Christopher D. Baggett

Energy costs of physical activities in children and adolescents

PURPOSE The primary aim was to determine the energy expenditure (EE: kcal.kg(-1).h(-1)) in terms of caloric cost and metabolic equivalents of activities commonly performed by children and adolescents. Secondary aims were to determine at what age and pubertal developmental stage values approach those of adults. METHODS In this descriptive study, 295 volunteer youth 8-18 yr of age completed 18 common physical activities (including rest) while EE was measured continuously with a portable metabolic system. Three sets of activities were assigned in random order for each subject. Activities ranged from television viewing and video game play to running and rope skipping. Pubertal development was estimated from a self-report questionnaire. RESULTS At rest, VO(2) and EE were highest in the youngest children and decreased with advancing age and higher pubertal stage in both genders. The age-adjusted and puberty-adjusted energy expenditure values were generally lower than the compendium MET values for sedentary and moderate activities but were more varied for high-intensity activities. However, the ratio of activity EE to REE was comparable in children and adults. CONCLUSIONS Energy expenditure per kilogram of body mass at rest or during exercise is greater in children than adults and varies with pubertal status, thus using the definition of a MET in the compendium of physical activities without adjustment is inadequate for energy estimation in children, until a child reaches Tanner Stage 5. However, the ratio of activity EE to resting EE in children appears to be similar or slightly less than in the compendium, suggesting that the compendium MET increments used with our adjusted EE values more closely approximate the true EE of activities in children than present adult norms.

The Population Burden of Heart Failure Attributable to Modifiable Risk Factors: The ARIC (Atherosclerosis Risk in Communities) Study

OBJECTIVES The goal of this study was to estimate the population burden of heart failure and the influence of modifiable risk factors. BACKGROUND Heart failure is a common, costly, and fatal disorder, yet few studies have evaluated the population-level influence of modifiable risk factors. METHODS From 14,709 ARIC (Atherosclerosis Risk in Communities) study participants, we estimated incidence rate differences (IRD) for the association between 5 modifiable risk factors (cigarette smoking, diabetes, elevated low-density lipoproteins, hypertension, and obesity) and heart failure. Potential impact fractions were used to measure expected changes in the heart failure incidence assuming achievement of a 5% proportional decrement in the prevalence of each risk factor. RESULTS Over an average of 17.6 years of follow-up, 1 in 3 African American and 1 in 4 Caucasian participants were hospitalized with heart failure, defined as the first hospitalization with International Classification of Diseases, Ninth Revision discharge codes of 428.x. Of the 5 modifiable risk factors, the largest IRD was observed for diabetes, which was associated with 1,058 (95% confidence interval [CI]: 787 to 1,329) and 660 (95% CI: 514 to 805) incident hospitalizations of heart failure/100,000 person-years among African-American and Caucasian participants, respectively. A 5% proportional reduction in the prevalence of diabetes would result in approximately 53 and 33 fewer incident heart failure hospitalizations per 100,000 person-years in African-American and Caucasian ARIC participants, respectively. When applied to U.S. populations, this reduction may prevent approximately 30,000 incident cases of heart failure annually. CONCLUSIONS Modest decrements in the prevalence of modifiable heart failure risk factors such as diabetes may substantially decrease the incidence of this major disease.

Tracking of physical activity and inactivity in middle school girls.

PURPOSE The purpose of this study was to describe and compare the levels of tracking of physical activity and inactivity as assessed by self-report and accelerometry in middle school girls during a 2-yr period. METHODS Participants (n = 951) were from the Trial of Activity for Adolescent Girls (TAAG). The TAAG intervention had minimal effect on physical activity; therefore, both intervention and control participants were included. Inactivity and physical activity were measured by accelerometry (MTI ActiGraph) and self-report (3-d physical activity recall). RESULTS Weighted kappa statistics ranged from 0.14 to 0.17 across inactivity, moderate-to-vigorous physical activity (MVPA), and vigorous physical activity (VPA) for self-report, from 0.13 to 0.20 for 3-d accelerometry, and from 0.22 to 0.29 for a 6-d accelerometry. Intraclass correlations ranged from 0.17 to 0.22 for self-report, 0.06 to 0.23 for 3-d accelerometry, and 0.16 to 0.33 for a 6-d accelerometry. In general, the estimates from the 6-d accelerometry tended to be higher than those from self-report, whereas few differences were observed between 3-d accelerometry and self-report. Odds ratios (OR) for being in the highest quintile at eighth grade for those in the highest quintile at sixth grade compared with those in any other quintile at sixth grade were 3.26 (95% confidence interval = 2.28-4.67), 3.64 (2.55-5.20), and 3.45 (2.42-4.93) for the 6-d accelerometry-measured inactivity, MVPA, and VPA. Corresponding OR from self-report were 2.44 (1.66-3.58) for inactivity, 2.63 (1.83-3.79) for MVPA, and 2.23 (1.54-3.23) for VPA. CONCLUSION Tracking of inactivity and physical activity in middle school girls was fair to moderate. Our results suggest that physical activity and inactivity habits are dynamic for most girls during early adolescence. Population-based efforts should be made in this age group to promote physical activity and offer alternatives to inactivity for all girls.

