Sex Specific Associations of Sex hormone With Brain Volumes and Cerebral Blood Flow: A Cross Sectional Observational Study Within the Look AHEAD Type 2 Diabetes Cohort.

Background: Females have greater brain volume and cerebral blood flow than males when controlling for intracranial volume and age. Brain volume decreases after menopause, suggesting a role of sex hormones. We studied the association of sex hormones with brain volume, white matter hyperintensity volumes and cerebral blood flow in people with Type 2 Diabetes and with overweight and obesity conditions that accelerate brain atrophy. Methods: We analyzed data from 215 participants with overweight or obesity and Type 2 Diabetes from the Look AHEAD Brain Magnetic Resonance Imaging ancillary study (mean age 68 years, 73% postmenopausal female). Estradiol and total testosterone levels were measured with electrochemoluminescence assays. The ratio of brain measurements to intracranial volume was analyzed to account for body size. We analyzed sex hormones as quantitative measures in males, whereas in females we grouped those with detectable vs. undetectable hormone levels (Estradiol <73 pmol/L [20 pg/mL]: 79%; Total Testosterone < 0.07 mmol/L [0.02 ng/mL]: 37% undetectable in females). Results: Females with detectable total testosterone levels had higher brain volume to intracranial volume ratio (median [25th, 75th percentile]: 0.85 [0.84, 0.86]) as compared to those with undetectable Total Testosterone levels (0.84 [0.83, 0.86]; rank sum p=0.04). This association was attenuated after age and body mass index adjustment (p=0.08). Neither white matter hyperintensity volumes or cerebral blood flow in females, nor any brain measures in males, were significantly associated with Estradiol or Total Testosterone. Conclusions: In postmenopausal females with Type 2 Diabetes with overweight and obesity, detectable levels of total testosterone were associated greater brain volume relative to intracranial volume, suggesting a protective role for testosterone in female brain health. Our findings are limited by a small sample size and low sensitivity of hormone assays. Our suggestive findings can be combined with future larger studies to assess clinically important differences. Trial Registration: NCT00017953.

Application of the D3 -creatine muscle mass assessment tool to a geriatric weight loss trial: A pilot study.

BACKGROUND: Traditionally, weight loss (WL) trials utilize dual energy X-ray absorptiometry (DXA) to measure lean mass. This method assumes lean mass, as the sum of all non-bone and non-fat tissue, is a reasonable proxy for muscle mass. In contrast, the D3 -creatine (D3 Cr) dilution method directly measures whole body skeletal muscle mass, although this method has yet to be applied in the context of a geriatric WL trial. The purpose of this project was to (1) describe estimates of change and variability in D3 Cr muscle mass in older adults participating in an intentional WL intervention and (2) relate its change to other measures of body composition as well as muscle function and strength. METHODS: The INVEST in Bone Health trial (NCT04076618), used as a scaffold for this ancillary pilot project, is a three-armed, 12-month randomized, controlled trial designed to determine the effects of resistance training or weighted vest use during intentional WL on a battery of musculoskeletal health outcomes among 150 older adults living with obesity. A convenience sample of 24 participants (n = 8/arm) are included in this analysis. At baseline and 6 months, participants were weighed, ingested a 30 mg D3 Cr tracer dose, provided a fasted urine sample 3-6 days post-dosage, underwent DXA (total body fat and lean masses, appendicular lean mass) and computed tomography (mid-thigh and trunk muscle/intermuscular fat areas) scans, and performed 400-m walk, stair climb, knee extensor strength, and grip strength tests. RESULTS: Participants were older (68.0 ± 4.4 years), mostly White (75.0%), predominantly female (66.7%), and living with obesity (body mass index: 33.8 ± 2.7 kg/m2 ). Six month total body WL was -10.3 (95% confidence interval, CI: -12.7, -7.9) kg. All DXA and computed tomography-derived body composition measures were significantly decreased from baseline, yet D3 Cr muscle mass did not change [+0.5 (95% CI: -2.0, 3.0) kg]. Of muscle function and strength measures, only grip strength significantly changed [+2.5 (95% CI: 1.0, 4.0) kg] from baseline. CONCLUSIONS: Among 24 older adults, significant WL with or without weighted vest use or resistance training over a 6-month period was associated with significant declines in all bioimaging metrics, while D3 Cr muscle mass and muscle function and strength were preserved. Treatment assignment for the trial remains blinded; therefore, full interpretation of these findings is limited. Future work in this area will assess change in D3 Cr muscle mass by parent trial treatment group assignment in all study participants.

Strategies to reduce the onset of sleeve gastrectomy associated bone loss (STRONG BONES): Trial design and methods.

