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1.
Nutrients ; 16(3)2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38337704

ABSTRACT

Newborns' eyes and brains are prone to oxidative stress. Lutein has antioxidant properties and is the main component of macular pigment essential for protecting the retina, but has low bioavailability, thereby limiting its potential as a nutritional supplement. Oil-in-water emulsions have been used as lutein delivery systems. In particular, octenylsuccinated (OS) starch is a biopolymer-derived emulsifier safe to use in infant foods, while exhibiting superior emulsifying capacity. This study determined the effects of an OS starch-stabilized lutein emulsion on lutein bioavailability in Sprague-Dawley neonatal rats. In an acute study, 10-day-old pups received a single oral dose of free lutein or lutein emulsion, with subsequent blood sampling over 24 h to analyze pharmacokinetics. The lutein emulsion group had a 2.12- and 1.91-fold higher maximum serum lutein concentration and area under the curve, respectively, compared to the free lutein group. In two daily dosing studies, oral lutein was given from postnatal day 5 to 18. Blood and tissue lutein concentrations were measured. The results indicated that the daily intake of lutein emulsion led to a higher lutein concentration in circulation and key tissues compared to free lutein. The OS starch-stabilized emulsion could be an effective and safe lutein delivery system for newborns.


Subject(s)
Lutein , Starch , Infant, Newborn , Humans , Rats , Animals , Emulsions , Animals, Newborn , Rats, Sprague-Dawley , Biological Availability
2.
J Acad Nutr Diet ; 123(12): 1713-1728, 2023 12.
Article in English | MEDLINE | ID: mdl-37429414

ABSTRACT

BACKGROUND: Challenging eating behaviors or feeding difficulties, commonly displayed in children with Down syndrome (DS), may amplify perceived stress in caregivers. If caregivers lack resources on how to accommodate the needs of the child with DS, they may find feeding the child stressful and resort to negative coping strategies. OBJECTIVE: The aim of this study was to understand the feeding stressors, resources, and coping strategies used by caregivers of children with DS. DESIGN: A qualitative analysis of interview transcripts was undertaken, framed around the Transactional Model of Stress and Coping. PARTICIPANTS/SETTING: Between September to November 2021, 15 caregivers of children (aged 2 through 6 years) with DS, were recruited from 5 states located in the Southeast, Southwest, and West regions of the United States. ANALYSIS: Interviews were audio-recorded, transcribed verbatim, and analyzed using deductive thematic analysis and content analysis approaches. RESULTS: Thirteen caregivers reported increased stress around feeding the child with DS. Stressors identified included concern about adequacy of intake and challenges associated with feeding difficulties. Stress related to feeding was higher among caregivers whose child was learning a new feeding skill or in a transitional phase of feeding. Caregivers used both professional and interpersonal resources in addition to problem- and emotion-based coping strategies. CONCLUSIONS: Caregivers identified feeding as a stressful event with higher stress reported during transitional phases of feeding. Caregivers reported that speech, occupational, and physical therapists were beneficial resources to provide support for optimizing nutrition and skill development. These findings suggest that caregiver access to therapists and registered dietitian nutritionists is warranted.


Subject(s)
Caregivers , Down Syndrome , Humans , Child , Adaptation, Psychological , Emotions
3.
J Appl Gerontol ; 42(1): 131-140, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36062816

ABSTRACT

Objectives: The purpose of this qualitative study was to explore factors associated with the ability of people with PD to perform food-related activities (FRAs). Methods: Eleven dyads, older adults with Parkinson disease (PD) and their care-partners (n = 22), completed virtual semi-structured interviews guided by the Social Cognitive Theory (SCT) that were independently analyzed by two coders via directed content analysis. Results: The following themes were identified-(1) Personal: perception of a healthy diet, perception of how nutrition influences PD, confidence in following a healthy diet, and barriers to performing FRA; (2) Environmental: previous sources of nutrition information and willingness to changing their diet with a registered dietitian; and (3) Behavioral: modifications to FRA due to food-medication interactions, and skills necessary to maintain a healthy diet. Discussion: Findings from this study highlight the need for nutrition intervention research to inform evidence-based guidelines in order to provide tailored education for people with PD and care-partners.


