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Background: Associations between childhood vitamin K consumption and cardiac structure and function have not been investigated. Objective: We determined associations between phylloquinone (vitamin K-1) intake and left ventricular (LV) structure and function in adolescents. Methods: We assessed diet with three to seven 24-h recalls and physical activity (PA) by accelerometry in 766 adolescents (aged 14–18 y, 50% female, 49% black). Fat-free soft tissue (FFST) mass and fat mass were measured by dual-energy X-ray absorptiometry. LV structure [LV mass (g)/height (m)2.7 (LV mass index) and relative wall thickness] and function [midwall fractional shortening (MFS) and ejection fraction] were assessed by echocardiography. Associations were evaluated by comparing the LV structure and function variables across tertiles of phylloquinone intake. Prevalence and OR of LV hypertrophy (LV mass index >95th percentile for age and sex) were also assessed by phylloquinone tertiles. Results: The prevalence of LV hypertrophy progressively decreased across tertiles of phylloquinone intake (P-trend < 0.01). Multinomial logistic regression—adjusting for age, sex, race, Tanner stage, systolic blood pressure, FFST mass, fat mass, socioeconomic status, PA, and intakes of energy, fiber, calcium, vitamin C, vitamin D, and sodium—revealed that compared with the highest phylloquinone intake tertile (reference group), the adjusted OR for LV hypertrophy was 3.3 (95% CI: 1.2, 7.4) for those in the lowest phylloquinone intake tertile. When LV structure variables were compared across phylloquinone intake tertiles adjusting for the same covariates, there were significant linear downward trends for LV mass index (6.5% difference, tertile 1 compared with tertile 3) and relative wall thickness (9.2% difference, tertile 1 compared with tertile 3; both P-trend ≤ 0.02). Conversely, significant linear upward trends across phylloquinone intake tertiles were observed for MFS (3.4% difference, tertile 1 compared with tertile 3) and ejection fraction (2.6% difference, tertile 1 compared with tertile 3; both P-trend < 0.04). Conclusion: Our adolescent data suggest that subclinical cardiac structure and function variables are most favorable at higher phylloquinone intakes.

Investigations in older individuals suggest that adequate nutrition and physical activity are particularly important to skeletal muscle health; however, data in adolescents are scant and equivocal. The objective was to determine the associations among diet, physical activity and skeletal muscle mass in adolescents.We assessed diet with four to seven 24-h recalls and physical activity by accelerometry in 640 adolescents. Using total body measures of fat-free soft tissue mass and fat mass assessed by dual-energy X-ray absorptiometry, the skeletal muscle mass index (SMMI) was derived by adjusting fat-free soft tissue mass for fat mass in addition to height.Skeletal muscle mass index (SMMI) was negatively associated with consumption of sugar-sweetened beverages (standardized beta coefficient [β] = -0.10, P = 0.001) and saturated fats (β = -0.28, P 0.001). SMMI was positively associated with physical activity (moderate + vigorous) (β = 0.20, P 0.001). In further analysis, we observed a significant interaction between physical activity and sugar-sweetened beverage intake on SMMI (P = 0.002).Our study in adolescence suggests that physical activity and consumption of both sugar-sweetened beverages and saturated fats are associated with skeletal muscle mass. More importantly, our findings suggest that sugar-sweetened beverage intake may attenuate the beneficial effects of physical activity on skeletal muscle mass.

The authors think the approach to weight reduction that makes sense in industrialized countries also will work in Third-World countries as they begin to face some of the problems that result from the introduction of labor-saving technology and diets rich in fats and sugars.

OBJECTIVES: The objectives were to characterize the vitamin D status of black and white adolescents residing in the southeastern United States (latitude: ∼33°N) and to investigate relationships with adiposity. METHODS: Plasma 25-hydroxyvitamin D levels were measured with liquid chromatography-tandem mass spectroscopy for 559 adolescents 14 to 18 years of age (45% black and 49% female). Fat tissues, physical activity, and cardiovascular fitness also were measured. RESULTS: The overall prevalences of vitamin D insufficiency ( CONCLUSIONS: Low vitamin D status is prevalent among adolescents living in a year-round sunny climate, particularly among black youths. The relationships between 25-hydroxyvitamin D levels, adiposity, physical activity, and fitness seem to be present in adolescence.