Background: Despite recognized improvements in obesity-related comorbidities, mounting evidence implicates surgical weight loss in the onset of skeletal fragility. Sleeve gastrectomy (SG) is the most commonly performed bariatric procedure and is associated with 3-7% axial bone loss in the year following surgery. Bisphosphonates are FDA-approved medications for the prevention and treatment of age-related bone loss and may represent a strategy to reduce bone loss following SG surgery. Methods: The Strategies to Reduce the Onset of Sleeve Gastrectomy Associated Bone Loss (STRONG BONES) trial (NCT04922333) is designed to definitively test whether monthly administration of the bisphosphonate, risedronate, for six months can effectively counter SG-associated bone loss. Approximately 120 middle-aged and older (≥40 years) SG patients will be randomized to six months of risedronate or placebo treatment, with skeletal outcomes assessed at baseline, six, and 12-months post-surgery. The primary outcome of the trial is 12-month change in total hip areal bone mineral density (aBMD), measured by dual energy x-ray absorptiometry (DXA). This will be complemented by DXA-acquired aBMD assessment at other skeletal sites and quantitative computed tomography (QCT) derived changes in bone quality. Change in muscle mass and function will also be assessed, as well as biomarkers of bone health, turnover, and crosstalk, providing mechanistic insight into intervention-related changes to the bone-muscle unit. Discussion: Results from the STRONG BONES trial have the potential to influence current clinical practice by determining the ability of bisphosphonate use to mitigate bone loss and concomitant fracture risk in middle-aged and older SG patients.

Weight changes during the COVID-19 shutdown in older individuals with type 2 diabetes: the Look AHEAD Study.

OBJECTIVE: The aims of this study were as follows: 1) examine weight changes in older adults (mean age = 76 years) with type 2 diabetes and overweight or obesity during the COVID-19 shutdown; and 2) compare the behavioral and psychosocial effects of the shutdown in those who had large weight losses (>5%), those who had small weight losses (2%-5%), those who remained weight stable (±2%), or those who gained weight (>2%). METHODS: Look AHEAD (Action for Health in Diabetes) participants (N = 2544) were surveyed during the COVID-19 shutdown (2020), and they self-reported their current weight, reasons for weight change, weight-related behaviors, psychosocial measures, and negative and positive effects of the pandemic on their lives. RESULTS: Comparing self-reported weight during the COVID-19 shutdown with earlier measured weight, Look AHEAD participants lost, on average, 2.2 kg during the COVID-19 shutdown: 47% lost >2%, and only 18% gained >2% (p < 0.0001). Decreases in physical activity and increases in screen time were reported frequently in all weight-change categories. Similarly, there were few differences among the categories on standardized psychosocial measures or self-reported effects of the shutdown on participants' lives. However, when differences were seen, the most negative impact was in those who gained weight. CONCLUSIONS: Although weight loss appeared more common than weight gain during the shutdown, the weight-change groups did not differ on most psychosocial and behavioral variables.

Psychological resilience in older adults with type 2 diabetes from the Look AHEAD Trial.

BACKGROUND: There is growing interest in identifying factors associated with healthy aging. This cross-sectional study evaluated associations of psychological resilience with factors associated with aging in older adults with type 2 diabetes mellitus (T2DM). METHODS: Participants were 3199 adults (72.2 ± 6.2 years of age, 61% female, 61% White, body mass index [BMI] = 34.2 ± 8.2 kg/m2 ) with T2DM enrolled in Look AHEAD (a multi-site randomized clinical trial comparing an intensive lifestyle intervention for weight loss to diabetes education and support). Participants were followed observationally after the 10-year intervention was discontinued. The following items were assessed approximately 14.4 years post-randomization in a cross-sectional analysis: Brief Resilience Scale; overnight hospitalizations in past year; physical functioning measured objectively (gait speed, grip strength) and via self-report (Pepper Assessment Tool for Disability; physical quality of life [QOL; SF-36]); a measure of phenotypic frailty based on having ≥3 of unintentional weight loss, low energy, slow gait, reduced grip strength, and physical inactivity. Depressive symptoms (PHQ-9) and mental QOL (SF-36) were also measured. Logistic/linear/multinomial regression was used to evaluate the association of variables with resilience adjusted for age, race/ethnicity, and gender. RESULTS: Greater psychological resilience was associated with lower BMI, fewer hospitalizations, better physical functioning (i.e., lower self-reported disability, better physical QOL, faster gait speed, greater grip strength, lower likelihood of frailty), fewer depressive symptoms, and greater mental QOL (all p < 0.05). Psychological resilience moderated the relationship of number of hospitalizations in the past year with self-reported disability and grip strength. CONCLUSIONS: Psychological resilience is associated with better physical function and QOL among older adults. Results should be interpreted cautiously given cross-sectional nature of analyses. Exploring the clinical benefits of resilience is consistent with efforts to shift the narrative on aging beyond "loss and decline" to highlight opportunities to facilitate healthy aging.

Associations between cognitive function and endogenous levels of estradiol and testosterone in adults with type 2 diabetes.

