Changes In Percent Body Fat Research Articles

Body Composition and Flexibility Changes in Exercising Breast Cancer Survivors

Subsequent to treatment for breast cancer, many people may adopt sedentary lifestyles due to psychosocial and physical side effects associated with their cancer experience. Sedentary lifestyles may lead to increased body weight and decreased flexibility. Increased body weight and body fat are associated with increased risk of co-morbidities and an increase in cancer mortality rates for women. Aerobic exercise has been shown to reduce body fat percentage and increase measures of flexibility in healthy populations. Flexibility and body composition changes in response to exercise have not been extensively reported for cancer survivors. PURPOSE: To examine the effect of an aerobic exercise program on body composition and flexibility measures in breast cancer survivors. METHODS: Twenty-one breast cancer survivors (43-79 years, at least one month post-treatment) were randomly assigned to either an exercise group (n=11) or control group (n= 10). The exercise group participated in a low to moderate intensity (30-50% heart rate reserve) aerobic exercise program three times a week for ten weeks. The control group did not participate in the exercise program or change their normal daily activities. Body composition was assessed utilizing a three site (tricep, iliac crest, thigh) skin-fold test. Flexibility was measured with the Modified Sit-and-Reach test. RESULTS: Statistical analysis revealed a significant improvement in body composition in the exercise group compared to the control group (p = .002). The exercise group decreased body fat by 1.5% (29.8% to 28.3%) while the control group showed no change in body fat percentage (32.7% to 33.2%). The exercise group showed a significant increase in lower body flexibility when compared to the control group (p = .006). The exercise group increased flexibility 13.4% (26.7 cm to 30.3 cm) while the control group decreased flexibility 3.3% (23.0 cm to 22.2 cm). CONCLUSIONS: These results indicate that low to moderate intensity exercise is effective in reducing body fat and increasing flexibility in breast cancer survivors. These changes may increase a personââ'â,,¢s ability to function physically and may reduce the risk of co-morbidities associated with increased body weight. Cancer survivors should be encouraged to adopt similar exercise programs.

Effects of an Entire Season on Physical Fitness in Elite Female Handball Players

Sixteen elite female handball players were studied to examine the effects of an entire season on anthropometric characteristics, physical fitness, and throwing velocity. One-repetition-maximum bench press (1RMBP), jumping explosive strength, power-load relationship of the leg and arm extensor muscles, 5- and 15-m sprint running time, endurance running, and handball throwing velocity were assessed in four periods. Individual volumes and intensities of training and competition were quantified for 11 activities. During the season, significant increases (P < 0.05-0.01) occurred in fat-free mass (1.8 +/- 1.2%), 1RMBP (11 +/- 7.4%), bench press (12-21%) and half-squat (7-13%) muscle power output, vertical jumping height (12 +/- 7.2%), throwing velocity (8 +/- 5.9%), and a significant decrease in percent body fat (9 +/- 8.7%). No changes were observed in sprint and endurance running. Significant correlations (P < 0.05-0.01) were observed between time devoted to games and changes in velocity at submaximal loads during bench press actions, as well as between changes in muscle velocity output of the upper and lower extremities and changes in throwing velocity. Changes in percent body fat or body mass correlated (P < 0.01) positively with changes in maximal strength and muscle power. The handball season resulted in significant increases in anthropometric characteristics, physical fitness, and throwing velocity. The correlations observed suggest the importance of including explosive strength exercises of the knee and elbow extensions. Special attention may be needed to be paid to the mode of body fat loss, to increase endurance capacity without interfering in strength gains. Official and training games may be an adequate stimulus for enhancing certain physical fitness characteristics in female elite handball players.

Personality characteristics in adolescence predict long-term changes in body fatness

Five personality characteristics were assessed in 312 adolescent boys and girls, and investigated in relation to the change in body fat percentage over 22 years of follow up. Boys with low levels of Social Inadequacy and girls with high levels of Recalcitrance showed relatively large gains in body fat percentage.

