The estrogen connection: the etiological relationship between diabetes, cancer, rheumatoid arthritis and psychiatric disorders

Biomarkers of the metabolic syndrome and breast cancer prognosis

In spite of its public health importance, our understanding of the mechanisms of breast carcinogenesis and progress is still evolving. The metabolic syndrome (MS) is a constellation of biochemical abnormalities including visceral adiposity, hyperglycemia, hyperinsulinemia, dyslipidemia and high blood pressure. The components of the MS have all been related to late-stage disease and even to a poor prognosis of breast cancer through multiple interacting mechanisms. In this review, we aim to present a summary of recent advances in the understanding of the contribution of the MS to breast cancer with the emphasis on the role of biomarkers of the MS in the prognosis of breast cancer.

Diabetes, metabolic syndrome, and breast cancer: a review of the current evidence

Incidences of breast cancer, type 2 diabetes, and metabolic syndrome have increased over the past decades with the obesity epidemic, especially in industrialized countries. Insulin resistance, hyperinsulinemia, and changes in the signaling of growth hormones and steroid hormones associated with diabetes may affect the risk of breast cancer. We reviewed epidemiologic studies of the association between type 2 diabetes and risk of breast cancer and the available evidence on the role of hormonal mediators of an association between diabetes and breast cancer. The combined evidence supports a modest association between type 2 diabetes and the risk of breast cancer, which appears to be more consistent among postmenopausal than among premenopausal women. Despite many proposed potential pathways, the mechanisms underlying an association between diabetes and breast cancer risk remain unclear, particularly because the 2 diseases share several risk factors, including obesity, a sedentary lifestyle, and possibly intake of saturated fat and refined carbohydrates, that may confound this association. Although the metabolic syndrome is closely related to diabetes and embraces additional components that might influence breast cancer risk, the role of the metabolic syndrome in breast carcinogenesis has not been studied and thus remains unknown.

Addressing the health and lifestyle issues of people with a mental illness: the Healthy Living Programme

OBJECTIVE

The physical health and well-being of mental health patients have been a concern to health professionals for many years. However, very few positive gains have been made to address this problem. This paper outlines the efforts of the Inner North Brisbane Mental Health Service, Royal Brisbane and Women's Hospital, to design and implement a structured educational programme, aimed at addressing and encouraging healthy lifestyle behaviours in its community mental health service recipients.

METHODS

Three programme modules were designed, addressing the topics of Nutrition and Healthy Eating, Physical Health, and Community Based Activities and Interests. Referral of patients to the programme was by their case manager or doctor. At the conclusion of each module, participants were asked to complete a satisfaction survey evaluating the programmes. The survey also gathered feedback regarding any suggestions and/or recommendations to improve content suitability and relevance.

RESULTS

Since commencing the Healthy Living Program, each module has been conducted at least twice, the topic of Healthy Eating receiving the most referrals and therefore conducted most frequently. To date, 35 satisfaction surveys have been evaluated. The overwhelming majority of respondents offered very positive feedback about the programme, most being able to identify some healthy lifestyle changes they planned to make in response to programme attendance.

CONCLUSIONS

This paper highlights the importance of incorporating healthy lifestyle programmes into mental health service delivery. The majority of patients who have attended the Healthy Living Program have indicated satisfaction with the content, but as yet information pertaining to long-term lifestyle change has not been collated. The next phase aims to examine whether the programme attendance has more long-term outcomes in improving health and well-being and promoting healthy behaviour change of mental health service recipients.

Quetiapine in the successful treatment of psychosis and comorbid brittle diabetes mellitus: a case report

BACKGROUND

As evidence of a biologic determinant of schizophrenia has been elaborated, an interest in the relationship between schizophrenia and autoimmune disorders has become increasingly more developed over the last decade. Pedigree analysis has shown that schizophrenia, like autoimmune disorders, is likely a heritable phenomenon, and a genetic liability in this disorder is hardly disputed. Research has indicated that physiologic connections between IFN-gamma and TNF-alpha are suggestive of a connection between the symptoms associated with schizophrenia and those of hypoglycemic events in IDDM. Autoimmune pathogeneses of schizophrenia have been hypothesized; however, the clinical delineation of a potentially corresponding subset of patients is rarely addressed.

CASE REPORT

We treated a 22-year-old white female who carried the concomitant diagnoses of Schizophrenia, IDDM, and Hypothyroidism with quetiapine and risperidone on an acute basis at our inpatient facility, and observed an apparent resolution of her brittle diabetes with the successful treatment of her psychotic disorder.

CONCLUSIONS

The well documented link between antipsychotic agents and changes in blood glucose may be of benefit in a subset of patients who suffer from both psychotic and diabetic disorders.