Background: Previous genome-wide association studies (GWAS) have identified a large number of genetic variants for obesity and its related traits, representing a group of potential key genes in the etiology of obesity. Emerging evidence suggests that epigenetics may play an important role in obesity. It has not been explored whether the GWAS-identified loci contribute to obesity through epigenetics (e.g., DNA (deoxyribonucleic acid) methylation) in addition to genetics. Method: A multi-stage cross-sectional study was designed. We did a literature search and identified 117 genes discovered by GWAS for obesity and its related traits. Then we analyzed whether the methylation levels of these genes were also associated with obesity in two genome-wide methylation panels. We examined an initial panel of seven adolescent obese cases and seven age-matched lean controls, followed by a second panel of 48 adolescent obese cases and 48 age- and gender-matched lean controls. The validated CpG sites were further replicated in two independent replication panels of youth (46 vs. 46 and 230 cases vs. 413 controls, respectively) and a general population of youth, including 703 healthy subjects. Results: One CpG site in the lymphocyte antigen 86 (LY86) gene, which showed higher methylation in the obese in both the initial (p = .009) and second genome-wide DNA methylation panel (p = .008), was further validated in both replication panels (meta p = .00016). Moreover, in the general population of youth, the methylation levels of this region were significantly correlated with adiposity indices (p ≤ .02), insulin resistance (p = .001), and inflammatory markers (p < .001). Conclusion: By focusing on recent GWAS findings in genome-wide methylation profiles, we identified a solid association between LY86 gene DNA methylation and obesity.

The current theory, known as the "theory ofenergy balance", perceives paediatric obesity, like adults' obesity, as the result of an excessively positive energy balance. Thus, prevention endeavours have focused on controlling calories intake and dietary education, with increases in physical activity (PA) having just a supporting role. Paradoxically, preventive programmes developed with this vision are not satisfactory, whereas some recent findings suggest, that in the growing body of youths, PA may stimulate stem cells to differentiate preferentially into lean tissue. These observations advocate the emergence of a new theoretical framework to childhood obesity prevention: the "developmental theory", which posits the pre-eminence of PA. As a result, preventive strategies that would emphasise vigorous PA rather than food intake control can help youths develop lean bodies, at the same time that they ingest sufficient amounts of the energy and accompanying nutrients needed for a healthy growth.

Prevention of osteoporosis is an increasingly salient public health concern as our society ages. This report describes the procedures used at an osteoporosis center to which people come for screening and counseling. The patients on whom this report is based were 53 non-smoking women, 1–10 years postmenopausal at the time of their first visit to the center, who chose not to undertake estrogen therapy, and who returned for a second visit in 12–18 months. They were classified as to adequacy of calcium intake (at least 750 mg/day) and exercise (at least 3 h/week of weight-bearing exercise) at both visits; complete data on calcium intake and exercise were available on 46 of the women. Bone densities were measured at the femoral neck and lumbar spine with dual energy X-ray absorptiometry, and at the distal radius with single photon absorptiometry. At the first visit, 67% of the women reported adequate exercise and 43% reported adequate calcium intake. At the second visit, the percentages in the adequate categories had increased to 74% for exercise (p=0.06) and 70% for calcium intake (p=0.02). Age at the first visit was inversely correlated with femoral (r=−0.40,p=0.003) and spinal (r=−0.36,p=0.009) bone densities; the correlation with radial bone density did not achieve significance (r=−0.27,p=0.55). Rather than declining, as would be expected in early postmenopausal women, bone density rose slightly, but not significantly, between visits for all three sites. Neither the first visit values nor the changes between visits were significantly different between groups divided on the basis of adequacy of calcium intake or exercise. These data suggest that bone density is related to age, that a visit to an osteoporosis center may help early postmenopausal women to maintain and improve healthy exercise and eating behaviors, and that bone density does not necessarily decline over a 12–18 month period in women who maintain such behaviors.

