Joan Dorn

The Relationship Between Motor Proficiency and Physical Activity in Children

OBJECTIVES. Youth with better motor abilities may find it easier to be physically active and may be more likely to engage in physical activity compared with peers with poorer motor competence. The purpose of this study was to examine the relationship between motor proficiency and physical activity in 8- to 10-year-old children. Self-efficacy toward physical activity was also assessed. METHODS. Sixty-five children (34 girls and 31 boys) were studied. Childrens physical activity was assessed by the Manufacturing Technologies Incorporated/Computer Science and Applications Incorporated model 7164 accelerometer, and their motor proficiency was determined by the Bruininks-Oseretsky Test of Motor Proficiency. The Childrens Self-Perceptions of Adequacy in and Predilection for Physical Activity scale measured childrens self-perceptions of adequacy in performing and desire to participate in physical activities. RESULTS. Childrens motor proficiency was positively associated with activity counts and percentage of time in moderate and moderate-to-vigorous intensity physical activity and inversely related to percentage of time in sedentary activity. Children in the greatest quartile of motor proficiency were the most physically active compared with children with lower levels of motor proficiency who had similar levels of physical activity. Children with greater standardized BMI were less physically active, more sedentary, and had poorer motor proficiency compared with children with a lower standardized BMI. Childrens Self-Perceptions of Adequacy in and Predilection for Physical Activity scores were positively associated with Bruininks-Oseretsky Test of Motor Proficiency standard score for boys. Childrens motor proficiency explained an additional 8.7% of the variance in physical activity in multiple linear regression after controlling for factors that may influence physical activity. CONCLUSIONS. Motor proficiency is positively associated with physical activity and inversely associated with sedentary activity in children, but there may be a threshold of motor proficiency above which children may be the most physically active. Childrens motor proficiency may be an appropriate target for increasing physical activity in youth.

Correlates of short and long sleep duration: a cross-cultural comparison between the United Kingdom and the United States: the Whitehall II Study and the Western New York Health Study.

The authors examined sociodemographic, lifestyle, and comorbidity factors that could confound or mediate U-shaped associations between sleep duration and health in 6,472 United Kingdom adults from the Whitehall II Study (1997-1999) and 3,027 US adults from the Western New York Health Study (1996-2001). Cross-sectional associations between short (<6 hours) and long (>8 hours) durations of sleep across several correlates were calculated as multivariable odds ratios. For short sleep duration, there were significant, consistent associations in both samples for unmarried status (United Kingdom: adjusted odds ratio (AOR) = 1.49, 95% confidence interval (CI): 1.15, 1.94; United States: AOR = 1.49, 95% CI: 1.10, 2.02), body mass index (AORs were 1.04 (95% CI: 1.01, 1.07) and 1.02 (95% CI: 1.00, 1.05)), and Short Form-36 physical (AORs were 0.96 (95% CI: 0.95, 0.98) and 0.97 (95% CI: 0.96, 0.98)) and mental (AORs were 0.95 (95% CI: 0.94, 0.96) and 0.98 (95% CI: 0.96, 0.99)) scores. For long sleep duration, there were fewer significant associations: age among men (AORs were 1.08 (95% CI: 1.01, 1.14) and 1.05 (95% CI: 1.02, 1.08)), low physical activity (AORs were 1.75 (95% CI: 0.97, 3.14) and 1.60 (95% CI: 1.09, 2.34)), and Short Form-36 physical score (AORs were 0.96 (95% CI: 0.93, 0.99) and 0.97 (95% CI: 0.95, 0.99)). Being unmarried, being overweight, and having poor general health are associated with short sleep and may contribute to observed disease associations. Long sleep may represent an epiphenomenon of comorbidity.

