Understanding osteoporosis

The neglected association between schizophrenia and bone fragility: a systematic review and meta-analyses

Schizophrenia is associated with increased risk of medical comorbidity, possibly including osteoporosis, which is a public health concern due to its significant social and health consequences. In this systematic review and meta-analysis, we aimed to determine whether schizophrenia is associated with bone fragility. The protocol for this review has been registered with PROSPERO (CRD42020171959). The research question and inclusion/exclusion criteria were developed and presented according to the PECO (Population, Exposure, Comparison, Outcome) framework. Schizophrenia was identified from medical records, DSM-IV/5 or the ICD. The outcomes for this review were bone fragility [i.e., bone mineral density (BMD), fracture, bone turnover markers, bone quality]. A search strategy was developed and implemented for the electronic databases. A narrative synthesis was undertaken for all included studies; the results from eligible studies reporting on BMD and fracture were pooled using a random effects model to complete a meta-analysis. The conduct of the review and reporting of results adhered to PRISMA guidelines. Our search yielded 3103 studies, of which 29 met the predetermined eligibility criteria. Thirty-seven reports from 29 studies constituted 17 studies investigating BMD, eight investigating fracture, three investigating bone quality and nine investigating bone turnover markers. The meta-analyses revealed that people with schizophrenia had lower BMD at the lumbar spine [standardised mean difference (SMD) -0.74, 95% CI -1.27, -0.20; Z = -2.71, p = 0.01] and at the femoral neck (SMD -0.78, 95% CI -1.03, -0.53; Z = -6.18, p ≤ 0.001). Also observed was a higher risk of fracture (OR 1.43, 95% CI 1.27, 1.61; Z = 5.88, p ≤ 0.001). Following adjustment for publication bias, the association between schizophrenia and femoral neck BMD (SMD -0.63, 95% CI -0.97, -0.29) and fracture (OR 1.32, 95% CI 1.28, 1.35) remained. Significantly increased risk of bone fragility was observed in people with schizophrenia. This association was independent of sex, participant number, methodological quality and year of publication.

Osteoporosis and low bone mass among schizophrenia and bipolar disorder: A cross-sectional study with newly diagnosed, drug-naïve subjects

BACKGROUND

A growing body of data shows that schizophrenia (SCZ) and bipolar disorder (BD) have substantial metabolic risks; however, few studies have focused on bone metabolism. This study aimed to assess the prevalence and associated influencing factors of low bone mass and osteoporosis in SCZ and BD before pharmacological effects occur.

METHODS

108 healthy controls (HCs) and drug-naïve individuals with SCZ (n = 56) and BD (n = 130) had their lumbar spine (L1-L4) and left femur (Neck/Trochanter/Ward's triangle) bone mineral density (BMD) determined using dual-energy X-ray absorptiometry. Besides, we measured bone turnover markers (BTMs) levels, including procollagen I N-terminal propeptide, osteocalcin, and C-terminal cross-linking telopeptide of type I collagen in different groups.

RESULTS

Individuals with SCZ and BD had significantly lower BMD and significantly higher prevalence of low bone mass and osteoporosis compared with HCs. In the main observation regions of the total lumbar (F = 18.368, p < 0.001) and left femur (F = 14.790, p < 0.001), BMD was lower in individuals with SCZ and BD than HCs, with SCZ showing lower BMD than BD. The osteocalcin (H = 11.421, p = 0.003) levels were significantly higher in SCZ and BD than HCs. Binary regression analysis showed that SCZ or BD was an independent risk factor for low bone mass and osteoporosis. In addition, sex, age, and BTMs also influenced the occurrence of low bone mass and osteoporosis.

LIMITATIONS

Cross-sectional study.

CONCLUSION

The results findings of the study might contribute to our understanding of the increased risk of bone metabolism in SCZ and BD.

CLINICAL TRIAL REGISTRATION

www.chictr.org.cn, identifier ChiCTR1900021379.