Subject(s)
Parkinson Disease , Humans , Aged , Parkinson Disease/psychology , Qualitative Research , Diet , Diet, Healthy , Nutritional Status
4.
Article in English | MEDLINE | ID: mdl-36142014

ABSTRACT

OBJECTIVE: The purpose of this mixed methods study was to explore the impact of COVID-19 on the ability of people with Parkinson disease (PwPs) and their care-partners to perform food-related activities (FRA) and PwPs' overall diet quality. METHODS: Using a convergent parallel mixed methods design, PwPs and their care-partners completed virtual dyadic semi-structured interviews about their FRA during the COVID-19 pandemic. PwPs completed Food Frequency Questionnaires (FFQ) to quantify their dietary intake in the previous 12 months. Qualitative data were analyzed by two coders using thematic analysis, and quantitative data from FFQs were descriptively analyzed to calculate diet quality scores. RESULTS: Eleven dyadic interviews revealed the following key themes: cooking more at home; changes with grocery shopping; less meals with non-household members. These changes were described to increase the care-partners' responsibilities and overall burden. Diet scores among PwPs were 73.0 ± 6.3 for the Healthy Eating Index 2015 (scale of 0-100), 29.2 ± 6.6 for the Mediterranean diet (scale of 0-55), and 10.4 ± 1.8 for the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet (scale 0-15). CONCLUSIONS: Diet scores revealed that PwPs consumed a high-quality diet during the pandemic. Findings from this study highlight the need for tailored nutrition education to support PwPs' care-partners.


Subject(s)
COVID-19 , Diet, Mediterranean , Parkinson Disease , COVID-19/epidemiology , Diet , Feeding Behavior , Humans , Meals , Pandemics , Parkinson Disease/epidemiology
5.
J Acad Nutr Diet ; 122(12): 2346-2355, 2022 12.
Article in English | MEDLINE | ID: mdl-36007840

ABSTRACT

In 2015, the Council on Research published their vision for scientific decision making, which provided nutrition and dietetics practitioners and practitioners-in-training key information on the Academy of Nutrition and Dietetics' newly developed scientific integrity principles. Given that it has been 7 years since the original publication, it was believed the original six principles should be revisited and updated. From the Subcommittee on Scientific Integrity Principles under the Council on Research, the 2015 principles were evaluated and updated with new literature and best practices for maintaining scientific integrity principles. After this review process, four new/updated principles were approved by the Council on Research. These include: 1) the ethical conduct of research and protection of human subjects, 2) funder's influence on the research question/methodology/education content and conflicts of interest, 3) review of research-related materials, and 4) maintain and promote a culture of scientific integrity. Moreover, it became clear that newer topics, including diversity, equity, and inclusion should be woven throughout the principles. This article presents the newly updated principles and resources related to scientific integrity principles. We envision that this document can be used by the Academy of Nutrition and Dietetics to educate members and serve as a guide to incorporate these principles into all research practices and at all levels of dietetics practice.


Subject(s)
Dietetics , Humans , Nutritional Status , Academies and Institutes , Educational Status , Decision Making
6.
J Nutr Educ Behav ; 52(7): 719-725, 2020 07.
Article in English | MEDLINE | ID: mdl-32276881