Body fat distribution, relative weight, and liver enzyme levels: A population‐based study

Regional body fat distribution may represent an independent risk factor for several conditions, especially metabolic and cardiovascular diseases; recent findings have shown that abdominal fat accumulation can be an independent predictor of hepatic steatosis. Very few studies, mostly using selected clinical samples, have focused on the relationship between indices of abdominal visceral fat accumulation and the most commonly used biochemical liver tests, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma‐glutamyltransferase (GGT). The aim of the present study was to evaluate the relation between central fat accumulation, as assessed by abdominal height, relative weight, as determined by body mass index (BMI), and liver function tests (ALT, AST, and GGT) in a random sample of 2,704 residents of Erie and Niagara Counties in New York State, 35–80 years of age and free from known hepatic disease. Multiple linear regression models were used, with liver enzymes as dependent variables with abdominal height and BMI as independent variables, and the inclusion of several covariates (age, race, education, smoking status, pack‐years of smoking, drinking status, and total ounces of ethanol in the past 30 days). Abdominal height was consistently a better correlate of ALT and GGT levels than BMI in both sexes. In addition, abdominal height was the most powerful independent predictor of ALT in both sexes as well as of GGT among women. In conclusion, these findings support a role for central adiposity independent from BMI in predicting increased levels of hepatic enzymes, likely as a result of unrecognized fatty liver. (HEPATOLOGY 2004;39:754–763.)

Relationship of Alcohol Drinking Pattern to Risk of Hypertension: A Population-Based Study

Epidemiological studies have demonstrated a positive relationship between heavy alcohol use and hypertension, but few studies have directly addressed the role of drinking pattern. This study was designed to investigate the association of current alcohol consumption and aspects of drinking pattern with hypertension risk in a sample of 2609 white men and women from western New York, aged 35 to 80 years, and free from other cardiovascular diseases. Hypertension was defined by systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg or use of antihypertensive medication. Odds ratios (95% confidence intervals) were computed after adjustment for several covariates. Compared with lifetime abstainers, participants reporting drinking on a daily basis (1.75 [1.13 to 2.72]) or mostly without food (1.64 [1.08 to 2.51]) exhibited significantly higher risk of hypertension. When analyses were restricted to current drinkers, daily drinkers and participants consuming alcohol without food exhibited a significantly higher risk of hypertension compared with those drinking less than weekly (1.65 [1.18 to 2.30]) and those drinking mostly with food (1.49 [1.10 to 2.00]), respectively. After additional adjustment for the amount of alcohol consumed in the past 30 days, the results were follows: 0.90 (0.58 to 1.41) for daily drinkers and 1.41 (1.04 to 1.91) for drinkers without food. For predominant beverage preference, no consistent association with hypertension risk was found across the various types of beverages considered (beer, wine, and liquor). In conclusion, drinking outside meals appears to have a significant effect on hypertension risk independent of the amount of alcohol consumed.

Results of a multicenter randomized clinical trial of exercise and long-term survival in myocardial infarction patients: the National Exercise and Heart Disease Project (NEHDP).

BACKGROUND This study examined whether a supervised exercise program improved 19-year survival in 30- to 64-year-old male myocardial infarction patients. METHODS AND RESULTS The men (n=651) were participants in the National Exercise and Heart Disease Project, a 3-year multicenter randomized clinical trial conducted in the United States (1976-1979). The treatment group (n=315) exercised for 8 weeks in a laboratory. Thereafter, they jogged, cycled, or swam in a gymnasium/pool setting guided by an individualized target heart rate. Participants in the control group (n=319) were to maintain normal routines but not participate in any regular exercise program. Participants were followed up until their death or December 31, 1995. Cox proportional hazards analysis revealed the all-cause mortality risk estimates (95% CIs) in the exercise group compared with controls to be 0.69 (0.39 to 1.25) after an average follow-up of 3 years, 0.84 (0.55 to 1.28) after 5 years, 0.95 (0.71 to 1.29) after 10 years, 1.02 (0.79 to 1.32) after 15 years, and 1.09 (0.87 to 1. 36) after 19 years. Cardiovascular disease (CVD) mortality risk estimates (95% CI) for the same follow-up periods were 0.73 (0.37 to 1.43), 0.98 (0.60 to 1.61), 1.21 (0.79 to 1.60), 1.14 (0.84 to 1.54), and 1.16 (0.88 to 1.52). However, each 1-MET increase in work capacity from baseline to the end of the original trial resulted in consistent reductions in all-cause and CVD mortality risk at each follow-up period, regardless of initial work-capacity level. CONCLUSIONS These findings indicate exercise-program participation resulted in nonsignificantly reduced mortality risks early in the follow-up period. Benefits diminished as time since participation increased, which suggests that the protective mechanisms associated with the program may be short term. Contamination between groups over time could also explain the diminished effects, because increased work capacity provided survival benefits up to 19 years.

