Papers by Katherine Samaras
Journal of the American College of Cardiology, Nov 1, 2019
BACKGROUND There is widespread consumer concern that statin use may be associated with impaired m... more BACKGROUND There is widespread consumer concern that statin use may be associated with impaired memory and cognitive decline. OBJECTIVES This study sought to examine the association between statin use and changes in memory and global cognition in the elderly population over 6 years and brain volumes over 2 years. Interactions between statin use and known dementia risk factors were examined. METHODS Prospective observational study of community-dwelling elderly Australians age 70 to 90 years (the MAS [Sydney Memory and Ageing Study], n ¼ 1,037). Outcome measures were memory and global cognition (by neuropsychological testing every 2 years) and total brain, hippocampal and parahippocampal volumes (by magnetic resonance) in a subgroup (n ¼ 526). Analyses applied linear mixed modeling, including the covariates of age, sex, education, body mass index, heart disease, diabetes, hypertension, stroke, smoking, and apolipoprotein Eε4 carriage. Interactions were sought between statin use and dementia risk factors. RESULTS Over 6 years there was no difference in the rate of decline in memory or global cognition between statin users and never users. Statin initiation during the observation period was associated with blunting the rate of memory decline. Exploratory analyses found statin use was associated with attenuated decline in specific memory test performance in participants with heart disease and apolipoprotein Eε4 carriage. There was no difference in brain volume changes between statin users and never users. CONCLUSIONS In community-dwelling elderly Australians, statin therapy was not associated with any greater decline in memory or cognition over 6 years. These data are reassuring for consumers concerned about statin use and risk of memory decline. (
The British Journal of Psychiatry, 2019
BackgroundSevere mental illness (SMI) is thought to be associated with lower diet quality and adv... more BackgroundSevere mental illness (SMI) is thought to be associated with lower diet quality and adverse eating behaviours contributing towards physical health disparities. A rigorous review of the studies looking at dietary intake in psychotic disorders and bipolar disorder is lacking.AimsTo conduct a systematic, comprehensive evaluation of the published research on dietary intake in psychotic disorders and bipolar disorder.MethodSix electronic databases were searched for studies reporting on dietary intakes in psychotic disorders and bipolar disorder. Dietary-assessment methods, and dietary intakes, were systematically reviewed. Where possible, data was pooled for meta-analysis and compared with healthy controls.ResultsIn total, 58 eligible studies were identified. People with SMI were found to have significantly higher dietary energy (mean difference 1332 kJ, 95% CI 487–2178 kJ/day, P = 0.002, g = 0.463) and sodium (mean difference 322 mg, 95% CI 174–490 mg, P < 0.001, g = 0.414)...
Frontiers in Psychiatry, 2018
Introduction: Antipsychotic medication (APM) initiation is associated with rapid and substantial ... more Introduction: Antipsychotic medication (APM) initiation is associated with rapid and substantial weight-gain and high rates of obesity. Obesity leads to premature onset of cardiometabolic diseases and contributes to the 15-20 year shortfall in life expectancy in those experiencing severe mental illness. Dietary energy intake excess is critical to weight management but is yet to be quantified in youth with first episode psychosis (FEP) receiving APM. This study aimed to describe the degree of energy overconsumption and the food sources contributing to this in youth with FEP. Materials and Methods: People aged 15-30 years with FEP receiving APM completed diet histories through qualified dietitians to assess energy imbalance and food sources. Outcome measures were: (i) energy balance; and (ii) intake of core and discretionary foods. Results: Participants (n = 93) were aged 15-29 years (mean = 21.4 ± 2.9 years) and exposed to APMs for a median for 8 months (Interquartile Range (IQR) 11 months). Energy balance was exceeded by 26%, by a median 1,837 kJ per day (IQR 5,365 kJ). APM polypharmacy and olanzapine were linked to larger excesses in dietary energy intake. The greatest contributors to energy intake were refined grain foods (33%) and discretionary foods (31%). Young people with FEP receiving APMs appear to have markedly excessive energy consumption, likely contributing to rapid weight-gain, and thereby seeding future poor physical health. Larger, prospective studies are needed to gain a greater understanding of dietary intake, and its effects on health, in people with FEP.
