Objectively-assessed physical activity and weight change in young adults: a randomized controlled trial

Background

Reductions in physical activity (PA) are common throughout young adulthood and low PA is associated with weight gain. The SNAP Trial previously reported that two self-regulation approaches to weight gain prevention reduced weight gain over a 2-year period in 18–35 year olds. Presented here are secondary analyses examining changes in PA and the relationship between PA and weight change over 2 years.

Methods

599 young adults (age: 27.4?±?4.4 yrs.; BMI: 25.4?±?2.6 kg/m²) were randomly assigned to 1 of 3 treatment arms: Small Changes (reduce calorie intake by 100 kcals/day & add 2000 steps/day), Large Changes (lose 2.3–4.5 kg initially & increase PA to ≥250 min/wk), or Self-guided (control condition). Small and Large Changes received 10, face-to-face group sessions (months 1–4), and two 4-week refresher courses each subsequent year. Body weight and PA were objectively-measured at baseline, 4 months, 1 and 2 years. Daily steps and bout-related moderate-to-vigorous intensity PA (MVPA: ≥3 METs, ≥10-min bouts) was calculated.

Results

Changes in bout-related MVPA and daily steps did not differ among treatment groups over the 2-year period (p’s?>?0.16). Collapsed across groups, participants gaining >1 lb. (n?=?187; 39.6%) had smaller changes in bout-related MVPA at 4 months, 1 and 2 years relative to those maintaining or losing weight (≤1 lb. weight gain; n?=?282, 60.4%, p’s?<?0.05). Averaged across time points, this difference equated to 47.8 min/week. Those gaining and not gaining >1 lb. did not differ on daily steps (p’s?>?0.10). Among participants engaging in ≥250 min/wk. of MVPA at 2 years (n?=?181), 30% gained >1 lb. from baseline to 2 years, which was not different from those engaging in 150–250 min/wk. (n?=?87; 36%; p?=?0.40), but this percentage was significantly lower when compared to those engaging in <150 min/wk. (n?=?176; 49%; p?<?0.001).

Conclusions

On average, PA differences were not observed between young adults assigned to small or large changes self-regulation interventions to prevent weight gain. Regardless of group assignment, higher levels of MVPA were associated with better weight gain prevention over 2 years. Our data suggest that achieving >150 min/week of MVPA is needed for weight gain prevention and that increasing MVPA, rather than steps, should be targeted.

Trial registration

www.clinicaltrials.gov (NCT01183689). Registered Aug 13, 2010.

     

冠心病合并糖尿病多支血管病变介入治疗与外科旁路移植术比较的Meta分析

目的 评价冠心病合并糖尿病多支血管病变介入治疗与外科旁路移植术治疗效果.方法 计算机检索Cochrane图书馆、MedLine、EMbase(1974-2014.11)、中国生物医学文献数据库、中国期刊全文数据库和万方数据库,收集冠心病合并糖尿病多支血管病变介入治疗与外科旁路移植术治疗的随机对照研究(RCT).有两名评价员按照纳入与排除标准选择文献,评价质量与提取资料,对符合纳入标准的研究以RevMan5.2软件进行Meta分析.结果 共纳入5个随机对照研究,共2288例患者.Meta分析结果显示,介入治疗与外科旁路移植比较,随访30 d患者全因病死率与MACE事件发生率差异无统计学意义,RR=0.42,95％CI(0.05～3.44),P=0.42.对随访1年以上的长期随访结果分析:全因病死率差异无统计学意义,RR=0.14,95％CI(0.47～2.78),P=0.77.MACE事件发生率,两组差异有统计学意义RR=1.65,95％CI(1.29～2.11),P＜0.0001.说明从远期MACE事件发生率而言外科旁路移植术对于治疗冠心病合并糖尿病伴多支血管病变患者更占优势.对于长期靶血管重建率Meta分析结果显示两组差异有统计学意义RR=3.08,95％CI(2.28～4.17),P＜0.00001.此结果说明外科旁路移植术更优于介入治疗,靶血管重建较介入治疗低.CCSⅡ级人数Meta分析结果显示,两组差异有统计学意义,RR=2.07,95％CI(1.50～2.87),P＜0.0001.外科旁路移植术随访1年后远期轻度心绞痛情况更少见.结论 冠心病伴糖尿病多支血管病变患者治疗上对于MACE事件发生率,长期靶血管重建,CCSⅡ级事件发生的情况看,外科旁路移植术疗效更优于介入治疗术.     