A population-based study of reduced sleep duration and hypertension: the strongest association may be in premenopausal women.

Objectives Recent evidence indicates that reduced sleep duration may be associated with an increased risk of hypertension with possibly stronger effects among women than men. We therefore examined cross-sectional sex-specific associations of sleep duration with hypertension in a large population-based sample from the Western New York Health Study (1996<2001). Methods Participants were 3027 white men (43.5%) and women (56.5%) without prevalent cardiovascular disease (median age 56 years). Hypertension was defined as blood pressure at least 140 or at least 90&mmHg or regular use of antihypertensive medication. Multivariate logistic regression analyses were performed to estimate odds ratios (ORs) of hypertension comparing less than 6&h of sleep per night versus the reference category (&6&h) while accounting for a number of potential confounders. Results In multivariate analyses, less than 6&h of sleep was associated with a significant increased risk of hypertension compared to sleeping at least 6&h per night, only among women [OR&=&1.66 (1.09 to 2.53)]. No significant association was found among men [OR&=&0.93 (0.62 to 1.41)]. In subgroup analyses by menopausal status, the effect was stronger among premenopausal women [OR&=&3.25 (1.37 to 7.76)] than among postmenopausal women [OR&=&1.49 (0.92 to 2.41)]. Conclusion Reduced sleep duration, by increasing the risk of hypertension, may produce detrimental cardiovascular effects among women. The association is independent of socioeconomic status, traditional cardiovascular risk factors, and psychiatric comorbidities, and is stronger among premenopausal women. Prospective and mechanistic evidence is necessary to support causality.

Reproducibility of Probing Depth Measurements Using a Constant-Force Electronic Probe: Analysis of Inter- and Intraexaminer Variability

BACKGROUND Probing depth (PD) is a commonly used method to determine periodontal disease severity in both treating and evaluating disease progression. Agreement among examiners collecting data in scientific investigations is necessary to establish reliable criteria for determining levels of periodontal attachment loss. The objective of our study was to evaluate inter- and intraexaminer variability of PD measurements among study examiners using a constant force periodontal probe, and to compare the variability of tooth-mean and quadrant-mean. METHODS Three examiners, who had been previously trained and calibrated, performed measurements on 20 volunteers. Intraand interexaminer variability of sites was determined by means of standard error of measurement (SE). Data analysis included determination of error for both quadrant mean and tooth mean. RESULTS PD measurements for the quadrant-mean were used to calculate the intraexaminer variability, resulting in a mean (SD) value for an SE of 0.40 mm (± 0.02). Interexaminer variability for quadrant mean was 0.16 mm (± 0.02). For tooth-mean SE, the intraexaminer variability values were equal to 0.38 mm (± 0.07), and interexaminer variability equal to 0.24 mm (± 0.05). CONCLUSIONS All three examiners participating in our study were able to obtain reliable measurements for PD, using the constant force electronic probe. Reproducibility did not vary appreciably when using the whole quadrant mean compared to the tooth mean. These trained examiners were able to provide reproducible measures under 0.5 mm. J Periodontol 2003;74:1736-1740.

Body Fat Distribution, Liver Enzymes, and Risk of Hypertension. Evidence From the Western New York Study

