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ASSOCIATIONS BETWEEN SERUM CONCENTRATIONS OF POLYCHLORINATED BIPHENYLS, SERUM CAROTENOIDS, AND THE PROBABILITY OF METABOLIC SYNDROME IN THE NATIONAL HEALTH AND NUTRITION EXAMINATION SURVEY 2003-2004Hofe, Carolyn R. 01 January 2012 (has links)
Diabetes and cardiovascular disease are leading causes of death and disability in the United States. These chronic diseases are clinical sequelae of metabolic syndrome (MetS), a condition that affects approximately one-third (1/3) of American adults. Metabolic syndrome occurs in response to environmental and genetic influences, among them food intake, a sedentary lifestyle, BMI, advancing age, and exposure to persistent organic pollutants (POPs). POPs are known to cause endocrine disruption and PCBs cause oxidative stress, disrupt endothelial cell integrity, and promote atherosclerosis. Nutrition plays a significant role in the prevention and management of these chronic diseases and has been shown to modulate the toxicity of PCBs. Serum carotenoid (SC) concentrations are the best biomarker indicative of fruit and vegetable intake and an improved nutritional status.
The purpose of this study was to investigate the relationship between serum carotenoid concentrations, serum concentrations of PCBs, and the probability of developing metabolic syndrome. The National Health and Nutrition Examination Survey (NHANES) is a program of the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention (CDC), that utilizes a cross-sectional sample survey design to collect, maintain, and disseminate the health and nutrition data of persons residing in the United States. Carotenoids and PCBs share similar biological pathways due in part to lipophilicity. Both concentrate to lipids in blood, are stored primarily in adipose tissue, and may competitively bind nuclear receptors.
A statistical interaction was sought between the two variables for their combined effect on the probability of metabolic syndrome. An increase in probability was observed in the first exposure quartile for many PCBs, individually and pooled, suggestive of a low dose endocrine effect. Statistical modeling consistently showed strong decreasing trends in the probability of metabolic syndrome with higher concentrations of serum carotenoids in the 3rd and 4th PCB exposure quartiles. These data suggest a protective effect of serum carotenoids, and therefore of fruit and vegetable intake, despite higher serum levels of PCBs, in the probability of developing metabolic syndrome.
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The Role of Arsenite in the Induction of C-Reactive Protein and Aberrant Insulin SignalingDruwe, Ingrid Leal January 2012 (has links)
Metabolic syndrome affects approximately 25% of the US population and increases risk for the development of cardiovascular disease, as well as, and Type 2 diabetes. Inorganic arsenite exposure has been associated with cardiovascular disease, insulin resistance and Type 2 diabetes. The mechanisms by which arsenic increases these health risks has not been fully elucidated. In this report we show two pathways by which arsenite may contribute to metabolic syndrome. First through induction of C-Reactive Protein (CRP) and secondly through inhibition of insulin stimulated glucose uptake. CRP is a clinical marker for metabolic syndrome and a predictive clinical marker for cardiovascular disease and type 2 diabetes. Treatment of HepG2 cells with arsenite resulted in elevated CRP production and secretion. In addition, treatment of FvB mice with 100 ppb sodium arsenite via drinking water for six months starting at weaning age resulted in dramatically higher levels of CRP in both the liver and inner medullary region of the kidney. Further, mouse Inner Medullary Collecting Duct cells (mIMCD-3), a mouse kidney cell line, were stimulated with CRP, which resulted in activation of NFkappaB. Pretreatment with Y27632, a Rho kinase inhibitor, prior to CRP stimulation attenuated NFkappaB activation. Additionally, L6 myocytes, an insulin responsive cell line, exposed to arsenite for 4 or 7 days showed decreased insulin-stimulated glucose uptake but no decrease in AKT activation. In addition, we found that ERK activity decreased, while p38 MAPK activity increased, in response to prolonged arsenite treatment. These data support the epidemiological evidence that chronic exposure to low physiologically relevant levels of arsenite can contribute to insulin resistance and type 2 diabetes. These data provide a novel pathway by which arsenic can contribute to metabolic syndrome, cardiovascular disease, insulin resistance and type 2 diabetes.