Assessment of Change in Body Fat Percentage with DXA and Eight-Electrode BIA in Centrally Obese Women

To compare estimates of change in percent body fat (Delta%BF) between DXA and BIA8 in abdominally obese women. Six-month longitudinal study of 106 women (baseline: age 48.2 +/- 7.6 yr; BMI 30.4 +/- 2.9 kg.m; %BFDXA 45.8 +/- 3.6%) participating in an exercise-oriented behavior-change program (walking and bicycling). Fatness was measured by DXA and Tanita BC-418 (BIA8). Agreement between methods was assessed, and regression analysis was used to find predictors of the deviation between methods for estimating changes in fat mass percentage. The methods differed significantly, both at baseline and follow-up (-5.0 and -4.4%BF, respectively; both P < 0.001). The mean Delta%BF was -1.1 +/- 2.5%BFDXA and -0.5 +/- 2.2%BFBIA8 (mean difference between methods 0.6 +/- 1.8%BF; P < 0.001; 95% limits of agreement -3.0 to 4.2%BF), with a range of -14.8 to 3.3%BFDXA and -9.4 to 3.5%BFBIA8. Approximately 49% of the variation in the difference between methods was explained by variations in age (beta = -0.05; P = 0.006), DeltaBMI (beta = 0.98; P < 0.001), and Delta%BFDXA (beta = -0.71; P < 0.001), indicating that the larger the change, the greater the discrepancy between methods. The difference between methods regarding Delta%BF was statistically significant, but it was of small magnitude. However, with increasing Delta%BF, increasing discrepancies were observed, implying that the BIA equipment may have limited validity for detecting larger fat losses. Both clinicians and researchers may benefit from awareness of this potential limitation.

Decrease in body fat during an ultra-endurance triathlon is associated with race intensity

Objective: To investigate whether adipose subcutaneous tissue or skeletal muscle mass decreased during a non-stop ultra-endurance triathlon. Design: Descriptive field study. Setting: The Triple Iron Triathlon Germany 2006 in Lensahn:...

Effects of long-term exercise and diet intervention on plasma adipokine concentrations

Background: In a randomized, controlled, 2 × 2 factorial trial on the effect of long-term changes in diet and exercise, a significant reduction in body weight and fat mass was observed. Alterations in leptin and plasminogen activator inhibitor-1 concentrations were previously reported from this study.Objective: We examined the separate and combined effects of a 1-y exercise and diet intervention on several adipokines; adiponectin, interleukin-6 and -8, tumor necrosis factor-α, monocyte chemoattractant protein-1, hepatocyte growth factor, nerve growth factor, C-reactive protein, and resistin.Design: One hundred eighty-eight men with several risk factors for diabetes and cardiovascular disease were randomly allocated to 4 groups: diet, exercise, combined diet and exercise, and control.Results: Plasma adiponectin concentrations remained unchanged, whereas body mass index and fat mass decreased after dietary changes and an increase in physical activity. In the control group, adiponectin concentrations were reduced. Analyzed according to the factorial design, only diet intervention had a significant (P = 0.03) positive effect on plasma adiponectin relative to control, and this effect was largely explained by changes in fat mass. After adjustment for change in percentage body fat, there were significant positive effects on tumor necrosis factor-α in all 3 intervention groups (P = 0.01 for the diet group, 0.03 for the exercise group, and 0.05 for the combined diet and exercise group). Minor changes were observed for the other adipokines. Neither baseline concentrations of nor changes in adiponectin and plasminogen activator inhibitor-1 were significantly correlated to the other adipokines, whereas concentrations of and changes in the other adipokines were significantly correlated.Conclusion: Diet intervention had a significant positive effect on adiponectin concentrations, which is largely explained by a reduction in fat mass.

Relationship between changes in body weight and waist circumference in Japanese

We investigated the correlation between changes in body weight and body composition parameters. We used the data of 2635 Japanese (40.2±12.2 years) at baseline and at 1-year follow-up from a database of 13522 subjects, which is available at the Okayama Southern Institute of Health in Okayama prefecture, Japan. Body weight, waist circumference at the umbilical level, hip circumference, and body fat percentage were used in the analyses. Body composition parameters were significantly reduced after 1 year. Changes in body weight significantly correlated with changes in waist circumference, changes in hip circumference, and changes in body fat percentage. A decrease in body weight of 3 kg corresponded to a 3.45 cm decrease in waist circumference in men and a 2.83 cm decrease in that in women. A decrease in body weight of 3 kg corresponded to an almost 3 cm decrease in waist circumference at the umbilical level in Japanese men and women.

