), Z- and T-scores. Cerebral cortical thickness (CT) (as indicator of gray matter status) and fractional anisotropy (FA) (as indicator of white matter integrity) were measured and served as the dependent variables in multilevel random regression models. BMD measures were the independent variables.

RESULTS

Femoral BMD measures were positively associated with CT at trend significance (total BMD: B=0.266, 95% CI: -0.019-0.552, p=0.067; Z-score: B=0.034, 95% CI: 0.001-0.067, p=0.046; T-score: B=0.034, 95% CI: 0.000-0.068, p=0.052). There were no significant associations between femoral BMD measures and FA.

CONCLUSIONS

The data suggest that in women with psychotic disorder, alterations in the neuroprotective effect of estrogen (as measured by BMD) impact cortical gray matter, but not white matter integrity. These findings merit further investigation and, if replicated, would lend support to the estrogen hypothesis of schizophrenia.