Eccentric exercise induces spatial changes in the mechanomyographic activity of the upper trapezius muscle.

In this study, we hypothesized that the recordings of multichannel mechanomyography (MMG) of the upper trapezius muscle would reveal spatially dependent manifestations in the presence of delayed onset muscle soreness occurring 24 hours after eccentric exercise (ECC). Sixteen participants performed high-intensity eccentric exercises (5 sets of 10 eccentric contractions at 100% of max elevation force) targeting the upper trapezius on their dominant side. Twelve accelerometers were attached to record MMG activity during submaximal exercise consisting of static and dynamic arm flexion and abduction. Measurements were taken before and 24 hours after ECC. Average rectified value (ARV), percentage of determinism (% DET), and recurrence (% REC) of the MMG signals were computed to estimate the level of muscular activity and the magnitude of regularity of the MMG. The ARV, % REC, and % DET maps revealed heterogeneous MMG activity of the upper trapezius 24 hours after ECC when compared with before. Increased ARV, % REC, and % DET were found 24 hours after ECC when compared with before. The study provides new key information on how a single muscle responds to ECC. Our findings suggest that multichannel MMG and nonlinear analyses may detect muscular and musculo-tendinous alterations due to ECC.

Exploring Perceptions of Barriers, Facilitators, and Motivators to Physical Activity Among Female Bariatric Patients: Implications for Physical Activity Programming.

PURPOSE: To explore barriers, facilitators, and motivators to adopting and maintaining regular physical activity among women with obesity who have undergone bariatric surgery. APPROACH: Individual interviews with women 3 to 24 months post-bariatric surgery. SETTING: Participants were recruited from a bariatric clinic in Montreal, Canada. PARTICIPANTS: Twelve women were recruited (mean age = 47 ± 9 years) using poster advertisements and word of mouth. Participants were on average 15 months postsurgery. METHOD: Each woman was interviewed once using a semistructured interview protocol. Recruitment was conducted until data saturation (i.e., no new information emerged). The interviews were transcribed, coded, and analyzed using inductive thematic analysis. RESULTS: Three interrelated themes emerged: the physical body, appraisal of the physical and social self, and the exercise environment. Barriers included weight-restricted mobility, side effects of surgery, body dissatisfaction, compromised psychological health, competing responsibilities, a lack of exercise self-efficacy and social support, reduced access to accommodating facilities, lack of exercise knowledge, and northern climate. Participants reported postsurgical weight loss, weight and health maintenance, enjoyment, body image, and supportive active relationships, as well as access to accommodating facilities and exercise knowledge, as facilitators and motivators. CONCLUSION: Suggested physical activity programming strategies for health care professionals working with this unique population are discussed. Physical activity and health promotion initiatives can also benefit from a cultural paradigm shift away from weight-based representations of health.

Physical activity and sitting time in bariatric surgery patients 1-16 years post-surgery.

Physical activity (PA) is an important adjunct to bariatric surgery in the treatment of severe obesity; however, patient PA levels prior to and in the short-term following surgery are usually low. Scarce data exist describing PA and sedentary behaviours in the long term following surgery. The objectives were to describe PA and sitting time in bariatric patients 1-16 years post-surgery and assess their associations with patient, surgery and weight-loss characteristics. A total of 398 bariatric patients (73% female; mean age 47 ± 11 years, mean 6 ± 4 years since surgery) completed a telephone questionnaire. Patients reported moderate-to-vigorous PA (MVPA: # sessions week(-1) ≥30 min), sitting time (h d(-1)) and change in PA and sitting time vs. pre-surgery (more/same/less). Associations with patient, surgery and weight-loss characteristics were assessed. Only 53% of patients reported ≥1 session week(-1) MVPA, mean sitting time was 7 ± 4 h d(-1), 74% of patients reported more PA and 53% reported less sitting, now vs. pre-surgery. Age, sex, smoking status, pre-surgery body mass index, time-since-surgery and percent excess weight lost were significantly associated with PA and/or sitting outcomes. Patients currently experiencing ≥50% excess weight loss had over three times the odds of reporting ≥1 session week(-1) MVPA (odds ratio [95% confidence interval] 3.28 [1.57, 6.89]) and almost four times greater odds of reporting 'more' PA vs. pre-surgery (3.78 [2.15, 6.62]) compared with their less successful counterparts. Results point to low PA and high sedentariness among bariatric patients in the long-term following surgery, associated with several characteristics. Associations with long-term weight management highlight the need for tailored interventions to promote active living in this patient population.

The effect of vitamin D and frailty on mortality among non-institutionalized US older adults.

