Sex Differences in Bone, Muscle, and Inflammatory Markers and Their Associations with Muscle Performance Variables.

The importance of various markers such as Sclerostin, Dickkopf-1 (DKK-1), Irisin, receptor activator of NF-kB ligand (RANKL), and Vitamin D have been well studied in bone metabolism. Additionally, inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and Interleukin 6 (IL-6) have been shown to hinder muscle protein synthesis, leading to the loss of muscle and strength. However, a research gap exists in understanding their role in muscle function and physical activity. Therefore, this study aims to explore the serum levels of Sclerostin, DKK-1, Irisin, IL-6, RANKL, Vitamin D, and TNF-α and assess their relationships with upper- and lower-body strength in young adults. In this study, 38 college-aged students (18-23 years), males and females, participated and completed the protocols. The participants' lower and upper body strength were assessed by the vertical jump test (Just Jump, Probotic, AL) with a Tendo FitroDyne (Tendo Sports Machines, Trencin, Slovak Republic) and handgrip (HG) dynamometry (Takei Scientific Instruments, Yashiroda, Japan), respectively. Fasting morning blood samples were analyzed for serum levels of biomarkers by ELISA. The results indicate significant sex differences in Sclerostin, DKK-1, Irisin, and Vitamin D levels (p < 0.05). Furthermore, a positive association was observed between Sclerostin, DKK-1, and Vitamin D, with lower body muscle performance variables (p < 0.05). Conversely, a significant negative correlation was observed between TNF-α and lower-body muscle performance variables (p < 0.05). The results suggest that these markers may have a distinct effect on muscle performance, underscoring the need for further investigation to elucidate the concept of muscle-bone crosstalk.

Associations of animal source foods, cardiovascular disease history, and health behaviors from the national health and nutrition examination survey: 2013-2016.

Background: Some individuals adopt vegetarian or plant-based diets to improve their health. Observational evidence suggests diets composed of higher amounts of animal-source foods (ASFs) are associated with increased risk for disease and early mortality. In many of these studies, those who ate fewer animal-source foods reported fewer disease risk factors and unhealthy behaviors, which could indicate bias. Purpose: This study aims to examine the relationships between ASF consumption, health behaviors, and cardiovascular disease (CVD) prevalence in a population-representative sample of U.S. civilians controlling for confounders. Methods: Respondent data were collected from the National Health and Nutrition Examination Survey (NHANES) 2013-2016 collection years. Collected data included demographics, ASF intake, healthy lifestyle variables, body mass index, and blood lipids. Results: There was a higher proportion of those with CVD history who consumed red meat (61.3%; C.I. 41.7%-77.8%), but the proportion was lower for white (23.3%; C.I. 12.6%-39.0%) and processed meat (15.4%; C.I. 6.5%-32.3%). When adjusted for sex, the odds of CVD history increased for red meat compared to processed meat consumption (OR 2.95; C.I. 1.14-7.66). Unhealthy lifestyle increased the odds of CVD history by nearly 8-fold (OR 7.8; C.I. 3.44-17.7). Individual factors including age, smoking history, body mass index, and blood lipids, and demographic factors, including education level, race, and income, were also associated with increased odds for CVD history. ROC analysis revealed 77.2% AUC for CVD history classified by individual factors (BMI ≥30 kg/m**2, ≤ 30 min moderate physical activity, smoker, fiber intake ≤25 g, dental visit more than two years ago, and age above 60 years). Three or more factors moderately predicted CVD history when optimized for sensitivity (73.4%) and specificity (71%). Adjusted for sex, the relationship between CVD and moderate physical activity became stronger possibly reflecting lifestyle changes. Despite evidence of lifestyle changes, modifiable risk factors persisted in the CVD group. CVD diagnosis in males was substantially delayed compared to females concerning the sex-specific age cutoff associated with higher risk. The healthy lifestyle group was characterized by earlier CVD diagnosis and fewer overall risk factors compared to the unhealthy lifestyle group. Conclusion: CVD history was strongly associated with demographic, lifestyle, and dietary factors. Future research should focus on multidimensional models for disease risk stratification and prevention, including individual, behavioral, and sociodemographic factors.

Sclerostin and Dickkopf-1 Characteristics According to Age and Physical Activity Levels in Premenopausal Women.