The purpose of this study was to test the hypothesis that physical training (PT), especially high-intensity PT, would have a favorable effect on components of the insulin resistance syndrome (IRS) in obese adolescents.Obese 13- to 16-yr-olds (N = 80) were randomly assigned to one of the following 8-month interventions; 1) lifestyle education (LSE)-alone every 2 wk, 2) LSE+moderate-intensity PT, and 3) LSE+high-intensity PT. PT was offered 5 d x wk(-1). Plasma triacylglycerol (TAG), total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), very low-density lipoprotein cholesterol (VLDLC), low-density lipoprotein cholesterol (LDLC), low-density lipoprotein (low density lipoprotein (LDL)) particle size, apolipoproteins AI and B, glucose, insulin, and blood pressure were measured with standardized methods.The intent-to-treat analyses for all subjects who completed pre- and post-tests regardless of their adherence to the interventions showed that the LSE+high-intensity PT group had more favorable changes than the LSE-alone group in TAG level (P = 0.012), TC/HDLC (P = 0.013), and diastolic blood pressure (P = 0.031). For efficacy analyses, all PT subjects who attended at least 2 d x wk(-1) (40%) were combined into one group (LSE+PT) and compared with the LSE-alone group. These two-group analyses showed significant interactions (P0.001) between baseline values and group membership for deltaTAG, deltaVLDLC, and deltaTC/HDLC, such that subjects who had the least favorable baseline values showed the most beneficial impact of the PT. Of particular interest was a favorable effect of the PT on LDL particle size.PT, especially high-intensity PT, had a favorable effect on several IRS markers in obese adolescents.

Objectives: To determine the relation of hemostatic markers to cardiovascular fitness and adiposity and the effect of physical training (PT) on these markers. Study design: Seventy-four obese teenagers were randomly assigned to 8 months of lifestyle education (LSE), LSE plus moderate-intensity PT, or LSE plus high-intensity PT. Measures included fibrinogen, plasminogen activator inhibitor-1 (PAI-1), D-dimer, C-reactive protein (CRP), fitness, percent body fat (%BF), and visceral adiposity (VAT). Results: At baseline, fibrinogen and CRP were significantly correlated with %BF and VAT (0.27 ≤ r ≤ 0.51), and fitness ( r = −0.39, r = −0.43, respectively); PAI-1 with %BF ( r = 0.30) and VAT ( r = 0.48); D-dimer with fitness ( r = −0.24). Although PT produced significant changes in fitness and adiposity, there were no significant group differences in the hemostatic markers. Change in PAI-1 was significantly correlated with its baseline value ( r = −0.47) and change in %BF ( r = 0.38). Changes in D-dimer and CRP were significantly correlated with their respective baseline values ( r = −0.68, r = −0.48, respectively). Conclusions: Unfavorable levels of fitness and adiposity were associated with higher levels of hemostatic markers, putting individuals with this profile at greater risk for future cardiovascular disease. No evidence was provided that 8 months of PT had a direct influence on these markers in obese youths. (J Pediatr 2002;141:415-20)

OWENS, SCOTT, BERNARD GUTIN, PAULE BARBEAU, MARK LITAKER, JERRY ALLISON, MATTHEW HUMPHRIES, TOMOKI OKUYAMA, AND NGOC-ANH LE. Visceral adipose tissue and markers of the insulin resistance syndrome in obese black and white teenagers. Obes Res. 2000;8:287‐293. Objective: To determine the relationships between visceral and general adiposity, cardiovascular fitness, and markers of the insulin resistance syndrome in obese black and white teenagers. Research Methods and Procedures: Cross-sectional survey of 81 obese 13- to 16-year-old youths. Visceral adipose tissue was measured with magnetic resonance imaging, and percentage body fat was measured with dual-energy X-ray absorptiometry. Cardiovascular fitness was assessed with a submaximal treadmill test. Fasting blood samples were analyzed for lipids/lipoproteins and insulin. Resting blood pressure was obtained using an automated cuff. Results: Visceral adipose tissue was significantly correlated with unfavorable levels of: triacylglycerol ( r 5 0.27, p , 0.05), total cholesterol ( r 5 0.27, p , 0.05), high-density lipoprotein cholesterol (r 52 0.26, p , 0.05), the ratio of total cholesterol/high-density lipoprotein cholesterol ( r 5 0.42, p , 0.01), low-density lipoprotein cholesterol ( r 5 0.27, p , 0.05), apolipoprotein B (r 5 0.38, p , 0.01), and systolic blood pressure (r 5 0.30, p , 0.01). Multiple regression analyses revealed that visceral adipose tissue was more powerful than percentage body fat for explaining variance in lipoproteins (e.g., for the ratio of total cholesterol/high-density lipoprotein cholesterol, r 2 5 0.13, p , 0.01, and for systolic blood pressure, r 2 5 0.07, p , 0.05). Ethnicity was the most powerful of the demographic predictors for blood lipids (r 2 5 0.15 for triacylglycerol with lower levels in blacks; r 2 5 0.10 for high-density lipoprotein cholesterol with higher levels in blacks; r 2 5 0.06 for the ratio of total cholesterol/high-density lipoprotein cholesterol with lower levels in blacks). Cardiovascular fitness was not retained as a significant predictor of markers of the insulin resistance syndrome. Discussion: Some of the deleterious relationships between visceral adiposity and markers for the insulin resistance syndrome seen in adults were already present in these obese young people.

