Farah A. Ramirez-Marrero

How many steps/day are enough? For older adults and special populations

Older adults and special populations (living with disability and/or chronic illness that may limit mobility and/or physical endurance) can benefit from practicing a more physically active lifestyle, typically by increasing ambulatory activity. Step counting devices (accelerometers and pedometers) offer an opportunity to monitor daily ambulatory activity; however, an appropriate translation of public health guidelines in terms of steps/day is unknown. Therefore this review was conducted to translate public health recommendations in terms of steps/day. Normative data indicates that 1) healthy older adults average 2,000-9,000 steps/day, and 2) special populations average 1,200-8,800 steps/day. Pedometer-based interventions in older adults and special populations elicit a weighted increase of approximately 775 steps/day (or an effect size of 0.26) and 2,215 steps/day (or an effect size of 0.67), respectively. There is no evidence to inform a moderate intensity cadence (i.e., steps/minute) in older adults at this time. However, using the adult cadence of 100 steps/minute to demark the lower end of an absolutely-defined moderate intensity (i.e., 3 METs), and multiplying this by 30 minutes produces a reasonable heuristic (i.e., guiding) value of 3,000 steps. However, this cadence may be unattainable in some frail/diseased populations. Regardless, to truly translate public health guidelines, these steps should be taken over and above activities performed in the course of daily living, be of at least moderate intensity accumulated in minimally 10 minute bouts, and add up to at least 150 minutes over the week. Considering a daily background of 5,000 steps/day (which may actually be too high for some older adults and/or special populations), a computed translation approximates 8,000 steps on days that include a target of achieving 30 minutes of moderate-to-vigorous physical activity (MVPA), and approximately 7,100 steps/day if averaged over a week. Measured directly and including these background activities, the evidence suggests that 30 minutes of daily MVPA accumulated in addition to habitual daily activities in healthy older adults is equivalent to taking approximately 7,000-10,000 steps/day. Those living with disability and/or chronic illness (that limits mobility and or/physical endurance) display lower levels of background daily activity, and this will affect whole-day estimates of recommended physical activity.

Lifetime adult weight gain, central adiposity, and the risk of pre- and postmenopausal breast cancer in the Western New York exposures and breast cancer study

While there are quite consistent data regarding associations of body weight and postmenopausal breast cancer, there are now accumulating data that would indicate that weight gain in adult life is more predictive of risk than absolute body weight. There is, however, little known about the relative impact of timing of weight gain in adult life as well as other characteristics of the weight and breast cancer association that might provide insight into the mechanism of the observation. We conducted a population‐based case control study of breast cancer (1996–2001), the Western New York Exposures and Breast Cancer Study. Included were 1,166 women with primary, histologically confirmed, incident breast cancer and 2,105 controls frequency‐matched on age, race and county of residence. Unconditional logistic regression was used to estimate odds ratios and 95% confidence intervals. We found increased risk of breast cancer associated with lifetime adult weight gain among post‐ but not premenopausal women, and there was a 4% increase in risk for each 5 kg increase in adult weight. Further there was a tendency toward a stronger association for those with higher waist circumference and those with positive estrogen or progesterone status, and who had never used HRT. We also found an association with risk for weight gain since first pregnancy and for weight gain between the time of the first pregnancy and menopause, independent of body mass index and lifetime adult weight gain. Our results suggest that there are time periods of weight gain that have greater impact on risk, and that central body fat, receptor status and hormone replacement therapy may all affect the observed association.

Self-Reported Physical Activity in Hispanic Adults Living With HIV: Comparison With Accelerometer and Pedometer

Limited information is available regarding physical activity (PA) and its assessment in Hispanics living with HIV. This study compared self‐reported PA using the International Physical Activity Questionnaire (IPAQ) with objectively measured PA using the ActiGraph accelerometer and DigiWalker pedometer in 58 Hispanic adults with HIV. IPAQ was administered before and after a 7‐day period in which subjects wore the ActiGraph and DigiWalker. PA classification was based on ≥ 150 min/wk (IPAQ, ActiGraph) and ≥ 10,000 steps/day (DigiWalker). IPAQ‐PA was higher than ActiGraph‐PA (423 ± 298 vs. 165 ± 134 min/wk, respectively) (p < .01). There was a mismatch in PA classification with the IPAQ, ActiGraph, and DigiWalker (active = 81%, 54%, and 17%, respectively). Hispanics with HIV highly overestimated self‐reported PA. Nurse scientists and other investigators must consider accelerometers or pedometers to assess PA in this 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.