Effects of Pedometers and Walking Poles on Exercise Compliance and Fat Losses in Sedentary Adults

PURPOSE: The purpose of this study was to compare body fat losses and compliance to exercise in previously sedentary individuals who were randomly-assigned to a pedometer group or pedometer-Nordic walking pole group. METHODS: Twenty-three sedentary adults were recruited to participate in an 8-week walking program, beginning on a staggered schedule as recruits enlisted in the study. Subjects were told that the study would compare physiological changes between two walking groups. Body fat % measurements were obtained on each subject using a BodPod prior to the walking intervention, and following 8-weeks of walking. For the first six weeks, participants were instructed to walk at least 90 minutes per week with a goal of reaching 150 minutes per week by week 7. Participants completed walking logs each week, in which they recorded date, time spent walking, and the number of steps per week. RESULTS: As of the date of this writing, three males and six females (46.7 + 12.4 yr) completed the 8-week program. The Nordic pole group averaged walking 119.2 min/ week (± 51.0 min) and the pedometer group averaged 140.8 min/week (± 85.2 min). The difference is not statistically significant (p = 0.264). No significant changes were observed in pre versus post % fat, within group, nor when comparing the two groups. However, the average change in percent body fat in the hiking pole group was - 3.0%, (± 2.5%; p = 0.123) and the average change in the pedometer only group was −0.3% (± 1.2%, p = 0.372), suggesting that statistically significant differences may be observed in the Nordic walking pole group once all subjects have completed the study. CONCLUSIONS: The current study observed no signficant differences in compliance or body fat changes between the pedometer and pedometer-Nordic walking pole groups. However these results are preliminary and may change once the remaining 14 subjects complete the study and are analyzed to determine if the trend towards greater fat losses in the pole group are are practically significant.

Effect of a 12-Month Randomized Clinical Trial of Exercise on Serum Prolactin Concentrations in Postmenopausal Women

Prolactin is associated with an increased risk of postmenopausal breast cancer; however, few modifiable factors are known to reduce prolactin concentrations. Therefore, we examined the effect of a 12-month moderate-intensity exercise intervention on serum prolactin concentrations as a secondary end point (primary end points were estrogens and androgens). We randomly assigned 173 postmenopausal women who were sedentary, overweight (body mass index >24 kg/m(2), body fat >33%), ages 50 to 75 years, and not using hormone therapy to an exercise intervention or stretching control group. The intervention was facility- and home-based (45 min, 5 days/wk moderate-intensity sports/recreational exercise). One hundred and seventy (98%) women completed the study. Prolactin concentrations were similar at baseline (P = 0.25, geometric mean exercisers = 6.9 and controls = 7.5 ng/mL). Overall, the intervention was not associated with changes in prolactin concentrations between exercisers and controls at 3 months (P = 0.46) or 12 months (P = 0.29). The intervention effect did not vary by baseline age, body mass index, parity, or change in percent body fat during the intervention. Among exercisers, there was a significant difference in prolactin concentrations by change in fitness (VO(2)max) between baseline and 12 months. Exercisers whose VO(2)max changed by <5% had a 5% increase in prolactin concentrations, whereas those who increased their VO(2)max by 5% to 15% and >15% had a 11% (P = 0.03) and 7% (P = 0.01) decrease in prolactin concentrations, respectively. Although the exercise intervention had little effect on prolactin concentrations overall, increasing physical fitness was associated with reduced prolactin concentrations among postmenopausal women.