Rheumatoid arthritis and schizophrenia: a negative association at a dimensional level

There is wide evidence for a decreased risk of rheumatoid arthritis in patients with schizophrenia. Nevertheless, very few studies have looked at the risk of schizophrenia in a group of patients with rheumatoid arthritis. We prospectively investigated, with the SCL-90R, 220 consecutive outpatients with rheumatoid arthritis and 196 consecutive outpatients with various medical conditions, half of them suffering from psoriatic arthritis (a medical condition close to rheumatoid arthritis). The SCL-90R appears to be a valuable tool to distinguish patients with schizophrenia from the outpatients of our sample, the former having more "paranoid ideation" (p = 0.004) and more "psychoticism" (p < 0.001) than the latter. The "paranoid ideation" dimension was significantly lower (25% decrease) in the sample of patients with rheumatoid arthritis compared to the combined control group (p = 0.005), ratings under the median value being more frequent in the former group (p = 0.025). Confounding factors might not explain this difference according to the regression logistic analysis performed. As patients with rheumatoid arthritis have a lower score of paranoid ideation than controls in our sample, even after controlling for age, gender and severity of the disease, these data represent further evidence for a decreased risk of schizophrenia in individuals with rheumatoid arthritis.

The effect of estrogen use on levels of glucose and insulin and the risk of type 2 diabetes in american Indian postmenopausal women : the strong heart study

OBJECTIVE

To examine the associations between estrogen use and levels of insulin and glucose as well as the effect of estrogen use on the risk of type 2 diabetes.

RESEARCH DESIGN AND METHODS

This report is based on 857 women who were both nondiabetic and postmenopausal at the baseline examination (1989-1992) and who completed a second examination (1993-1995) an average of 4 years later. The participants were divided into three groups: never, past, and current users based on their baseline estrogen use status. ANCOVA was used to compare the insulin and glucose levels among estrogen use groups. Logistic regression was used to evaluate the association between estrogen use and the incidence of type 2 diabetes.

RESULTS

Postmenopausal estrogen use was associated with lower fasting glucose (0.2 mmol/l lower) but higher 2-h glucose levels (0.4 mmol/l higher) compared with never users. It was not significantly associated with the risk of type 2 diabetes compared with past and never users, based on American Diabetes Association or World Health Organization definitions of diabetes or on only a 2-h glucose level > or = 11.1 mmol/l. However, the risk of type 2 diabetes increased with increasing duration of estrogen use among current users, with an odds ratio of 1.10 per year of use (95% CI: 1.01-1.19).

CONCLUSIONS

The data suggest that estrogen use in American Indian postmenopausal women may relate to deterioration of glucose tolerance. Longer duration of estrogen use among current users may relate to an increased risk of type 2 diabetes.

Insulin receptors and insulin action in the brain: review and clinical implications

Insulin receptors are known to be located on nerve cells in mammalian brain. The binding of insulin to dimerized receptors stimulates specialized transporter proteins that mediate the facilitated influx of glucose. However, neurons possess other mechanisms by which they obtain glucose, including transporters that are not insulin-dependent. Further, insulin receptors are unevenly distributed throughout the brain (with particularly high density in choroid plexus, olfactory bulb and regions of the striatum and cerebral cortex). Such factors imply that insulin, and insulin receptors, might have functions within the central nervous system in addition to those related to the supply of glucose. Indeed, invertebrate insulin-related peptides are synthesized in brain and serve as neurotransmitters or neuromodulators. The present review summarizes the structure, distribution and function of mammalian brain insulin receptors and the possible implications for central nervous system disorders. It is proposed that this is an under-studied subject of investigation.

Effect of dietary fat on the development of non-insulin dependent diabetes mellitus in obese Zucker diabetic fatty male and female rats

The obese Zucker diabetic fatty male rat (ZDF/Gmi¿trade mark omitted¿-fa) has become a widely used animal model of NIDDM, in contrast to the obese ZDF females that rarely develop NIDDM. However, preliminary observations suggest that obese ZDF females may become diabetic on high-fat diets. Therefore, we studied the effect of dietary fat on development of NIDDM, dyslipidemia, and alterations in organ-specific serum panels in obese ZDF males and females. Results indicated different effects of dietary fat-content on development of diabetes in males and females. Males, even on low fat-content diets, developed diabetes but the process was accelerated as a function of dietary fat-content, whereas only the highest fat-content diet induced development of NIDDM in obese ZDF females. Additionally, triglyceride/apolipoprotein B ratios demonstrated gender-specific differences in the nature of circulating lipoprotein particles independent of diabetic state with values for females approximately twice those of males indicating more highly triglyceride-enriched lipoprotein particles in females. We conclude that the obese ZDF female rat has the potential to become an important animal model of NIDDM especially in women where few models currently exist.