BACKGROUND/OBJECTIVES: Although both frailty and low vitamin D have been separately associated with an increased risk for adverse health, their joined effects on mortality have not been reported. The current study examined prospectively the effects of frailty and vitamin D status on mortality in US older adults. SUBJECTS/METHODS: Participants aged ≥ 60 years in The Third National Health and Nutrition Examination Survey with 12 years of mortality follow-up were included in the analysis (n=4731). Frailty was defined as meeting three or more criteria and pre-frailty as meeting one or two of the five frailty criteria (low body mass index (BMI), slow walking, weakness, exhaustion and low physical activity). Vitamin D status was assessed by serum 25-hydroxyvitamin D (25(OH)D) and categorized into quartiles. Analyses were adjusted for gender, race, age, smoking, education, latitude and other comorbid conditions. RESULTS: Serum 25(OH)D concentrations were lowest in participants with frailty, intermediate in participants with pre-frailty and highest in participants without frailty. The odds of frailty in the lowest quartile of serum 25(OH)D was 1.94 times the odds in the highest quartile (95% confidence interval (CI): 1.09-3.44). Mortality was positively associated with frailty, with the risk among participants who were frail and had low serum 25(OH)D being significantly higher than those who were not frail and who had high concentrations of serum 25(OH)D (hazards ratio 2.98; 95% CI: 2.01-4.42). CONCLUSION: Our results suggest that low serum 25(OH)D is associated with frailty, and there is additive joint effects of serum 25(OH)D and frailty on all-cause mortality in older adults.

Novel neuropeptide Y1 and Y5 receptor gene variants: associations with serum triglyceride and high-density lipoprotein cholesterol levels.

Neuropeptide Y (NPY) appears to play a critical role in the integration of appetite and energy expenditure through NPY Y1 and Y5 receptor subtypes. Moreover, the NPY Y1 receptor is highly expressed on human adipocytes, where it inhibits lipolysis. The genes encoding these receptors are transcribed co-ordinately in opposite directions from a common promoter in a region of chromosome 4 that has been previously linked to triglyceride and small low-density lipoprotein (LDL) particle concentration. Therefore, the purpose of this investigation was to examine the relationship between polymorphisms in the genes encoding NPY Y1 and Y5 and the development of obesity and dyslipidemia. We screened the promoter and coding regions and identified four polymorphic variants. One of these, a cytosine to thymine (C-->T) substitution in the untranslated region between the genes for NPY Y1 and Y5 (allele frequency 0.11), was significantly associated with both lower fasting triglyceride level (152 vs 125 mg/dl), and higher high-density lipoprotein (HDL) concentrations (49 vs 45 mg/dl) (p < 0.01) in 306 obese subjects. Given the stimulatory effect of NPY on adipocyte lipoprotein lipase (LPL) activity, and the lack of association of other polymorphisms with serum lipid levels, we hypothesize that this is a gain-in-function polymorphism.

A meta-analytic investigation of linkage and association of common leptin receptor (LEPR) polymorphisms with body mass index and waist circumference.

METHODS: We analyzed data pooled from nine studies on the human leptin receptor (LEPR) gene for the association of three alleles (K109R, Q223R and K656N) of LEPR with body mass index (BMI; kg/m(2)) and waist circumference (WC). A total of 3263 related and unrelated subjects from diverse ethnic backgrounds including African-American, Caucasian, Danish, Finnish, French Canadian and Nigerian were studied. We tested effects of individual alleles, joint effects of alleles at multiple loci, epistatic effects among alleles at different loci, effect modification by age, sex, diabetes and ethnicity, and pleiotropic genotype effects on BMI and WC. RESULTS: We found that none of the effects were significant at the 0.05 level. Heterogeneity tests showed that the variations of the non-significant effects are within the range of sampling variation. CONCLUSIONS: We conclude that, although certain genotypic effects could be population-specific, there was no statistically compelling evidence that any of the three LEPR alleles is associated with BMI or WC in the overall population.

Pooling analysis of genetic data: the association of leptin receptor (LEPR) polymorphisms with variables related to human adiposity.