Moderators of the Effects of Exercise Training in Breast Cancer Patients Receiving Chemotherapy

We have previously reported that aerobic and resistance exercise training in breast cancer patients receiving chemotherapy is beneficial but the responses were heterogeneous. Researchers recommend that clinical trials should routinely conduct and report subgroup analyses to guide the next generation of studies and inform clinical practice. PURPOSE: To examine prespecified and exploratory moderators of the effects of exercise training in the Supervised Trial of Aerobic versus Resistance Training (START). METHODS: We conducted a multicenter randomized controlled trial in Canada between 2003 and 2005 that randomized 242 breast cancer patients initiating chemotherapy to usual care (n=82), resistance exercise (RET; n=82), or aerobic exercise (AET; n=78) for the duration of their chemotherapy. Our endpoints of interest were quality of life (QoL), physical fitness, and body composition. Our primary prespecified moderator analysis was patient preference on QoL. Secondary prespecified moderator analyses were age, disease stage, and chemotherapy regimen. Marital status was explored as a moderator of QoL. RESULTS: Patient preference (p for interaction=.003) and marital status (adjusted p for interaction=.039) moderated the effects of exercise training on QoL. Participants that preferred RET improved QoL more when assigned to RET and participants that had no preference improved QoL more when assigned to AET. Unmarried participants improved QoL with exercise training but married participants did not. Age moderated aerobic fitness changes (p for interaction=.015), chemotherapy regimen moderated muscular strength gains (p for interaction=.016), and disease stage moderated lean body mass gains (p for interaction<.001) and percent body fat change (adjusted p for interaction=.055). Younger participants, those receiving non-taxane-based chemotherapies, and those with more advanced disease stage experienced the better outcomes. The interactions were not explained by differences in exercise adherence. CONCLUSION: Patient preference moderated the effects of exercise training on QoL. Other important demographic and medical factors also altered exercise training responses. These results should be confirmed in future randomized trials and, if replicated, may inform clinical practice.

Effect of Infant Feeding on Maternal Body Composition

Women gain total body weight and accrue body fat during pregnancy. Breastfeeding has been suggested as an efficient means of promoting postpartum weight loss due to its high energy cost. We investigated the effect of infant feeding mode on maternal body composition. This study evaluated maternal weight and percent body fat changes in exclusively breastfeeding versus mixed feeding mothers during the first 12 weeks postpartum using the BOD POD. Twenty four mothers aged 19 – 42 years were studied. Participants were recruited from Athens-Clarke County and surrounding areas of the State of Georgia, USA. The study was conducted between November 2005 and December 2006. Prepregnancy weight was higher in mixed feeding mothers than in exclusively breastfeeding mothers (68.4 kg vs. 61.4 kg) but the difference was not statistically significant. At 12 weeks postpartum, exclusively breastfeeding mothers had lost more total body weight than mixed feeding mothers (4.41 ± 4.10 kg versus 2.79 ± 3.09 kg; p = 0.072). There was no significant difference in fat weight change between the two groups (4.38 ± 2.06 kg versus 4.17 ± 2.63 kg). However, mixed feeding mothers lost slightly more percent body fat than exclusively breastfeeding mothers (1.90 ± 4.18 kg versus 1.71 ± 3.48 kg), but the difference was not statistically significant. The trend in percent body fat loss was significant among exclusively breastfeeding mothers (p = 0.034) but not mixed feeding mothers (p = 0.081). Exclusively breastfeeding mothers consumed more calories than mixed feeding mothers (1980 ± 618 kcal versus 1541 ± 196 kcal p = 0.08). Physical activity levels were, however, higher in mixed feeding mothers than exclusively breastfeeding mothers. Our results provide further evidence that exclusive breastfeeding promotes greater weight loss than mixed feeding among mothers even in the early postpartum period. This suggests that there is the need to encourage mothers to exclusively breastfeed as a means of overweight and obesity prevention.

