Change in Objectively Measured Activity Levels Resulting from the EMPOWER Study Lifestyle Intervention.

Purpose: To examine changes in physical activity (PA) during a behavioral weight-loss intervention and determine baseline factors associated with PA goal achievement. Methods: Overweight/obese community-dwelling adults with valid PA accelerometer data (N=116; mean age 51.7 years; 89% female; 83% non-Hispanic White) were recruited into a single-arm prospective cohort study examining the effects of a 12-month intervention that included 24 in-person group sessions, weight-loss, calorie, fat gram, and PA goals, self-monitoring, and feedback. Minutes of moderate-to-vigorous (MV) PA and steps were measured using a waist-worn accelerometer (ActiGraph GT3x) at baseline, 6 months, and 12 months. Achievement of the 150 minute/week MVPA goal was examined using total minutes and bout minutes (i.e., counting only PA occurring in bouts ≥10 minutes in length). Change in PA was analyzed using non-parametric tests for multiple comparisons. Associations of factors with meeting the PA goal were modeled using binary logistic regression. Results: At 6 months, there were increases from baseline in MVPA (median [p25, p75]: 5.3 [-0.9, 17.6] minutes/day) and steps (863 [-145, 2790] steps/day), both p<0.001. At 12 months, improvements were attenuated (MVPA: 2.4 [-2.0, 11.4] minutes/day, p=0.047; steps: 374[-570, 1804] p=0.14). At 6 months, 33.6% of individuals met the PA goal (using total or bout minutes). At 12 months, the percent meeting the goal using total MVPA [31%] differed from bout MVPA [22.4%]. Male gender (OR=4.14, p=0.027) and an autumn program start (versus winter; OR=3.39, p=0.011) were associated with greater odds of goal achievement at 6 months. Conclusions: The intervention increased PA goal achievement at 6 and 12 months with many making clinically meaningful improvements. Our results suggest female participants may require extra support toward improving PA levels.

Long-term effects of lifestyle and metformin interventions in DPP on bone density.

In the Diabetes Prevention Program Outcome Study (DPPOS), a cohort at high risk of diabetes, randomization to intensive lifestyle intervention or metformin, both associated with weight loss, did not have long-term negative effects on BMD compared with the placebo group. Potential positive effects of metformin on bone warrant further investigation. INTRODUCTION: Randomization to lifestyle intervention (ILS) or metformin in the Diabetes Prevention Program (DPP) resulted in weight loss and reduced progression to diabetes. Weight loss is associated with reduced bone mineral density (BMD), but the long-term effects of these interventions on BMD are unknown. In the DPP Outcome Study (DPPOS), we determined if randomization to ILS or metformin, compared with placebo, was associated with differences in BMD approximately 16 years later. METHODS: Of 3234 DPP participants, 2779 continued in DPPOS and were offered ILS in group format. Those randomized to metformin were offered unmasked metformin. At DPPOS year 12, 1367 participants had dual-energy X-ray absorptiometry scans. BMD in metformin and ILS groups was compared to placebo using sex-specific linear regression models, adjusted for age, race/ethnicity, and weight and weight-bearing activity at DPP baseline. RESULTS: At DPPOS year 12, mean age was 66.5 (±9.5) years. Femoral neck BMD was similar in the ILS and placebo groups in men (difference = -0.021 g/cm2, 95%CI (-0.063, 0.021)) and in women (+0.014 g/cm2, 95%CI (-0.014, 0.042)). Femoral neck BMD was higher in the metformin compared to placebo group although not statistically different in men (+0.017 g/cm2, 95% CI (-0.023, 0.058)) and in women (+0.019 g/cm2, 95% CI (-0.009, 0.047)). Prevalence of osteoporosis was low and similar across treatment groups in men (0.9%; p=0.745) and women (2.4%; p=0.466). CONCLUSION: In a cohort at high risk of diabetes, lifestyle intervention or metformin did not appear to have long-term negative effects on BMD. Potential positive effects of metformin on bone warrant further research.

Long-term changes in dietary and food intake behaviour in the Diabetes Prevention Program Outcomes Study.