We aimed to compare serum concentrations of sclerostin and DKK-1 in young (20-30 yrs, n = 25) and middle-aged (35-45 yrs, n = 25) premenopausal women and based on physical activity (PA) status. PA status was assessed by the International Physical Activity Questionnaire (low-moderate (≤ 2999 MET-min/week) and high (≥ 3000 MET-min/week). Serum sclerostin and DKK-1 levels were measured in fasting morning blood samples by ELISA. Areal bone mineral density (aBMD) was measured by DXA, and non-dominant tibia bone characteristics were assessed by pQCT. After adjusting for total body aBMD, middle-aged women had significantly (p < 0.001) higher (0.54 ± 0.01 ng/mL) serum sclerostin than young women (0.41 ± 0.01 ng/mL), and sclerostin was positively correlated with age (rs = 0.065, p ≤ 0.001) and total PA score (rs = 0.33, p = 0.021). Young women had higher left trochanter aBMD (p = 0.036) than middle-aged women and aBMD variables were higher (all p ≤ 0.043) in the high active group. Middle-aged women had higher 38% cortical vBMD than young women (p = 0.021), otherwise young women had higher values for pQCT variables (all p ≤ 0.036). Sclerostin showed significant correlations (r = 0.32 to 0.58, all p ≤ 0.026) with spine aBMD for the entire cohort and for each age group. Middle-aged women had significant correlations between sclerostin and hip aBMD sites (r = 0.043 to 0.56, all p ≤ 0.031). Sclerostin and cortical vBMD were positively correlated in the entire cohort (r = 0.35 to 0.50; both p < 0.013); split by age group, middle-aged women had positive correlations (r = 0.45 to 0.61 age and, all p ≤ 0.021) between sclerostin and pQCT variables. No significant differences for physical activity were observed for serum DKK-1 concentrations. Serum sclerostin concentrations were positively associated with age and bone characteristics in premenopausal women; however, these findings were not evident for circulating DKK-1. Further research is needed to elucidate the mechanisms for the discordant results in these Wnt inhibitors.

Site-Specific Bone Differences and Energy Status in Male Competitive Runners and Road Cyclists.

The interaction between mechanical loading and energy availability on bone health in male endurance athletes merits further investigation. The purpose of this study was to compare bone status in male competitive runners and road cyclists and to investigate the influence of energy availability (EA) on bone mineral density (BMD). 18 competitive runners and 19 road cyclists (20-50 years) participated in this study. Areal BMD and body composition were assessed by dual energy x-ray absorptiometry. Volumetric bone variables at the 4% and 66% tibia sites were assessed by peripheral quantitative computed tomography. Energy availability (EA, 7-day dietary and exercise logs) and resting metabolic rate (RMR, open circuit spirometry) were measured as indicators of energy status. Bone loading history, calcium intake, and training history were assessed by questionnaires. After adjusting for age, runners had significantly greater (p < 0.05) areal BMD (femoral neck, left total hip), Z-scores (total body, hips sites), total bone mineral content and trabecular variables (bone mineral content, volumetric BMD, bone strength index) at tibia 4% site, and total volumetric BMD at tibia 66% site than the cyclists (p ≤ 0.05). At the tibia 66% site, cyclists had significantly greater (p < 0.05) total area, periosteal circumference, endosteal circumference, and strength-strain index than runners. Energy variables were similar for runners and cyclists; however, RMR and RMR ratio (measured RMR/predicted RMR) were significantly lower in cyclists (p < 0.001). In conclusion, there were site-specific differences in hip and tibia bone characteristics between runners and cyclists. RMR was associated with several bone outcomes; however, EA was not related to bone health in runners or to dual energy x-ray absorptiometry bone variables in cyclists.

An extension of the extended parallel process model to promote heart-healthy exercise behavior: An experimental study.

Background: The prevalence of heart disease has increased and is a leading cause of death in the U.S. Despite the importance of physical activity, only one-third of adults in the United States meet the amount of physical activity recommended by the Centers for Disease Control and Prevention (CDC). The purpose of this study was to extend the extended parallel process model (EPPM) by adding a 'barrier' (a construct from Health Belief Model) and exploring the roles of threat, efficacy, and barrier on participants' self-efficacy, attitudes, and intentions toward exercise. Methods: A between-subject experimental design was conducted online in 2018 in the U.S. A total of 446 participants were recruited from the Amazon Mechanical Turk age 18 or above. The participants were first provided with stimuli messages about physical activity behaviors. Then participants' responses to self-efficacy, intention, and attitudes toward exercise were assessed. Results: The results found an interaction between efficacy and barrier to participants' attitudes toward exercise [F(1,435)=4.35, P=0.038, η2 part=0.01]. The results also showed that there was a statistically significant effect of barriers on participants' self-efficacy regarding exercise behavior [F(1,442)=4.21, P=0.04, η2 part=0.009]. However, three-way interactions of threat, efficacy, and barrier were not found in attitudes or intentions to exercise. Conclusion: The findings suggested that addressing an individual's perceived barrier regarding a health behavior may lead to an increase in self-confidence ensuing in higher physical activity. Future studies should further explore how addressing barriers may influence other health behaviors to design unique and effective health messages.