Analysis of raw pooled data from distinct studies of a single question generates a single statistical conclusion with greater power and precision than conventional metaanalysis based on within-study estimates. However, conducting analyses with pooled genetic data, in particular, is a daunting task that raises important statistical issues. In the process of analyzing data pooled from nine studies on the human leptin receptor (LEPR) gene for the association of three alleles (K109R, Q223R, and K656N) of LEPR with body mass index (BMI; kilograms divided by the square of the height in meters) and waist circumference (WC), we encountered the following methodological challenges: data on relatives, missing data, multivariate analysis, multiallele analysis at multiple loci, heterogeneity, and epistasis. We propose herein statistical methods and procedures to deal with such issues. With a total of 3263 related and unrelated subjects from diverse ethnic backgrounds such as African-American, Caucasian, Danish, Finnish, French-Canadian, and Nigerian, we tested effects of individual alleles; joint effects of alleles at multiple loci; epistatic effects among alleles at different loci; effect modification by age, sex, diabetes, and ethnicity; and pleiotropic genotype effects on BMI and WC. The statistical methodologies were applied, before and after multiple imputation of missing observations, to pooled data as well as to individual data sets for estimates from each study, the latter leading to a metaanalysis. The results from the metaanalysis and the pooling analysis showed that none of the effects were significant at the 0.05 level of significance. Heterogeneity tests showed that the variations of the nonsignificant effects are within the range of sampling variation. Although certain genotypic effects could be population specific, there was no statistically compelling evidence that any of the three LEPR alleles is associated with BMI or waist circumference in the general population.

Television watching, energy intake, and obesity in US children: results from the third National Health and Nutrition Examination Survey, 1988-1994.

OBJECTIVES: To examine the relationship between television watching, energy intake, physical activity, and obesity status in US boys and girls, aged 8 to 16 years. METHODS: We used a nationally representative cross-sectional survey with an in-person interview and a medical examination, which included measurements of height and weight, daily hours of television watching, weekly participation in physical activity, and a dietary interview. Between 1988 and 1994, the Third National Health and Nutrition Examination Survey collected data on 4069 children. Mexican Americans and non-Hispanic blacks were oversampled to produce reliable estimates for these groups. RESULTS: The prevalence of obesity is lowest among children watching 1 or fewer hours of television a day, and highest among those watching 4 or more hours of television a day. Girls engaged in less physical activity and consumed fewer joules per day than boys. A higher percentage of non-Hispanic white boys reported participating in physical activity 5 or more times per week than any other race/ethnic and sex group. Television watching was positively associated with obesity among girls, even after controlling for age, race/ethnicity, family income, weekly physical activity, and energy intake. CONCLUSIONS: As the prevalence of overweight increases, the need to reduce sedentary behaviors and to promote a more active lifestyle becomes essential. Clinicians and public health interventionists should encourage active lifestyles to balance the energy intake of children.

Improving rates of advance directive discussions among managed care nursing home enrollees.

BACKGROUND: Discussions about advance directives should be offered to all nursing home residents. Managed Medicare programs for nursing home residents allow for the development of performance improvement initiatives to ensure that these discussions occur and are documented. PURPOSE: To assess the effectiveness of an intervention to increase discussion and documentation of advance directives for enrollees in a managed Medicare program for nursing home residents, and to evaluate whether this intervention affected preferences for cardiopulmonary resuscitation (CPR) and hospitalization among enrollees. SUBJECTS: Participants were 4,248 enrollees in a managed Medicare program in 1996, and 6,598 enrollees in 1997, in Georgia, Maryland, Massachusetts, Minnesota, Arizona, and Florida. DESIGN: Descriptive study of a quality improvement initiative. METHODS: A chart review was conducted in the fall of 1996 to determine the prevalence of documented advance directive discussions among all enrollees, and the preferences regarding CPR and hospitalization. Because the discussion rates varied across sites, and were lower than expected, each site developed strategies to improve advance directive discussion and documentation. One year later, a similar survey was conducted to determine the efficacy of the interventions, as well as to assess the impact, if any, on rates of desire for CPR and hospitalization. RESULTS: Documented discussions of advance directives increased across the six sites from 73% to 85% (P < 0.001). The overall percentage of patients desiring CPR did not change following the intervention (18%). However, there were geographical differences in the desire for CPR among enrollees, with those in Minnesota (8%), Arizona (11%), and Florida (12%) desiring it the least, and those in Massachusetts (20%), Georgia (29%), and Maryland (29%) desiring it the most. The overall percentage of desire for hospitalization decreased from 65% to 62% (P < 0.001). Enrollees in Georgia were most likely to want hospitalization (87%), and enrollees in Minnesota were the least likely to want hospitalization (57%). CONCLUSIONS: In a managed care program, documentation of advance directive discussions can be increased with focused efforts. Overall, most enrollees did not desire CPR, but a majority desired hospitalization. Despite the similarity of interventions and program philosophy across sites, significant geographic variations in desire for CPR and hospitalization remained.

Insulin response to glucose is lower in individuals homozygous for the Arg 64 variant of the beta-3-adrenergic receptor.