AIMS: To compare change in dietary intake, with an emphasis on food groups and food intake behaviour, over time across treatment arms in a diabetes prevention trial and to assess the differences in dietary intake among demographic groups within treatment arms. METHODS: Data are from the Diabetes Prevention Program and Diabetes Prevention Program Outcomes Study. Participants were randomized to a lifestyle intervention (n = 1079), metformin (n = 1073) or placebo (n = 1082) for an average of 3 years, after which the initial results regarding the benefits of the lifestyle intervention were released and all participants were offered a modified lifestyle intervention. Dietary intake was assessed using a food frequency questionnaire at baseline and at 1, 5, 6 and 9 years after randomization. RESULTS: Compared with the metformin and placebo arms, participants in the lifestyle arm maintained a lower total fat and saturated fat and a higher fibre intake up to 9 years after randomization and lower intakes of red meat and sweets were maintained for up to 5 years. Younger participants had higher intakes of poultry and lower intakes of fruits compared with their older counterparts, particularly in the lifestyle arm. Black participants tended to have lower dairy and higher poultry intakes compared with white and Hispanic participants. In the lifestyle arm, men tended to have higher grain, fruit and fish intakes than women. CONCLUSIONS: Changes in nutrient intake among participants in the lifestyle intervention were maintained for up to 9 years. Younger participants reported more unhealthy diets over time and thus may benefit from additional support to achieve and maintain dietary goals.

Associations between accelerometer-derived physical activity and regional adiposity in young men and women.

OBJECTIVE: Empirical evidence supports an inverse relationship between physical activity (PA) and adiposity, but studies using detailed measures of both are scarce. The relationship between regional adiposity and accelerometer-derived PA in men and women are described. DESIGN AND METHODS: Cross-sectional analysis included 253 participants from a weight loss study limited to ages 20-45 years and BMI 25-39.9 kg m(-2) . PA data were collected with accelerometers and expressed as total accelerometer counts and average amount of time per day accumulated in different intensity levels [sedentary, light-, and moderate-to-vigorous intensity PA (MVPA)]. Accumulation of time spent above 100 counts was expressed as total active time. Computed tomography (CT) was used to measure abdominal and adipose tissue (AT). Multivariate linear regression analyses were used to assess the relationship between regional adiposity (dependent variable) and the various PA levels (independent variable), and were executed separately for men and women, adjusting for wear time, age, race, education, and BMI. RESULTS: Among males, light activity was inversely associated with total AT (ß = -0.19; P = 0.02) as well as visceral AT (VAT) (ß = -0.30; P = 0.03). Among females sedentary time was positively associated with VAT (ß = 0.11; P = 0.04) and total active time was inversely associated with VAT (ß = -0.12; P = 0.04). CONCLUSIONS: Findings from this study suggest that PA intensity level may influence regional adiposity differently in men and women. Additional research is needed in larger samples to clarify the difference in these associations by sex, create recommendations for the frequency, duration and intensity of PA needed to target fat deposits, and determine if these recommendations should differ by sex.

A new approach of measuring muscle impairment during a functional task: quadriceps muscle activity recorded during chair stand.

BACKGROUND: Biologic changes are expected to occur prior to disability. Compared with physical disability measures, measures of muscle impairment may be an earlier indicator of functional decline. The purpose of this study was to describe a new approach of measuring muscle impairment during a functional task. METHODS: Right quadriceps muscle activity was recorded using surface electromyography (sEMG) from 160 older women (age 73.9 +/- 3.9 years, mean +/- SD). Specific patterns of muscle activity during the chair stand task were determined using an exploratory principal components factor analysis (PCFA). Muscle activity parameters were validated by comparison to the Physical Performance Test, gait speed, and the Functional Status Questionnaire. RESULTS: The PCFA indicated two factors (magnitude and timing) that represented important components of quadriceps muscle activity during chair stand, explaining 68.6% of the variance in performance. The slope of the rise of muscle activity represents a combination of the magnitude and timing components of muscle activity. Compared with women with a slope <1, women with a slope > or = 1 walked faster (1.17 m/s vs 1.09 m/s; p = .02) and reported less difficulty with activities of daily living (ADL) (98.6 vs 95.8; p = .003) and instrumental ADL (97.3 vs 92.2; p = .001). CONCLUSIONS: Quadriceps muscle activity recorded during chair stand is a valid and reliable measure of muscle performance during a functional task. As a biologic measure of muscle activation, sEMG may identify muscle impairment, which could indicate functional decline earlier than measures of functional status.

Physical activity, physical fitness, and insulin and glucose concentrations in an isolated Native Canadian population experiencing rapid lifestyle change.