VALIDITY OF SKINFOLDS TO MEASURE CHANGE

VALIDITY OF SKINFOLDS TO MEASURE CHANGE

Fat mass gain is lower in calcium-supplemented than in unsupplemented preschool children with low dietary calcium intakes

Dietary calcium may play a role in the stimulation of lipolysis and the inhibition of lipogenesis, thereby reducing body fat. The aim was to determine whether an association existed between change in percentage body fat (%BF) or fat mass and calcium intake in children aged 3-5 y. A secondary analysis of a 1-y randomized calcium and activity trial in 178 children was conducted. Three-day diet records and 48-h accelerometer readings were obtained at 0, 6, and 12 mo. Body composition was measured by dual-energy X-ray absorptiometry at 0 and 12 mo. The decrease in %BF was less in girls (-0.6 +/- 2.8%) than in boys (-1.5 +/- 2.6%; P = 0.03) and correlated with age (r = 0.19, P = 0.01) and maternal body mass index (r = 0.19, P = 0.02). Changes in fat mass were not significantly different by activity group or between children randomly assigned to receive calcium or placebo (0.5 +/- 0.9 and 0.6 +/- 0.8 kg, respectively; P = 0.32). Similar findings were observed for the change in %BF. No correlations between %BF and fat mass changes and dietary calcium (r = -0.01, P = 0.9 and r = -0.05, P = 0.5) or total (dietary + supplement) calcium intake (r = -0.02, P = 0.8 and r = -0.06, P = 0.4) were observed. Among children in the lowest tertile of dietary calcium (<821 mg/d), fat mass gain was lower in the calcium group (0.3 +/- 0.5 kg) than in the placebo group (0.8 +/- 1.1 kg) (P = 0.04) but was not correlated with mean total calcium intake (r = -0.20). These findings support a weak relation between changes in fat mass gain and calcium intake in preschool children, who typically consume below recommended amounts of dietary calcium.

Energy expenditure and substrate oxidation predict changes in body fat in children

The hypothesis that alterations in energy metabolism predict body fat gain is controversial. The aim of this study was to determine which components of energy metabolism were most important in predicting fat gain in children aged 10.8 +/- 0.6 y. A 2-y longitudinal study to examine whether components of energy metabolism are predictors of body fat gain was conducted in 114 preadolescent African American and white children aged 9-11 y by measuring total daily energy expenditure on the basis of doubly labeled water (DLW), resting metabolic rate, the thermic effect of food, energy expended in physical activity, and substrate oxidation after a meal. The primary endpoint was the 2-y change in percentage body fat (%BF). Individual variables of energy metabolism predicted up to 7% of the variance in changes in %BF over the 2-y interval in the whole group. Predictors of change in body fatness tended to be sex and race specific. Protein oxidation during a test meal explained a significant portion of the variance in change in %BF in the overall group and in nearly all of the subgroups. Multivariate prediction models accounted for 10-41% of the variance in change in %BF. Tanner stage at 2-y follow-up was highly predictive of change in body fatness and improved the overall prediction, accounting for 24-62% of the variance in change in %BF in those groups in which Tanner entered the model. This study provides evidence that total daily energy expenditure, resting metabolic rate, substrate oxidation, and total energy intake are predictors of gain in body fatness during late childhood in boys and girls.

Improvements in glucose tolerance and insulin sensitivity after lifestyle intervention are related to changes in serum fatty acid profile and desaturase activities: the SLIM study

The aim of this study was to investigate whether lifestyle intervention-induced changes in serum fatty acid profile of cholesteryl esters and estimated desaturase activities are related to improvements in insulin sensitivity in subjects at risk of type 2 diabetes. In the Study on Lifestyle Intervention and Impaired Glucose Tolerance Maastricht (SLIM), 97 men and women with IGT were randomised to a combined diet and exercise programme (47 intervention) or a control group (50 control subjects). At baseline and after 1 year the following assessments were made: an OGTT, an exercise test to determine maximal aerobic capacity, anthropometry, and analysis of the serum fatty acid profile of cholesteryl esters. The lifestyle programme was effective in reducing the intake of total and saturated fat, increasing physical activity, reducing obesity and improving insulin sensitivity and glucose tolerance. Regression analysis of the total population showed that an increase in the C20:4 n-6/C20:3 n-6 ratio (estimated Delta5-desaturase activity) and reductions in the C18:3 n-6/C18:2 n-6 ratio (estimated Delta6-desaturase activity) and the C16:1 n-7/C16:0 ratio (estimated Delta9-desaturase activity or stearoyl-CoA desaturase-1) were significantly associated with a decrease in homeostasis model assessment for insulin resistance. After adjustment for lifestyle changes (change in percentage body fat, aerobic capacity and saturated fat intake), these associations were partly reduced, but remained statistically significant. Lifestyle-induced changes in fatty acid profile of cholesteryl esters and desaturase activities were independently related to changes in insulin sensitivity in subjects at risk of type 2 diabetes.