Background: Physical training can improve hemostatic function in adults, thereby reducing heart disease risk, but no information is available in children on whether physical training can enhance hemostatic function. Objective: The purpose of this investigation was to examine the effects of a physical training program on hemostatic variables in a biethnic group of obese children. Design: Children were randomly assigned to 2 groups. Group 1 participated in physical training for 4 mo and then ceased physical training for 4 mo, whereas group 2 did no physical training for the first 4 mo and then participated in physical training for 4 mo. Plasma hemostatic variables [fibrinogen, plasminogen activator inhibitor 1 (PAI-1), and D-dimer) were measured at months 0, 4, and 8. Results: Analyses of variance revealed no significant group-by-time interactions for the hemostatic variables. When data from both groups were combined there was a significant decrease in D-dimer after 4 mo of physical training (P < 0.05). Factors explaining individual differences in responsiveness to the physical training revealed that individuals with greater percentage fat before physical training showed greater reductions in fibrinogen and D-dimer, and that blacks showed greater reductions in D-dimer than whites (P < 0.05). Stepwise multiple linear regression showed that only higher prephysical training concentrations of fibrinogen, PAI-1, and D-dimer explained significant proportions of the variation in changes in these variables. Conclusions: In obese children, 4-mo periods of physical training did not lead to significant changes in hemostatic variables. Children with greater adiposity and concentrations of hemostatic factors before physical training showed greater reductions in hemostatic variables after physical training than did children with lesser values.

GUTIN, BERNARD, SCOTT OWENS, TOMOKI OKUYAMA, SHARON RIGGS, MICHAEL FERGUSON, AND MARK LITAKER. Effect of physical training and its cessation on percent fat and bone density of children with obesity. Obes Res. Objective We determined the effect of 4-month periods of physical training (PT) and detraining on percent fat (percent fat) and bone density of children with obesity. Research Methods and Procedures Subjects were 79 7- to 11-year-old children with obesity; 34 were white, 44 were black, and 1 was Asian, 26 were male and 53 were female. They were randomly assigned to two groups: group 1 engaged in PT for the first 4 months, while group 2 engaged in PT during the second 4 months. Body composition was measured with dual energy absorptiometry, and diet was measured with 4 days of recall for each 4-month period. PT was offered 5 dayslweek for 40 minuteslsession, heart rate monitors were worn, and no dietary information was given; mean attendance was 80%, and mean heart rate per session was 157 bpm. Results Group by time interactions across the three time-points (from analysis of variance) were significant for percent fat (p =

In adults, a low density lipoprotein cholesterol (LDL-C)/apolipoprotein B-100 (ApoB) ratio is an indicator of ApoB-enriched small dense LDL, which is associated with premature coronary artery disease (CAD). Since this LDL subclass may be inherited, we investigated whether a low LDL-C/ApoB ratio was associated with a positive family history of premature CAD in young children.Subjects were 66 children aged 7 to 11 years who were recruited through a school-based family history survey, flyers, and hospital newspaper advertisements. They were divided according to family history and assessed for fatness, blood pressure, lipids, lipoproteins, and apoproteins.Family history interacted with gender such that girls with a positive family history had a lower LDL-C/ApoB ratio than girls with a negative family history, while the opposite was true in boys; ie, family history-positive boys had a higher ratio than family history-negative boys. The association of a low ratio with a positive family history was seen most clearly in white girls. Family history-positive whites had higher ApoB than family history-negative whites, whereas the pattern was reversed in the blacks. The LDL-C/ApoB ratio and ApoB were not related to other CAD risk factors such as fatness, blood pressure, or other lipids and lipoproteins.In young children, a low LDL-C/ApoB ratio and high ApoB levels were associated with a positive family history of CAD only in the white girls, suggesting that this group is at increased risk of genetically mediated CAD.