The Australian and New Zealand journal of psychiatry, 2018
The Lancet Psychiatry, 2017
The British journal of psychiatry : the journal of mental science, Feb 3, 2016
Nutrition interventions would appear fundamental for weight management and cardiometabolic risk r... more Nutrition interventions would appear fundamental for weight management and cardiometabolic risk reduction in people experiencing severe mental illness (SMI). Comprehensive evaluation of nutrition interventions is lacking. To subject randomised controlled trials of nutrition interventions in people with SMI to systematic review and meta-analysis, and to measure anthropometric and biochemical parameters and nutritional intake. An electronic database search identified trials with nutrition intervention components. Trials were pooled for meta-analysis. Meta-regression analyses were performed on anthropometric moderators. Interventions led to significant weight loss (19 studies), reduced body mass index (17 studies), decreased waist circumference (10 studies) and lower blood glucose levels (5 studies). Dietitian-led interventions (6 studies) and studies delivered at antipsychotic initiation (4 studies) had larger effect sizes. Evidence supports nutrition interventions as standard care in...
Australian journal of primary health, Jan 22, 2016
Cardiometabolic morbidity is a significant contributor to the poorer health outcomes experienced ... more Cardiometabolic morbidity is a significant contributor to the poorer health outcomes experienced by people with intellectual disability (ID). Tailoring cardiometabolic monitoring tools developed for the general population to better fit the altered risk profiles and extra needs of people with ID may help to improve health outcomes. This paper describes a new cardiometabolic monitoring framework designed to address the extra needs of people with ID. The framework was adapted from a generalist guideline after a process of extensive consultation with the original authors and over 30 ID and cardiometabolic experts. In addition to standard cardiometabolic monitoring practice, the framework encourages clinicians to: anticipate and address barriers to care such as communication difficulties and fear of blood tests; account for socioeconomic and genetic factors altering baseline cardiometabolic risk; and carefully rationalize psychotropic prescription. Together with this framework, a toolkit...
British Journal of Nutrition, 2016
Severe mental illness is characterised by a 20-year mortality gap due to cardiometabolic disease.... more Severe mental illness is characterised by a 20-year mortality gap due to cardiometabolic disease. Poor diet in those with severe mental illness is an important and modifiable risk factor. The present study aimed to (i) examine baseline nutritional intake in youth with first-episode psychosis (FEP), (ii) evaluate the feasibility and acceptability of nutritional intervention early in FEP and (iii) to evaluate the effectiveness of early dietary intervention on key nutritional end points. Participants were recruited over a 12-month period from a community-based programme specifically targeting young people aged 15–25 years with newly diagnosed FEP. Individual dietetic consultations and practical group sessions were offered as part of a broader lifestyle programme. Dietary assessments were conducted before and at the end of the 12-week intervention. Participants exceeded recommended energy and Na intakes at baseline. Retention within the nutrition intervention was 67 %, consistent with o...
Therapeutic advances in endocrinology and metabolism, 2012
Type 2 diabetes is common in older people and is associated with higher risk of both vascular dem... more Type 2 diabetes is common in older people and is associated with higher risk of both vascular dementia and Alzheimer's disease. This review examines the evidence for increased risk of dementia and mild cognitive impairment in patients with diabetes and the role of potential confounders. The relationship of diabetes and impaired fasting glucose with brain structure is also reviewed, focusing on longitudinal studies in older people. The pathophysiology underlying cognitive change in type 2 diabetes is examined with reference to vascular disease, hypoglycaemia, inflammation and insulin levels. Implications for clinical care in older people with diabetes are discussed, with a recommendation for cognitive evaluation as a routine part of end-organ, diabetes complication review.
International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity, 2001
To construct a simple physiological model of leptin kinetics, based on measures of body size and ... more To construct a simple physiological model of leptin kinetics, based on measures of body size and composition, which is suitable for investigating the influence of genetic and other influences on circulating leptin levels in humans. Consideration of the kinetics of the secretion and clearance of leptin led to a predicted linear relationship between ln(leptin), ln(fat mass), and a function of non-fat body compartments. Results obtained from this model were compared with those from two published empirical models based on adjustment for fat mass alone or for body mass index. Overnight fasted leptin levels, body composition data (dual-energy X-ray absorptiometry) and questionnaire responses were obtained from 527 twin pairs (127 monozygotic, 400 dizygotic; 37 male (age 18-68 y, BMI 18-32 kg/m2), 489 female (age 18-71, BMI 17-44) drawn from the St Thomas' UK Adult Twin Registry. In a partial correlation analysis ln(fat mass) and ln(height) (r=0.80, P<0.0001) and r=-0.22, P<0.000...