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Moterų antropometrinių ir medžiagų apykaitos rodiklių pokyčių ilgalaikis ryšys su metabolinio sindromo rizika / Long-term relation between anthropometric and metabolic changes in women with a risk of the metabolic syndromeVolochovič, Jelena 23 December 2010 (has links)
Disertacijoje tyrinėjami moterų antropometriniai ir medžiagų apykaitos pokyčiai nėštumo metu ir praėjus 20 metų po gimdymo. Pagrindinis darbo tikslas – įvertinti moterų antropometrinius ir medžiagų apykaitos pokyčius, įvykusius per 20 metų bei įvertinti metabolinio sindromo ilgalaikės rizikos sąsajos su moterų kūno sandaros ir medžiagų apykaitos pokyčiais, įvykusiais dar buvusių nėštumų metu. Tyrimo rezultatai parodė, kad per 20 metų tiriamosioms vystosi nepalankus kūno sandaros pokyčiai (kūno masės, KMI padidėjimas, riebalinio audinio centralizacijos tendencija) ir medžiagų apykaitos pokyčiai (proaterogeninio pobūdžio dislipidemiją, padidėjusia serumo gliukozės koncentracija bei padidėjęs atsparumas insulinui). Tyrimas taip pat atskleidė ankstyvuosius kūno sandaros skirtumus tarp sveikųjų ir metaboliniu sindromu sergančiųjų moterų. Pasiūlyti du antropometriniai rodikliai, kurie galėtų padėti prognozuoti ilgalaikę metabolinio sindromo išsivystymo riziką - santykinis žasto trigalvio raumens klostės pokytis ir absoliučiojo pasyviosios kūno masės prieaugio nėštumo laikotarpiu santykis su naujagimio gimimo mase. Be to, tyrime įvertintas kraujo serumo adipokinų koncentracijos ir jų išvestinių rodiklių ryšys su moterų fiziologinėmis ir patologinėmis būklėmis. / This work research is the longest known research of observing the body structure and metabolic changes in women during pregnancy and 20 years after it. Tasks of work – to assess the changes in the anthropometric and metabolic parameters in women within twenty years; to assess the relations of a long-term risk of metabolic syndrome with the body composition and metabolic changes in women had happened during their previous pregnancies. The research data show unfavourable long-term changes in the women’s body structure parameters (body mass and BMI increased, adipose tissue centralization was determined) and metabolic parameters (a proatherogenic dyslipidaemia, the glucose concentration increased and resistance of insulin increased). The work data show the first body markers were already detected during pregnancy for the women who had the metabolic syndrome at the end of the research. We found two anthropometric indicators which could help to prognosticate a long-time risk of the development of metabolic syndrome the relative change in the triceps skin fold and the ratio between the absolute growth in the passive body mass during pregnancy and the neonate’s birth mass. Besides, the research assessed the relation of the adipokines profile parameters with physiological and pathological conditions in women.