OBJECTIVE: Little is known about the relation of physical activity and physical fitness to insulin resistance and glucose intolerance in isolated subarctic Native Canadian populations. The purpose of this effort was to examine the relation between activity and fitness and obesity and glucose concentrations in such a unique population. RESEARCH DESIGN AND METHODS: This study describes 530 men and women from the community of Sandy Lake, Ontario, located in the boreal forest region of central Canada. Fasting blood glucose and insulin concentrations were determined after an overnight fast. Past year physical activity levels were assessed using a modified version of an interviewer-administered questionnaire. Maximal oxygen uptake, a measure of cardiovascular fitness, was estimated using a submaximal step test. RESULTS: Total (leisure and occupational) physical activity and physical fitness were significantly associated with fasting insulin concentrations after adjusting for age, BMI or percent body fat, waist circumference, and fasting glucose concentration in men but not in women. The relations between physical activity, fitness, and fasting glucose concentrations were not as strong or as consistent as they were when fasting insulin concentration was the dependent variable. CONCLUSIONS: In this isolated Native Canadian community, both physical activity and fitness were independently associated with fasting insulin concentrations, suggesting a beneficial role of physical activity/fitness on insulin sensitivity that is separate from any influence of activity on body composition. The fact that this relation was found in men but not in women is most likely explained by issues related to the measurement of activity and fitness in this study and the fact that the women in this population appear to be less active than the men.

Physical activity and cardiovascular risk factors in a developing population.

PURPOSE: Noncommunicable diseases are emerging in developing countries. However, few studies have been conducted in those countries to evaluate the role of physical activity in the development of cardiovascular diseases. This study investigated physical activity and its relationship to risk factors for cardiovascular disease in a large population (N = 799) of civil servants from Benin City, Nigeria. METHODS: Physical activity levels were estimated by an interviewer-administered questionnaire, which determined the average hours per week over the past year spent in occupational and leisure activities. Time spent walking or biking to work was assessed as well. Other major measures included body mass index (BMI), waist-hip ratio (WHR), blood pressures, plasma insulin level, lipid profiles, and diet. RESULTS: More of the physical activity was attributed to occupational than to leisure activities. Compared with women, men had a higher activity level. No significant trend was observed across age groups. Male senior staff (a marker of higher socioeconomic status) had a lower physical activity level than male junior staff. Physical activity, especially time walking or biking to work, was inversely correlated with weight, BMI, WHR, blood pressures, insulin, total cholesterol, LDL and HDL cholesterol, and triglycerides in men, while such correlations were not consistent in women. In multivariate analysis in men, blood pressure and insulin were independently associated with BMI but not with walking, while an independent inverse association was seen between walking and BMI. CONCLUSION: Lack of physical activity was associated with adverse risk profiles for cardiovascular disease in this developing population.

Association of physical activity and serum insulin concentrations in two populations at high risk for type 2 diabetes but differing by BMI.

OBJECTIVE: Physical activity and insulin sensitivity are related in epidemiological studies, but the consistency of this finding among populations that greatly differ in body size is uncertain. The present multiethnic epidemiological study examined whether physical activity was related to insulin concentrations in two populations at high risk for diabetes that greatly differ by location, ethnic group, and BMI. RESEARCH DESIGN AND METHODS: The study populations consisted of 2,321 nondiabetic Pima Indian men and women aged 15-59 years from Arizona and 2,716 nondiabetic men and women aged 35-54 years from Mauritius. Insulin sensitivity was estimated by mean insulin concentration (average of the fasting and postload insulin), and total (i.e., leisure and occupational) physical activity was assessed by questionnaire. RESULTS: Pima men and women who were more active had significantly (P < 0.05) lower mean insulin concentrations than those less active (BMI and age-adjusted means were 179 vs. 200 and 237 vs. 268 pmol/l). Similar findings were noted in Mauritian men and women (94 vs. 122 and 127 vs. 148 pmol/l). In both populations, activity remained significantly associated with mean insulin concentration controlled for age, BMI, waist-to-thigh or waist-to-hip ratio, and mean glucose concentrations. CONCLUSIONS: Physical activity was negatively associated with insulin concentrations both in the Pima Indians, who tend to be overweight, and in Mauritians, who are leaner. These findings suggest a beneficial role of activity on insulin sensitivity that is separate from any influence of activity on body composition.