ABSTRACT

OBJECTIVE: To compare changes in mindful eating habits between students receiving a mindful eating intervention (MEI) vs those who were engaged in usual course work. METHODS: From 2017 to 2019, 109 nutrition and medical students completed a quasi-experimental study, including usual course work either with or without the addition of a 5-week MEI. The Mindful Eating Questionnaire (MEQ) was completed before and after the MEI. Repeated measures MANOVA was used to detect differences in changes in the overall MEQ score and its 5 subscales between groups. RESULTS: Within the MEI group (n = 64), overall MEQ, disinhibition, and eating with awareness scores increased significantly (P < .001, P < .001, and P = .004, respectively). No significant changes were noted within the comparison group (n = 45). Significant between-group differences were noted for the changes in the overall MEQ (P = .03) and disinhibition scores (P = .01). CONCLUSIONS AND IMPLICATIONS: MEI participation may improve students' overall mindful eating scores. Future research could assess a larger cohort of participants, including health care professionals from other disciplines, assess additional mindfulness measures, and follow students for a longer period to determine the long-term effects on participants' mindful eating.


Subject(s)
Feeding Behavior , Health Occupations/education , Mindfulness , Adult , Curriculum , Female , Humans , Male , Nutritional Sciences/education , Students, Health Occupations , Young Adult
7.
Nutr Clin Pract ; 35(4): 675-679, 2020 Aug.
Article in English | MEDLINE | ID: mdl-31990081

ABSTRACT

BACKGROUND: Current guidelines advise against using enteral nutrition (EN) support for patients with advanced dementia (AD) because of negative outcomes. However, research suggests that some registered dietitian nutritionists (RDNs) in acute-care settings still recommend EN for this patient population. The purpose of this study was to identify workplace characteristics that influence the EN recommendations of acute-care RDNs who care for patients with AD. METHODS: A random sample of 5000 RDNs in the United States were invited to participate in a web-based survey in which RDNs self-reported the likelihood that they would recommend EN for a patient with AD. Inclusion criteria specified that participants were at least 18 years of age, were an RDN in the United States, and currently provide nutrition care to older adults with dementia. χ2 tests compared RDN recommendations by workplace characteristics. Logistic regression was used to determine factors associated with recommending EN for patients with AD. RESULTS: Respondents included 204 acute-care RDNs. RDNs in rural or suburban locations were 2.4 times more likely to recommend EN compared with those in urban facilities (95% CI, 1.1-5.1). RDNs who were the only nutrition provider at their facility were 3.3 times more likely to recommend EN than those in facilities with multiple RDNs (95% CI, 1.4-7.9). CONCLUSION: Acute-care RDNs who are isolated either in rural facilities or because they lack other RDN colleagues at their facility may benefit from targeted interventions to increase knowledge and promote adherence to evidence-based guidelines.


Subject(s)
Dementia/therapy , Enteral Nutrition/statistics & numerical data , Guideline Adherence/statistics & numerical data , Nutritionists/statistics & numerical data , Workplace/statistics & numerical data , Adult , Aged , Aged, 80 and over , Dietetics/standards , Enteral Nutrition/standards , Female , Health Care Surveys , Humans , Logistic Models , Male , Middle Aged , Nutritionists/psychology , Rural Health Services/statistics & numerical data , Social Isolation , United States , Urban Health Services/statistics & numerical data , Workplace/psychology
8.
Nutr Clin Pract ; 35(4): 634-641, 2020 Aug.
Article in English | MEDLINE | ID: mdl-30729569

ABSTRACT

BACKGROUND: Current guidelines discourage tube-feeding older adults with advanced dementia (AD), as this practice does not improve nutrition status or survival and decreases quality of life in these patients. Because registered dietitians (RDs) often provide feeding recommendations for patients with AD, this study aimed to identify factors that influenced RDs' feeding tube recommendations for older adults with AD. METHODS: A random sample of RDs who work with older adults in the United States completed a validated, electronic survey. Logistic regression analysis was used to identify factors related to the likelihood of RDs recommending a feeding tube for patients with AD. Independent variables included participant demographics and the 6 subscales of the Attitudes Toward Tube-Feeding in Advanced Dementia Questionnaire, which measured individual and environmental influences on RDs' recommendations. RESULTS: Among the 662 RDs who responded, 72.2% were unlikely to recommend a feeding tube in patients with AD, and 15.4% were likely to do so (with the remaining being "neutral"). Factors associated with avoiding recommending a feeding tube include significantly higher total knowledge [odds ratio (OR) = 1.47, 95% CI (1.30, 1.66)] and personal values scores [OR = 7.51, 95% CI (3.96, 14.24)] and employment in long-term care settings [OR 3.29, 95% CI (1.38, 7.80)]. CONCLUSION: In this survey, most RDs were likely to make recommendations that are consistent with current guidelines for tube feeding patients with AD. RDs who work outside the long-term care setting may benefit from additional training. Future research is needed to understand how personal values may influence recommendations.


