Carl J. Caspersen

Introduction to a Collection of Physical Activity Questionnaires

Physical activity has emerged as an important risk factor for many chronic diseases, such as coronary heart disease and diabetes. As part of an effort to improve public health by increasing physical activity levels of the nation, the Centers for Disease Control and Prevention and the American Colleg

Physical activity trends among 26 states, 1986-1990

Data to monitor physical activity from large, representative samples are rare. Therefore, we conducted standardized telephone surveys for 26 states participating in the Behavioral Risk Factor Surveillance System from 1986 through 1990. More than 34,800 adults aged 18 and older responded annually. We scored leisure time physical activity data into four patterns: 1) physically inactive, 2) irregularly active, 3) regularly active, not intensive, and 4) regularly active, intensive. Over time, roughly 6 in 10 persons were physically inactive or irregularly active. While almost 4 in 10 persons were regularly active, less than 1 in 10 were regularly active, intensive. There were statistically significant decreases (-2.3%) in physically inactive persons and significant increases (+2.1%) in persons classified as regularly active, intensive. The irregularly active pattern did not change, while only men of all ages and men less than age 30 increased the regularly active, not intensive pattern (+1.7% and +3.8, respectively). Improvements across the activity patterns varied by demographic group: women and older adults made the most beneficial changes, while races other than white and the least educated groups had unfavorable changes. Despite many improvements, most persons still did little or no physical activity, signaling the need for enhanced intervention efforts.

Test-retest reliability of the Minnesota Leisure Time Physical Activity Questionnaire☆

The test-retest reliability of the Minnesota Leisure Time Physical Activity Questionnaire was assessed by two administrations of the questionnaire at a five-week interval in 140 adults from a general population sample and at a two-week interval in 150 male participants in the Multiple Risk Factor Intervention Trial (MRFIT). In both study populations, there was a slight, nonsignificant drop in reported leisure time energy expenditure between the test and the retest. The largest test-retest differences in estimated energy expenditure were found among those reporting greater levels of energy expenditure. Nevertheless, in both study populations Spearman rank correlation coefficients between the test and retest were high--0.79 to 0.88 for total activity and ranging 0.69-0.86 among the light, moderate, and heavy intensity subcategories. The high reliability of the Minnesota Leisure Time Physical Activity Questionnaire corroborates its utility in epidemiologic research.

Epidemiology of walking and type 2 diabetes.

PURPOSE Diabetes is prevalent, deadly, serious, and costly. It affects an estimated 20.8 million Americans in 2005, having doubled from 1980, and is expected to reach at least 29 million by 2050. In 2002, diabetes was responsible for an estimated

Examining variations of resting metabolic rate of adults: a public health perspective.

132 billion in costs. Diabetes concerns leaders in public health and clinicians, and its personal, social, and economic burdens require preventive efforts such as the promotion of walking. As such, we reviewed the limited epidemiologic data of walking and incident diabetes (two studies) and walking and mortality outcomes among diabetic persons (three studies). METHODS We abstracted information from each paper to identify characteristics of the study population, details of the disease outcomes (diabetes incidence, mortality outcomes, or cardiovascular disease events among persons with diabetes), relative risks, risk reductions, and adjustment for covariates. RESULTS The reviewed studies were adjusted for important covariates such as age, body mass index, the coexistence of other nonwalking and vigorous activities, and so on and for biases such as differential misclassification of exposure. The strength of the observed reductions in risk were between approximately 20% and 40% for incident diabetes and between 40% and 55% for mortality due to all causes and due to cardiovascular disease (and related nonfatal events). Moderate to faster pace of walking seemed to enhance risk reduction. These reductions fit well with results of earlier reviews of physical activity and diabetes, and basically corresponded to 2-3 h of weekly walking. CONCLUSION Available dose-response data between walking and the aforementioned outcomes suggest that public health recommendations for physical activity might also apply to walking in particular. Regardless, important areas remain for future research on walking and diabetes.

