Effects of Vitamin D with Calcium and Associations of Mean 25-Hydroxyvitamin D Levels with 3-Year Change in Muscle Performance in Healthy Older Adults in the Boston STOP IT Trial

The purpose of this analysis was to assess whether (1) daily vitamin D₃ plus calcium supplementation vs. placebo or (2) the mean 25-hydroxyvitamin D [25(OH)D] level achieved during a 3-year trial was associated with muscle performance or balance in the Boston STOP IT study. Methods We conducted exploratory analyses in 386 men and women age 65 years and older who participated in the Boston STOP IT trial and had one or more muscle performance or balance assessments at baseline and 3 years. Participants were treated with 700 IU of vitamin D₃ plus 500 mg of calcium or with double placebo daily for 3 years. Plasma 25(OH)D was measured at baseline, 6, 12, 18, 24, and 36 months; muscle performance (timed walk, grip strength, and chair-rise) and two balance tests, the one-leg stand and tandem stand, were assessed at baseline and 3 years only. Results Supplementation with vitamin D3 and calcium had no favorable effect on any muscle performance measure. The 3-year mean 25(OH)D levels were 22.7 ± 6.3 (SD) in the placebo and 30.8 ± 7.5 ng/ml in the supplemented groups (p < 0.001). The 3-year mean 25(OH)D level was positively associated with change in one-leg stand time (p = 0.04), but not with the other measures. Conclusion Vitamin D3 and calcium supplementation had no favorable effect on muscle performance or balance in this relatively healthy older population. A higher 3-year mean 25(OH)D level may favor balance, as indicated by longer one-leg stand time, but this observation should be confirmed.

Brain Α-Tocopherol Concentration is Inversely Associated with Neurofibrillary Tangle Counts in Brain Regions Affected in Earlier Braak Stages: A Cross-Sectional Finding in the Oldest Old

Objectives

Higher vitamin E status has been associated with lower risk of Alzheimer's disease (AD). However, evidence of the association of vitamin E concentration in neural tissue with AD pathologies is limited.

Design

The cross-sectional relationship between the human brain concentrations of α- and γ-tocopherol and the severity of AD pathologies - neurofibrillary tangle (NFT) and neuritic plaque (NP) - was investigated.

Setting & Participants

Brains from 43 centenarians (≥ 98 years at death) enrolled in the Phase III of the Georgia Centenarian Study were collected at autopsy.

Measurements

Brain α- and γ-tocopherol concentrations (previously reported) were averaged from frontal, temporal, and occipital cortices. NP and NFT counts (previously reported) were assessed in frontal, temporal, parietal, entorhinal cortices, amygdala, hippocampus, and subiculum. NFT topological progression was assessed using Braak staging. Multiple linear regression was performed to assess the relationship between tocopherol concentrations and NP or NFT counts, with and without adjustment for covariates.

Results

Brain α-tocopherol concentrations were inversely associated with NFT but not NP counts in amygdala (β = -2.67, 95% CI [-4.57, -0.79]), entorhinal cortex (β = -2.01, 95% CI [-3.72, -0.30]), hippocampus (β = -2.23, 95% CI [-3.82, -0.64]), and subiculum (β = -2.52, 95% CI [-4.42, -0.62]) where NFT present earlier in its topological progression, but not in neocortices. Subjects with Braak III-IV had lower α-tocopherol (median = 69,622 pmol/g, IQR = 54,389-72,155 pmol/g) than those with Braak I-II (median = 72,108 pmol/g, IQR = 64,056-82,430 pmol/g), but the difference was of borderline significance (p = 0.063). γ-Tocopherol concentrations were not associated with either NFT or NP counts in any brain regions assessed.

Conclusions

Higher brain α-tocopherol level is specifically associated with lower NFT counts in brain structures affected in earlier Braak stages. Our findings emphasize the possible importance of α-tocopherol intervention timing in tauopathy progression and warrant future clinical trials.

Investigation of the Diet-Gut-Muscle Axis in the Osteoporotic Fractures in Men Study

OBJECTIVES

To investigate the association between dietary fiber density (grams of fiber consumed per 100 kcal) with the gut-muscle axis in older adult men.

DESIGN

Cross-sectional study.

SETTING

Osteoporotic Fractures in Men (MrOS) cohort participants at Visit 4 (2014-16).

PARTICIPANTS

Older adult men (average age, 85y) from the MrOS study.