The role of tumor necrosis factor-alpha in the pathogenesis of anorexia and bulimia nervosa, cancer cachexia and obesity

In this paper a new immunological model of anorexia and bulimia nervosa will be presented in which the inflammatory cytokines are conceived as the fundamental regulators of body metabolism. This conception differs from the conventional view in which the inflammatory cytokines are perceived primarily as peptide molecules utilized by the immune system to control infection, inflammation and tissue or neuronal damage. Given that the inflammatory cytokines are also fundamental regulators of body metabolism, when they become dysregulated they create physiological chaos which results in the development of a number of autoimmune, metabolic and psychiatric disorders. In this proposed immunological model of anorexia and bulimia nervosa, elevated tumor necrosis factor-alpha features as the primary cause of these conditions. Pathophysiological parallels are drawn between anorexia nervosa and cancer cachexia in terms of the causal role the cytokines, neuropeptides and neurotransmitters play in the manifestation of shared symptoms. These shared symptoms include elevated tumour necrosis factor-alpha, down-regulated interleukin-2 and interleukin-4 and depletion of lean body mass. Furthermore, the following neuropeptides are dysregulated in both anorexia nervosa and cancer cachexia: vasoactive intestinal peptide, cholecystokinin, corticotropin-releasing factor, neuropeptide Y, peptide YY and beta-endorphin. In addition, in anorexia and bulimia nervosa, secretion of the neurotransmitter serotonin is inhibited while norepinephrine is enhanced. It will be argued that the causal interplay between the cytokines, neuropeptides and neurotransmitters initiates a cascade of biochemical events which may result in either anorexia or bulimia nervosa, or cancer cachexia. The extent to which these inflammatory cytokines, neuropeptides and neurotransmitters are causally efficacious in the pathogenesis of other autoimmune disorders, such as diabetes mellitus and rheumatoid arthritis, will also be addressed.

Schizophrenia as a membrane lipid disorder which is expressed throughout the body

Clinical, biochemical and genetic evidence now indicates that schizophrenia is a disorder of membrane phospholipid metabolism associated with increased loss of highly polyunsaturated fatty acids from membranes owing to enhanced activity of a phospholipase A2. This changes the properties of membranes throughout the body and is responsible for such physical abnormalities as reduced vasodilator responses to niacin and histamine and altered immunological functions. A modest membrane abnormality is likely to produce its most serious consequences in the brain, which requires the co-ordinated sequential and parallel activities of millions of neurons. The concept leads to testable proposals for relatively simple and safe treatment modalities.

Immunological influences in attention-deficit disorder and schizophrenia; is there a link between these two conditions?

This paper aims to explore the influence of the immune system on the pathobiochemistry of movement disorders (Tourette syndrome, obsessive compulsive disorders and attention-deficit disorder, with and without hyperactivity) and schizophrenia. In children, a temporal relationship has been observed between contraction of a group A beta-hemolytic streptococcal infection and subsequent presentation with one of the movement disorders. Pathology investigations reveal that elevated antineuronal antibodies are associated with movement disorders. Similarly, elevations in interleukin-1 beta and interleukin-6 have been reported in schizophrenia. It is now known that the immune system can be activated by conditions other than a viral or bacterial infection, such as: neurological insult, neurotoxicity--endogenous and environmental, neurotransmitter and cholesterol dysregulation. These latter avenues of immune system activation will be explored with respect to schizophrenia.

Possible relevance of phospholipid abnormalities and genetic interactions in psychiatric disorders: the relationship between dyslexia and schizophrenia

The fatty acids of cell membrane phospholipids are essential for normal membrane structures, for the functioning of membrane-bound and membrane-associated proteins and for normal cell-signalling responses. In dyslexia, there is evidence for reduced incorporation of docosahexaenoic acid and arachidonic acid into cell membranes, while in schizophrenia, there is evidence for an increased rate of docosahexaenoic acid and arachidonic acid loss from membranes because of enhanced phospholipase A2 activity. The presence of both defects will cause a much greater degree of abnormality than either one alone. It is hypothesized that unequivocal clinical schizophrenia may occur when both genes are present in the same individual. The dyslexia gene along will produce dyslexia while the schizophrenia gene alone may produce bipolar or schizoaffective disorders. These proposals could explain: 1. The reduced asymmetry of the brain, especially of the planum temporale in both schizophrenia and dyslexia; 2. The schizotypal personality characteristics of dyslexics; 3. The increased risks of dyslexia in families with a schizophrenic proband; 4. The increased risks of bipolar and schizoaffective disorders in families with a schizophrenic proband; 5. The earlier onset and possibly increased severity of both disorders in males since females have a lower requirement for arachidonic acid and docosahexaenoic acid; 6. The absence of selective pressure against schizophrenia since reproduction would be impaired only when the schizophrenic gene coexisted with a dyslexic gene. The schizophrenic gene alone might even lead to improved reproductive performance.