To determine whether changes in aerobic fitness and body mass index are related to the age-related rise in blood pressure in healthy preschool children.Longitudinal analyses of 196 free-living children aged 5 years at baseline who were followed over a mean of 19.7 months. Aerobic fitness was assessed using a treadmill. All measures were obtained on multiple occasions at scheduled visits as part of a longitudinal cohort study.An inner-city medical center.Blood pressure was measured using an automated Dinamap device.Mean systolic blood pressure was 95.3 mmHg (SD 8.38) at baseline and increased by 4.46 mmHg per year. Mean diastolic blood pressure was 53.9 mmHg (SD 5.81) at baseline and did not change significantly. Children in the highest quintile of increase in fitness had a significantly smaller increase in systolic blood pressure compared to children in the lowest quintile (2.92 vs 5.10 mmHg/year; P = .03). Children in the lowest quintile of increase in body mass index did not differ significantly in rate of increase in systolic blood pressure compared to children in the highest quintile (3.92 vs 4.96 mmHg/year). In a multiple regression model including baseline systolic blood pressure, fitness, height, body mass index, and other covariates, greater increase in fitness (P = .03) and lesser increase in body mass index (P.01) were associated with lower rates of increase in systolic blood pressure. In a similar multivariate analysis, an increase in fitness was also associated with a lower rate of increase in diastolic blood pressure (P = .02).Young children who increase their aerobic fitness or decrease their body mass index reduce the rate of the age-related increase in blood pressure. These observations may have implications for development of interventions directed at the primary prevention of hypertension.

OBJECTIVE To assess the knowledge of osteoporosis risk factors among young women, their beliefs about the disease, and to what extent they practice preventive behaviors, such as adequate calcium intake and physical activity. DESIGN Cross-sectional survey. SETTING/PARTICIPANTS One hundred twenty-seven women (mean age, 19.6 years; 92% were white) enrolled in a required undergraduate health course at a midwestern state university. RESULTS One hundred fourteen (90%) of the survey respondents had heard about osteoporosis, but only 49 (43%) of the 114 had received information from either a health care provider or a school. There was a significant relationship between receiving osteoporosis information and the ability to correctly identify risk factors (P < or = .006). Only 6.7% of the women reported getting both adequate "osteoprotective" exercise per week and the recommended 1200 mg of calcium per day. Respondents believed that it was unlikely that osteoporosis would develop in them. They also expressed less responsibility and concern about osteoporosis and believed that it is less serious than other common causes of morbidity and mortality in women, such as heart disease and breast cancer (P < or = .02). There was no significant relationship between risk-factor identification and exercise habits, calcium intake, or beliefs about osteoporosis. CONCLUSIONS The majority of young women are not consuming the recommended daily amount of calcium and are lacking sufficient osteoprotective exercise for building healthy bone. Health care providers and educational institutions either have missed opportunities to educate young women about osteoporosis or such information has not been received and retained. Increasing levels of osteoporosis awareness may not be associated with influencing beliefs or behaviors. However, because of the importance of building an adequate bone mass in early life, our data suggest that the development and evaluation of comprehensive osteoporosis educational interventions targeted at younger women are warranted.

This paper reports the results of a study of the gait of 102 patients with osteoarthritis of the knee. Functional status was measured by a 6-min test of walking distance; the stride characteristics associated with the walk test were assessed. Stride characteristics were measured by a Stride Analyzer. Patients were randomized to an 8-week educational and walking program (the intervention group) or to a weekly telephone survey (the control group). The intervention group patients had a 15% increase in walking distance (P < 0.0001) and increases of 9.1% in stride length at free walking speeds (P < 0.007) and 17% in stride length at fast walking speeds (P < 0.01) compared to the control group. The results of this study have shown that the walking and educational program was effective in improving gait function in patients with osteoarthritis of the knee.

Walking is an ideal physical activity for patients with osteoarthritis because it can help to improve functional status without exacerbating pain or necessitating an increase in the use of medication. Although patient education programs designed to encourage walking have become increasingly important in the management of this condition, there is no single synthesis or other published source of theory and intervention strategies to guide the practitioner in the development of such programs. This paper describes a hospital-based patient education program designed to enhance the functional capacity of who have osteoarthritis of the knee by encouraging the adoption and maintenance of walking. The paper describes the goals, objectives, process, and impact of the program; the principal theoretical model utilized in the design of the program; and how concepts and intervention strategies from the literatures on patient compliance and patient education, exercise compliance, behavioral psychology, and relapse prevention have been operationalized and integrated in a walking program that we have evaluated for safety and efficacy.