The effect of Indian or Anglo dietary preference on the incidence of diabetes in Pima Indians.

OBJECTIVE: In short-term studies, adoption of a traditional diet is associated with reduction in metabolic abnormalities often found in populations experiencing rapid lifestyle changes. We examined the long-term effects of a self-assessed traditional or nontraditional dietary pattern on the development of type 2 diabetes in 165 nondiabetic Pima Indians. RESEARCH DESIGN AND METHODS: Dietary intake was assessed in 1988 by a quantitative food frequency method, and subjects were asked to classify their diet as "Indian," "Anglo," or "mixed." The Indian diet reflects a preference for Sonoran-style and traditional desert foods. The Anglo diet reflects a preference for non-Sonoran-style foods typical of the remaining regions of the U.S. RESULTS: In women, the intake of complex carbohydrates, dietary fiber, insoluble fiber, vegetable proteins, and the proportion of total calories from complex carbohydrate and vegetable proteins were significantly higher (P < 0.05) in the Indian than in the Anglo diet. The mixed diet was intermediate in of all these constituents. In men, the intake for these nutrients was also higher in the Indian than in the Anglo group, but not significantly. Diabetes developed in 36 subjects (8 men and 28 women) during 6.2 years of follow-up (range 0.9-10.9). The crude incidence rates of diabetes were 23. 35, and 63 cases per 1,000 person-years in the Indian. mixed, and Anglo groups, respectively. After adjustment for age, sex, BMI, and total energy intake in a proportional hazards model, the risk of developing diabetes in the Anglo-diet group was 2.5 times as high (95%) CI 0.9-7.2) and the rate in the mixed-diet group was 1.3 times as high (0.6-3.3) as in the Indian-diet group. CONCLUSIONS: This study suggests that the adoption of an Anglo diet may increase the risk of developing diabetes in Pima Indians, but it does not provide unequivocal evidence for or against this hypothesis.

Physical activity and reduced risk of ovarian cancer.

OBJECTIVE: To examine the relation between leisure-time physical activity and ovarian cancer. METHODS: We used data from a population based case-control study. Cases (n = 767) were women 20-69 years of age in whom epithelial ovarian cancer was diagnosed during 1994-1998 and who resided in a defined region of Pennsylvania, New Jersey, or Delaware. Controls (n = 1367) were ascertained by using random-digit dialing and Health Care Financing Administration files and were frequency-matched to cases for age and county of residence. Information on lifetime leisure-time physical activity was obtained during in-person interviews. RESULTS: Leisure-time physical activity was significantly associated with reduced occurrence of ovarian cancer (P =.01). After adjustment for age, parity, oral contraceptive use, tubal ligation, family history of ovarian cancer, race, and body mass index, women with the highest level of activity had an odds ratio of 0.73 (95% CI 0.56, 0.94) for ovarian cancer compared with women with the lowest level of activity. When the relation was analyzed by various recalled time periods during life, the odds ratios for the highest versus the lowest category of activity at ages 14-17, 18-21, 22-29, 30-39, 40-49, and >50 years ranged from 0.64-0.78. CONCLUSION: Leisure-time physical activity is associated with reduced occurrence of epithelial ovarian cancer.

Ethnic and cultural issues in assessing physical activity.

Although the physical activity questionnaire, in general, is the most common measure of physical activity levels in minority subgroups, additional measures may be needed to supplement the information collected by questionnaire alone. The most frequent types of physical activities performed in many of these minority groups are often lower intensity activities. However, when assessing activity by questionnaire, we know that lower intensity activities like walking and housework tend to be less reproducible than higher intensity activities such as many of the organized sports (Kriska et al., 1990; Sallis et al., 1985). Therefore, the activity questionnaire alone may not be the best way to quantify these lower intensity, variable frequency, life-style activities. As Figure 3 reminds us, measurement of lower intensity activities may require the use of more objective measures. One feasible approach may be to use a simple, inexpensive, objective measure of activity like an activity monitor or a pedometer. Step monitors are now successfully being used to estimate levels of movement expressed as "daily steps taken throughout the day" and to document activity changes in intervention efforts. However, activity monitors also have their own set of limitations such as the inability of capturing cycling, swimming, and upper body movement. Likewise, monitors certainly are not as practical as physical activity questionnaires in assessing activity in population studies. It is likely that a combination of the two methods of activity assessment would work best. Individuals who have scored low on the activity questionnaire could be given a step monitor to further evaluate their physical activity levels. Although promising, much more work needs to be done in this area.