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Long-term relation between anthropometric and metabolic changes in women with a risk of the metabolic syndrome / Moterų antropometrinių ir medžiagų apykaitos rodiklių pokyčių ilgalaikis ryšys su metabolinio sindromo rizikaVolochovič, Jelena 23 December 2010 (has links)
This work research is the longest known research of observing the body structure and metabolic changes in women during pregnancy and 20 years after it. Tasks of work – to assess the changes in the anthropometric and metabolic parameters in women within twenty years; to assess the relations of a long-term risk of metabolic syndrome with the body composition and metabolic changes in women had happened during their previous pregnancies. The research data show unfavourable long-term changes in the women’s body structure parameters (body mass and BMI increased, adipose tissue centralization was determined) and metabolic parameters (a proatherogenic dyslipidaemia, the glucose concentration increased and resistance of insulin increased). The work data show the first body markers were already detected during pregnancy for the women who had the metabolic syndrome at the end of the research. We found two anthropometric indicators which could help to prognosticate a long-time risk of the development of metabolic syndrome the relative change in the triceps skin fold and the ratio between the absolute growth in the passive body mass during pregnancy and the neonate’s birth mass. Besides, the research assessed the relation of the adipokines profile parameters with physiological and pathological conditions in women. / Disertacijoje tyrinėjami moterų antropometriniai ir medžiagų apykaitos pokyčiai nėštumo metu ir praėjus 20 metų po gimdymo. Pagrindinis darbo tikslas – įvertinti moterų antropometrinius ir medžiagų apykaitos pokyčius, įvykusius per 20 metų bei įvertinti metabolinio sindromo ilgalaikės rizikos sąsajos su moterų kūno sandaros ir medžiagų apykaitos pokyčiais, įvykusiais dar buvusių nėštumų metu. Tyrimo rezultatai parodė, kad per 20 metų tiriamosioms vystosi nepalankus kūno sandaros pokyčiai (kūno masės, KMI padidėjimas, riebalinio audinio centralizacijos tendencija) ir medžiagų apykaitos pokyčiai (proaterogeninio pobūdžio dislipidemiją, padidėjusia serumo gliukozės koncentracija bei padidėjęs atsparumas insulinui). Tyrimas taip pat atskleidė ankstyvuosius kūno sandaros skirtumus tarp sveikųjų ir metaboliniu sindromu sergančiųjų moterų. Pasiūlyti du antropometriniai rodikliai, kurie galėtų padėti prognozuoti ilgalaikę metabolinio sindromo išsivystymo riziką - santykinis žasto trigalvio raumens klostės pokytis ir absoliučiojo pasyviosios kūno masės prieaugio nėštumo laikotarpiu santykis su naujagimio gimimo mase. Be to, tyrime įvertintas kraujo serumo adipokinų koncentracijos ir jų išvestinių rodiklių ryšys su moterų fiziologinėmis ir patologinėmis būklėmis.
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Shiftwork, sleep disturbances and cardiometabolic risk in female hospital employeesLajoie, PASCALE 25 September 2013 (has links)
Background: Epidemiologic evidence supports the association between shiftwork and the development of cardiovascular disease. Sleep disturbances are associated with a variety of adverse cardiometabolic outcomes and they may lie on the causal pathway between the exposure to shiftwork and cardiovascular disease.
Objectives: 1) To describe sleep quality in a group of shift-working and day-working female hospital employees; 2) To determine the association between shiftwork status and sleep disturbances in this group and to determine the effect of lifetime exposure to shiftwork on current sleep disturbances; and 3) To explore whether sleep disturbances mediate the relationship between shiftwork and cardiometabolic risk.
Methods: A cross-sectional study was conducted among female hospital employees: participants were 132 women working only during the day, and 98 women who worked a shift schedule of two 12-hour days, followed by two 12-hour nights and five days off. Sleep quality was assessed with the Pittsburgh Sleep Quality Index questionnaire. The primary outcome of interest was the metabolic syndrome defined in accordance with the 2009 Joint Interim Studies consensus statement.
Results: Shiftwork was associated with poor sleep latency (odds ratio (OR)= 2.08 95% CI: 1.11-3.92), poor sleep efficiency (OR=2.35 95% CI: 1.21- 4.54), and poor global sleep quality (OR=1.88 95% CI: 1.02-3.49), while the impact of past shiftwork history was inconclusive. The OR for the association of shiftwork with the metabolic syndrome was 2.00 (95% CI: 0.89-4.51), and there was no evidence of mediation by sleep disturbances in the relationship of shiftwork and the metabolic syndrome.