Many studies have suggested that the positive effect of running on bone mass does not fully compensate for the negative effects of athletic amenorrhea. These studies have made this conclusion based on measurements of bone at a limited number of sites. This study used dual-photon absorptiometry to measure bone mineral content and bone mineral density in the total body as well as in several regions in amenorrheic runners (N = 13), eumenorrheic runners (N = 13), and sedentary controls (N = 12). The subjects were 21-35 years old. Runners had run at least 40 km/week for at least the past 3 years. Controls had body mass indices similar to those of the runners. The amenorrheic women had significantly lower values for total bone mineral content (P = .01), total bone mineral density (P = .04), and total bone mineral content as a percent of normal values (P = .04) than eumenorrheic women, but they were not significantly different from the controls. When total bone mineral content and total bone mineral density were adjusted for body weight, there were no significant differences among the groups. The eumenorrheic subjects had significantly greater bone mineral density in the trunk than the amenorrheic women; eumenorrheics and controls had significantly greater bone mineral density in the spine compared with amenorrheics. Lumbar spine bone mineral density showed a trend toward greatest values for controls and lowest for amenorrheic women (P = .069), although this measurement is relatively imprecise. Arms and legs showed no significant differences among the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Objective To assess the effect of a program of supervised fitness walking and patient education on functional status, pain, and use of medication in patients with osteoarthritis of the knee. Design An 8-week randomized, controlled trial. Setting Inpatient and outpatient services of an orthopedic hospital in an academic medical center. Patients A total of 102 patients with a documented diagnosis of primary osteoarthritis of one or both knees participated in the study. Data were obtained on 47 of 51 intervention patients and 45 of 51 control patients. Interventions An 8-week program of supervised fitness walking and patient education or standard routine medical care. Measurements Patients were evaluated and outcomes assessed before and after the intervention using a 6-minute test of walking distance and scores on the physical activity, arthritis impact, pain, and medication subscales of the Arthritis Impact Measurement Scale (AIMS). Results Patients randomly assigned to the walking program had a 70-meter increase in walking distance relative to their baseline assessment, which represents an improvement of 18.4% (95% Cl, 9.8% to 27.0%). In contrast, controls showed a 17-meter decrease in walking distance relative to their baseline assessment (P less than 0.001). Improvements in functional status as measured by the AIMS physical activity subscale were also observed in the walking group but not in the control group (P less than 0.001); patients assigned to the walking program improved 39% (Cl, 15.6% to 60.4%). Although changes in scores on the arthritis impact subscale were similar in the two groups (P = 0.093), the walking group experienced a decrease in arthritis pain of 27% (Cl, 9.6% to 41.4%) (P = 0.003). Medication use was less frequent in the walking group than in the control group at the post-test (P = 0.08). Conclusions A program of supervised fitness walking and patient education can improve functional status without worsening pain or exacerbating arthritis-related symptoms in patients with osteoarthritis of the knee.

Part of the reduction in bone density observed in older people is due to disuse rather than the aging process itself. While some mechanical stress is needed to maintain optimal bone density, it is not clear just which types of exercise are most valuable or whether appropriate exercise might reduce the need for estrogen therapy in postmenopausal women. Cross-sectional studies. Physical activity, aerobic fitness, and strength have all been correlated with bone density. Young people who use a specific part of the body in vigorous exercise exhibit enhanced bone density in that part of the body, but not necessarily in other regions. Older people who have been active for many years seem to exhibit generally enhanced bone density. Prospective studies. Most regimens which used vigorous aerobic and strength training enhanced bone density, but walking is relatively ineffective for prevention of postmenopausal bone loss. Most studies using specific bone-loading exercise have shown substantial increases in bone density at the specific sites loaded. Elderly people seem capable of responding favorably to vigorous exercise. No direct comparisons of exercise and estrogen therapy have been reported. Excessive exercise. Extremely high volumes of exercise may overwhelm a person's adaptive capacity, leading to stress fractures. For example, young women athletes who suffer from menstrual dysfunction exhibit reduced bone density and musculoskeletal disorders. Clinical implication. Although the evidence is far from conclusive, an exercise regimen should probably include vigorous total body exercise, including strength and aerobic training.