Evaluating an individualized lifestyle and life skills intervention to prevent antipsychotic-induced weight gain in first-episode psychosis
Early Intervention in Psychiatry, 2015
Initiating antipsychotic medication frequently induces rapid, clinically significant weight gain.... more Initiating antipsychotic medication frequently induces rapid, clinically significant weight gain. We aimed to evaluate the effectiveness of a lifestyle and life skills intervention, delivered within 4 weeks of antipsychotic medication initiation, in attenuating weight gain in youth aged 14-25 years with first-episode psychosis (FEP). We undertook a prospective, controlled study in two early psychosis community services. Intervention participants (n = 16) received a 12-week individualized intervention delivered by specialist clinical staff (nurse, dietician and exercise physiologist) and youth peer wellness coaches, in addition to standard care. A comparison group was recruited from a similar service and received standard care (n = 12). The intervention group experienced significantly less weight gain at 12 weeks compared to standard care (1.8 kg, 95% CI -0.4 to 2.8 vs. 7.8 kg, 4.8-10.7, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Thirteen per cent (2/16) of the intervention group experienced clinically significant weight gain (greater than 7% of baseline weight), while 75% (9/12) of the standard care group experienced this level of weight gain. Similar positive effects of the intervention were observed for waist circumference. A lifestyle and life skills intervention delivered as part of standard care attenuated antipsychotic-induced weight gain in young people with FEP. The intervention was acceptable to the young people referred to the service. Such interventions may prevent the seeding of future disease risk and in the long-term help reduce the life expectancy gap for people living with serious mental illness.
The Australian and New Zealand journal of psychiatry, 2014
Community Mental Health Journal, 2014
Individual dietetic consultations were trialled in a community-based first-episode psychosis prog... more Individual dietetic consultations were trialled in a community-based first-episode psychosis program. Participants received eight individualised dietetic consultations, plus weekly shopping tours and cooking groups. The outcome measure was waist circumference (WC). In total, 30 patients commenced the program. An intention-to-treat analysis revealed, a statistically significant reduction in WC (mean = 2.1 ± 5.4 cm, t = 2.1, df = 29, p = 0.04). Similar results were found for the 14 participants who attended all eight sessions (mean WC reduction = 2.9 ± 4.7 cm, t = 2.3, df = 13, p = 0.04). Dietetic consultations were feasible and effective in reducing WC, and could enhance programs to reduce cardiometabolic risk in youth with psychosis using lifestyle interventions.
Acta Psychiatrica Scandinavica, 2014
Early lifestyle intervention attenuates antipsychotic-induced weight gain in first episode psychosis
‘Seeing the Doc at 11am, cooking group at midday, and hitting the gym at 2pm’. Patient and staff perspectives of an embedded lifestyle intervention within an early psychosis programme
ORAL PRESENTATION “Seeing the Doc at 11am, cooking group at midday, and hitting the gym at 2pm”. ... more ORAL PRESENTATION “Seeing the Doc at 11am, cooking group at midday, and hitting the gym at 2pm”. Patient and staff perspectives of an embedded lifestyle intervention within an early psychosis programme Andrew Watkins1,2, Joel Pilgrim1, Jackie Curtis1,3, Simon Rosenbaum1,3, Scott Teasdale3, Megan Kalucy1, Katherine Samaras4,5, Philip B Ward2,6 1Early Psychosis Programme, The Bondi Centre, South Eastern Sydney Local Health District 2Faculty of Health, University of Technology Sydney, Australia 2School of Psychiatry, University of New South Wales, Australia 4Department of Endocrinology, St Vincent’s Hospital, Darlinghurst, Australia 5Diabetes and Obesity Program, Garvan Institute of Medical Research, Darlinghurst, Australia 6Schizophrenia Research Unit, South Western Sydney Local Health District, Liverpool, Australia Keeping the Body In Mind (KBIM) is an intensive 12-week, strength-based multidisciplinary lifestyle intervention delivered at the initiation of anti-psychotic treatment fo...