Conclusion: In this study, a rapid forward rotating 2-shift system is associated with self-reported poor sleep quality, while the long-term effects of sleep disturbances on cardiometabolic risk requires further study. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2013-09-24 21:16:38.768
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Psychological well-being and biological correlates in African women / Elizabeth M. BothaBotha, Elizabeth Maria January 2006 (has links)
The aim of this study was to explore, from different perspectives, whether obesity
related variables are associated with facets of psychological well-being, with a vision to
future enhancement of health and the quality of life of people in the African context.
This study was undertaken from the perspective of positive psychology and focused on
the metabolic syndrome and obesity as biological facets. This research was conducted
as part of the multidisciplinary POWIRS (Profiles of Obese Women with Insulin
Resistance Syndrome) project. African (n=102) and Caucasian (1 15) women took part
in a cross-sectional design. The thesis consists of 3 articles: I) Childhood relationships
and bio-psycho-.gocia1 well-being in African women, 2) Psychological well-being and
rhe metabolic syndrome in African and Caucasian women, and 3) Psychological wellbeing
and (the absence of obesity in African and Caucasian women.
In this study psychological well-being was conceptualized and operationalized
by means of the General Health Questionnaire (GHQ); Sense of Coherence Scale
(SOC-29); Affectometer 2 (AFM) (short form); Fortitude Questionnaire (FORQ);
Cognitive Appraisa1 Questionnaire (CAQ); Psychological Well-being Scales (SPWB);
Quality of Childhood Relationship Questionnaire (QCR); Satisfaction with Life Scale
(SWLS) and the Jarel Spiritual Well-Being Scale (SWS-H). These scales were chosen
to include hedonic as well as eudaimonic psychological well-being facets, but also an
index of psychological symptoms. As far as possible, scales with acceptable
psychometric properties as described in international as well as South African context
were selected.
The first article focused on whether African women with a recalled higher level
of quality of childhood relationships mould differ significantly with regard to
biological, psychological and social well-being from women with a recalled lower level
of quality of childhood relationships. Body mass index (BMI) was used as objective
measure of obesity to operationalize physical health. Findings were that the recalled
quality of childhood relationships is linked with obesity and psycho-social well-being
in this group of African women.
The second article focused on psychological well-being and (the absence of) the
metabolic syndrome (MS). It explored the possible association between comprehensive
psychological well-being and MS in different cultural contexts, and explored whether
African and Caucasian women without MS markers and those with MS differ on
specific indices of psychological well-being. The criteria of the NCEP ATPIII mere
implemented to determine markers of MS, and the absence of markers of MS was used
as measure of physical health. Findings were that an association is found in Caucasian
women between comprehensive psychological well-being and the absence of the
metabolic syndrome, but not in the case of African women. Caucasian women without
metabolic syndrome markers had significantly higher levels of psycho-social wellbeing
than uomen with the metabolic syndrome. but a less apparent pattern of
differences emerged for African women. MS markers for African women should be
further explored.
The third article explored facets of psychological well-being as predictors for
(the absence of) obesity (measured by BMI and WHR) in African and Caucasian
women, and whether similar or different psychological well-being facets will emerge as
predictors of obesity in different cultural contexts. Obesity was operationalized in terms
of waist-hip-ratio (WHR) and body-mass-index (BMI). The finding was that clusters of
psychological well-being facets are practical significant predictors of obesity (measured
by BMI and WHR) and that these clusters differ in some respects for African and
Caucasian women.
It was concluded that, firstly. findings support holistic conceptualizations of
health such as proposed by the WHO (1999). Secondly, it may be worthwhile to
include facets of psychological well-being in already existing intervention programmes.
The development of strengths that focus on life skills and behaviours related to positive
interpersonal relationships, optimistic cognitive attributional styles, finding a sense of
purpose and meaningfulness in life, may be particularly beneficial. Sensitivity for
cultural contexts is indicated. In view of the increase in the occurrence of obesity in
childhood and adolescence it is recommended that educational training programmes
should be implemented early in life in order to facilitate protective strengths and to
promote bio-psycho-social health in individuals and communities. Advocacy for more
attention to psycho-social and protective factors in public health is needed. / Thesis (Ph.D. (Psychology))--North-West University, Potchefstroom Campus, 2006.