This study investigated metabolic and nutritional factors in association with athletic menstrual dysfunction (AMD). Three groups of women were studied: amenorrheic runners (amenorrheic), eumenorrheic runners (eumenorrheic), and eumenorrheic sedentary controls (sedentary). Amenorrheic and eumenorrheic were similar in age, weight, percent body fat by hydrodensitometry, training pace and mileage, best 10 km race time, years running, and maximal oxygen consumption. When adjusted for body weight or for fat-free mass by analysis of covariance, RMR was significantly lower in amenorrheic than in eumenorrheic and sedentary. The daily caloric intakes of the groups did not differ significantly, but the amenorrheic scored significantly higher than the eumenorrheic and sedentary on a scale of aberrant eating patterns. Amenorrheic high mileage runners seem to have a less adequate diet than eumenorrheic runners but appear to maintain energy balance and stable weight through a reduction in RMR.

Objective. Little is known about the relations of fitness and fatness to left ventricular structure and function in obese adolescents. This project had 2 purposes: 1) to determine the correlations of cardiovascular fitness and adiposity to left ventricular parameters in obese adolescents; and 2) to see the effect of 8 months of physical training (PT) at low and high intensities. Design. Obese 13- to 16-year-olds (N = 81) were tested at baseline and then randomly assigned to lifestyle education (LSE) alone, LSE plus moderate-intensity PT, or LSE plus high-intensity PT. Follow-up testing was conducted 8 months later. Because no significant differences were found between moderate-intensity and high-intensity PT, the groups were combined to form a LSE + PT group. Intervention. Eight months of PT, offered 5 days per week with the target energy expenditure for all PT participants being 250 kcal/session, and LSE every 2 weeks. Outcome Measures. Left ventricular mass divided by height to the 2.7th power (LVM/Ht2.7), midwall fractional shortening (MFS), and relative wall thickness (RWT) were measured using M-mode echocardiography. Cardiovascular fitness was measured by a maximal multistage treadmill test; percent body fat (%BF) with dual-energy radiograph absorptiometry; and visceral adipose tissue (VAT) with magnetic resonance imaging. Results. At baseline, high levels of VAT were associated with higher RWT (r = 0.30) and lesser MFS (r = −0.29). Compared with the LSE-alone group, the LSE + PT group significantly improved in cardiovascular fitness and decreased in %BF and VAT. However, there were no significant differences between groups on changes in LVM/Ht2.7, MFS, or RWT. Individual changes in cardiovascular fitness, %BF, and VAT did not correlate significantly with interindividual changes in left ventricular structure and function. Conclusions. High levels of VAT were associated with unfavorable left ventricular structure and function. However, no evidence was provided that an 8-month PT program, which improved cardiovascular fitness and reduced general and visceral adiposity, improved left ventricular structure and function. Future studies consisting of longer training programs and/or greater weight reductions are needed to see whether the adverse left ventricular effects of obesity can be ameliorated by exercise training.

Many studies have suggested that the positive effect of running on bone mass does not fully compensate for the negative effects of athletic amenorrhea. These studies have made this conclusion based on measurements of bone at a limited number of sites. This study used dual-photon absorptiometry to measure bone mineral content and bone mineral density in the total body as well as in several regions in amenorrheic runners (N = 13), eumenorrheic runners (N = 13), and sedentary controls (N = 12). The subjects were 21-35 years old. Runners had run at least 40 km/week for at least the past 3 years. Controls had body mass indices similar to those of the runners. The amenorrheic women had significantly lower values for total bone mineral content (P = .01), total bone mineral density (P = .04), and total bone mineral content as a percent of normal values (P = .04) than eumenorrheic women, but they were not significantly different from the controls. When total bone mineral content and total bone mineral density were adjusted for body weight, there were no significant differences among the groups. The eumenorrheic subjects had significantly greater bone mineral density in the trunk than the amenorrheic women; eumenorrheics and controls had significantly greater bone mineral density in the spine compared with amenorrheics. Lumbar spine bone mineral density showed a trend toward greatest values for controls and lowest for amenorrheic women (P = .069), although this measurement is relatively imprecise. Arms and legs showed no significant differences among the groups.(ABSTRACT TRUNCATED AT 250 WORDS)