The Effect of Sport Participation on Bone

Mechanical loading – or physical activity – is essential in the bone remodeling process as well as optimizing the densitometric and geometric properties of bone throughout the lifespan. Participation in sports is a common mode of physical activity that can enhance bone mass accrual at younger ages and facilitate bone mass maintenance at older ages. Research suggests that sport participation continued from adolescence into high school and college provides added benefits on aBMD and cortical bone measures and these benefits remain 10-15 years after retirement from sport. However, in most studies, the higher rates of bone loss after sport cessation in the athlete population leads to similar aBMD measures as non-athletes by fifty to sixty years of age. The following chapters introduce research studies that use DXA and pQCT measures during collegiate sport participation and after sport cessation to evaluate the short- and long-term effects on aBMD, cortical and trabecular bone parameters. The topics of the influence of a training season on bone and body composition of female collegiate soccer players, the response of aBMD to a range of years of retirement from collegiate soccer and football, and the comparison of DXA and pQCT measures between groups with various sport-seasons of high school and college sport participation multiple years after sport cessation are reported. Overall, participation in sport provides short-term benefits on bone; however, this benefit does not persist beyond the mid-fifties

Cross-Sectional and Longitudinal Association between Glycemic Status and Body Composition in Men: A Population-Based Study

This study sought to evaluate the associations between changes in glycemic status and changes in total body (TB), trunk, and appendicular fat (FM) and lean mass (LM) in men. A population-based study of men aged 20–66 years at baseline were included in cross-sectional (n = 430) and three-year longitudinal (n = 411) analyses. Prediabetes was defined as fasting glucose 100–125 mg/dL. Type 2 diabetes (T2D) was determined by: self-reported diabetes, current anti-diabetic drug use (insulin/oral hypoglycemic agents), fasting glucose (≥126 mg/dL), or non-fasting glucose (≥200 mg/dL). Body composition was evaluated by dual-energy X-ray absorptiometry. Longitudinal analyses showed that changes in TB FM and LM, and appendicular LM differed among glycemic groups. Normoglycemic men who converted to prediabetes lost more TB and appendicular LM than men who remained normoglycemic (all, p \u3c 0.05). Normoglycemic or prediabetic men who developed T2D had a greater loss of TB and appendicular LM than men who remained normoglycemic (both, p \u3c 0.05). T2D men had greater gains in TB FM and greater losses in TB and appendicular LM than men who remained normoglycemic (all, p \u3c 0.05). Dysglycemia is associated with adverse changes in TB and appendicular LM

Pregnancy Survey of Smoking and Alcohol Use in South Dakota American Indian and White Mothers

INTRODUCTION: American Indian populations are believed to have relatively high tobacco use and alcohol consumption before and during pregnancy compared with other populations despite little evidence. METHODS: Population-based survey distributed 2-6 months postpartum to 1,814 South Dakota mothers having a live birth in 2014. Prevalence of self-reported smoking and alcohol use before and during pregnancy were calculated for American Indian and white mothers and AORs were determined controlling for Hispanic status, marital status, age, education, and income. Analysis was completed in 2017-2018. RESULTS: Smoking among American Indian mothers was similar to white mothers before and during pregnancy (AOR=1.60, 95% CI=0.95, 2.67 and AOR=0.67, 95% CI=0.37, 1.21, respectively). Among smokers, a higher percentage of American Indian mothers smoked less than six cigarettes/day than white mothers (AOR=6.79, 95% CI=3.21, 14.35, before and AOR=4.85, 95% CI=1.08, 21.7, during pregnancy), and American Indian mothers had greater odds of quitting (AOR=3.60, 95% CI=1.74, 7.43). No difference in relapse rates by race were found (AOR=0.57, 95% CI=0.19, 1.72). Alcohol consumption before pregnancy was less among American Indian than white mothers (AOR=0.53 95% CI=0.30, 0.94), and among those who drank no differences by race in drinks/week were observed (AOR for American Indians drinking more than four drinks/week=1.20, 95% CI=0.56, 2.55) or binge drinking (AOR=1.50, 95% CI=0.75, 3.04). Rates of alcohol consumption during pregnancy and topics covered by healthcare providers during prenatal visits did not differ by race. CONCLUSIONS: After adjusting for covariates, no differences by race in smoking rates before or during pregnancy were observed and American Indian mothers who smoked were more likely to smoke fewer cigarettes and quit smoking during pregnancy than white mothers. Lower alcohol consumption among American Indian mothers before pregnancy challenges the commonly held belief of elevated alcohol consumption among American Indians compared with other races

