Comparison of Physical Activity by Lifestyle Between Two Rural Pediatric Population Groups.

BACKGROUND: Obesity prevalence is higher among rural populations than urban, including youth. Reduced physical activity levels are associated with childhood obesity. It could be assumed that the obesity disparity between rural and urban children is attributable, in part, to differences in physical activity levels; however, previous research quantifying and comparing physical activity levels between rural and urban youth are mixed. Lifestyle may be more important than geographic location in determining physical activity levels. Therefore, the objective of this study was to compare sex and lifestyle group (Hutterite vs. non-Hutterite) differences in physical activity in a free-living, rural pediatric population. METHODS: Youth (n=58) were instructed to wear accelerometers for seven days. Mean percent time in light, moderate or vigorous activity during waking hours was calculated. Two-way ANOVAs and multiple regression models were used for analyses. RESULTS: Percent time in vigorous activity was significantly greater for Hutterite males than Hutterite females, and Hutterite males had greater percent time in vigorous activity and moderate plus vigorous activity than non-Hutterite males. CONCLUSIONS: There is evidence to support differences in rural lifestyles to be associated with differences in physical activity levels between children living in the same geographic location, particularly among males. Active transportation and having a safe environment for unstructured outdoor play may account for activity and lifestyle differences between the two rural groups.

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 < 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 < 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 < 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 < 0.05). These findings support significant effects of high school and/or college sports participation on bone mass and geometry in men throughout adulthood.

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.

Rural vs. non-rural differences and longitudinal bone changes by DXA and pQCT in men aged 20-66 years: A population-based study.

The purpose of this research was to determine whether there were differences in estimated means and rates of change in BMC, bone area, BMD and measures of bone geometry among men (n=544) from three distinct populations (Hutterite [rural], rural non-Hutterite, non-rural), and whether activity levels or calcium intake explain these population differences. Men were enrolled in the South Dakota Rural Bone Health Study and followed for 7.5 years to estimate means and rates of change in bone mass, density, size and geometry. Femoral neck (FN) and spine measurements were obtained every 18 months by DXA and distal radius (4% and 20%) measurements by pQCT. Activity measurements and calcium intake were obtained quarterly for the first 3 years and at 54, 72, and 90 months. Rural men had greater percent time in moderate plus vigorous activity (mean ± SD: 22 ± 10 vs. 15 ± 8%, p<0.001) and greater lean mass (69 ± 9 vs. 66 ± 10 kg, p=0.05) than non-rural men. Both rural populations (Hutterite and rural men) had larger femoral neck (FN) bone area and greater 20% radius cross-sectional area than non-rural men ([least square means ± SE] FN area: 5.90 ± 0.02 and 5.86 ± 0.02 vs. 5.76 ± 0.03 cm(2), p<0.001 and p=0.03 respectively and cross-sectional area: 171.0 ±1.3 and 165.5 ± 1.5 vs. 150.3 ± 1.6mm(2), both p<0.001). Despite lower cortical vBMD in Hutterite and rural men compared to non-rural men (1182 ± 2 and 1187 ± 2 vs. 1192 ± 2 mm(2), p<0.001 and p=0.06 respectively), bone strength (pSSI) was greater (429 ± 5 and 422 ± 5 vs. 376 ± 6 mm(3), both p<0.001). The rates of change in femoral neck BMC and aBMD and trabecular vBMD also differed by rural lifestyle, with greater losses among non-rural men in their 20s and 60s compared to both Hutterite and rural populations (time-by-age-by-group interactions, both p<0.01). Physical activity was not found to be a potential mediator of population differences. Baseline calcium intake was associated with FN aBMD (p=0.04), and increases in calcium intake were associated with spine BMC (p=0.04) and inversely associated with cortical area (p=0.02). There was some evidence for mediation by either baseline calcium intake or changes in calcium intake over the study period, but the influence on population differences were negligible. We speculate that rural-non-rural differences in bone occur earlier in life or are a result of factors that have not yet been identified.

Resistant starch type 4-enriched diet lowered blood cholesterols and improved body composition in a double blind controlled cross-over intervention.

A metabolic health crisis is evident as cardiovascular diseases (CVD) remain the leading cause of mortality in the United States. Effects of resistant starch type 4 (RS4), a prebiotic fiber, in comprehensive management of metabolic syndrome (MetS) remain unknown. This study examined the effects of a blinded exchange of RS4-enriched flour (30% v/v) with regular/control flour (CF) diet on multiple MetS comorbidities. In a double blind (participants-investigators), placebo-controlled, cluster cross-over intervention (n = 86, age≥18, 2-12 week interventions, 2-week washout) in the United States, individuals were classified as having MetS (With-MetS) or not (No-MetS) following International Diabetes Federation (IDF)-criteria. RS4 consumption compared with CF resulted in 7.2% (p = 0.002) lower mean total cholesterol, 5.5% (p = 0.04) lower non-HDL, and a 12.8% (p < 0.001) lower HDL cholesterol in the With-MetS group. No-MetS individuals had a 2.6% (p = 0.02) smaller waist circumference and 1.5% (p = 0.03) lower percent body fat following RS4 intervention compared to CF. A small but significant 1% increase in fat-free mass was observed in all participants combined (p = 0.02). No significant effect of RS4 was observed for glycemic variables and blood pressures. RS4 consumption improved dyslipidemia and body composition. Incorporation of RS4 in routine diets could offer an effective strategy for public cardio-metabolic health promotion.

Longitudinal effects of fat and lean mass on bone accrual in infants.