Evaluation of cytocompatibility and bending modulus of nanoceramic/polymer composites

In an attempt to simulate the microstructure and mechanical properties of natural bone, novel nanoceramic/polymer composite formulations were fabricated and characterized with respect to their cytocompatibility and mechanical properties. The bending moduli of nanocomposite samples of either poly(L-lactic acid) (PLA) or poly(methyl methacrylate) (PMMA) with 30, 40, and 50 wt % of nanophase (<100 nm) alumina, hydroxyapatite, or titania loadings were significantly (p < 0.05) greater than those of pertinent composite formulations with conventional, coarser grained ceramics. The nanocomposite bending moduli were 1-2 orders of magnitude larger than those of the homogeneous, respective polymer. For example, compared with 0.06 GPa for the 100% PLA, the bending modulus of 50/50 nanophase alumina/PLA composites was 3.5 GPa. Osteoblast adhesion on the surfaces of the nanophase alumina/PLA composites increased as a function of the nanophase ceramic content. Most importantly, osteoblast adhesion on the 50/50 nanophase alumina/PLA substrates was similar to that observed on the 100% nanophase ceramic substrates. Similar trends of osteoblast adhesion were observed on the surfaces of the nanophase titania/polymer and nanophase hydroxyapaptite/polymer composites that were tested. In contrast, fibroblast adhesion on the nanophase composites was either similar or lower than that observed on the conventional composites with either PLA or PMMA and minimum on all tested neat nanophase substrates. The calcium content in the extracellular matrix of cultured osteoblasts was also enhanced on the nanoceramic/PLA composite substrates tested as a function of the nanophase ceramic loading and duration of cell culture. The results of the present in vitro study provide evidence that nanoceramic/polymer composite formulations are promising alternatives to conventional materials because they can potentially be designed to match the chemical, structural, and mechanical properties of bone tissue in order to overcome the limitations of the biomaterials currently used as bone prostheses.     

Hydroxylapatite with substituted magnesium, zinc, cadmium, and yttrium. II. Mechanisms of osteoblast adhesion.

The present in vitro study investigated osteoblast adhesion on hydroxylapatite (HA) doped with either cadmium (Cd), zinc (Zn), magnesium (Mg), or yttrium (Y). Compared with any other dopant tested in the present study, osteoblast adhesion was significantly (p < 0.05) greater on HA doped with Y after 4 h; in addition, osteoblast adhesion increased with concentration (2-7 mol%) of Y in HA. The findings that HA doped with greater amounts of Y adsorbed higher concentrations of calcium and, subsequently, of vitronectin and collagen (proteins known to mediate osteoblast adhesion), but not of albumin, laminin, and fibronectin, may explain the observed enhanced adhesion of osteoblasts on these substrates. Interactions (i.e., adsorption and configuration/bioactivity) of vitronectin and collagen may have been promoted by increased porosity of doped HA. Through doping with Y, the present study provided the first evidence that HA can be synthesized and processed with improved cytocompatibility properties for osteoblast adhesion, and thus offered essential information for the design of novel proactive bioceramics. Proactive bioceramics which elicit specific, timely, and desired responses from surrounding cells and tissues are necessary for improving bonding of orthopaedic/dental implants to juxtaposed bone; such osseointegration will, undoubtedly, enhance implant efficacy.     

Immunolocalization of calbindin D28k and vitamin D receptor during root formation of murine molar teeth

Cells in the epithelial rest of Malassez (ERM cells) express calbindin D28k (CB); however, the hormonal regulation of CB in ERM cells remains to be elucidated. We investigated the immunohistochemical localization of CB and 1,25-dihydroxyvitamin D3 receptor (VDR) during root formation of mouse molar teeth in order to clarify whether the expression of CB in ERM cells is dependent on vitamin D. At the early stage of root formation (postnatal (PN) days 10-14), both CB- and VDR-immunoreactive cells were observed intermittently along the root surface. In the apical portion, almost all CB-immunoreactive cells showed VDR immunoreactivity; however, VDR-immunoreactive cells in the most apical portion were immunonegative for CB. In the middle and cervical portions, the distributions of the two proteins were completely different. At the late stage of root formation (PN28d) and in adult animals, CB immunoreactivity was distributed in cells found along the acellular cementum at the bifurcation region, as well as between the dentin and cellular cementum in the apical portion (although these lacked immunoreactivity for VDR). The present results indicate that CB expression in newly disrupted cells from Hertwig's epithelial root sheath occurs in a vitamin-D dependent manner, whereas the expression of CB in mature ERM cells may be independent of vitamin D.     

New skeletal dysplasia with unique brachydactyly

We report on 2 male propositi, their mothers, and a maternal aunt with a new skeletal dysplasia associated with a unique pattern of digital malformation, variable mild short stature, and mild bowleg with proximal overgrowth of the fibula. The digital malformations comprise a pattern of brachydactyly which includes short, abducted thumbs, short index fingers, and markedly short, abducted great toes. The radiographic findings include hypoplastic thumbs and great toes with short first metacarpals and first metatarsals, absent distal phalanges of the index fingers and second toes, and coalescence of the carpal and tarsal bones. Radiographs of the long bones show mild metaphyseal and epiphyseal irregularity, tibial spurs, and relative elongation of the fibulae. The males are very similarly affected whereas the females show phenotypic variation and are generally less severely affected. The family histories from 2 fairly extensive pedigrees suggest X-linked dominant inheritance.