Subject(s)
Dementia/therapy , Enteral Nutrition/psychology , Health Knowledge, Attitudes, Practice , Nutritionists/psychology , Social Values , Workplace/psychology , Adult , Attitude of Health Personnel , Enteral Nutrition/standards , Female , Health Care Surveys , Humans , Male , Middle Aged , Odds Ratio , United States
10.
Nutr Clin Pract ; 34(3): 359-370, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30070730

ABSTRACT

Weight restoration is an important first step in treating patients with anorexia nervosa (AN), because it is essential for medical stabilization and reversal of long-term complications. Tube feeding may help facilitate weight restoration, but its role in treatment remains unclear. This study aimed to review the literature describing the efficacy, safety, tolerance, and long-term effects of nasogastric (NG) refeeding for patients with AN. Four electronic databases were systematically searched through May 2018. Boolean search terms included "anorexia nervosa," "refeeding," and "nasogastric tube feeding." Ten studies were eligible for inclusion: 8 retrospective chart reviews, 1 prospective cohort, and 1 randomized controlled trial. Nine of the studies were performed in-hospital. In 8 studies, NG nutrition resulted in an average rate of weight gain exceeding 1 kg/wk. In 4 of 5 studies including an oral-only control group, mean weekly weight gain and caloric intake were significantly higher in tube-fed patients. Six studies provided prophylactic phosphate supplementation, all with <1% occurrence rate of refeeding hypophosphatemia. Seven studies reported on other physiological disturbances, 6 evaluated medical and gastrointestinal side effects, 3 considered psychological outcomes, and 4 assessed patients postdischarge. Results indicated that NG feeding was not associated with an increased risk for adverse outcomes. Overall, in these studies, NG nutrition was considered safe and well tolerated, and effectively increased caloric intake and rate of weight gain in patients with AN. However, results are limited by weaknesses in study designs, and more rigorous methods are needed for development of evidence-based, standardized refeeding protocols.


Subject(s)
Anorexia Nervosa/therapy , Enteral Nutrition/instrumentation , Intubation, Gastrointestinal/methods , Refeeding Syndrome/prevention & control , Adolescent , Adult , Child , Energy Intake , Enteral Nutrition/adverse effects , Enteral Nutrition/methods , Female , Humans , Hypophosphatemia , Male , Middle Aged , Weight Gain
11.
J Nutr Gerontol Geriatr ; 37(3-4): 183-203, 2018.
Article in English | MEDLINE | ID: mdl-30513275

ABSTRACT

Registered Dietitians (RDs) should participate in interdisciplinary feeding discussions for patients with advanced dementia, but research on how RDs make such feeding recommendations is scarce. This study developed and validated a theory-based questionnaire to assess the knowledge, beliefs, and attitudes of RDs regarding feeding tube use among older adults with advanced dementia. The instrument was drafted based on the Social Ecological Model, and face and content validity were established through an expert panel review. Pilot testing with 70 RDs provided an initial measure of internal consistency reliability and reduced the number of items in the survey. Efficacy testing with 662 RDs allowed for a second analysis of internal consistency reliability and eliminated additional items. Construct validity was then established using validation by extreme groups and exploratory factor analysis, yielding six subscales, each with adequate internal consistency and test-retest correlation coefficients: (I) Total Knowledge, (II) Knowledge Self-Efficacy, (III) Religion/Spirituality/Culture, (IV) Personal Values, (V) Perceived Organization and Training, and (VI) Perceived Policy. The survey, based on the Social Ecological Model, was deemed a valid and reliable tool to assess RDs' knowledge and attitudes regarding feeding tube use among older adults with advanced dementia.