There are conflicting reports on the influence of lean and fat mass on bone accrual during childhood. No infant's studies have been reported that describe the influence of changes in body composition with changes in bone accrual during the first year of life. The objective of this research was to test the hypothesis that greater gains in lean mass will have a positive effect on bone mineral content (BMC) accrual, while greater gains in fat mass will have a negative effect on BMC accrual in infants. Longitudinal data from 3 previous infant studies were used. Linear mixed models, adjusting for age, sex, dietary calcium, and length were used to investigate longitudinal and cross-sectional associations between total body BMC and lean and fat mass in the individual studies and in a combined analysis. In both individual and combined analyses, we found that lean and fat mass were positively associated with whole body BMC accrual (all, P<0.001). The cross-sectional association of BMC and dietary calcium was negative in one study (P<0.05). No differences in BMC change between sexes were observed in three studies. Our results showed positive cross-sectional and longitudinal associations between total body BMC and lean mass in infants. In contradiction to our hypothesis for fat mass, we found a positive cross-sectional and longitudinal association between total body BMC and fat mass in infants.

Cross-sectional versus longitudinal associations of lean and fat mass with pQCT bone outcomes in children.

CONTEXT: Cross-sectional associations for lean mass (LM) and fat mass (FM) with bone may not reflect longitudinal associations. OBJECTIVE: Cross-sectional and longitudinal associations of LM and FM with radial bone measurements in children were compared. DESIGN AND PARTICIPANTS: We conducted a longitudinal study on 370 (232 females) children, 8-18 yr of age. MAIN OUTCOME MEASURES: LM and FM were measured by dual-energy absorptiometry. Peripheral quantitative computed tomography at the 4% radius (4R) and 20% radius (20R) measured bone mineral content (BMC), volumetric bone mineral density (vBMD), area, and strength [polar stress strain index (pSSI)]. RESULTS: Males at 20R had negative FM cross-sectional and longitudinal associations with cortical area and BMC and pSSI (P < 0.02); negative cross-sectional association with total area (P < 0.001); and negative longitudinal association with cortical thickness (P < 0.001). Females at 20R had FM cross-sectional association with total area, cortical BMC, and pSSI and longitudinal associations with cortical BMC and area, vBMD, and pSSI that went from positive to negative with age and, in some cases, varied with menarche. Both sexes at 4R had a negative FM cross-sectional association with BMC and area (P < 0.001) but negative longitudinal association with vBMD (P < 0.05). LM associations with bone outcomes were generally positive, except for negative longitudinal associations with cortical BMC and vBMD in young females (P < 0.01). LM associations were greater magnitude than FM associations and often depended on age. CONCLUSIONS: For males and older females, cross-sectional associations indicated a reduced bone size with higher FM, whereas longitudinal associations showed a decrease in cortical area without changes in bone size. LM was positively associated with BMC and area.

Rates of bone loss in young adult males.

Osteoporosis-related fractures occur more frequently in women compared with men, but mortality is greater in men compared with women. Peak bone mass is a significant predictor of osteoporosis and fracture risk; therefore, it is important to optimize peak bone mass during young adulthood. Several recent longitudinal studies, which are summarized in this article, have investigated bone changes among young men. Cortical bone loss does not appear to be significant until individuals reach their mid-30s and is associated with decreased sex hormone concentrations. Significant trabecular bone loss in young men aged in their 20s has been reported and is associated with reduced lean mass and activity levels, especially among former athletes. Whether changes in activity levels among nonathletes lead to bone loss among young men requires further investigation.

Higher BMC and areal BMD in children and grandchildren of individuals with hip or knee replacement.

The relationship between aBMD and osteoarthritis (OA) remains unclear. We compared aBMD, BMC and bone size among children and grandchildren of Hutterites with hip or knee replacement (n=23 each) to children and grandchildren of age- and sex-matched controls (178 children and 267 grandchildren). There were no differences in anthropometric measures or activity levels between case and control probands, but femoral neck (FN) and spine (LS) aBMD and Z-scores were greater in cases than controls (0.89 vs. 0.80 g/cm2; 1.15 vs. 1.03 g/cm2; 1.5 vs. 0.8; 2.4 vs. 1.2: all p<0.05). Hip, FN and LS aBMD (1.05 vs. 0.97, 0.92 vs. 0.84, 1.15 vs. 1.03 g/cm2), BMC (34.1 vs. 32.0, 4.58 vs. 4.27, 69.5 vs. 62.4 g) and Z-scores (1.0 vs. 0.4; 0.9 vs. 0.2; 1.3 vs. 0.2) were greater in daughters of cases than controls (hip BMC p=0.06, others p<0.05); there were no differences between sons. Grandchildren (aged 8-39 years) were categorized as growing (premenarcheal or male<14 years) or not growing (> or =2 years post-menarcheal or males> or =18 years): 33 were not classified. Post-menarcheal, but not premenarcheal, granddaughters of cases had greater hip, FN and LS aBMD Z-scores (0.7 vs. -0.1; 0.6 vs. -0.1; 0.8 vs. -0.3); greater hip and spine aBMD (1.03 vs. 0.95, 1.10 vs. 0.98 g/cm2); greater femoral neck and spine BMC (4.77 vs. 4.21, 66.7 vs. 55.4 g); and greater spine bone area (60.7 vs. 56.6 cm2) compared to granddaughters of controls (all, p<0.05), which remained significant when height, weight, and age were included as covariates. Growing grandsons of cases were taller and heavier than control grandsons, and a greater hip aBMD among grandsons of cases (0.88 vs. 0.76 g/cm2) was the only bone difference that remained significant after taking into account body size differences. Grandsons who were not growing had greater spine bone area (1.19 vs. 1.08 cm2) if their grandparent had OA compared to grandsons whose grandparents did not have OA. We speculate that there is a genetic basis for OA that leads to early differences in growth patterns among boys and greater peak bone mass and aBMD among girls.