&ggr;-Glutamyltransferase (GGT) has been associated with hypertension (HTN); however, the nature of this association remains unclear. GGT is a marker of alcohol consumption, but it is also related to the infiltration of fat in the liver (fatty liver). The association between GGT and HTN was examined in a 6-year longitudinal investigation among 1455 men and women who returned for the follow-up visit. Baseline variables included serum GGT, blood pressure, and anthropometric measures. Incident HTN was defined as blood pressure ≥140/90 or on antihypertensive medication at the follow-up visit. To eliminate individuals with potential liver pathology, analyses focused only on individuals with GGT within its normal range (n=897). Participants were divided in quintiles (Q) based on their baseline GGT levels. Multiple logistic regression analyses [odds ratio (95% confidence intervals)] revealed a significant association of GGT with incident hypertension [2.1 (1.1 to 4.0) Q5 versus Q1]. In subgroup analyses, GGT and HTN were significantly associated among both noncurrent and current drinkers, but only for participants above the median of anthropometric measures [eg, body mass index >26.4, 2.3 (0.9 to 5.7), waist circumference >86.1 cm, 3.7 (1.4 to 9.9), and abdominal height >19.8 cm, 3.1 (1.2 to 8.5), for Q5 versus Q1, in fully adjusted models]. These findings suggest that the association between GGT and hypertension is not caused solely by alcohol consumption and indicate that serum GGT, within its normal range, may predict hypertension among individuals with increased central fat distribution, suggesting that fatty liver may represent an important underlying mechanism for this association.

Kinetic changes with fatigue and relationship to injury in female runners

PURPOSE This research examined how ground reaction forces (GRF) changed with fatigue induced by an exhaustive treadmill run in female runners. A separate retrospective and prospective analysis correlated initial magnitude of GRF and fatigue-induced changes in GRF with lower-extremity injury. METHODS Ninety adult female runners had vertical GRF measured before and after an exhaustive treadmill run. Subjects initially were questioned about previous running injuries, and were contacted during the following year and asked to report any additional running injuries. RESULTS Fatigue induced by the exhaustive treadmill run resulted in decreased impact peak and loading rates in all runners by an average of 6 and 11%, respectively. The changes in GRF were attributed to altered running cadence, step length, and lower-extremity joint kinematics. It is unclear whether these changes were attempts by the runners to minimize impact forces and protect against injury, or represented a fatigue-induced loss of optimal performance capabilities. An interaction between injury in the previous year and change in impact loading rate with fatigue was observed, suggesting previously injured runners are exposed to relatively higher impact forces over time. CONCLUSION Habitual female runners appear to adapt their running style with fatigue, resulting in altered GRF. Changes in GRF with fatigue may be associated with lower-extremity running injuries.

Correlates of compliance in a randomized exercise trial in myocardial infarction patients.

PURPOSE Exercise-based rehabilitation programs have been associated with decreased morbidity and mortality after myocardial infarction. Unfortunately, attendance is often poor, and information is limited regarding predictors of long-term compliance to such programs. This study examined factors associated with exercise session compliance over 3 yr in male myocardial infarction (MI) survivors. METHODS Subjects were participants in the National Exercise and Heart Disease Project, a 3-yr (1976-1979) multicenter, randomized clinical trial (N = 651); 308 men, 30-64 yr of age, were randomized to the exercise treatment group, that met three times/week throughout the study. Compliance was defined as the number of sessions attended/number of sessions conducted. Patient characteristics at enrollment were considered as possible predictors of compliance. RESULTS Compliance decreased as time since enrollment increased with the largest decrease observed after the first 8 wk. Compliance correlated positively with exercise test measures [last completed stage (r = 0.17, P < 0.01), peak heart rate (r = 0.11, P = 0.06)], high density lipoprotein (HDL) cholesterol (r = 0.15, P = 0.10), age (r = 0.11, P = 0.07), and inversely with body mass index (r = -0.19, P = 0.001), sum of three skinfolds (r = -0.15, P < 0.01), total cholesterol (r = -0.18, P < 0.01), triglycerides (r = -0.16, P < 0.01), and depression (r = -0.09, P < 0.11). Current smokers were less compliant than former and nonsmokers (r = -0.21, P < 0.001). The correlations with last completed stage, BMI, skinfolds, total cholesterol, and smoking status were statistically significant. The model explained 22.2% of the variance in compliance (r2 = 0.222). Baseline work capacity was among the most consistent predictors of early and late compliance. CONCLUSION Compliance decreased over time. Men already at high risk for repeat events due to elevated risk factors were less compliant. These findings have important clinical implications regarding screening, intervention, and participation in potential cardiac rehabilitation program dropouts.