D2 dopamine receptor gene (DRD2) Taq1A (rs1800497) affects bone density

Schizophrenia patients are susceptible to lower bone mineral density (BMD). However, studies exploring the genetic effects are lacking. Genes that affect the activity of antipsychotics may be associated with BMD, particularly in patients receiving long-term antipsychotic treatment. We aimed to explore the relationship between the dopamine receptor D₂ (DRD2) gene Taq1A (rs1800497) polymorphism and BMD in chronic schizophrenia patients. We recruited schizophrenia patients (n = 47) and healthy controls (n = 39) from a medical center in Taiwan and collected data that may affect BMD. Patients’ BMD was measured by dual-energy X-ray absorptiometer (DEXA). DRD2 rs1800497 was genotyped through polymerase chain reaction–Restriction Fragment Length Polymorphism (PCR–RFLP). Among all participants, subjects with DRD2 rs1800497(T;T) allele had lower DEXA T score and DEXA Z score compared to those with rs1800497(C;T) and rs1800497(C;C) alleles (p = 0.008, 0.003, respectively). In schizophrenia patients, subjects with rs1800497(T;T) allele also had lower DEXA Z score compared to the other two alleles (p = 0.045). Our findings suggest that individuals with the DRD2 rs1800497(T;T) had lower BMD than those with the rs1800497(C;T) and rs1800497(C;C) genotypes. Therefore, genes should be considered as one of the risk factors of lower BMD.

Effects of Antipsychotics on Bone Mineral Density in Patients with Schizophrenia: Gender Differences

Low bone mineral density (BMD) and osteoporosis are common in patients with schizophrenia and detrimental to illness prognosis and life quality. Although the pathogenesis is not fully clear, series of studies have revealed factors related to low BMD such as life style, psychotic symptoms, medication use and the activity of bone absorption markers. It has been known that antipsychotic-induced hyperprolactinemia plays a critical role on decreased BMD. However, it remains uncertain whether the risk factors differ between men and women. According to the effect on prolactin, antipsychotics can be classified into two groups: prolactin-sparing (PS) and prolactin-raising (PR). Our previous study has demonstrated that clozapine which is among the PS antipsychotics is beneficial for BMD when compared with PR antipsychotics in women with chronic schizophrenia. We have also found that risks factors associated with low BMD are different between men and women, suggesting that gender-specific risk factors should be considered for intervention of bone loss in patients with schizophrenia. This article reviews the effects of antipsychotics use on BMD with particular discussion for the differences on gender and age, which implicate the alterations of sex and other related hormones. In addition, currently reported protective and risk factors, as well as the effects of medication use on BMD including the combination of antipsychotics and other psychotropic agents and other potential medications are also reviewed.

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.

Schizophrenia and the risk of fractures: a systematic review and comparative meta-analysis

BACKGROUND

People with schizophrenia experience increased rates of osteoporosis and may be at heightened risk of fractures. We conducted a systematic review and meta-analysis to investigate fractures among people with schizophrenia compared to people without mental illness.

METHOD

We systematically searched major electronic databases from inception until October 2014. Articles were included that reported the number of fractures in people with schizophrenia and a control group. Two independent authors conducted searches, completed methodological assessment and extracted data. Data were narratively synthesized, and a random-effects incidence rate ratio (IRR) meta-analysis was performed.

RESULTS

Eight studies were included encompassing 48,384 people with schizophrenia (49.9-75.2 years, 41%-100% female) and 3,945,783 controls. The pooled adjusted rate of fractures per 1000 person-years was 5.54 [95% confidence interval (CI)=4.92-5.57] in people with schizophrenia and 3.48 (95% CI=3.39-3.64) in control participants. The comparative meta-analysis showed that people with schizophrenia experience an increased rate of fractures compared to control participants (IRR 1.72, 95% CI=1.24-2.39, I2=49%; n=168,914). There were insufficient data to conduct moderation analysis, but the narrative review consistently highlighted that antipsychotic medication was an important risk factor for fractures.

CONCLUSION

People with schizophrenia are at significantly increased risk of fractures. Future research is required to understand the mechanisms and should seek to validate fracture prediction algorithms used in the general population. Importantly, there is a need to develop preventative strategies to improve bone health and reduce fracture risk involving the wider multidisciplinary team and incorporating falls-prevention strategies.

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.

The effects of novel and newly approved antipsychotics on serum prolactin levels: a comprehensive review