Subject(s)
Attitude of Health Personnel , Dementia , Enteral Nutrition , Geriatric Assessment/methods , Nutrition Assessment , Nutritional Requirements , Aged , Dementia/diagnosis , Dementia/therapy , Enteral Nutrition/methods , Enteral Nutrition/psychology , Female , Health Care Surveys , Health Knowledge, Attitudes, Practice , Humans , Male , Patient Acuity , Reproducibility of Results , Surveys and Questionnaires , United States
12.
J Nutr Gerontol Geriatr ; 36(1): 1-17, 2017.
Article in English | MEDLINE | ID: mdl-28140779

ABSTRACT

Dementia is a progressive, debilitating disease that often results in weight loss, malnutrition, and dehydration. Feeding tubes are often prescribed; however, this practice can lead to complications. The purpose of this systematic review was to examine the use of feeding tubes in elderly demented patients from a social ecological perspective. Results indicated that family members often receive inadequate decision-making education. Many health care professionals lack knowledge of evidence-based guidelines pertaining to feeding tube use. Organizational and financial reimbursement structures influence feeding tube use. Feeding practices for patients with advanced dementia is a complex issue, warranting approaches that target each level of the Social Ecological Model.


Subject(s)
Dementia/nursing , Enteral Nutrition , Aged , Caregivers , Decision Making , Enteral Nutrition/adverse effects , Enteral Nutrition/economics , Health Knowledge, Attitudes, Practice , Health Personnel , Humans , Quality of Life , Social Environment
13.
J Nutr Educ Behav ; 48(2): 122-30.e1, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26589341

ABSTRACT

OBJECTIVE: To explore predictors of intention of college students to use calorie labels on fast-food menus and differences in calories ordered after viewing calorie information. DESIGN: Quasi-experimental design. Participants selected a meal from a menu without calorie labels, selected a meal from the same menu with calorie labels, and completed a survey that assessed demographics, dietary habits, Theory of Planned Behavior constructs, and potential barriers to use of calorie labeling. SETTING: A southern university. PARTICIPANTS: Undergraduate university students (n = 97). MAIN OUTCOME MEASURES: Predictors of intention to use calorie labels and whether calories selected from the nonlabeled menu differed from the labeled menu. ANALYSIS: Confirmatory factor analysis, exploratory factor analysis, multiple regression, and paired t tests. RESULTS: Participants ordered significantly fewer calories (P = .02) when selecting from the labeled menu vs the menu without labels. Attitudes (P = .006), subjective norms (P < .001), and perceived behavioral control (P = .01) predicted intention to use calorie information but did not predict a difference in the calories ordered. Hunger (P = .03) and cost (P = .04) were barriers to using the calorie information. CONCLUSIONS AND IMPLICATIONS: If students can overcome barriers, calorie labeling could provide information that college students need to select lower-calorie items at fast-food restaurants.


Subject(s)
Consumer Health Information , Food Labeling/statistics & numerical data , Food Preferences/psychology , Nutrition Policy , Students/psychology , Students/statistics & numerical data , Adult , Cross-Sectional Studies , Female , Humans , Male , Surveys and Questionnaires , United States , Universities , Young Adult
14.
J Acad Nutr Diet ; 115(11): 1815-31, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26233887