Type 2 diabetes mellitus (type 2 DM) is a polygenic disorder with a variable phenotype that includes both insulin resistance and insulin secretory dysfunction. The Arg 64 beta-3-adrenergic receptor variant allele is associated with an earlier age of onset of type 2 DM. The purpose of this study was to examine the in vivo pathophysiology of this variant allele to determine its contribution to the components of glucose metabolism. We used the frequently sampled iv glucose tolerance tests, minimal model analysis, and analysis of covariance to examine age- and fat-mass-adjusted differences among genotypes. The results demonstrate that individuals homozygous for the Arg 64 allele secrete significantly less insulin in response to a glucose infusion (562+/-116 vs. 962+/-94 pmol/microL), have the highest fasting glucose levels (100.4+/-1.9 vs. 92.48+/-1.60 mg/dL), and have lower glucose effectiveness (0.014+/-0.003 vs. 0.019+/-0.002 min(-1)), compared with those homozygous for the Trp 64 allele. This first report of decreased acute insulin release and lower glucose effectiveness in the Arg 64 genotype may help explain the earlier onset of type 2 DM observed in several populations of individuals with the Arg64 beta-3-adrenergic receptor variant allele.

Race/ethnicity, social class and their relation to physical inactivity during leisure time: results from the Third National Health and Nutrition Examination Survey, 1988-1994.

BACKGROUND: Physical inactivity is more prevalent among racial and ethnic minorities than among Caucasians. It is not known if differences in participation in leisure time physical activity are due to differences in social class. Thus, this paper provides estimates of the prevalence of physical inactivity during leisure time and its relationship to race/ethnicity and social class. METHODS: This was a national representative cross-sectional survey with an in-person interview and medical examination. Between 1988 and 1994, 18,885 adults aged 20 or older responded to the household adult and family questionnaires as part of the Third National Health and Nutrition Examination Survey . Mexican-Americans and African-Americans were over-sampled to produce reliable estimates for these groups. Multiple assessment of social class included education, family income, occupation, poverty status, employment status, and marital status. RESULTS: The age-adjusted prevalence (per 100) of adults reporting leisure time inactivity is lower among Caucasians (18%) than among African-Americans (35%) and Mexican-Americans (40%). African-American and Mexican-American men and women reported higher prevalence of leisure time inactivity than their Caucasian counterparts across almost every variable, including education, family income, occupation, employment, poverty and marital status. CONCLUSIONS: Current indicators of social class do not seem to explain the higher prevalence of physical inactivity during leisure time among African-American and Mexican-American. More research is needed to examine the effect of other constructs of social class such as acculturation, safety, social support and environmental barriers in promoting successful interventions to increase physical activity in these populations.

Deep vein thrombosis as a complication of megestrol acetate therapy among nursing home residents.

OBJECTIVES: To describe a cluster of cases of proximal deep vein thrombosis among nursing home residents treated with megestrol acetate, to identify other risk factors for deep vein thrombosis development among these patients, and to alert physicians to this potential complication of megestrol acetate therapy. DESIGN: Retrospective review. SETTING: A 129-bed Maryland nursing home. PARTICIPANTS: Nineteen residents prescribed megestrol acetate between November 1997 July 1998, identified by computerized pharmacy records. MEASUREMENTS: Demographic data (including identification of known risk factors for deep vein thrombosis development) were collected along with information on the indications for megestrol acetate therapy and its duration, diagnostic studies related to detection of deep vein thrombosis and their results, and patient outcomes following diagnosis of deep vein thrombosis. RESULTS: Megestrol acetate was prescribed for 18 nutritionally at-risk patients and one with uterine cancer. Six (32%) patients developed deep vein thrombosis signs and symptoms, and all diagnoses were confirmed as proximal deep vein thromboses with Doppler studies. (No diagnosis of deep vein thrombosis were made among any nursing home patients not being treated with megestrol acetate during the observation period.) All patients diagnosed with deep vein thrombosis were hospitalized and anticoagulated, but none were diagnosed with pulmonary embolus or died. The length [median (range)] of megestrol acetate treatment was similar regardless of whether deep vein thrombosis developed [117 (57-244) versus 143 (2-294) days, respectively, P = 0.83]. Stratification by length of treatment in 50-day increments revealed that most patients who developed deep vein thrombosis did so after 50 days of treatment (P = 0.046). CONCLUSION: A high incidence of deep vein thrombosis was identified among nursing home residents treated with megestrol acetate, even among ambulatory individuals with no other known risk factors. Because the efficacy of megestrol acetate treatment in nursing home residents with weight loss is unproven, the risk of deep vein thrombosis must be considered when prescribing megestrol acetate, and its use to treat nutritionally at-risk nursing home residents should be limited.