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Body composition, physical activity and C-reactive protein in children : the PLAY study / Berna HarmseHarmse, Berna January 2006 (has links)
Obesity is currently the most common and costly nutritional problem in
developed countries and ten percent of the world's school-aged children are
estimated to be overweight to some extent. Low-grade systemic inflammation
is increasingly emerging as a significant component of the metabolic
syndrome. Youth in lower income families are particularly vulnerable because
of poor diet and limited opportunities for physical activity. In developing
countries obesity among youth is rising among the urban poor, possibly due to
their exposure to Westernised diets coinciding with a history of under-nutrition.
The aim of this study was to assess the association between serum CRP and
physical activity and to assess the association between serum CRP and body
composition in black high-school children from a township in the North West
Province (NWP), South Africa.
Methods and results: The study group consisted of 193 school children
between the ages 13 to 18 years (78 boys and 115 girls) residing in lkageng,
the township outside of Potchefstroom in the North West Province, South
Africa. Children were from a black ethnic group, living in a poor socioeconomic
setting. Demographic and body composition measurements were
taken and fasting blood samples were drawn for serum C-reactive protein
(CRP) measurements. The difference between serum CRP of overfat versus
girls with a normal fat percentage was non-significant (p = 0.46). Boys with
body fat percentage >20% (n=16) had .a mean serum CRP of 1.42 2.16
mg/L and for boys with a normal fat percentage (n=53) mean serum CRP was
0.89 k 1.62 mg/L. The Mann-Whitney U-test for the difference between mean
CRP of the two groups of boys was Z=1.39, p=0.16 (no significant
difference), but with a trend of higher serum CRP concentration in the boys
with higher % body fat. For the boys, the only positive partial correlation was
between serum CRP and triceps skinfold (r=0.327, p=0.045). In the girls'
group no statistically significant partial correlations were found between CRP
and body composition variables. There was no significant difference between
serum CRP concentrations of the three physical activity categories of girls.
Interestingly, there was an inverse correlation between percentage body fat and fitness in the boys' group (r=-0.509 and p= 0.008). The difference in log
CRP between activity groups showed a trend of lower serum CRP with higher
physical activity in the girls.
Conclusion: This study showed no statistically significant associations
between serum CRP and body composition, except for the positive correlation
between triceps skin fold and serum CRP in boys, or CRP and physical
activity, but clear trends were noted of an inverse association between CRP
and physical activity in the girls. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2007
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Metabolic syndrome marker cut-off points and target organ damage revisited in an urban South African cohort : the SABPA study / Svelka HoebelHoebel, Svelka January 2012 (has links)
Objectives: The aim of this study was to determine the prevalence of MetS among
different African populations using the new Joint Statement Criteria. Hereafter we
aimed to determine whether waist or neck circumference is the best predictor of
MetS risk after ethnic, gender and age-specific cut-points were developed. Lastly, we
aimed to determine whether afore-mentioned cut-point can predict
albumin:creatinine ratio as a marker of target organ damage. Methods: The study
sample (N=409) comprised of urban African (men, N=101; women, N=99) and
Caucasian (men, N=101; women, N=108) teachers from the Dr. Kenneth Kaunda
Education district in the North-West Province, South Africa. Participants were aged
between 25 and 65 years. Anthropometric measurements, albumin:creatinine ratio
and other markers of the metabolic syndrome (MetS) (systolic and diastolic blood
pressure [SBP and DBP], glucose, triglycerides [TG] and high density lipoprotein
[HDL]) were determined. Results: Africans (65 and 63 % for men and women) and
Caucasian men (73%) showed high prevalence of MetS; ROC analysis determined
neck circumference (NC) cut-points of 39 and 35 cm for young and older African
men, 32 and 35 cm for young and older African women, 40 and 41 cm for Caucasian
men and 34 and 33 cm for Caucasian women. This NC cut-point can be used to
determine metabolic syndrome risk in all groups, except in African women; ROC
developed waist circumference (WC) cut-points were 91 cm for all African male
groups, 84, 81 and 84 cm for young, older and total group of African women.
