Changes in body weight, C-reactive protein, and total adiponectin in non-obese women after 12 months of a small-volume, home-based exercise program

Linking Physical Activity to Breast Cancer Risk via Inflammation, Part 1: The Effect of Physical Activity on Inflammation

The protective effect of physical activity on breast cancer incidence may partially be mediated by inflammation. Systematic searches of Medline, EMBASE, and SPORTDiscus were performed to identify intervention studies, Mendelian randomization studies, and prospective cohort studies that examined the effects of physical activity on circulating inflammatory biomarkers in adult women. Meta-analyses were performed to generate effect estimates. Risk of bias was assessed, and the Grading of Recommendations Assessment, Development, and Evaluation system was used to determine the overall quality of the evidence. Thirty-five intervention studies and one observational study met the criteria for inclusion. Meta-analyses of randomized controlled trials (RCT) indicated that, compared with control groups, exercise interventions reduced levels of C-reactive protein (CRP) [standardized mean difference (SMD) = -0.27, 95% confidence interval (CI) = -0.62 to 0.08), tumor necrosis factor alpha (TNFα, SMD = -0.63, 95% CI = -1.04 to -0.22), interleukin-6 (IL6, SMD = -0.55, 95% CI = -0.97 to -0.13) and leptin (SMD = -0.50, 95% CI = -1.10 to 0.09). Owing to heterogeneity in effect estimates and imprecision, evidence strength was graded as low (CRP, leptin) or moderate (TNFα and IL6). High-quality evidence indicated that exercise did not change adiponectin levels (SMD = 0.01, 95% CI = -0.14 to 0.17). These findings provide support for the biological plausibility of the first part of the physical activity-inflammation-breast cancer pathway.

The effects of home-based stair and normal walking exercises on lower extremity functional ability, fall risk factors, and cardiovascular health risk factors in middle-aged older women

The purpose of this study was to exam 12 weeks of stair and normal walking effects on lower extremity functional ability and cardiovascular health risk factors in middle-aged older women. Twenty-four subjects were assigned either to the stair walking group (SWG, 57.40±6.11 years, n=10) or the normal walking group (NWG, 57.28±16.83 years, n= 14). They performed exercises 3 times per week, 60 min per day for 12 weeks. Lower extremity functional ability (lower extremity muscular strength, walking speed, active and static balance ability, and agility) and cardiovascular health risk factors were compared by time and groups using a two-way repeated analysis of variance and mean values were compared within group using paired t-test. As results, significant time differences were found in lower extremity muscular strength, walking speed and active balance; no time and group interactions were found. Also, significant time differences were found in systolic blood pressure, diastolic blood pressure, total cholesterol, triglycerides, fasting glucose. Significant time and group interactions were found in body fat. In addition, significant time differences within the groups were found in lower extremity muscular strength, walking speed, active balance in SWG and NWG; systolic blood pressure in SWG; systolic blood pressure, diastolic blood pressure, total cholesterol, triglycerides, and fasting glucose in NWG. These results indicated that home-based stair and normal walking exercises can be utilized to improve lower extremity functional ability and cardiovascular health risk factors in middle-aged and older women.

Association between physical activity and the expression of mediators of inflammation in normal breast tissue among premenopausal and postmenopausal women

Physical activity is associated with decreased breast cancer risk. The underlying biological mechanisms could include the reduction of the local inflammation in the breast tissue. We conducted a cross-sectional study to assess the association between the physical activity and the protein expression levels of eleven mediators of inflammation in normal breast tissue of 164 women having breast cancer. Information on total physical activity (household, occupational and recreational) performed during a one-year period was collected using a questionnaire. Normal breast tissue was obtained from mastectomy blocks distant from the tumor. The expression of the mediators of inflammation in normal breast tissue was visually evaluated by immunohistochemistry. Multivariate linear regression analyses were used to assess the prevalence ratios (PR) and 95% confidence intervals (CI) for higher protein expression levels of the mediators of inflammation in normal breast tissue across quartiles of physical activity. Higher total physical activity was associated with lower expression levels of the pro-inflammatory mediator TNF-α in normal breast epithelial tissue among all (PR=0.64, 95% CI=0.44-0.93 for the fourth quartile; P_trend=0.013), premenopausal (PR=0.61, 95% CI=0.41-0.91 for the fourth quartile; P_trend=0.014) and postmenopausal women (PR=0.45, 95% CI=0.21-0.96 for the fourth quartile; P_trend=0.022). Conversely, higher total physical activity was associated with higher expression levels of the anti-inflammatory mediator IL-10 in normal breast epithelial tissue among all (PR=1.66, 95% CI=0.97-2.85 for the fourth quartile; P_trend=0.071) and postmenopausal women (PR=4.69, 95% CI=1.26-17.43 for the fourth quartile; P_trend=0.010). Our findings suggest a beneficial effect of physical activity on the local inflammatory profile in the breast tissue.

