Glucose tolerance and physical fitness: An epidemiologic study in an entire community

A modification of the Harvard Step Test was administered to approximately 4700 males and females, age 10–69 in Tecumseh, Michigan. Heart rate response to this standardized exercise test is an estimate of capacity for muscular work. A blood sample was drawn 1 h after a glucose challenge on the same day the exercise test was given. Four skinfolds were measured as an index of body fatness. It was the purpose of this analysis to study the relationship of glucose tolerance to heart rate response to exercise.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47419/1/421_2004_Article_BF00421779.pd

Serum Uric Acid and Achievement in High School

The relationship of serum uric acid concentration and school achievement was studied in 467 high school children in Tecumseh, Michigan. Serum uric acid (SUA) was determined by the spectrophotometric method. No statistically significant relationships were found between SUA and intelligence quotient or average academic grades. There was also no significant difference in SUA among the overachievers (higher grade point average than predicted by IQ) as compared to the underachievers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37724/1/1780160310_ftp.pd

Effects of a web-based personalized intervention on physical activity in European adults: a randomized controlled trial

Background: The high prevalence of physical inactivity worldwide calls for innovative and more effective ways to promote physical activity (PA). There are limited objective data on the effectiveness of Web-based personalized feedback on increasing PA in adults. Objective: It is hypothesized that providing personalized advice based on PA measured objectively alongside diet, phenotype, or genotype information would lead to larger and more sustained changes in PA, compared with nonpersonalized advice. Methods: A total of 1607 adults in seven European countries were randomized to either a control group (nonpersonalized advice, Level 0, L0) or to one of three personalized groups receiving personalized advice via the Internet based on current PA plus diet (Level 1, L1), PA plus diet and phenotype (Level 2, L2), or PA plus diet, phenotype, and genotype (Level 3, L3). PA was measured for 6 months using triaxial accelerometers, and self-reported using the Baecke questionnaire. Outcomes were objective and self-reported PA after 3 and 6 months. Results: While 1270 participants (85.81% of 1480 actual starters) completed the 6-month trial, 1233 (83.31%) self-reported PA at both baseline and month 6, but only 730 (49.32%) had sufficient objective PA data at both time points. For the total cohort after 6 months, a greater improvement in self-reported total PA (P=.02) and PA during leisure (nonsport) (P=.03) was observed in personalized groups compared with the control group. For individuals advised to increase PA, we also observed greater improvements in those two self-reported indices (P=.006 and P=.008, respectively) with increased personalization of the advice (L2 and L3 vs L1). However, there were no significant differences in accelerometer results between personalized and control groups, and no significant effect of adding phenotypic or genotypic information to the tailored feedback at month 3 or 6. After 6 months, there were small but significant improvements in the objectively measured physical activity level (P<.05), moderate PA (P<.01), and sedentary time (P<.001) for individuals advised to increase PA, but these changes were similar across all groups. Conclusions: Different levels of personalization produced similar small changes in objective PA. We found no evidence that personalized advice is more effective than conventional “one size fits all” guidelines to promote changes in PA in our Web-based intervention when PA was measured objectively. Based on self-reports, PA increased to a greater extent with more personalized advice. Thus, it is crucial to measure PA objectively in any PA intervention study

Changes in physical activity following a genetic-based internet-delivered personalized intervention: randomized controlled trial (Food4Me)

Background: There is evidence that physical activity (PA) can attenuate the influence of the fat mass- and obesity-associated (FTO) genotype on the risk to develop obesity. However, whether providing personalized information on FTO genotype leads to changes in PA is unknown. Objective: The purpose of this study was to determine if disclosing FTO risk had an impact on change in PA following a 6-month intervention. Methods: The single nucleotide polymorphism (SNP) rs9939609 in the FTO gene was genotyped in 1279 participants of the Food4Me study, a four-arm, Web-based randomized controlled trial (RCT) in 7 European countries on the effects of personalized advice on nutrition and PA. PA was measured objectively using a TracmorD accelerometer and was self-reported using the Baecke questionnaire at baseline and 6 months. Differences in baseline PA variables between risk (AA and AT genotypes) and nonrisk (TT genotype) carriers were tested using multiple linear regression. Impact of FTO risk disclosure on PA change at 6 months was assessed among participants with inadequate PA, by including an interaction term in the model: disclosure (yes/no) × FTO risk (yes/no). Results: At baseline, data on PA were available for 874 and 405 participants with the risk and nonrisk FTO genotypes, respectively. There were no significant differences in objectively measured or self-reported baseline PA between risk and nonrisk carriers. A total of 807 (72.05%) of the participants out of 1120 in the personalized groups were encouraged to increase PA at baseline. Knowledge of FTO risk had no impact on PA in either risk or nonrisk carriers after the 6-month intervention. Attrition was higher in nonrisk participants for whom genotype was disclosed (P=.01) compared with their at-risk counterparts. Conclusions: No association between baseline PA and FTO risk genotype was observed. There was no added benefit of disclosing FTO risk on changes in PA in this personalized intervention. Further RCT studies are warranted to confirm whether disclosure of nonrisk genetic test results has adverse effects on engagement in behavior change