Longitudinal changes in physical activity in a biracial cohort during adolescence.

PURPOSE: This report describes the development and use of two self-report methods and an objective measure to assess longitudinal changes in physical activity in a large biethnic cohort of young girls from childhood through adolescence. METHODS: The NHLBI Growth and Health Study (NGHS) is a multicenter study of obesity development in 2379 black and white girls followed from ages 9-10 yr to 18-19 yr (NGHS years 1-10). A Caltrac activity monitor was used to objectively quantify activity levels in years 3-5. A 3-d diary (AD) and a habitual patterns questionnaire (HAQ) were administered annually and biannually, respectively, to subjectively quantify physical activity levels. The changing pattern of activities as the girls matured during the 10-yr study period necessitated periodic form changes. Empirical analytic approaches were developed to help distinguish between true longitudinal changes in activity levels from potential numerical artifacts resulting from modifications in forms. RESULTS: The longitudinal activity data indicate a steep decline in the level of reported activity from baseline to year 10 as indicated by AD scores (446.8 to 292.1 MET-min x d(-1), 35%) as well as by HAQ scores (29.3 to 4.9 MET-times x wk(-1), 83%). This parallel trend in the pattern of the decline in activity among the two self-report methods was mirrored by a similar decline using the Caltrac method of physical activity assessment. From years 3 to 5, the AD decreased by 22%, whereas both the HAQ and Caltrac declined by 21%. CONCLUSION: The longitudinal data on physical activity collected in the NGHS cohort further confirm a dramatic decrease in the overall level of physical activity during the transition from childhood to adolescence. The consistency among the three methods indicate that both the AD and HAQ are useful tools for the assessment of activity levels in adolescent girls.

American College of Sports Medicine position stand. Exercise and type 2 diabetes.

Physical activity, including appropriate endurance and resistance training, is a major therapeutic modality for type 2 diabetes. Unfortunately, too often physical activity is an underutilized therapy. Favorable changes in glucose tolerance and insulin sensitivity usually deteriorate within 72 h of the last exercise session: consequently, regular physical activity is imperative to sustain glucose-lowering effects and improved insulin sensitivity. Individuals with type 2 diabetes should strive to achieve a minimum cumulative total of 1,000 kcal x wk(-1) from physical activities. Those with type 2 diabetes generally have a lower level of fitness (VO2max) than nondiabetic individuals. and therefore exercise intensity should be at a comfortable level (RPE 10-12) in the initial periods of training and should progress cautiously as tolerance for activity improves. Resistance training has the potential to improve muscle strength and endurance, enhance flexibility and body composition, decrease risk factors for cardiovascular disease, and result in improved glucose tolerance and insulin sensitivity. Modifications to exercise type and/or intensity may be necessary for those who have complications of diabetes. Individuals with type 2 diabetes may develop autonomic neuropathy, which affects the heart rate response to exercise, and as a result, ratings of perceived exertion rather than heart rate may need to be used for moderating intensity of physical activity. Although walking may be the most convenient low-impact mode, some persons, because of peripheral neuropathy and/or foot problems, may need to do non-weight-bearing activities. Outcome expectations may contribute significantly to motivation to begin and maintain an exercise program. Interventions designed to encourage adoption of an exercise regimen must be responsive to the individual's current stage of readiness and focus efforts on moving the individual through the various "stages of change."

Self-administered questionnaire compared with interview to assess past-year physical activity.

PURPOSE: The Modifiable Activity Questionnaire (MAQ) is a physical activity questionnaire shown to be both valid and reliable and was initially designed to be interviewer-administered. After translation and adaptation into French, the objective of the study was to compare past-year physical activity data obtained by self-administration of this questionnaire and by interviewer-administration. METHODS: 84 subjects (22 men, 62 women, age 36-63 yr) enrolled in an ongoing prospective study in France (the SUpplementation en VItamines et Minéraux AntioXydants or SU.VI.MAX study) completed both versions of the questionnaire in a randomized order with a mean (SD) delay of 7.9 (5.8) d between the two modes. Past-year leisure and occupational physical activity were expressed as both h x wk(-1) and MET-h x wk(-1) of activity, and television watching was expressed as h x d(-1). Analysis of variance on ranks was used to compare activity variables obtained by self-administration and interview. Agreement was assessed by nonparametric intraclass correlation coefficients. RESULTS: A significant effect of the mode of administration was found only for past-year leisure physical activity with lower values reported in self-administered conditions compared with interview. However, a high level of concordance between the two modes of administration was observed for all variables as shown by the intraclass correlation coefficients: 0.90 for leisure physical activity (h x wk(-1)), 0.82 for occupational activity (h x wk(-1)), 0.83 for total (leisure and occupational combined) physical activity (h x wk(-1)), and 0.97 for television viewing (h x d(-1)). CONCLUSIONS: The agreement between the two modes of administration of the questionnaire suggests that the self-administered version of the MAQ is a valuable tool to assess past-year physical activity and inactivity in self-administered conditions. This instrument could be used in large-scale population studies investigating the relationships between physical activity and health outcomes.