Physical activity in a cohort of HIV-positive and HIV-negative injection drug users

Abstract Physical activity is beneficial for persons with HIV infection but little is known about the relationships between physical activity, HIV treatment and injection drug use (IDU). This study compared physical activity levels between HIV-negative and HIV-positive injection drug users (IDUs) and between HIV-positive participants not on any treatment and participants on highly active antiretroviral therapy (HAART). Anthropometric measurements were obtained and an interviewer-administered modified Paffenbarger physical activity questionnaire was administered to 324 participants in a sub-study of the AIDS Linked to Intravenous Experiences (ALIVE) cohort, an ongoing study of HIV-negative and HIV-positive IDUs. Generalized linear models were used to obtain univariate means and to adjust for confounding (age, gender, employment and recent IDU). Vigorous activity was lower among HAART participants than HIV-positive participants not on treatment (p=0.0025) and somewhat lower than HIV-negative participants (p=0.11). Injection drug use and viral load were not associated with vigorous activity. Energy expenditure in vigorous activity was also lower among HAART participants than both HIV-negative and HIV-positive participants not on treatment. Thus, HIV-positive participants on HAART spend less time on vigorous activity independent of recent IDU. More research is needed into the reasons and mechanism for the lack of vigorous activities, including behavioral, psychological and physiological reasons.

Transport and health: a look at three Latin American cities

Transport is associated with environmental problems, economic losses, health and social inequalities. A number of European and US cities have implemented initiatives to promote multimodal modes of transport. In Latin America changes are occurring in public transport systems and a number of projects aimed at stimulating non-motorized modes of transport (walking and cycling) have already been implemented. Based on articles from peer-reviewed academic journals, this paper examines experiences in Bogotá (Colombia), Curitiba (Brazil), and Santiago (Chile), and identifies how changes to the transport system contribute to encourage active transportation. Bus rapid transit, ciclovias, bike paths/lanes, and car use restriction are initiatives that contribute to promoting active transportation in these cities. Few studies have been carried out on the relationship between transport and physical activity. Car ownership continues to increase. The public health sector needs to be a stronger activist in the transport policy decision-making process to incorporate health issues into the transport agenda in Latin America.

Self-Reported and Objective Physical Activity in Postgastric Bypass Surgery, Obese and Lean Adults: Association With Body Composition and Cardiorespiratory Fitness

BACKGROUND This study aimed to 1) describe physical activity (PA) in 15 post gastric bypass surgery (GB), 16 obese (Ob), and 14 lean (L) participants (mean ± se: age = 37.1 ± 1.6, 30.8 ± 1.9, 32.7 ± 2.3 yrs.; BMI = 29.7 ± 1.2, 38.2 ± 0.8, 22.9 ± 0.5 kg/m2, respectively); and 2) test associations between PA, body composition, and cardiorespiratory fitness (VO2max). METHODS Participants completed a PA questionnaire after wearing accelerometers from 5-7 days. Body composition was determined with DEXA and CT scans, and VO2max with open circuit spirometry. ANOVA was used to detect differences between groups, and linear regressions to evaluate associations between PA (self-reported, accelerometer), body composition, and VO2max. RESULTS Self-reported moderate to vigorous PA (MVPA) in GB, Ob, and L participants was 497.7 ± 215.9, 988.6 ± 230.8, and 770.7 ± 249.3 min/week, respectively (P = .51); accelerometer MVPA was 185.9 ± 41.7, 132.3 ± 51.1, and 322.2 ± 51.1 min/week, respectively (P = .03); and steps/day were 6647 ± 141, 6603 ± 377, and 9591 ± 377, respectively (P = .03). Ob showed a marginally higher difference between self-report and accelerometer MVPA (P = .06). Accelerometer-MVPA and steps/day were inversely associated with percent fat (r = -0.53, -0.46), and abdominal fat (r = -0.36, -0.40), and directly associated with VO2max (r = .36). CONCLUSIONS PA was similar between GB and Ob participants, and both were less active than L. Higher MVPA was associated with higher VO2max and lower body fat.