Dietary Fat Intake Predicts 1-Year Change in Body Fat in Adolescent Girls With Type 1 Diabetes

The purpose of this study was to determine whether objectively measured physical activity and dietary macronutrient intake differentially predict body fat in adolescent girls with type 1 diabetes and control girls. This study comprised 23 girls (12-19 years) with type 1 diabetes and 19 age-matched healthy control girls. At baseline, physical activity and energy intake were assessed for 7 consecutive days by accelerometry and a structured food diary, respectively. Body composition was measured by dual-energy X-ray absorptiometry at baseline and after 1 year. Fat intake was positively related to a 1-year change in percentage body fat (P = 0.006), after adjustment for total energy intake. No significant interaction was observed (case-control group x main exposure), indicating that the association between fat intake and gain in body fat was similar in both groups. Physical activity did not predict gain in body fat; however, total physical activity was positively associated with a gain in lean body mass (P < 0.01). Girls treated with six daily dosages of insulin increased their percentage of body fat significantly more than those treated with four daily injections (P < 0.05). In this prospective case-control study, we found that fat intake predicted gain in percentage of body fat in both adolescent girls with type 1 diabetes and healthy control girls. The number of daily insulin injections seems to influence the accumulation of body fat in girls with type 1 diabetes.

Fish Oils Produce Anti-inflammatory Effects and Improve Body Weight in Severe Heart Failure

Fish oils have been shown to reduce production of tumor necrosis factor-alpha (TNF-alpha) in healthy subjects. We sought to evaluate the effects of fish oils on pro-inflammatory cytokines and body weight in patients with advanced heart failure. Fourteen patients (New York Heart Association [NYHA] Class III to IV heart failure) were randomized in a double-blinded trial to active therapy with 8 g of n-3 fatty acids (Group A, n = 7) or placebo (Group B, n = 7) for 18 weeks. TNF-alpha and interleukin-1 (IL-1) production were measured by radioimmunoassay after endotoxin stimulation of peripheral blood mononuclear cells. Placebo-treated patients had a 44% increase in TNF-alpha (from 1.28 to 1.84 pg/ml; p = 0.07) but no significant change in IL-1 (from 0.68 to 0.78 pg/ml) production. n-3 fatty acids resulted in a 59% reduction in TNF-alpha (from 1.64 to 0.68 pg/ml; p = 0.02) and 39% decrease in IL-1 (from 1.98 to 1.21 pg/ml; p = 0.09) production. There was an inverse correlation between change in TNF-alpha production and change in percent body fat (r = -0.6; p = 0.02). Fish oils decrease TNF-alpha production in heart failure and improve body weight. Fish oil therapy may represent a novel therapeutic approach in late-stage heart failure characterized by cardiac cachexia.

