Showing papers by "Patty S. Freedson published in 2004"

Development and validation of a Pregnancy Physical Activity Questionnaire.

Abstract: CHASAN-TABER, L., M. D. SCHMIDT, D. E. ROBERTS, D. HOSMER, G. MARKENSON, and P. S. FREEDSON. Development and Validation of a Pregnancy Physical Activity Questionnaire. Med. Sci. Sports Exerc., Vol. 36, No. 10, pp. 1750 –1760, 2004. Purpose: The effect of physical activity during pregnancy on maternal and fetal health remains controversial and studies have yet to identify the optimal dose of physical activity associated with favorable pregnancy outcomes. The aim of this study was to develop and validate a pregnancy physical activity questionnaire (PPAQ). Methods: To ascertain the type, duration, and frequency of physical activities performed by pregnant women, three 24-h physical activity recalls were administered to 235 ethnically diverse prenatal care patients at a large tertiary care facility in western Massachusetts. The relative contribution of each activity to between-person variance in energy expenditure was used to establish the list of activities for the PPAQ. The PPAQ is self-administered and asks respondents to report the time spent participating in 32 activities including household/caregiving, occupational, sports/exercise, transportation, and inactivity. To validate the PPAQ, 54 pregnant women completed the PPAQ and then wore a Manufacturing Technology, Inc. actigraph for the following 7 d. At the end of the 7-d period, the PPAQ was repeated. Results: Intraclass correlation coefficients used to measure reproducibility of the PPAQ were 0.78 for total activity, 0.82 for moderate activity, 0.81 for vigorous activity, and ranged from 0.83 for sports/exercise to 0.93 for occupational activity. Spearman correlations between the PPAQ and three published cut points used to classify actigraph data ranged from 0.08 to 0.43 for total activity, 0.25 to 0.34 for vigorous activity, 0.20 to 0.49 for moderate activity, and 0.08 to 0.22 for light-intensity activity. Correlations were higher for sports/exercise and occupational activities as compared to household/caregiving activities. Conclusions: The PPAQ is a reliable instrument and a reasonably accurate measure of a broad range of physical activities during pregnancy. Key Words: ACTIVITY ASSESSMENT, EPIDEMIOLOGIC METHODS, EXERCISE, REPRODUCIBILITY OF RESULTS, WOMEN

Seasonal variation in serum cholesterol levels: treatment implications and possible mechanisms.

Abstract: Background A variety of studies have noted seasonal variation in blood lipid levels. Although the mechanism for this phenomenon is not clear, such variation could result in larger numbers of people being diagnosed as having hypercholesterolemia during the winter. Methods We conducted a longitudinal study of seasonal variation in lipid levels in 517 healthy volunteers from a health maintenance organization serving central Massachusetts. Data collected during a 12-month period for each individual included baseline demographics and quarterly anthropometric, blood lipid, dietary, physical activity, light exposure, and behavioral information. Data were analyzed using sinusoidal regression modeling techniques. Results The average total cholesterol level was 222 mg/dL (5.75 mmol/L) in men and 213 mg/dL (5.52 mmol/L) in women. Amplitude of seasonal variation was 3.9 mg/dL (0.10 mmol/L) in men, with a peak in December, and 5.4 mg/dL (0.14 mmol/L) in women, with a peak in January. Seasonal amplitude was greater in hypercholesterolemic participants. Seasonal changes in plasma volume explained a substantial proportion of the observed variation. Overall, 22% more participants had total cholesterol levels of 240 mg/dL or greater (≥6.22 mmol/L) in the winter than in the summer. Conclusions This study confirms seasonal variation in blood lipid levels and suggests greater amplitude in seasonal variability in women and hypercholesterolemic individuals, with changes in plasma volume accounting for much of the variation. A relative plasma hypervolemia during the summer seems to be linked to increases in temperature and/or physical activity. These findings have implications for lipid screening guidelines. Further research is needed to better understand the effects of a relative winter hemoconcentration.

Effects of a single bout of exercise on resting heart rate variability.

Abstract: POBER, D. M., B. BRAUN, and P. S. FREEDSON. Effects of a Single Bout of Exercise on Resting Heart Rate Variability. Med. Sci. Sports Exerc., Vol. 36, No. 7, pp. 1140–1148, 2004.Purpose:Chronic exercise training has been shown to have a positive influence on cardiac autonomic function as asse