What can physicians do about obesity?

Obesity is a serious and very common health problem. In 1998, the American Heart Association announced the addition of obesity to its list of major risk factors that people can control to prevent death and disability from coronary heart disease ((1)).

Exercise benefits patients with osteoarthritis.

Osteoarthritis is the most prevalent joint disease in the United States. In 1998, the estimated prevalence in this country was 43 million ((1)). Between 1988 and 1994, 18.1% of US men and 23.5% of US women reported that they had experienced significant knee pain ((1)). The prevalence of self-reported arthritis in the United States is projected to increase from 15% of the population in 1990, to 18% (59 million people) in 2000, an increase of 20% ((2)).

Prevalence of significant knee pain among older Americans: results from the Third National Health and Nutrition Examination Survey.

OBJECTIVE: To assess the prevalence of persistent knee pain among older adults in the US. DESIGN: A nationally representative cross-sectional survey with an in-person interview and medical examination SETTING AND PARTICIPANTS: Between 1988 and 1994, 6596 adults aged 60 to 90+ years were examined as part of the National Health and Nutrition Examination Survey III. Mexican Americans and non-Hispanic blacks were over-sampled to produce reliable estimates for these groups. MAIN OUTCOME MEASUREMENTS: Participants were asked to report whether they had experienced knee pain on most days for the 6 weeks preceding their medical exam. RESULTS: Overall, 18.1% of US men and 23.5% of US women aged 60 years and older reported knee pain. Sixty- to ninety-year-old men reported knee pain less frequently than their age-matched female counterparts. There was a trend for reports of knee pain to increase steadily as these adults aged from 60 to 85 years. The highest prevalence of knee pain was reported among 85- to 90-year-old men (23.7%) and women (30.0%). Among non-Hispanic white adults older than age 60, 18.4% of men and 22.0% of women reported knee pain. Reports of knee pain among non-Hispanic black men and Mexican American men were similar to those of their non-Hispanic white counterparts. In contrast, 26.4% of Mexican American women and 32.8% of non-Hispanic black women reported knee pain. We also found that difficulty in performing physical functioning activities was associated with a higher prevalence of knee pain. CONCLUSIONS: Many US adults older than age 60 years report knee pain, and the prevalence is higher in older adults. Reports of knee pain are highest among non-Hispanic black women and the oldest Americans. Intervention strategies are needed to prevent and better manage knee pain among older US adults to stem the adverse health consequences and diminished quality of life associated with this common problem.

Tumor necrosis factor-alpha-238 and -308 polymorphisms do not associated with traits related to obesity and insulin resistance.

Tumor necrosis factor-alpha (TNF-alpha) is expressed primarily in adipocytes, and elevated levels of this cytokine have been linked to obesity and insulin resistance. The purpose of this investigation was to test whether the TNF-alpha-308 polymorphism (previously linked to insulin resistance and increased leptin levels) and the TNF-alpha-238 polymorphism (linked to decreased insulin resistance) were associated with insulin resistance or obesity-related traits in 424 subjects self-referred to the Johns Hopkins Weight Management Center (JHWMC). There were no differences in allele frequencies of either polymorphism by obesity category in the JHWMC and a lean control group. Despite previous smaller studies that have linked insulin resistance and the 308 allele, we found no such relationship in the JHWMC population. Instead, homozygotes for this allele had a significantly lower BMI than their counterparts without the polymorphism. In addition, we found no relationship between the 238 polymorphism and BMI, fasting glucose, or log of fasting insulin.

Impact of weight loss on health-related quality of life.

To examine the effect of treatment-induced weight loss on Health-Related Quality of Life (HRQL), 38 mildly-to-moderately overweight persons recruited to participate in a study to examine the efficacy of a lifestyle modification treatment program completed a sociodemographic questionnaire, the Beck Depression Inventory (BDI), the Medical Outcomes Study Short-Form Health Survey (SF-36, as an assessment of HRQL), and underwent a series of clinical evaluations prior to treatment. After baseline evaluations, participants were randomly assigned to either a program of lifestyle physical activity or a program of traditional aerobic activity. Participants again completed the SF-36 and BDI after the 13-week treatment program had ended. Weight loss averaged 8.6 +/- 2.8 kg over the 13-week study. We found that weight loss was associated with significantly higher scores (enhanced HRQL), relative to baseline, on the physical functioning, role-physical, general health, vitality and mental health domains of the SF-36. The largest improvements were with respect to the vitality, general health perception and role-physical domains. There were no significant differences between the lifestyle and aerobic activity groups on any of the study measures. These data indicate that, at least in the short-term, weight loss appears to profoundly enhance HRQL.