Objectively Measured Physical Activity and Body Fat Gains in Women

PURPOSE: To determine the extent to which objectively measured physical activity (PA) affects risk of weight and body fat gains in middle-aged women. A secondary aim was to ascertain the extent to which age and energy intake confound the above associations. METHODS: A prospective cohort design was used with 4 yrs between the baseline and follow-up assessments. Subjects were 166 women who were non-smokers and non-obese (BMI <30), with a mean age of 41.4 (+ 2.9) years, at baseline. At baseline, subjects wore a CSA (now MTI) accelerometer over the left hip for 7 consecutive days. The sum of all activity counts was used to index PA. PA was divided into quartiles and the middle-two quartiles were collapsed to form three PA groups (Low, Moderate, High). Body weight was measured using a computerized scale and body fat percentage was assessed using DXA (Hologic, 4500W). Energy intake was measured using weighed food logs kept during the same 7 days subjects wore the accelerometers. Everything eaten was first weighed on an Ohaus digital scale and then recorded on a food log. A registered dietitian entered all of the food record data, and energy intake was computed using the Esha Research software. RESULTS: Mean weight change over the 4 yrs was 1.0+ 5.0 kg. Mean change in body fat percentage was 1.5 + 3.7 percentage points. Weight change over the 4 yrs differed significantly across the three PAgroups (F = 3.9, P = 0.023). Women in the Low PA (2.2 + 5.3 kg) and Moderate PA (1.2 + 5.0 kg) groups gained significantly more weight over the 4-year study compared to those in the High PA group (−0.7 + 4.3 kg) who lost weight. Similarly, women in the Low PA (2.4 +3.8 % points) and Moderate PA (1.7 + 3.1 % points) groups gained significantly more in body fat percentage than those in the High PA (0.3 + 4.2 % points) group (F = 3.6, P = 0.031). Adjusting for age and energy intake had little effect on the associations. Incidence data used to calculate relative risk showed that the risk of gaining ≥3.5 kg over the 4 yrs was 3.2 times greater for women in the low PA group compared to those in the high PA group (95% CI: 1.3–7.9). Risk of gaining 3.5 kg or more was 1.7 times greater in the Low PA group compared to the Moderate PA group (95% CI: 1.0–2.9). The likelihood of losing 1 kg or more of body weight over the study was 1.5 times greater in the High PA group compared to the Low PA group (95% CI: 1.1–2.0). CONCLUSIONS: Middle-aged women who engage in low levels of physical activity are at greatly increased risk of weight and body fat gains over a 4-year period compared to women who engage in higher levels of activity. Similarly, high physical activity levels increase the likelihood that women will lose weight and body fat over 4 yrs compared to low levels of activity.

Beta Cell Function, Insulin Resistance and Plasma Adiponectin Concentrations are Predictors for the Change of Postprandial Glucose in Non-diabetic Subjects at Risk for Type 2 Diabetes

Insulin resistance, impaired insulin secretion, and low adiponectin levels have been shown to be predictors for type 2 diabetes. However, it is not yet clear whether these associations (1) are independent of changes in body weight, or (2) are valid for changes in glucose tolerance in the prediabetic state. Sixty-two non-diabetics (50 with normal glucose tolerance) aged 41 +/- 11 years, BMI 30.5 +/- 5.3 kg/m2 (mean +/- SD) were studied twice with a standard oral glucose tolerance test (oGTT, mean follow-up time 3.0 +/- 1.8 years (mean +/- SD) [range 0.5-6.5 years]). Insulin sensitivity and insulin secretion were estimated from oGTT using validated indices. Two-hour blood glucose during oGTT deteriorated over time (baseline 2 h glucose 6.32 +/- 0.21 VS. follow-up 2 h glucose 7.14 +/- 0.22 mM, p < 0.001) while the percentage body fat did not change (32.7 +/- 1.2 VS. 32.6 +/- 1.2%, p = 0.46). Follow-up 2 h blood glucose was predicted by adiponectin (p = 0.01), baseline insulin sensitivity (p = 0.02) and baseline insulin secretion relative to insulin sensitivity (p = 0.03) independent of sex, age, baseline 2 h blood glucose or change in percentage body fat. Our results suggest that low adiponectin levels, insulin resistance and low beta cell function predict the continuous deterioration of glucose tolerance in early prediabetic states, independent of changes in adiposity. Therefore, the early influence of these parameters should be the subject of future prevention programs to prevent deterioration of glucose tolerance.

No Effect of Exercise on Insulin-Like Growth Factor 1 and Insulin-Like Growth Factor Binding Protein 3 in Postmenopausal Women: a 12-Month Randomized Clinical Trial

A meta-analysis indicated that increased circulating concentrations of insulin-like growth factor 1 (IGF-1) are associated with increased risks for colorectal, prostate, and premenopausal breast cancers, and that increased concentrations of IGF binding protein 3 (IGFBP-3) are associated with