MEASUREMENTS

Men who were in the highest tertiles for dietary fiber density and the percentage of whole body lean mass were defined as T3T3 (n=42), whereas men who were in the lowest and intermediate tertiles for these variables were defined as T1T1 (n=32), T1T3 (n=24), and T3T1 (n=13), respectively. Additionally, measures of physical function, including the short physical performance battery (SPPB) score and grip strength were higher in T3T3 when compared with T1T1. Gut bacterial abundance was quantified with use of 16S v4 rRNA sequencing, and the bacterial functional potential was derived from the 16S data with PICRUSt. Chao1, ACE, Shannon, Simpson, and Fisher indices were used as measures of α-diversity. Weighted and unweighted Unifrac, and Bray-Curtis were used as measures of β-diversity. Age, physical activity score, smoking, and number of medications-adjusted DESeq2 models were used to identify bacteria and functions that were different when comparing T3T3 with T1T1, but that were not also different when comparing T3T3 with T1T3 or T3T1.

RESULTS

α-diversity was not different, but significant differences for β-diversity (unweighted UniFrac, Bray-Curtis) were identified when comparing T3T3 with T1T1. Known butyrate-producing bacteria, including Ruminococcus, Lachnospira, and Clostridia, and gene counts for butyrate production (KEGG IDs: K01034, K01035) were higher in T3T3, when compared with T1T1.

CONCLUSION

These data suggest that a high-fiber diet may positively impact butyrate-producing genera and gene counts, which collectively may be involved in mechanisms related to the percentage of whole body lean mass and physical functioning in older adult men. Future studies aimed at testing the causative role of this hypothesis are of interest.

Evaluation of opt-out inpatient HIV screening at an urban teaching hospital

This study evaluated opt-out inpatient HIV screening delivered by admitting physicians, and compared number of HIV tests and diagnoses to signs and symptoms-directed HIV testing (based on physician orders) in the emergency department (ED). The opt-out inpatient HIV screening program was conducted over a one year period in patients who were admitted to the 386-bed University of California San Diego (UCSD) teaching hospital. Numbers of HIV tests and diagnoses were compared to those observed among ED patients who underwent physician-directed HIV testing during the same time period. Survey data were collected from a convenience sample of patients and providers regarding the opt-out testing program. Among 8488 eligible inpatients, opt-out HIV testing was offered to 3017 (36%) patients, and rapid antibody testing was performed in 1389 (16.4%) inpatients, resulting in 6 (0.4% of all tests) newly identified HIV infections (5/6 were admitted through the ED). Among 27,893 ED patients, rapid antibody testing was performed in 88 (0.3%), with 7 (8.0% of all tests) new HIV infections identified. HIV diagnoses in the ED were more likely to be men who have sex with men (MSM) (p = 0.029) and tended to have AIDS-related opportunistic infections (p = 0.103) when compared to HIV diagnoses among inpatients. While 85% of the 150 physicians who completed the survey were aware of the HIV opt-out screening program, 44% of physicians felt that they did not have adequate time to consent patients for the program, and only 30% agreed that a physician is best-suited to consent patients. In conclusion, the yield of opt-out HIV rapid antibody screening in inpatients was comparable to the national HIV prevalence average. However, uptake of screening was markedly limited in this setting where opt-out screening was delivered by physicians during routine care, with limited time resources being the major barrier.

Clinical judgment versus the Pneumonia Severity Index in making the admission decision

The Pneumonia Severity Index (PSI) is a validated risk assessment tool for patients with community-acquired pneumonia (CAP). Guidelines endorse outpatient treatment for patients deemed low risk, but experience shows that such patients are frequently hospitalized. We investigated the limitations of the PSI as a triage tool by examining outcomes in patients whose disposition from the Emergency Department differed from that predicted by the PSI. PSI scores were calculated by retrospective chart review for all adults with CAP presenting to the Emergency Department of a university medical center. Disposition was classified as consistent with the PSI when low-risk patients were discharged and high-risk patients were admitted. Charts of low-risk patients whose disposition was inconsistent with the PSI were abstracted for documentation of comorbidities contributing to the admission decision, as well as length of stay and level of care. There were 174 patients with CAP who met inclusion criteria, and 32% had a disposition inconsistent with the PSI. Eighty-six percent of the inconsistencies involved low-risk patients admitted to the hospital, and 41% of all low-risk patients with CAP were hospitalized. Hypoxia contributed to the decision to admit in 48% of these patients. Average length of stay was 5.2 days, and 78% of patients remained in the hospital > 48 h. Hypoxia was the most frequent factor contributing to admission of low-risk patients with CAP. Low-risk inpatients had a significant length of stay, suggesting that clinical judgment appropriately superseded the PSI in these cases.

Experimental evidence for modulations in the relative double-photoionization cross section of C60 from threshold up to 280 eV

The relative double-photoionization cross section of neutral C60 clusters was investigated using monochromatized synchrotron radiation between 18 and 283 eV. Our measurement of the double-to-single photoionization ratio reveals two modulating components that are superimposed on a smooth ratio curve from threshold (19.0 eV) up to 280 eV, when inner-shell excitations become possible. The maxima in the modulation can be related to geometrical dimensions of the C60 cluster.