ABSTRACT

As the number of older adults in the United States continues to grow, the American health care system will face the unique challenge of providing care for these individuals, including many who will be diagnosed with some form of dementia. As dementia progresses, patients require increasing amounts of care and nutrient intake usually declines. This tends to result in weight loss, malnutrition, and increased morbidity and mortality. Various interventions have been developed with the goal of improving meal intake and reducing unintentional weight loss in patients with dementia. Several studies have shown that meal intake improves with the provision of adequate assistance, either from staff members or from volunteer feeding assistants. Some studies have focused on the method of meal service and its influence on meal intake and nutrition status. Both buffet-style and family-style dining have shown promising results in terms of improving meal intake and quality of life among older adults in long-term-care settings. Other environment-related interventions include improving lighting and visual contrast, altering the dining room to more closely resemble a home-style setting, using the aroma of food to stimulate appetite, using routine seating arrangements, and using relaxing or familiar music in the dining room to provide a calmer environment. The purpose of this review is to evaluate the research on environment-based interventions to improve nutritional status among older adults with dementia, to describe potential for practical applications, and to identify gaps in the existing literature whereon further research is warranted.


Subject(s)
Dementia , Diet , Environment , Nutritional Status , Aged , Energy Intake , Humans , Long-Term Care , Malnutrition/prevention & control , Meals , Quality of Life
15.
J Sch Health ; 84(3): 185-94, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24443780

ABSTRACT

BACKGROUND: Obesity affects nearly 17% of US children and youth 2-19 years old and 10% of infants and toddlers under the age of 2 years. One strategy for addressing obesity is to discourage sugar-sweetened beverage (SSB) consumption. Compared with their older school-aged counterparts, children ≤ 5 years depend largely on parents for the purchase and serving of SSBs. Therefore, recognizing parental factors associated with children's intake of SSBs is important. METHODS: This study used cross-sectional data from parents of children ≤ 5 years old to examine SSB consumption and associated factors. Elements of the Health Belief Model and Theory of Reasoned Action facilitated data analysis and interpretation. RESULTS: The most consistent predictor of SSB intake was child age. Nearly 94% of children aged 3-5 years consumed sweetened milk products, 88% consumed fruity drinks, 63% consumed sodas, and 56% consumed sports drinks and sweet tea. Adjusting for all other factors, the only parental psychosocial factor associated with SSB intake was self-efficacy (predicting fruity drinks consumption). CONCLUSIONS: More children drink SSBs as they get older. Interventions designed to prevent SSB consumption should occur early, before children reach preschool age. Additional study of parental factors influencing SSB intake in early childhood is recommended.


Subject(s)
Beverages/statistics & numerical data , Dietary Sucrose/administration & dosage , Adult , Child, Preschool , Cross-Sectional Studies , Female , Humans , Infant , Male , Middle Aged , Obesity/prevention & control , Odds Ratio , Parents , Young Adult
16.
J Acad Nutr Diet ; 113(12): 1675-82, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24021733

ABSTRACT

Older adults with multiple comorbidities are often undernourished or at high risk for becoming so, especially after a recent hospitalization. Randomized controlled trials of effective, innovative interventions are needed to support evidence-based approaches for solving nutritional problems in this population. Self-management approaches where participants select their own behavioral goals can enhance success of interventions. The purpose of this study was to evaluate the feasibility and efficacy of a multilevel self-management intervention to improve nutritional status in a group of high-risk older adults. The Behavioral Nutrition Intervention for Community Elders (B-NICE) trial used a prospective randomized controlled design to determine whether the intervention, compared to standard care, maintained or increased caloric intake (depending on baseline body mass index) and, consequently, stabilized or increased body weight. Participants were 34 Medicare-eligible, age 65 years old or older, homebound adults who were consuming insufficient calories and/or had a history of weight loss ≥2.5% over 6 months. The intervention took place within participants' homes. Outcome measures, including energy intake (based on collection of three 24-hour dietary recalls) and body weights were assessed at baseline and at 60 days post randomization. The primary analyses included analyses of covariance and Pearson's χ(2). We hypothesized that the intervention would result in increased caloric intake and weight gain in underweight older adults and increased or stabilized caloric intake and weight for everyone else. The intervention was feasible; however, it did not result in differences between groups for desired outcomes of either caloric intake or body weight. Future interventions might either deliberately involve caregivers or reduce burden for both patients and caregivers.


