Comparing the activPAL software's Primary Time in Bed Algorithm against Self-Report and van der Berg's Algorithm

The purpose of this study was to compare activPAL algorithm-estimated values for time in bed (TIB), wake time (WT) and bedtime (BT) against self-report and an algorithm developed by van der Berg and colleagues. Secondary analyses of baseline data from the Community Activity for Prevention Study (CAPS) were used in which adults ≥ 18 years wore the activPAL for seven days. Mixed-effects models compared differences between TIB, WT, and BT for all three methods. Bland-Altman plots examined agreement and the two-one-sided test examined equivalence. activPAL was not equivalent to self-report or van der Berg in estimating TIB, but was equivalent to self-report for estimating BT, and was equivalent to van der Berg for estimating WT. The activPAL algorithm requires adjustments before researchers can use it to estimate TIB. However, researchers can use activPAL's option to manually enter self-reported BT and WT to estimate TIB and better understand 24-hour movement patterns.

Bone mineral density at femoral neck and lumbar spine in adults with type 1 diabetes: a meta-analysis and review of the literature

We performed a meta-analysis to evaluate the femoral neck and lumbar spine bone mineral density (BMD) in adults with type 1 diabetes (T1D) compared with controls. Adults with T1D have modestly lower BMD at femoral neck and lumbar spine than adults without diabetes.

INTRODUCTION

Fracture risk is four to sixfold higher in adults with T1D. Since BMD is one of the major contributors for fracture risk, we performed a meta-analysis to evaluate differences in femoral neck and lumbar spine BMD between adults with T1D and controls.

METHODS

MEDLINE, Ovid, and the Cochrane library and abstracts from various scientific meetings were searched. Studies reporting the femoral neck and/or lumbar spine BMD in adults (age > 20 years) with T1D in comparison with people without diabetes were selected. General linear mixed models were used to assess differences in BMD at femoral neck and lumbar spine between subjects with T1D and controls adjusting for age, sex, and dual x-ray absorptiometry (DXA) instruments.

RESULTS

Sixteen studies met the inclusion criteria. The femoral neck BMD was modestly lower in adults with T1D compared to controls (-0.055 g/cm²; 95% CI: -0.065, -0.045). There were no differences in lumbar spine BMD between adults with T1D and controls (0.0062 g/cm²; 95% CI -0.04, 0.016). However, in a sensitivity analysis, lumbar spine BMD was modestly lower in adults with T1D compared to controls (-0.035 g/cm²; -0.049, -0.02). Studies using Lunar DXA instruments have reported higher lumbar spine and femoral neck BMD compared to studies using Hologic DXA instruments.

CONCLUSION

Femoral neck and lumbar spine BMD were modestly lower in adults with T1D compared to controls. However, this modest reduction in femoral neck and lumbar spine BMD cannot explain much higher observed fracture risk in adults with T1D.

Expression of the putative ORF1 capsid protein of Torque teno sus virus 2 (TTSuV2) and development of Western blot and ELISA serodiagnostic assays: correlation between TTSuV2 viral load and IgG antibody level in pigs

Porcine Torque teno virus (TTV) has a single-stranded circular DNA genome and is currently classified into a new genus Iotatorquevirus with two species in a newly established family Anelloviridae. Viral DNA of both porcine TTV species (TTSuV1 and TTSuV2) has a high prevalence in both healthy and diseased pigs worldwide and multiple infections of TTSuV with distinct genotypes or subtypes of the same species has been documented in the United States and in Europe. However, the prevalence of specific TTSuV antibodies in pigs remains unknown. In this study, the putative ORF1 capsid protein from TTSuV2 isolate PTTV2c-VA was expressed in Escherichia coli. The purified recombinant ORF1 protein was used as the antigen for the development of Western blot and indirect ELISA to detect TTSuV2-specific IgG antibodies in pig sera. The results revealed a relatively high rate of seropositivity to TTSuV2 in conventional pigs from different sources but not in gnotobiotic pigs. Overall, pigs with undetectable TTSuV2 viral load were more likely to have a lower anti-TTSuV2 antibody level. An analysis of 10 conventional pigs during a 2-month period showed that decreased viral loads or presumed virus clearance were associated with elevated anti-ORF1 IgG antibody levels. Interestingly, porcine circovirus associated disease (PCVAD)-affected pigs had a significantly lower level of TTSuV2 antibody than PCVAD-unaffected pigs (p<0.01). This is the first study to establish essential serodiagnostic tools for investigation of TTSuV seroprevalence and infection dynamics, which will help elucidate the potential pathogenicity of TTSuV infection in pigs.