Prevalence of Diagnosed Arthritis and Arthritis-Attributable Activity Limitation Among Adults With and Without Diagnosed Diabetes: United States, 2008–2010

PURPOSE There has not been a recent comprehensive effort to examine existing studies on the resting metabolic rate (RMR) of adults to identify the effect of common population demographic and anthropometric characteristics. Thus, we reviewed the literature on RMR (kcal·kg(-1)·h(-1)) to determine the relationship of age, sex, and obesity status to RMR as compared with the commonly accepted value for the metabolic equivalent (MET; e.g., 1.0 kcal·kg(-1)·h(-1)). METHODS Using several databases, scientific articles published from 1980 to 2011 were identified that measured RMR, and from those, others dating back to 1920 were identified. One hundred and ninety-seven studies were identified, resulting in 397 publication estimates of RMR that could represent a population subgroup. Inverse variance weighting technique was applied to compute means and 95% confidence intervals (CI). RESULTS The mean value for RMR was 0.863 kcal·kg(-1)·h(-1) (95% CI = 0.852-0.874), higher for men than women, decreasing with increasing age, and less in overweight than normal weight adults. Regardless of sex, adults with BMI ≥ 30 kg·m(-2) had the lowest RMR (<0.741 kcal·kg(-1)·h(-1)). CONCLUSIONS No single value for RMR is appropriate for all adults. Adhering to the nearly universally accepted MET convention may lead to the overestimation of the RMR of approximately 10% for men and almost 15% for women and be as high as 20%-30% for some demographic and anthropometric combinations. These large errors raise questions about the longstanding adherence to the conventional MET value for RMR. Failure to recognize this discrepancy may result in important miscalculations of energy expended from interventions using physical activity for diabetes and other chronic disease prevention efforts.

Absolute and relative energy costs of walking in a Brazilian adult probability sample.

OBJECTIVE To estimate the prevalence of diagnosed arthritis among U.S. adults and the proportion of arthritis-attributable activity limitation (AAAL) among those with arthritis by diagnosed diabetes mellitus (DM) status. RESEARCH DESIGN AND METHODS We estimated prevalences and their ratios using 2008–2010 U.S. National Health Interview Survey of noninstitutionalized U.S. adults aged ≥18 years. Respondents’ arthritis and DM status were both based on whether they reported a diagnosis of these diseases. Other characteristics used for stratification or adjustment included age, sex, race/ethnicity, education level, BMI, and physical activity level. RESULTS Among adults with DM, the unadjusted prevalences of arthritis and proportion of AAAL among adults with arthritis (national estimated cases in parentheses) were 48.1% (9.6 million) and 55.0% (5.3 million), respectively. After adjusting for other characteristics, the prevalence ratios of arthritis and of AAAL among arthritic adults with versus without DM (95% CI) were 1.44 (1.35–1.52) and 1.21 (1.15–1.28), respectively. The prevalence of arthritis increased with age and BMI and was higher for women, non-Hispanic whites, and inactive adults compared with their counterparts both among adults with and without DM (all P values < 0.05). Among adults with diagnosed DM and arthritis, the proportion of AAAL was associated with being obese, but was not significantly associated with age, sex, and race/ethnicity. CONCLUSIONS Among U.S. adults with diagnosed DM, nearly half also have diagnosed arthritis; moreover, more than half of those with both diseases had AAAL. Arthritis can be a barrier to physical activity among adults with diagnosed DM.

Secular changes in prediabetes indicators among older-adult Americans, 1999-2010.