Subject(s)
Behavior Therapy , Malnutrition/therapy , Aged , Aged, 80 and over , Behavior Therapy/methods , Body Mass Index , Energy Intake , Female , Home Care Services , Homebound Persons , Humans , Male , Prospective Studies , Self Care , Weight Gain
17.
J Nutr Gerontol Geriatr ; 30(4): 384-402, 2011.
Article in English | MEDLINE | ID: mdl-22098180

ABSTRACT

We conducted a study designed to evaluate the efficacy and feasibility of a multilevel self-management intervention to improve nutritional intake in a group of older adults receiving Medicare home health services who were at especially high risk for experiencing undernutrition. The Behavioral Nutrition Intervention for Community Elders (B-NICE) trial used a prospective randomized controlled design to determine whether individually tailored counseling focused on social and behavioral aspects of eating resulted in increased caloric intake and improved nutrition-related health outcomes in a high-risk population of older adults. The study was guided by the theoretical approaches of the Ecological Model and Social Cognitive Theory. The development and implementation of the B-NICE protocol, including the theoretical framework, methodology, specific elements of the behavioral intervention, and assurances of the treatment fidelity, as well as the health policy implications of the trial results, are presented in this article.


Subject(s)
Behavior Therapy , Counseling , Diet , Energy Intake , Malnutrition/prevention & control , Self Care , Aged , Attitude to Health , Evaluation Studies as Topic , Female , Health Behavior , Health Policy , Home Care Services , Humans , Male , Medicare , Prospective Studies , Psychological Theory , Risk , Treatment Outcome , United States
18.
Obesity (Silver Spring) ; 19(7): 1469-75, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21436797

ABSTRACT

Insulin resistance has been associated with the accumulation of fat within skeletal muscle fibers as intramyocellular lipid (IMCL). Here, we have examined in a cross-sectional study the interrelationships among IMCL, insulin sensitivity, and adiposity in European Americans (EAs) and African Americans (AAs). In 43 EA and 43 AA subjects, we measured soleus IMCL content with proton-magnetic resonance spectroscopy, insulin sensitivity with hyperinsulinemic-euglycemic clamp, and body composition with dual-energy X-ray absorptiometry. The AA and EA subgroups had similar IMCL content, insulin sensitivity, and percent fat, but only in EA was IMCL correlated with insulin sensitivity (r = -0.47, P < 0.01), BMI (r = 0.56, P < 0.01), percent fat (r = 0.35, P < 0.05), trunk fat (r = 0.47, P < 0.01), leg fat (r = 0.40, P < 0.05), and waist and hip circumferences (r = 0.54 and 0.55, respectively, P < 0.01). In a multiple regression model including IMCL, race, and a race by IMCL interaction, the interaction was found to be a significant predictor (t = 1.69, DF = 1, P = 0.0422). IMCL is related to insulin sensitivity and adiposity in EA but not in AA, suggesting that IMCL may not function as a pathophysiological factor in individuals of African descent. These results highlight ethnic differences in the determinants of insulin sensitivity and in the pathogenesis of the metabolic syndrome trait cluster.


Subject(s)
Insulin Resistance/ethnology , Lipid Metabolism , Muscle Fibers, Skeletal/metabolism , Obesity, Abdominal/ethnology , Abdominal Fat/pathology , Absorptiometry, Photon , Adiposity/ethnology , Adult , Black or African American , Body Mass Index , Cross-Sectional Studies , Humans , Magnetic Resonance Spectroscopy , Metabolic Syndrome/epidemiology , Metabolic Syndrome/ethnology , Metabolic Syndrome/etiology , Middle Aged , Obesity/ethnology , Obesity/etiology , Obesity/metabolism , Obesity, Abdominal/etiology , Obesity, Abdominal/metabolism , Risk Factors , United States/epidemiology , White People , Young Adult
19.
Obesity (Silver Spring) ; 19(1): 43-8, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20559297