Predicting Resting Energy Expenditure in Healthy Puerto Rican Adults

Equations to predict resting energy expenditure (REE) can be influenced by cultural and climatic factors. The purpose of this cross-sectional study was to evaluate the validity of the Harris-Benedict and Mifflin-St Jeor equations to predict REE in 48 healthy Puerto Rican adults (23 men, 25 women; aged 21 to 60 years, tested between January and March 2007) using indirect calorimetry as the criterion method for comparison. Weight, height, and skinfold thickness were measured. One-way analysis of variance was used to determine differences between the REE measured and predicted with the two equations, and independent t tests were used to detect differences between men and women. Linear and multiple regressions were conducted to determine relationships between the measured and predicted REE and to evaluate factors influencing REE. The REE predicted with Harris-Benedict and Mifflin-St Jeor were not statistically different from the REE measured with indirect calorimetry (mean±standard deviation: 1,555±268, 1,500±285, and 1,633±299 kcal/day, respectively; P=0.08). There was a strong correlation between the REE measured and predicted with Harris-Benedict and Mifflin-St Jeor (r=0.83, 0.87, respectively; P=0.0001). Mean REE was higher in men compared to women, and fat-free mass was the most influencing factor on REE. The Harris-Benedict and Mifflin-St Jeor are both valid equations for the prediction of REE in healthy Puerto Rican adults living in a tropical climate such as Puerto Rico. Both equations are appropriate for dietetics practitioners to use in assessing energy requirements in this population.

Long-Term Participation in a Community-Based Fitness Program for Hispanic Adults Living with HIV Influences Health-Related Outcomes Fitness in Hispanic Adults Living with HIV

This study primarily evaluated the effects of a nine-month community-based exercise program on cardiometabolic risk factors and physical fitness for adults living with the human immunodeficiency virus (HIV). We evaluated several cardiometabolic measures (total cholesterol, triglycerides, and body composition), physical fitness variables (cardiorespiratory endurance, muscle strength and endurance, and flexibility), health status (Karnofsky) and immune profile (CD4) of adults living with HIV who participated in a community-based exercise program for a period of nine months. The exercise program adhered to guidelines from The American College of Sports Medicine and comprised of an aerobic, muscular strengthening/endurance, and neuromuscular training components. Participants were tested at baseline and every three months thereafter. Results showed positive changes in lipid profile (p < 0.040), body composition (p < 0.008), and muscle performance (p < 0.046) without affecting the immune system amongst the participants. In summary, it appears that adults living with HIV could benefit from participating in a community-based exercise programs without affecting their immune system.

Transporte e saúde: um olhar sobre três cidades latino-americanas

O transporte esta associado a problemas ambientais, perdas economicas, de saude da populacao e as desigualdades sociais. Em cidades da Europa e da America existem esforcos para promover o transporte multimodal. Na America Latina, ha projetos em andamento para mudar os sistemas de transporte e incentivar o transporte nao motorizado (caminhar e andar de bicicleta). Com base em uma revisao de artigos publicados em revistas academicas identificou-se como as mudancas no transporte contribuiram para promover o transporte ativo em Bogota (Colombia), Curitiba (Brasil) e Santiago (Chile). Apesar de que nestas tres cidades se estejam implementando iniciativas para promover o transporte ativo (sistema de onibus articulado, ciclovias, pistas de ciclismo e restricoes ao uso do automovel particular), poucos estudos tem sido desenvolvidos sobre a relacao entre transporte e atividade fisica utilitaria. O uso de carro particular continua aumentando. O setor da saude tem de ser um ativista forte para incorporar a saude publica na agenda de transportes na America Latina.