Objectively measured physical activity in European adults: cross-sectional findings from the Food4Me study

Background Comparisons of objectively measured physical activity (PA) between residents of European countries measured concurrently with the same protocol are lacking. We aimed to compare PA between the seven European countries involved in the Food4Me Study, using accelerometer data collected remotely via the Internet. Methods Of the 1607 participants recruited, 1287 (539 men and 748 women) provided at least 3 weekdays and 2 weekend days of valid accelerometer data (TracmorD) at baseline and were included in the present analyses. Results Men were significantly more active than women (physical activity level = 1.74 vs. 1.70, p < 0.001). Time spent in light PA and moderate PA differed significantly between countries but only for women. Adherence to the World Health Organization recommendation to accumulate at least 150 min of moderate-equivalent PA weekly was similar between countries for men (range: 54–65%) but differed significantly between countries for women (range: 26–49%). Prevalence estimates decreased substantially for men and women in all seven countries when PA guidelines were defined as achieving 30 min of moderate and vigorous PA per day. Conclusions We were able to obtain valid accelerometer data in real time via the Internet from 80% of participants. Although our estimates are higher compared with data from Sweden, Norway, Portugal and the US, there is room for improvement in PA for all countries involved in the Food4Me Study

Measurement of Physical Activity in Population Studies: A Review

The purpose of this review is to provide the reader with a current “state-of-the-art” in the assessment of habitual physical activity in human subjects. A discussion of the direct measurement of physical activity includes the use of observations, diaries, instruments and questionnaires. Most investigators of habitual physical activity in populations are usually interested in energy expenditure; hence the usefulness of direct measurements of energy expenditure are described and the possibilities and limitations of estimates of energy expenditure based on physiological observations are summarized

Familial Relationships in Maximal Oxygen Uptake

The Tecumseh, Michigan Community Health Study provided an opportunity to study the familial relationships in maximal oxygen uptake capacity (VO 2 max). A total of 1066 males and 119 females, age 10-69 were given a multi-staged treadmill test. Maximal oxygen uptake was measured in subjects up to age 40. In older subjects maximal oxygen uptake was estimated by fitting a straight line to measured submaximal oxygen uptake and heart rate at various treadmill grades. Age, weight and body fatness (skinfolds) are related to V02 max. In studying the familial relationships in V()2 max, the influence of these three variables was removed by regression analysis. Among fathers less than 40 years of age, the father-son relationship in V()2 max was moderately high (r = 0.66). For all fathers and sons the correlation coefficient was 0.34. Both of these coefficients are statistically significant. In 70 pairs of brothers, the relationship in V02 max was not statistically significant. The correlation coefficient for 27 husband-wife pairs was also not statistically significant

Variability of Some Objective Measures of Physical Activity

The purpose of this study was to determine how many days subjects should be monitored to provide an estimate of habitual physical activity in employed men engaged in a wide range of occupations. Caloric intake, movement recorders (accelerometers and pedometers), and heart rate were the measurements studied in 30 subjects who were monitored during their waking hours for 7 continuous days. A repeated measures ANOVA showed no significant difference between days (P \u3e 0.05) for any of the measures when only weekdays were compared. However, when weekend days were included a majority of the measures showed a significant F-ratio (P \u3c 0.05). An estimate was made of the number of days required to measure a 7-d period with less than 5% error. The average for all the different measures was 4.9 d. It appears that at least 5 or 6 d are needed to minimize the intra-individual variance a reasonable degree. Weekdays as well as weekend days need to be included

Muscular Strength and Body Size

Upper arm strength, right and left grip strength, and several anthropometric measures were recorded during a comprehensive medical examination in an epidemiological study in Tecumseh, Michigan. In the present analysis the relationship between muscular strength and body size was determined to facilitate comparisons of strength among individuals irrespective of differences in size, and more generally to derive sex, age and size specific standards for evaluating results of strength tests. Preliminary regressions of arm strength and summed grip strength on age and twelve size variables were performed. Most of the explained variation in strength variables was accounted for by five size variables, height, weight, biacromial diameter, arm girth, and triceps skinfold thickness. A canonical analysis was performed on the three strength variables and the five selected size variables, age and sex specific. After comparison of the relative weighting of strength variables in the subgroups, the unweighted sum of strength measures was adopted as a strength index. The regressions of the index on the five size variables provide age, sex and size specific means for use as a standard. Comparison of the multiple correlation coefficients from the regressions with the corresponding canonical correlation coefficients indicates the nearly optimal character of the index