Physical activity and the prevention of type 2 diabetes mellitus: how much for how long?

From observational studies to clinical trials in a variety of populations and age groups, evidence is mounting in support of the hypothesis that physical activity plays a significant role in the prevention of type 2 diabetes mellitus. Based on the current findings, it is likely that physical activity can reduce the risk of diabetes mellitus development. What is less clear is how much physical activity is necessary, and for how long. Obviously, we are more likely to see the anticipated physiological changes if we maximise the dose. Yet, although maximal is better from a physiological point of view, we 'in the trenches' have also recognised the fact that a sedentary individual will most likely not continue to undergo a high intensity activity exercise regimen. In contrast, evidence is mounting regarding long term compliance to moderate levels of activity, which appear to be easier to adopt in one's lifestyle and are less likely to result in injury. More importantly, there appear to be beneficial changes in insulin sensitivity and glucose tolerance in the sedentary individual who incorporates moderate levels of activity such as walking into the their lifestyle, although the onset of beneficial metabolic changes appear to occur much more slowly and less dramatically than what occurs with a high intensity regimen. Even if activity is shown to be beneficial, we are faced with the challenge of reaching the sedentary individuals who would most likely benefit from an increase in physical activity in the first place. This task is a difficult one because of the difficulty in quantifying the sum total of an entire day's worth of movement, rather than that of a few relatively higher intensity leisure activities. What is needed is a measure or combination of measures of physical activity that are simple to use, relatively inexpensive, and adequately capture the subtle changes in physical activity through the day that we are encouraging. It is unlikely that the protective nature of a physically active lifestyle in preventing diabetes mellitus will have a lasting impact once a switch to a sedentary way of life is made. Therefore, from a public health viewpoint, long term commitments to increased activity are required. This is the ultimate challenge.

Correlates of quantitative ultrasound in the Women's Healthy Lifestyle Project.

Quantitative ultrasound (QUS) assessment of bone is a strong predictor of hip fractures and is currently an FDA-approved tool to identify women at risk of osteoporosis. However, few studies have investigated the lifestyle and genetic correlates of QUS in women. This study investigated the cross-sectional associates of several lifestyle, demographic and genetic factors with calcaneal QUS parameters (broadband ultrasound attenuation (BUA) and speed of sound (SOS)) in 393 women aged 45-53 years. Leisure-time and historical physical activity, dietary calcium and protein, body composition, vitamin D receptor genotypes, menopause status, other health behaviors, calcaneal QUS parameters and bone mineral density (BMD) were assessed at a single clinic visit. Lean mass, recent physical activity and African-American race were the strongest correlates of SOS whereas dietary protein, calcium and recent physical activity were the strongest correlates of BUA. These predictors explained 13% and 6% of the variance in SOS and BUA, respectively. Smoking, alcohol intake, education, hormone replacement therapy, calcium and vitamin D supplements, historical physical activity and vitamin D receptor genotypes were not significantly associated with BUA or SOS. Lean body mass and premenopausal status were the strongest correlates of lumbar BMD whereas lean body mass, physical activity, African-American race and body mass index were significantly related to femoral neck BMD. Physical activity remained predictive of SOS after controlling for lumbar BMD. The spectrum and magnitude of risk factors for SOS and BUA, including lean body mass, physical activity, race, protein and calcium intake, parallel previously observed predictors of BMD.

Knowledge, attitudes and behaviors related to physical activity among Native Americans with diabetes.