Twin Research (1999), 1999
Obesi ty, i nsul i n r esi stance and di stur bed gl ucose metabol i sm cl uster w i thi n the I ... more Obesi ty, i nsul i n r esi stance and di stur bed gl ucose metabol i sm cl uster w i thi n the I nsul i n Resi stance Syndr ome (I RS). Whether thi s r efl ects shar ed geneti c or envi r onmental factor s detectabl e i n 'nor mal ' popul ati ons (not sel ected for I RS featur es) i s unk now n. Thi s study esti mated (i ) geneti c i nfl uences on I RS tr ai ts and (i i ) shar ed and speci fi c geneti c and envi r onmental factor s on the r el ati onshi ps betw een these tr ai ts i n heal thy femal e tw i ns. Fasti ng i nsul i n, gl ucose, total and centr al fat w er e measur ed i n 59 monozygoti c (M Z) and 51 di zygoti c (DZ) femal e tw i n pai r s aged ( ± SD) 52 ± 13 year s. Body fat w as measur ed by dual -ener gy X-r ay absor pti ometr y, i nsul i n r esi stance and secr eti on by a modi fi ed homeostasi s model assessment. Usi ng i ntr acl ass cor r el ati on coeffi ci ents and uni var i ate model -fi tti ng anal yses, geneti c i nfl uences w er e found i n total fat, centr al fat, i nsul i n r esi stance, fasti ng gl ucose and i nsul i n secr eti on, w i th geneti c factor s expl ai ni ng 64, 57, 59, 75 and 68% of thei r var i ance, r especti vel y, usi ng the l atter techni que. I n matched anal ysi s i ntr a-pai r di ffer ences i n total and centr al fat r el ated to i ntr a-pai r di ffer ences i n i nsul i n r esi stance (r 2 = 0.19, P < 0.001). M ul ti var i ate model -fi tti ng show ed a cl ose geneti c r el ati onshi p betw een total and centr al fat (r = 0.88). The geneti c cor r el ati on betw een I R and centr al fat (0.41) w as si gni fi cantl y gr eater than that for total fat (0.24), suggesti ng that centr al fat i s not onl y a pr edi ctor of, but shar es consi der abl e geneti c i nfl uence w i th, i nsul i n r esi stance. I n Chol esk y anal ysi s, these geneti c i nfl uences w er e separ ate fr om those shar ed betw een centr al and total fat. I n concl usi on, both shar ed and speci fi c geneti c factor s r egul ate components of the I RS i n heal thy females. However, there were discrete genetic influences on β-cell insulin secretion, not shared w i th other I RS components, suggesti ng that a separ ate geneti c pr opensi ty exi sts for Type 2 di abetes. These fi ndi ngs suggest w e may under stand the geneti c and envi r onmental i nfl uences on I RS fr om the study of the nor mal popul ati on. Keyw or ds: tw i ns, i nsul i n, i nsul i n resi stance, gl ucose, geneti c epi demi ol ogy, fat, vi sceral fat, abdomi nal fat, DXA
Twin Research (2000), 2000
Homeostasi s model assessment (HOM A ) pr ovi des i ndi ces of i nsul i n secr eti on (β) and ins... more Homeostasi s model assessment (HOM A ) pr ovi des i ndi ces of i nsul i n secr eti on (β) and insulin r esi stance (R) der i ved fr om fasti ng pl asma gl ucose (FPG) and fasti ng pl asma i nsul i n (FPI ) l evel s. How ever, these i ndi ces coul d not account for a si gni fi cant her i tability of fasting plasma glucose (FPG) (h 2 = 0.75, P < 0.01) i n a gr oup of 214 femal e tw i ns. Thi s r esul t i s consi stent w i th a mi scl assi fi cati on betw een effects due to i nsul i n secr eti on and r esi stance i n the HOM A i ndi ces. We report here evidence of such misclassification in the HOMA indices and describe a minor modification to the model which corrects it. Direct measures of insulin resistance (euglycaemic clamp) and secretion (i.v. glucose bolus) were obtained in 43 non-diabetic subjects. Heritability was estimated by statistical modelling of genetic and environmental influences in data from 214 non-di abeti c femal e subjects. M odi fi ed HOM A (HOM A ') i ndi ces w er e obtai ned fr om β' = (Ln(FPI ) -c)/FPG and R' = (Ln(FPI ) -c)* FPG w her e c i s a constant der i ved fr om r egr essi on anal ysi s of Ln(FPI ) vs FPG. I ndi ces fr om both model s cor r el ated w i th the di r ect measur es si mi l ar l y (r = 0.63 (R), 0.49 (R'), 0.45 (β), 0.39 (β'), al l P < 0.01). Di r ectl y measur ed i nsul i n r esi stance and secr eti on w er e not si gni fi cantl y cor r el ated (r = 0.13, P = 0.21). How ever, unmodi fi ed HOM A -β and R w er e str ongl y r el ated (r = 0.78, P < 0.0001 