Feasibility and Effects on Muscle Function of an Exercise Program for Older Adults

Study objective was to determine feasibility and compliance with a 3-month exercise intervention in older adults, and if peripheral quantitative computed tomography muscle measures and jumping mechanography could detect changes in muscle mass and function.Methods A parallel group, nonblinded, pilot trial with individuals 70 yr or older randomized to control group of walking-only (WALK) or an intervention group of walking combined with exercises to improve balance and strength (W + EX). Both groups attended similar weekly nutrition education sessions. Body composition, muscle density, intramuscular adipose tissue area, and muscle function were assessed before and after the intervention using dual-energy x-ray, peripheral quantitative computed tomography, functional tests, and mechanography.Results Eighty-five (90%) of 94 individuals enrolled completed (41WALK, 44W + EX). Eighty-six percent of participants attended seven or more nutrition sessions, and log sheets, used to assess exercise compliance, were returned by 66% of participants, and of those, 88% logged activity on 50%+ days. Sixty-seven percent of participants stated that they increased activity levels, and 82% stated that they felt better overall. Both groups increased lean and lost fat mass, resulting in decreases in fat percentage (all, P \u3c 0.05). Intramuscular adipose tissue area decreased and muscle density increased among WALK (P \u3c 0.05 and P = 0.056, respectively) but were not different between groups. Improvement in force efficiency and chair-rise power were greater among W + EX group than WALK (5.9% ± 1.8% vs −1.2% ± 2.0% [P = 0.01] and 0.25 ± 0.19 W·kg−1 and −0.37 ± 0.23 W·kg−1 [P = 0.04], respectively). Differences in mechanography results became greater in a per-protocol analysis

Sports Participation in High School and College Leads to High Bone Density and Greater Rates of Bone Loss in Young Men: Results from a Population-Based Study

Estimated lifetime risk of an osteoporotic fracture in men over the age of 50 years is substantial and lifestyle factors such as physical activity may explain variation in bone mass and bone loss associated with aging. Men (n = 253) aged 20–66 years were followed for 7.5 years and factors that influence changes in means and rates of change in bone mass, density, and size using dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) were investigated; in particular, seasons of sports participation during high school and college. Men with greater sports participation had higher total hip bone mineral content (BMC) (48.4 ± 0.9 and 48.6 ± 0.9 g for 7–12 and 13+ seasons vs. 45.6 ± 0.8 and 45.4 ± 0.7 g for 0 and 1–6 seasons, respectively p  \u3c  0.05) and areal bone mineral density (aBMD) (1.082 ± 0.015 and 1.087 ± 0.015 g/cm2 for 7–12 and 13+ seasons vs. 1.011 ± 0.015 and 1.029 ± 0.013 g/cm2 for 0 and 1–6 seasons, respectively p  \u3c  0.05) than men who participated in less sport-seasons. However, men with higher sports participation also had greater rates of bone loss in their mid-twenties at the hip (BMC − 0.8 and − 1.2% and aBMD − 0.8 and − 0.9% for 7–12 and 13+ seasons of sport participation, respectively) compared to those with 0 seasons of sport participation (BMC − 0.6% and aBMD − 0.6%) (all p \u3c 0.05). Similar results were observed for femoral neck aBMD. Men with 7+ seasons of sport participation had higher cross-sectional area at the 20% distal radius site than those with no sports participation (all p  \u3c  0.05). These findings support significant effects of high school and/or college sports participation on bone mass and geometry in men throughout adulthood