Since the 1970s, clinicians have increasingly become more familiar with hyperprolactinemia (HPRL) as a common adverse effect of antipsychotic medication, which remains the cornerstone of pharmacological treatment for patients with schizophrenia. Although treatment with second-generation antipsychotics (SGAs) as a group is, compared with use of the first-generation antipsychotics, associated with lower prolactin (PRL) plasma levels, the detailed effects on plasma PRL levels for each of these compounds in reports often remain incomplete or inaccurate. Moreover, at this moment, no review has been published about the effect of the newly approved antipsychotics asenapine, iloperidone and lurasidone on PRL levels. The objective of this review is to describe PRL physiology; PRL measurement; diagnosis, causes, consequences and mechanisms of HPRL; incidence figures of (new-onset) HPRL with SGAs and newly approved antipsychotics in adolescent and adult patients; and revisit lingering questions regarding this hormone. A literature search, using the MEDLINE database (1966-December 2013), was conducted to identify relevant publications to report on the state of the art of HPRL and to summarize the available evidence with respect to the propensity of the SGAs and the newly approved antipsychotics to elevate PRL levels. Our review shows that although HPRL usually is defined as a sustained level of PRL above the laboratory upper limit of normal, limit values show some degree of variability in clinical reports, making the interpretation and comparison of data across studies difficult. Moreover, many reports do not provide much or any data detailing the measurement of PRL. Although the highest rates of HPRL are consistently reported in association with amisulpride, risperidone and paliperidone, while aripiprazole and quetiapine have the most favorable profile with respect to this outcome, all SGAs can induce PRL elevations, especially at the beginning of treatment, and have the potential to cause new-onset HPRL. Considering the PRL-elevating propensity of the newly approved antipsychotics, evidence seems to indicate these agents have a PRL profile comparable to that of clozapine (asenapine and iloperidone), ziprasidone and olanzapine (lurasidone). PRL elevations with antipsychotic medication generally are dose dependant. However, antipsychotics having a high potential for PRL elevation (amisulpride, risperidone and paliperidone) can have a profound impact on PRL levels even at relatively low doses, while PRL levels with antipsychotics having a minimal effect on PRL, in most cases, can remain unchanged (quetiapine) or reduce (aripiprazole) over all dosages. Although tolerance and decreases in PRL values after long-term administration of PRL-elevating antipsychotics can occur, the elevations, in most cases, remain above the upper limit of normal. PRL profiles of antipsychotics in children and adolescents seem to be the same as in adults. The hyperprolactinemic effects of antipsychotic medication are mostly correlated with their affinity for dopamine D2 receptors at the level of the anterior pituitary lactotrophs (and probably other neurotransmitter mechanisms) and their blood-brain barrier penetrating capability. Even though antipsychotics are the most common cause of pharmacologically induced HPRL, recent research has shown that HPRL can be pre-existing in a substantial portion of antipsychotic-naïve patients with first-episode psychosis or at-risk mental state.

Effects of antipsychotics on bone mineral density and prolactin levels in patients with schizophrenia: a 12-month prospective study

OBJECTIVE

Effects of conventional and atypical antipsychotics on bone mineral density (BMD) and serum prolactin levels (PRL) were examined in patients with schizophrenia.

METHODS

One hundred and sixty-three first-episode inpatients with schizophrenia were recruited, to whom one of three conventional antipsychotics (perphenazine, sulpiride, and chlorpromazine) or one of three atypical antipsychotics (clozapine, quetiapine, and aripiprazole) was prescribed for 12 months as appropriate. BMD and PRL were tested before and after treatment. Same measures were conducted in 90 matched healthy controls.

RESULTS

Baseline BMD of postero-anterior L1-L4 range from 1.04 ± 0.17 to 1.42 ± 1.23, and there was no significant difference between the patients group and healthy control group. However, post-treatment BMD values in patients (ranging from 1.02 ± 0.15 to 1.23 ± 0.10) were significantly lower than that in healthy controls (ranging from 1.15 ± 0.12 to 1.42 ± 1.36). The BMD values after conventional antipsychotics were significantly lower than that after atypical antipsychotics. The PRL level after conventional antipsychotics (53.05 ± 30.25 ng/ml) was significantly higher than that after atypical antipsychotics (32.81 ± 17.42 ng/ml). Conditioned relevance analysis revealed significant negative correlations between the PRL level and the BMD values after conventional antipsychotics.

CONCLUSION

The increase of PRL might be an important risk factor leading to a high prevalence of osteoporosis in patients with schizophrenia on long-term conventional antipsychotic medication.

Osteoporosis and fracture risk in people with schizophrenia

PURPOSE OF REVIEW

Excessive bone mineral density (BMD) loss has been associated with schizophrenia, but its mechanisms and clinical implications are less clear. The aim of this review was to summarize the risk of osteoporosis and bone fractures in schizophrenia patients. Moreover, we aimed to examine the impact of antipsychotic-induced hyperprolactinemia on bone metabolism.