vs 0.13) demonstr ati ng substanti al mi scl assi fi cati on. The r el ati onshi p betw een β' and R' (r = 0.13) w as not di ffer ent fr om that betw een the tw o di r ect measures and significant heritability of β' (h 2 = 0.68, P < 0.01) and R' (h 2 = 0.59, P < 0.05) w as evi dent i n the tw i n data. The pr oposed modi fi cati on to HOM A si gni fi cantl y r educes mi scl assi fi cation and reveals separate components of insulin resistance and insulin secretion in the heritability of FPG. Twin Research (2000) 3, 148-151. Keyw or ds: i nsul i n resi stance, i nsul i n secreti on, di abetes mel l i tus, non-i nsul i n-dependent, mathemati cal model
Schizophrenia Research, 2014
Methods: Thirty-five schizophrenia patients and twenty healthy control subjects participated in t... more Methods: Thirty-five schizophrenia patients and twenty healthy control subjects participated in the study. Patients were assessed with the Scale Assessment of Insight Expanded (SAI-E) and the Beck Cognitive Insight Scale (BCIS). Implicit S-E was measured with the Implicit Self-Esteem Task, using a working memory 2-Back task, while primed with a "Stupid" of "Clever" verbal stimulus. Explicit S-E was measured with an adjusted version of the WCST used by Koren et al. (2004). Patients were allowed to use the additional feedback to their advantage. They had the opportunity to in-or exclude a response in their total score and even correct their answer. Results: Cognitive insight (BCIS composite score) was positively related to both implicit S-E (r=0.393 p <0.05; Implicit Self-Esteem Task) and explicit S-E (rho = 0.346, p<0.05, WCST with feedback hint). No significant relationship was found between clinical insight and implicit/explicit S-E. Patients and controls did not significantly differ on both tasks. Discussion: Caregivers and mental health workers often try to convince patients that their psychotic beliefs may be incorrect, but these attempts are typically in vain and do not lead to better insight. This poor insight may be the result of a general underlying problem in the implicit and explicit use of feedback of others to modify one's self-image. Indeed, our present findings suggest that patients with impaired cognitive insight are less sensitive for implicit and explicit S-E. They seem to fail in integrating the information, including a mental illness, into their self-image. This gives us a better understanding of how impaired insight is related to implicit and explicit S-E.
Psychoneuroendocrinology, 2012
This study addresses the paucity of research on the prospective relationship between a range of i... more This study addresses the paucity of research on the prospective relationship between a range of inflammatory markers and symptoms of depression and anxiety during aging. In the Sydney Memory and Aging Study, the relationships between remitted depression, current and first onset of symptoms of depression or anxiety (Geriatric Depression Scale and Goldberg Anxiety Scale (GDS, GAS), and markers of systemic inflammation (C-reactive protein (CRP), interleukins-1b, -6, -8, -10, -12, plasminogen activator inhibitor-1 (PAI-1), serum amyloid A, tumor necrosis factor-a, and vascular adhesion molecule-1) were investigated. The sample consists of N = 1037 non-demented community-dwelling elderly participants aged 70-90 years assessed at baseline and after 2-years. All analyses were adjusted for gender, age, years of education, total number of medical disorders diagnosed by a doctor, cardiovascular disorders, endocrine disorders, smoking, body mass index, currently using anti-depressants, NSAIDS or statins and diabetes mellitus. The results show a significant linear relationship between increasing levels of IL-6 and depressive symptoms at baseline only, whereas IL-8 was associated with depressed symptoms at baseline and at 2 years follow-up. In addition, IL-8 was associated with first onset of mild to moderate depressive symptoms over 2 years. Logistic regression analyses showed that PAI-1 (OR = 1.37, 95% CI = 1.10-1.71, p = 0.005) was associated with remitted depression. Results for anxiety symptoms were negative. The findings are suggestive of IL-6
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Papers by Katherine Samaras