Association between Physical Activity and Risk of Stroke Subtypes: The Atherosclerosis Risk in Communities Study

Background: The relationship between stroke subtypes and physical activity is unclear. Methods: Using data from 13,069 men and women aged 45–64 years who participated in the Atherosclerosis Risk in Communities Study, physical activity was assessed by self-report using the Baecke questionnaire at baseline (1987–1989). The American Heart Association’s ideal cardiovascular health guidelines served as a basis for the calculation of three physical activity categories: poor, intermediate, and ideal. Stroke and its subtypes were ascertained from physician review of medical records. Multivariable adjusted hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox regression models. Results: During a median follow-up of 18.8 years, a total of 648 incident ischemic strokes occurred. Significant inverse associations were found between physical activity categories and total, total ischemic, and nonlacunar stroke in adjusted models (age, sex, race-center, education, cigarette-years). Compared with poor physical activity, the adjusted HR (95% CI) for ideal physical activity were 0.78 (0.62–0.97) for total, 0.76 (0.59–0.96) for total ischemic, 0.85 (0.51–1.40) for lacunar, 0.77 (0.47–1.27) for cardioembolic, and 0.71 (0.51–0.99) for nonlacunar stroke. Additional adjustments for waist-to-hip ratio, systolic blood pressure, antihypertensive medication, diabetes, left ventricular hypertrophy and laboratory parameters attenuated the HR. Further sex- and race-specific analyses revealed that the association was predominantly observed among males and among African-Americans. Conclusion: These data suggest a tendency toward a reduced risk of total, total ischemic, and nonlacunar stroke with higher levels of physical activity.

Association of Delays in Surgery for Melanoma With Insurance Type

Importance Timely receipt of treatment for cancer is an important aspect of health care quality. It is unknown how delays of surgery for melanoma vary by insurance type. Objective To analyze factors associated with delays between diagnosis and surgery for melanoma in patients with Medicare, Medicaid, or private insurance. Design, Setting, and Participants Retrospective cohort study of patients who received a diagnosis of melanoma between 2004 and 2011 in North Carolina using data from the North Carolina Cancer Registry linked to administrative claims from Medicare, Medicaid, and private insurance. Inclusion criteria were incident patients with a diagnosis of melanoma stage 0 to III and with continuous insurance enrollment from at least 1 month prior to the month of diagnosis to 12 months after diagnosis of melanoma. Main Outcomes and Measures Surgical delay, defined as definitive surgical excision occurring more than 6 weeks after melanoma diagnosis. Generalized linear models with log link, Poisson distributions, and robust standard errors were used to estimate adjusted risk ratios (RRs) to model risk of delay in definitive surgery. Results A total of 7629 patients were included (4210 [55%] female; mean [SD] age, 64 [15] years), 48% (n = 3631) Medicare, 48% (n = 3667) privately insured, and 4% (n = 331) Medicaid patients. Privately insured patients were least likely to experience a delay in definitive surgery, followed by Medicare and Medicaid patients (519 [14%], 609 [17%], and 79 [24%], respectively; P < .001). After demographic adjustment, the risk of surgical delay was significantly increased in patients with Medicaid compared with private insurance (RR, 1.36; 95% CI, 1.09-1.70). Delays were more likely in nonwhite patients (RR, 1.38; 95% CI, 1.02-1.87). Surgical delays were less likely if the physician performing the surgery (RR, 0.82; 95% CI, 0.72-0.93) or the diagnosing clinician (RR, 0.81; 95% CI, 0.71-0.93) was a dermatologist as compared with a nondermatologist. Conclusion and Relevance Surgical treatment delays were common but were less prevalent in patients diagnosed or surgically treated by a dermatologist. Medicaid patients experienced the most surgical delays. A reduction in delays in melanoma surgery could be achieved through better access to specialty care and cross-disciplinary coordination.

Temporal trends in medical therapies for ST- and Non-ST elevation myocardial infarction: (From the atherosclerosis risk in communities [aric] surveillance study)

Reports from large studies using administrative data sets and event registries have characterized recent temporal trends and treatment patterns for acute myocardial infarction. However, few were population based, and fewer examined differences in patterns of treatment for patients presenting with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI). The aim of this study was to examine 22-year trends in the use of 10 medical therapies and procedures by STEMI and NSTEMI classification in 30,986 definite or probable myocardial infarctions in the Atherosclerosis Risk in Communities (ARIC) Community Surveillance Study from 1987 to 2008. Weighted multivariate Poisson regression, controlling for gender, race and center classification, age, and Predicting Risk of Death in Cardiac Disease Tool score, was used to estimate average annual percentage changes in medical therapy use. From 1987 to 2008, 6,106 hospitalized events (19.7%) were classified as STEMIs and 20,302 (65.5%) as NSTEMIs. Among patients with STEMIs, increases were noted in the use of angiotensin-converting enzyme inhibitors (6.4%, 95% confidence interval [CI] 5.7 to 7.2), antiplatelet agents other than aspirin (5.0%, 95% CI 4.0% to 6.0%), lipid-lowering medications (4.5%, 95% CI 3.1% to 5.8%), β blockers (2.7%, 95% CI 2.4% to 3.0%), aspirin (1.2%, 95% CI 1.0% to 1.3%), and heparin (0.8%, 95% CI 0.4% to 1.3%). Among patients with NSTEMIs, the use of angiotensin-converting enzyme inhibitors (5.5%, 95% CI 5.0% to 6.1%), antiplatelet agents other than aspirin (3.7%, 95% CI 2.7% to 4.7%), lipid-lowering medications (3.0%, 95% CI% 1.9 to 4.1%), β blockers (4.2%, 95% CI 3.9% to 4.4%), aspirin (1.9%, 95% CI 1.6% to 2.1%), and heparin (1.7%, 95% CI 1.3% to 2.1%) increased. Among patients with STEMIs, decreases in the use of thrombolytic agents (-7.2%, 95% CI -7.9% to -6.6%) and coronary artery bypass grafting (-2.4%, 95% CI -3.6% to -1.2%) were observed. Similar increases in percutaneous coronary intervention and decreases in the use of thrombolytic agents and coronary artery bypass grafting were noted among all patients. In conclusion, trends of increasing use of evidence-based therapies were found for patients with STEMIs and those with NSTEMIs over the past 22 years.