RECENT FINDINGS

Fifteen of 16 studies (93.8%) reported lower BMD or higher prevalence of osteoporosis in at least one region, or in at least one subgroup of schizophrenia patients compared with controls, but results were inconsistent across measured areas. Higher fracture risk was associated with schizophrenia in 2/2 studies (independently: n = 1), and 3/4 studies with antipsychotics. Reasons for this difference include insufficient exercise, poor nutrition, smoking, alcohol use, and low vitamin D levels. Altogether, 9/15 (60.0%) studies examining the relationship between antipsychotic-induced hyperprolactinemia and BMD loss found some effects of hyperprolactinemia. However, results were mixed, samples and effects were small, and only two studies were prospective.

SUMMARY

Schizophrenia is associated with reduced BMD and fracture risk. Prevention, early detection, and intervention are required. The relative contributions of antipsychotic-related hyperprolactinemia and unhealthy lifestyle behaviors remain unclear, needing to be assessed in well designed, prospective studies, including bone turnover markers as intermediary endpoints.

Physical illness in patients with severe mental disorders. I. Prevalence, impact of medications and disparities in health care

The lifespan of people with severe mental illness (SMI) is shorter compared to the general population. This excess mortality is mainly due to physical illness. We report prevalence rates of different physical illnesses as well as important individual lifestyle choices, side effects of psychotropic treatment and disparities in health care access, utilization and provision that contribute to these poor physical health outcomes. We searched MEDLINE (1966 - August 2010) combining the MeSH terms of schizophrenia, bipolar disorder and major depressive disorder with the different MeSH terms of general physical disease categories to select pertinent reviews and additional relevant studies through cross-referencing to identify prevalence figures and factors contributing to the excess morbidity and mortality rates. Nutritional and metabolic diseases, cardiovascular diseases, viral diseases, respiratory tract diseases, musculoskeletal diseases, sexual dysfunction, pregnancy complications, stomatognathic diseases, and possibly obesity-related cancers are, compared to the general population, more prevalent among people with SMI. It seems that lifestyle as well as treatment specific factors account for much of the increased risk for most of these physical diseases. Moreover, there is sufficient evidence that people with SMI are less likely to receive standard levels of care for most of these diseases. Lifestyle factors, relatively easy to measure, are barely considered for screening; baseline testing of numerous important physical parameters is insufficiently performed. Besides modifiable lifestyle factors and side effects of psychotropic medications, access to and quality of health care remains to be improved for individuals with SMI.

The role of interleukin-6 in rheumatoid arthritis-associated osteoporosis

INTRODUCTION

Osteoporosis is highly prevalent in patients with rheumatoid arthritis (RA) and is a frequent cause of fractures, disability, reduced quality of life and increased use of healthcare resources.

DISCUSSION

Factors associated with the development of osteoporosis and fractures in patients with RA include disease activity, inflammation, gender, age, low body mass and glucocorticoid exposure. Several processes contribute towards the pathology of RA-associated osteoporosis, and increased osteoclast activation and subsequent bone resorption mediated by pro-inflammatory cytokines are thought to play major roles. Given the key effects of interleukin-6 (IL-6) in both RA and osteoporosis, and its ability to modulate other inflammatory mediators, IL-6 may be an important factor specifically associated with osteoporosis in patients with RA.

CONCLUSION

The development of agents that modulate the actions of IL-6 and those of other pro-inflammatory mediators of bone loss may provide alternative osteoporosis management strategies for patients with RA than existing general osteoporosis therapies.

Adverse endocrine and metabolic effects of psychotropic drugs: selective clinical review

The article critically reviews selected, clinically significant, adverse endocrine and metabolic effects associated with psychotropic drug treatments, including hyperprolactinaemia, hyponatraemia, diabetes insipidus, hypothyroidism, hyperparathyroidism, sexual dysfunction and virilization, weight loss, weight gain and metabolic syndrome (type 2 diabetes mellitus, dyslipidaemia and hypertension). Such effects are prevalent and complex, but can be managed clinically when recognized. They encourage continued critical assessment of benefits versus risks of psychotropic drugs and underscore the importance of close coordination of psychiatric and general medical care to improve long-term health of psychiatric patients. Options for management of hyperprolactinaemia include lowering doses, switching to agents such as aripiprazole, clozapine or quetiapine, managing associated osteoporosis, carefully considering the use of dopamine receptor agonists and ruling out stress, oral contraceptive use and hypothyroidism as contributing factors. Disorders of water homeostasis may include syndrome of inappropriate antidiuretic hormone (SIADH), managed by water restriction or slow replacement by hypertonic saline along with drug discontinuation. Safe management of diabetes insipidus, commonly associated with lithium, involves switching mood stabilizer and consideration of potassium-sparing diuretics. Clinical hypothyroidism may be a more useful marker than absolute cut-offs of hormone values, and may be associated with quetiapine, antidepressant and lithium use, and managed by thyroxine replacement. Hyper-parathyroidism requires comprehensive medical evaluation for occult tumours. Hypocalcaemia, along with multiple other psychiatric and medical causes, may result in decreased bone density and require evaluation and management. Strategies for reducing sexual dysfunction with psychotropics remain largely unsatisfactory. Finally, management strategies for obesity and metabolic syndrome are reviewed in light of the recent expert guidelines, including risk assessment and treatments, such as monoamine transport inhibitors, anticonvulsants and cannabinoid receptor antagonists, as well as lifestyle changes.