[Adiponectin in health and disease]

Over the past 20 years after the discovery of adiponectin, much knowledge about its effect in health and disease has been gained. Adiponectin has antidiabetic, antiatherogenic, anti-inflammatory, immunomodulatory, metabolic, vasoprotective, and antiapoptotic properties. However, an understanding stems from the given literature review that much remains to be explored. Adiponectin has not yet commonly used in clinical practice, but cardiologists, endocrinologists, pediatricians, oncologists, and physicians of many specialties are interested in its preventive and therapeutic applications.

Effects of body weight reduction on plasma leptin and adiponectin/leptin ratio in obese patients with type 1 diabetes mellitus

The aim of this study was to explore the changes in the adipokines leptin and adiponectin in obese patients with type 1 diabetes mellitus (T1DM) who underwent seven days of fasting and 21 days of low-calorie diet (LCD). The plasma leptin and adiponectin concentrations were measured in 14 obese patients with T1DM at baseline, immediately after 7 days of fasting, and after 21 days of LCD. 13 non-obese patients with T1DM were studied only after an overnight fasting. Bioimpedance technique was used for determination of body composition. Obese T1DM patients lost 6.0 kg (6.0; 6.8) (median, 25 %; 75 %) and decreased their fat tissue after fasting and LCD. Plasma leptin in obese T1DM was significantly higher than in non-obese T1DM patients: 9.10 (5.06; 25.89) vs. 1.71 (1.12; 7.08) microg . l(-1) and transiently decreased immediately after fasting: 3.45 microg . l(-1) (1.47; 7.00), (P<0.05). Adiponectin/leptin ratio in obese T1DM was significantly lower than in non-obese T1DM patients: 0.67 (0.57; 1.49) vs. 3.50 (2.46; 6.30) . 10(3) and transiently increased immediately after fasting: 2.22 (1.26; 3.24) . 10(3), (P<0.05). We conclude that obese patients with T1DM are characterized by hyperleptinemia that is reduced by prolonged fasting, but only slightly affected by low calorie diet.

Validity of electronically administered Recent Physical Activity Questionnaire (RPAQ) in ten European countries

OBJECTIVE

To examine the validity of the Recent Physical Activity Questionnaire (RPAQ) which assesses physical activity (PA) in 4 domains (leisure, work, commuting, home) during past month.

METHODS

580 men and 1343 women from 10 European countries attended 2 visits at which PA energy expenditure (PAEE), time at moderate-to-vigorous PA (MVPA) and sedentary time were measured using individually-calibrated combined heart-rate and movement sensing. At the second visit, RPAQ was administered electronically. Validity was assessed using agreement analysis.

RESULTS

RPAQ significantly underestimated PAEE in women [median(IQR): 34.9 (22.3, 52.8) vs. 40.6 (32.4, 50.9) kJ/kg/day, 95%LoA: -44.4, 66.1 kJ/kg/day) and overestimated PAEE in men [45.9 (30.6, 71.1) vs. 45.5 (34.1, 57.6) kJ/kg/day, 95%LoA: -44.8, 102.6 kJ/kg/day]. Using individualised definition of 1MET, RPAQ significantly underestimated MVPA in women [median(IQR): 63.7 (30.5, 126.9) vs. 73.6 (47.8, 107.2) min/day, 95%LoA: -127.4, 311.9 min/day] and overestimated MVPA in men [90.0 (42.3, 188.6) vs. 83.3 (55.1, 125.0) min/day, 95%LoA: -134.8, 427.3 min/day]. Correlations (95%CI) between subjective and objective estimates were statistically significant [PAEE: women, rho = 0.20 (0.15-0.26); men, rho = 0.37 (0.30-0.44); MVPA: women, rho = 0.18 (0.13-0.24); men, rho = 0.31 (0.24-0.38)]. When using non-individualised definition of 1MET (3.5 mlO2/kg/min), MVPA was substantially overestimated (16 min/day, and 32 min/day in women and men, respectively). Revisiting occupational intensity assumptions in questionnaire estimation algorithms with occupational group-level empirical distributions reduced median PAEE-bias in manual (38.8 kJ/kg/day vs. 6.8 kJ/kg/day, p<0.001) and heavy manual workers (63.6 vs. -2.8 kJ/kg/day, p<0.001) in an independent hold-out sample [corrected].

CONCLUSION

Relative validity of RPAQ-derived PAEE and MVPA is comparable to previous studies but underestimation of PAEE is smaller. Electronic RPAQ may be used in large-scale epidemiological studies including surveys, providing information on all domains of PA.