Suggested WC cut-points for Caucasian men were 93 cm for the young group and
97 cm for older as well as total Caucasian male groups, while cut-points for
Caucasian women were 87 cm, 79 cm and 84 cm for young, older and total
Caucasian women. These WC cut-points were good measures of metabolic
syndrome risk in all groups; neither cut-point of WC nor NC could increase the risk of
albumin:creatinine ratio. Conclusion: African women as a group present with few
MetS risk factors and glucose is associated with renal function risk in Africans; NC
cut-points may be used as an additional anthropometric marker to predict the
metabolic syndrome in a South African cohort, but not in African women; WC cutpoints
demonstrated to be good predictors of the metabolic syndrome in the same South African cohort, especially among men; WC would seem to be the best
measure of MetS risk in all African populations, although NC can also be used for
this purpose in all African populations, except in African women. / Thesis (PhD (Human Movement Science))--North-West University, Potchefstroom Campus, 2012
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Common People : Physical health, lifestyle and quality of life in persons with psychosis and their striving to be like everybody elseWärdig, Rikard January 2015 (has links)
Background: As psychosis is often a lifelong disorder, improved health-related quality of life (HRQoL) can be a relevant treatment goal. Persons with psychosis have significantly reduced physical health. Research has demonstrated a great excess of mortality due to cardiovascular diseases, as psychosis may lead to an inactive lifestyle and difficulties making healthy lifestyle choices. Metabolic side effects of second-generation antipsychotics are also common. Many are therefore affected by the metabolic syndrome. The overall situation calls for action by developing health promotion interventions suitable for this group. In recent years, there has been an increased interest in the physical health of persons with psychosis. However, efforts have not been optimally tailored to the needs of this group, and health care services have not done enough, despite being aware of the problem. Aim: The general aim of this thesis was to study HRQoL, and metabolic risk factors in persons with psychosis, and by a health promotion intervention and through the participants’ own perspective contribute to an improvement in lifestyle interventions. Methods: Study 1 had a cross-sectional cohort study design that was carried out in specialised psychiatric outpatient departments in Sweden. The patients (n=903) were diagnosed with a psychotic disorder and invited consecutively to participate. A prospective population-based study of public health in the south-east of Sweden (n=7238) served as reference group. Patients were assessed using psychiatric questionnaires, including the Global Assessment of Functioning (GAF). Health-related quality of life was assessed using the EQ5D, both for patients and the population. Several other health status outcomes relevant to the metabolic syndrome were measured, together with lifestyle habits and clinical characteristics. Study II, III and IV were based on a lifestyle intervention for persons with psychosis. Study II was a longitudinal intervention study with a matched reference sample. The purpose of the lifestyle intervention was to promote a healthier lifestyle by combining theoretical education with physical activities. The intervention group consisted of 42 participants. A matching procedure was made in which two individuals per participant were matched (n=84) into a reference group. The reference sample was matched for sex, BMI class, and being of as similar an age as possible. Socio-demographics were collected and metabolic risk factors relevant to the metabolic syndrome were measured. Symptom severity was measured using Clinical Global Impression (CGI), and HRQoL was assessed using EQ5D. Measurements were made at baseline and at a one-year follow-up. In study III, a qualitative exploratory study was conducted in order to explore prerequisites for a healthy lifestyle. Data were collected through individual interviews (n=40), using a semi-structured interview guide with participants who had undergone the lifestyle intervention. Data were collected 6–7 months after the intervention had been completed. Conventional content analysis was used. Study IV was also based on these 40 interviews and aimed to describe how persons with psychosis perceive participation in a lifestyle intervention. A phenomenographic analysis approach was used. Results/conclusions: Persons with psychosis are at great additional risk of physical comorbidity. Almost half of the patients met the criteria for metabolic