Affective Disorders, Bone Metabolism, and Osteoporosis

The nature of the relationship between affective disorders, bone mineral density (BMD), and bone metabolism is unresolved, although there is growing evidence that many medications used to treat affective disorders are associated with low BMD or alterations in neuroendocrine systems that influence bone turnover. The objective of this review is to describe the current evidence regarding the association of unipolar and bipolar depression with BMD and indicators of bone metabolism, and to explore potential mediating and confounding influences of those relationships. The majority of studies of unipolar depression and BMD indicate that depressive symptoms are associated with low BMD. In contrast, evidence regarding the relationship between bipolar depression and BMD is inconsistent. There is limited but suggestive evidence to support an association between affective disorders and some markers of bone turnover. Many medications used to treat affective disorders have effects on physiologic systems that influence bone metabolism, and these conditions are also associated with a range of health behaviors that can influence osteoporosis risk. Future research should focus on disentangling the pathways linking psychotropic medications and their clinical indications with BMD and fracture risk.

Antipsychotic-induced hyperprolactinaemia, hypogonadism and osteoporosis in the treatment of schizophrenia

Treatment of schizophrenic illness usually involves the long-term administration of antipsychotic drugs. Most antipsychotic agents antagonise the actions of endogenous dopamine (DA) at DA-2 receptors in the brain. The relative affinity for, and binding time to, DA-2 receptors was considered to be one of the key determinants of the antipsychotic potency of classical antipsychotic drugs. Some newer atypical antipsychotics, of which clozapine is the prototype, have a relatively poor affinity for DA-2 receptors; whereas other atypical antipsychotics are potent DA-2 antagonists. The propensity of antipsychotic agents to cause hyperprolactinaemia is related to their potency in antagonising DA-2 receptors on the anterior pituitary. In our studies, bone loss was consistently related to DA-2 antagonist potency of antipsychotic drugs, rather than their classification using conventional 'typical' versus 'atypical' systems. It is established that hyperprolactinaemia causes suppression of the reproductive endocrine axis and consequent bone mineral density (BMD) loss. Results from our group and others have demonstrated that a similar pathophysiological process is occurring in individuals with antipsychotic-induced hyperprolactinaemia. We found high rates of osteoporosis and osteopenia in those taking long-term antipsychotic drugs, and this was related to the dose and duration of treatment. Bone loss was associated with hypogonadism in male and female groups. Young Caucasian women appear to be particularly vulnerable to developing hyperprolactinaemia and the associated hypogonadism and bone loss. The occurrence of menstrual dysfunction should alert clinical suspicions of hyperprolactinaemia and bone de-mineralisation. Lastly, there are no published trials examining the effects of hormone replacement on BMD in those taking long-term antipsychotic drugs, but preliminary findings from our studies suggest that active management of bone loss in those with antipsychotic-associated bone disease may halt or even reverse this process.

Clinical questions and uncertainty--prolactin measurement in patients with schizophrenia and bipolar disorder

Many antipsychotic medications have the potential to raise prolactin levels leading to a range of negative consequences. In addition to symptoms such as gynaecomastia, galactorrhoea, menstrual irregularities and sexual dysfunction it is becoming clear that there are a number of important and potentially serious long-term consequences, including a loss of bone mineral density and a possible association with the development of breast cancer. It is clear, therefore, that the tendency to raise prolactin should be an important consideration in the use of antipsychotics but, to a large degree, this area has been neglected in clinical practice and research when compared with other potential adverse effects. We consider some of the practical clinical issues in prolactin measurement and the management of high results. We will identify the areas of uncertainty that remain for clinicians and consider the practical questions that future research should address.