ABSTRACT

The prevalence of type 2 diabetes is greater among African Americans (AA) vs. European Americans (EA), independent of obesity and lifestyle. We tested the hypothesis that intramyocellular lipid (IMCL) or extramycellular lipid (EMCL) would be associated with insulin sensitivity among healthy young women, and that the associations would differ with ethnic background. We also explored the hypothesis that adipokines and estradiol would be associated with muscle lipid content. Participants were 57 healthy, normoglycemic, women and girls mean age 26 (±10) years; mean BMI 27.3 (±4.8) kg/m²; 32 AA, 25 EA. Soleus IMCL and EMCL were assessed with ¹H magnetic resonance spectroscopy (MRS); insulin sensitivity with an insulin-modified frequently sampled intravenous glucose tolerance test and minimal modeling; body composition with dual-energy X-ray absorptiometry; and intra-abdominal adipose tissue (IAAT) with computed tomography. Adiponectin, leptin, and estradiol were assessed in fasting sera. Analyses indicated that EMCL, but not IMCL, was greater in AA vs. EA (2.55 ± 0.16 vs. 1.98 ± 0.18 arbitrary units, respectively, P < 0.05; adjusted for total body fat). IMCL was associated with insulin sensitivity in EA (r = -0.54, P < 0.05, adjusted for total fat, IAAT, and age), but not AA (r = 0.16, P = 0.424). IMCL was inversely associated with adiponectin (r = -0.31, P < 0.05, adjusted for ethnicity, age, total fat, and IAAT). In conclusion, IMCL was a significant determinant of insulin sensitivity among healthy, young, EA but not AA women. Further research is needed to determine whether the component lipids of IMCL (e.g., diacylglycerol (DAG) or ceramide) are associated with insulin sensitivity in an ethnicity specific manner.


Subject(s)
Insulin Resistance/ethnology , Insulin Resistance/physiology , Lipid Metabolism , Muscle, Skeletal/metabolism , Absorptiometry, Photon , Adiponectin/blood , Adiposity/physiology , Adolescent , Adult , Body Composition/physiology , Estradiol/blood , Female , Health , Humans , Individuality , Leptin/blood , Lipid Metabolism/physiology , Magnetic Resonance Spectroscopy , Muscle Fibers, Skeletal/diagnostic imaging , Muscle Fibers, Skeletal/metabolism , Muscle, Skeletal/diagnostic imaging , Young Adult
20.
Open Obes J ; 2: 137-144, 2010.
Article in English | MEDLINE | ID: mdl-22039395

ABSTRACT

Intramyocellular lipid (IMCL) has been inversely associated with insulin sensitivity in some, but not all, studies. This study utilized fast, high-resolution, magnetic resonance spectroscopic imaging (MRSI) to: investigate relationships between muscle lipids (IMCL and extramyocellular lipid (EMCL)) and insulin sensitivity in muscles of varying oxidative capacity, explore ethnic differences in these relationships, and determine whether a eucaloric, low-fat dietary intervention would reduce IMCL and increase insulin sensitivity. Subjects were 30 healthy, African-American (AA; n=14) and European-American (EA; n=16) males, BMI 26.49 (±5.57) kg/m(2), age 21.80 (±7.84) yrs. Soleus and tibialis anterior muscle lipids were quantified using MRSI. Insulin sensitivity was assessed via intravenous glucose tolerance test. A 2-week, eucaloric, low-fat diet intervention was conducted in a sub-group (n=12) subjects with assessments at baseline and post-intervention. Neither IMCL nor EMCL levels differed between ethnicities. In the total group, and within EA (but not AA), both tibialis anterior IMCL and EMCL were inversely associated with insulin sensitivity (P<0.05 for both); soleus muscle lipids were not associated with insulin sensitivity. Soleus, but not tibialis anterior, IMCL declined in both ethnic groups (average 25.3%; p<0.01) following dietary intervention; insulin sensitivity was unchanged. Results suggest that an association of muscle lipids with insulin sensitivity may be influenced by the oxidative capacity of the muscle group studied and may vary with ethnicity.

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