Sclerostin and parathyroid hormone responses to acute whole-body vibration and resistance exercise in young women.

Whole-body vibration (WBV) has been shown to improve bone mineral density, and muscle strength and power. No studies to date have examined sclerostin and parathyroid hormone (PTH) responses to WBV combined with resistance exercise (RE). This randomized crossover study compared acute serum sclerostin and PTH responses to RE and WBV + RE in young women (n = 9) taking oral contraceptives. Participants were exposed to 5 1-min bouts of vibration (20 Hz, 3.38 peak-peak displacement, separated by 1 min of rest) before high intensity resistance exercise. Fasting blood samples were obtained before (PRE), immediately after WBV (POSTWBV), immediately post RE (IP) and 30 min post RE (30P). Pre-exercise sclerostin and PTH levels were not significantly different between conditions. Sclerostin levels significantly (p < 0.05) increased from PRE to IP for the WBV + RE condition, then decreased back to the pre-exercise level. PTH significantly decreased from PRE to 30P (p < 0.05) and IP to 30P (p < 0.01) for both conditions. Correcting for hemoconcentration eliminated the significant sclerostin responses, but the significant decrease in PTH remained (p < 0.05). There were no significant relationships found between sclerostin and PTH. In conclusion, sclerostin concentrations increased in response to the WBV + RE condition, which may have been mediated by plasma volume shifts. There was no transient PTH increase, but it showed a large decrease at 30P for both conditions. Based on these findings, the addition of WBV exposures prior to high intensity RE did not alter sclerostin and PTH responses to RE in young women.

Association between bone-specific physical activity scores and pQCT-derived measures of bone strength and geometry in healthy young and middle-aged premenopausal women.

The aim of this study was to determine if bone-specific physical activity questionnaire (BPAQ) scores were positively related to bone health in healthy young and middle-aged premenopausal women. The total BPAQ was a stronger predictor of bone strength and bone mineral density of hip in young women as compared to middle-aged premenopausal women. PURPOSE: The purpose of this study was to determine whether the BPAQ scores were predictive indices of volumetric BMD (vBMD), bone strength, and bone geometry in young and middle-aged premenopausal women. METHODS: Healthy young (n = 60) and middle-aged premenopausal women (n = 54) between the ages of 18 and 50 years were recruited for this study. Areal bone mineral density (aBMD) of lumbar spine and dual proximal femur (FN; femoral neck) was measured using DXA. We assessed vBMD of the tibia 4%, 38%, and 66% by peripheral quantitative computed tomography (pQCT). The BPAQ was used to obtain a comprehensive account of lifetime physical activity related to bone health. RESULTS: Pearson's correlation tests showed positive correlations between total BPAQ and aBMD of the right FN (r = 0.313, p = 0.015) and the left FN (r = 0.307, p = 0.017) in young women while not found in middle-aged premenopausal women (p > 0.05). A positive relationship was only observed between total BPAQ and tibia 38% vBMD in middle-aged premenopausal women (r = 0.283, p = 0.038). All bone geometry variables were associated with total BPAQ (r = 0.280-0.422, p = 0.03-0.001) in young women. The Strength-Strain Index of tibia 38% (r = 0.350, p = 0.006) and 66% (r = 0.406, p = 0.001) was associated with total BPAQ in young women. In both young and middle-aged premenopausal women, when age, bone-free lean body mass (BFLBM), and total BPAQ were included in a stepwise multiple linear regression analysis, BFLBM was a significant predictor of all aBMD variables, accounting for 7-25.7% (p = 0.043-0.001). CONCLUSIONS: The total BPAQ score-derived physical activity was more predictive of positive bone characteristics in young women than in middle-aged premenopausal women.