syndrome. In addition, persons with psychosis had significantly lower HRQoL in all dimensions in the EQ5D, except for the pain/discomfort dimension. The only risk factor included in the metabolic syndrome that was associated with lower HRQoL was elevated blood pressure. Raised LDL-cholesterol was also related to lower HRQoL, together with low GAF, older age, high BMI, and female gender. The intervention study demonstrated that HRQoL was significantly improved in the intervention group when comparing EQ-VAS at baseline and at the one-year follow-up. It can be concluded that our intervention was not powerful enough to influence the metabolic factors to any greater extent. The key prerequisite for a healthy lifestyle seemed to be a wish to take part in the society and a longing to live like everybody else. However, many became stuck in a constant state of planning instead of taking action towards achieving a healthy lifestyle. Support by health care professionals is therefore also a prerequisite for a healthy lifestyle. This support should target the transition from thought to action and facilitate the participants’ ability to mirror themselves against healthy people in society by introducing activities they perceive that “common people” do. The challenge for health care professionals is to find a moderate intervention level that does not underestimate or overestimate the person’s capacity. This can facilitate continued participation, and participants can thereby find new social contacts and achieve health benefits.
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Joint Mixed-Effects Models for Longitudinal Data Analysis: An Application for the Metabolic SyndromeThorp, John, III 11 November 2009 (has links)
Mixed-effects models are commonly used to model longitudinal data as they can appropriately account for within and between subject sources of variability. Univariate mixed effect modeling strategies are well developed for a single outcome (response) variable that may be continuous (e.g. Gaussian) or categorical (e.g. binary, Poisson) in nature. Only recently have extensions been discussed for jointly modeling multiple outcome variables measures longitudinally. Many diseases processes are a function of several factors that are correlated. For example, the metabolic syndrome, a constellation of cardiovascular risk factors associated with an increased risk of cardiovascular disease and type 2 diabetes, is often defined as having three of the following: elevated blood pressure, high waist circumference, elevated glucose, elevated triglycerides, and decreased HDL. Clearly these multiple measures within a subject are not independent. A model that could jointly model two or more of these risk factors and appropriately account for between subjects sources of variability as well as within subject sources of variability due to the longitudinal and multivariate nature of the data would be more useful than several univariate models. In fact, the univariate mixed-effects model can be extended in a relatively straightforward fashion to define a multivariate mixed-effects model for longitudinal data by appropriately defining the variance-covariance structure for the random-effects. Existing software such as the PROC MIXED in SAS can be used to fit the multivariate mixed-effects model. The Fels Longitudinal Study data were used to illustrate both univariate and multivariate mixed-effects modeling strategies. Specifically, jointly modeled longitudinal measures of systolic (SBP) and diastolic (DBP) blood pressure during childhood (ages two to eighteen) were compared between participants who were diagnosed with at least three of the metabolic syndrome risk factors in adulthood (ages thirty to fifty-five) and those who were never diagnosed with any risk factors. By identifying differences in risk factors, such as blood pressure, early in childhood between those who go on to develop the metabolic syndrome in adulthood and those who do not, earlier interventions could be used to prevent the development cardiovascular disease and type 2 diabetes. As demonstrated by these analyses, the multivariate model is able to not only answer the same questions addressed as the univariate model, it is also able to answer additional important questions about the association in the evolutions of the responses as well as the evolution of the associations. Furthermore, the additional information gained by incorporating information about the correlations between the responses was able to reduce the variability (standard errors) in both the fixed-effects estimates (e.g. differences in groups, effects of covariates) as well as the random-effects estimates (e.g. variability).
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