BACKGROUND Walking is commonly recommended for enhancing energy expenditure (EE), a basic principle in weight management, and cardiorespiratory fitness. However, walking EE varies with characteristics of a given population, especially by sex and age. PURPOSE The studys purpose was to measure EE of walking as influenced by physical and physiological characteristics of a sample of adults (≥ 20 yr) living in Niterói, Rio de Janeiro, Brazil. METHODS Walking EE and HR were measured during a submaximal multistage treadmill test. The test stages lasted for 3 min each and started at a speed of 1.11 m·s(-1) and a grade of 0%. In the second stage, the grade was maintained at 0%, but the speed was increased to 1.56 m·s(-1) and maintained at this speed but with grade raised by 2.5% at each stage until 10% at stage 6. We measured resting oxygen consumption (MET m) before the test with the participants sitting quietly. RESULTS MET m (mL O2·kg(-1)·min(-1), mean ± SE) was lower both in women (2.85 ± 0.03) and in men (2.97 ± 0.04) by almost 19% and 15%, respectively, compared with the conventionally estimated MET (METe) of 3.5 mL O2·kg(-1)·min(-1). Walking EE for any given speed and grade had an absolute intensity, expressed as multiples of MET m or MET e, that was practically equal between sexes and age groups, but it incurred higher individual physiological demand or relative intensity for women and older adults. CONCLUSIONS Resting EE reflected by using METe is overestimated in the adult population of Niterói. Prescription of activities to counteract the existing worldwide obesity epidemic should be ideally based on individual physiological information, especially among women and older individuals.

Caspersen et al. Respond

BACKGROUND Sex-specific prediabetes estimates are not available for older-adult Americans. PURPOSE To estimate prediabetes prevalence, using nationally representative data, in civilian, non-institutionalized, older U.S. adults. METHODS Data from 7,995 participants aged ≥50 years from the 1999-2010 National Health and Nutrition Examination Surveys were analyzed in 2013. Prediabetes was defined as hemoglobin A1c=5.7%-6.4% (39-47 mmol/mol [HbA1c5.7]), fasting plasma glucose of 100-125 mg/dL (impaired fasting glucose [IFG]), or both. Crude and age-adjusted prevalences for prediabetes, HbA1c5.7, and IFG by sex and three age groups were calculated, with additional adjustment for sex, age, race/ethnicity, poverty status, education, living alone, and BMI. RESULTS From 1999 to 2005 and 2006 to 2010, prediabetes increased for adults aged 50-64 years (38.5% [95% CI=35.3, 41.8] to 45.9% [42.3, 49.5], p=0.003) and 65-74 years (41.3% [37.2, 45.5] to 47.9% [44.5, 51.3]; p=0.016), but not significantly for adults aged ≥75 years (45.1% [95% CI=41.1, 49.1] to 48.9% [95% CI=45.2, 52.6]; p>0.05). Prediabetes increased significantly for women in the two youngest age groups, and HbA1c5.7 for both sexes (except men aged ≥75 years), but IFG remained stable for both sexes. Men had higher prevalences than women for prediabetes and IFG among adults aged 50-64 years, and for IFG among adults aged ≥75 years. Across demographic subgroups, adjusted prevalence gains for both sexes were similar and most pronounced for HbA1c5.7, virtually absent for IFG, but greater for women than men for prediabetes. CONCLUSIONS Given the large, growing prediabetes prevalence and its anticipated burden, older adults, especially women, are likely intervention targets.

Relationship of walking to mortality among US adults with diabetes.

We thank Arredondo for his interest in our article and his description of the economic burden of diabetes for older adults in Mexico, a middle-income country. Clearly, many countries contribute to a huge and growing worldwide diabetes problem. Projections from 2010 to 2030 estimate that diabetes cases among adults aged 65 years and older will increase by 207% (from 27 to 83 million cases) in developing countries and by 81% (from 26 to 47 million cases) in developed countries.1 Correspondingly, the global economic burden from 2010 to 2030 is projected to increase dramatically for diabetes and its many complications and comorbid conditions.2 Regarding comorbid conditions, which add to costs, diabetes co-occurs with many other chronic conditions more so among those aged 65 years and older than among those who are younger (6.5 vs 2.9 conditions, respectively) in the United Kingdom.3 Governments of poorer countries spend less per capita on diabetes, leaving substantial costs to be paid by other means. Arredondo noted that older adult Mexicans with diabetes incur large out-of-pocket costs. Even in the more affluent United States, Medicare beneficiaries have an annual median out-of-pocket cost of