OBJECTIVE: Native Americans (NA) have higher diabetes morbidity and mortality compared to other ethnic groups. Although exercise plays an important role in diabetes management, little is known about exercise among Native Americans with diabetes. Our goal was to describe knowledge, attitudes and behaviors related to exercise in Native American participants in New Mexico. DESIGN: Bilingual community members administered a questionnaire to assess knowledge, stage of change (a measure of exercise readiness), and physical activity behavior. Hemoglobin A1c (HbA1c) was measured by DCA 2000 analyzer. Height and weight were measured to calculate body mass index (BMI). Average random blood glucose (RBS) levels and diabetes duration were assessed through chart audit. SETTING: Questionnaires were completed in offices in or near the communities. PARTICIPANTS: 514 Native Americans with diabetes were identified as potential participants, 40% (142 women, 64 men) participated. RESULTS: 37% of participants knew exercise lowers blood sugar. 82% reported they were in the preparation, action, or maintenance stage of change for exercise behavior. Seventy seven percent of this population did not meet the Surgeon General's recommendation for accumulating 30 minutes of leisure time endurance exercise on most days of the week. However, 67% of participants fell within the "high activity" category for all moderate and vigorous activities. Average age, BMI and HbA1c were 58.5 yrs., 30.5 kg/m2, 8.6%, respectively. CONCLUSIONS: Interventions to increase physical activity awareness and participation could improve diabetes management and overall health for Native Americans. When evaluating physical activity, researchers need to consider usual activities of daily living and leisure time activities specific to that population. Failure to do so would be ethnocentric and could lead to inappropriate conclusions.

A randomized walking trial in postmenopausal women: effects on physical activity and health 10 years later.

BACKGROUND: It is important to determine if permanent lifestyle changes may result from physical activity interventions and whether health may be affected by these changes. OBJECTIVE: To conduct a 10-year follow-up of physical activity and self-reported health status in participants of a randomized clinical trial of walking intervention. METHODS: Of the original 229 volunteer postmenopausal women who participated in the original clinical trial, 196 (N = 96 intervention and 100 controls) completed the 10-year follow-up telephone interview. The interview protocol included questions on self-reported walking for exercise and purposes other than exercise, the Paffenbarger sport and exercise index, functional status, and various chronic diseases and conditions. RESULTS: The median values for both usual walking for exercise and total walking were significantly higher for walkers compared with controls (for both, P = .01), with median differences of 706 and 420 kcal/wk, respectively. After excluding women who reported heart disease during the original trial, 2 women in the walking group (2%) and 11 women in the control group (12%) reported physician-diagnosed heart disease over the last 10 years (P = .07). There were also fewer hospitalizations, surgeries, and falls among women in the walking group, although these differences were not statistically significant (P>.05). CONCLUSIONS: Although limited by self-report, this study may be the first to demonstrate long-term exercise compliance to a randomized control trial in older women and to suggest that health benefits may have ensued as a result of these increased activity levels.

Occupational status and cardiovascular disease risk factors in the rapidly developing, high-risk population of Mauritius.

This study examined the relation between occupation and cardiovascular disease (CVD) risk factors in 2,795 individuals between ages 35 and 54 years from the rapidly developing island nation of Mauritius. Participants attended a 1992 population-based survey of noncommunicable disease (89.1 % response rate). Occupational status, physical activity in the previous year, cigarette smoking, and alcohol consumption were assessed by questionnaire. Anthropometric and metabolic measures included body mass index (kg/m2),waist-to-hip ratio, fasting serum high density lipoprotein cholesterol and low density lipoprotein cholesterol (LDL cholesterol), triglycerides, 2-hour postload plasma glucose and serum insulin concentrations, and blood pressure. In comparison with professional/skilled workers, age-adjusted means of insulin and glucose, LDL cholesterol, triglycerides, and systolic and diastolic blood pressures were significantly (p < 0.05) lower, and the age-adjusted mean for high density lipoprotein cholesterol was significantly higher for unskilled men. In women, risk factors other than LDL cholesterol varied significantly (p < 0.05) across occupational categories, with homemakers tending to have the least favorable profile. Unskilled workers reported significantly more physical activity (p < 0.01), alcohol consumption, and cigarette smoking (men only) (p < 0.05) than did the other groups. Adjustment for multiple covariates revealed an independent association between occupational status and most CVD risk factors, with physical activity attenuating this association. These results elucidate mediating behaviors of CVD risk across occupational categories that could be applied to intervention strategies in Mauritius.