AIMS: To assess associations that endogenous estradiol and testosterone levels have with cognitive function in older adults with Type 2 diabetes mellitus (T2DM). METHODS: We use data from the Look AHEAD clinical trial of behavioral weight loss. Endogenous estradiol and total testosterone levels were determined using stored serum from 996 individuals, mean age 69 years, at two times (averaging 4 years apart) during years 8-18 of follow-up. One to four standardized assessments of attention, executive function, memory, and verbal fluency were collected during this follow-up. Mixed effects models and multiple imputation were used to assess associations that estradiol and total testosterone levels had with body mass index and cognitive function. RESULTS: Estradiol levels were not associated with cognitive function in either sex. Total testosterone levels were not associated with cognitive function in women, but greater total testosterone levels were associated with better verbal fluency in men (p < 0.001), most strongly among those carrying the APOE-e4 allele (interaction p = 0.02). The weight loss intervention left a legacy of relatively lower cognitive functioning among women, which was not mediated by current levels of sex hormones. CONCLUSIONS: Behavioral weight loss intervention does not affect cognitive functioning through mechanisms related to estradiol or testosterone. CLINICALTRIALS: gov Identifier: NCT00017953.

Impact of COVID-19 on life experiences reported by a diverse cohort of older adults with diabetes and obesity.

OBJECTIVE: This study aimed to measure the impact of the COVID-19 pandemic on self-reported life experiences in older adults with diabetes and obesity. METHODS: Participants were surveyed in 2020 regarding negative and positive impacts of the pandemic across domains of personal, social, and physical experiences. A cumulative negative risk index (a count of all reported negative impacts of 46 items) and a positive risk index (5 items) were characterized in relation to age, sex, race/ethnicity, BMI, and multimorbidity. RESULTS: Response rate was high (2950/3193, 92%), average age was 76 years, 63% were women, and 39% were from underrepresented populations. Women reported more negative impacts than men (6.8 vs. 5.6; p < 0.001 [of 46 items]) as did persons with a greater multimorbidity index (p < 0.001). Participants reporting African American/Black race reported fewer negative impacts than White participants. Women also reported more positive impacts than men (1.9 vs. 1.6; p < 0.001 [of 5 items]). CONCLUSIONS: Older adults with diabetes and obesity reported more positive impacts of the pandemic than negative impacts, relative to the number of positive (or negative) items presented. Some subgroups experienced greater negative impacts (e.g., for women, a greater multimorbidity index). Efforts to reestablish personal, social, and physical health after the pandemic could target certain groups.

Changes in the Prevalence of Symptoms of Depression, Loneliness, and Insomnia in U.S. Older Adults With Type 2 Diabetes During the COVID-19 Pandemic: The Look AHEAD Study.

OBJECTIVE: To evaluate changes in the prevalence of depressive symptoms, loneliness, and insomnia among older adults with type 2 diabetes from 2016 to 2020 and to assess risk factors for these conditions including demographics, multimorbidity, BMI, treatment group, and pre-coronavirus 2019 (COVID-19) measure scores. RESEARCH DESIGN AND METHODS: This was a prospective, observational study of participants from the Look AHEAD (Action for Health in Diabetes) cohort study. Data were from two assessments before COVID-19 (visit 1: April 2016-June 2018 and visit 2: February 2018-February 2020) and one assessment during COVID-19 (visit 3: July-December 2020). Surveys were administered to assess depressive symptoms, loneliness, and insomnia. RESULTS: The study included 2829 adults (63.2% female, 60.6% White, mean [SD] age 75.6 [6.0] years). The prevalence of mild or greater depressive symptoms did not change significantly between the two pre-pandemic visits (P = 0.88) but increased significantly from pre- to during COVID-19 (19.3% at V2 to 30.4% at V3; P < 0.001). Higher odds of mild or greater depressive symptoms at V3 were associated with being female (adjusted odds ratio [OR] 1.4 [95% CI 1.1-1.7]), identifying as non-Hispanic White (OR 1.4 [95% CI 1.1-1.7]), having obesity (OR 1.3 [95% CI 1.0-1.5]), and reporting mild or greater depressive symptoms at V1 (OR 4.0 [95% CI 2.9-5.4]), V2 (OR 4.4 [95% CI 3.2-5.9]), or both visits (OR 13.4 [95% CI 9.7-18.4]). The prevalence of loneliness increased from 12.3% at V1 to 22.1% at V3 (P < 0.001), while the prevalence of insomnia remained stable across visits at 31.5-33.3%. CONCLUSIONS: The prevalence of mild or greater depressive symptoms in older adults with diabetes was more than 1.6 times higher during COVID-19 than before the pandemic.

Obstructive Lung Disease and Obstructive Sleep Apnea (OLDOSA) cohort study: 10-year assessment.

STUDY OBJECTIVES: Asthma, chronic obstructive pulmonary disease (COPD), and obstructive sleep apnea (OSA) are very prevalent disorders. Their coexistence in the same individual has an unclear effect on natural history and long-term outcomes. METHODS: The OLDOSA (Obstructive Lung Disease and Obstructive Sleep Apnea) cohort enrolled 4,980 veterans with an acute hospitalization and in whom asthma, COPD, OSA, overlapping conditions, or none of these disorders at baseline had been diagnosed. Pulmonary function, polysomnography, positive airway pressure (PAP) recommendations and adherence, and vital status were collected and analyzed. Various proportional hazards models were built for patients with OSA to test the effect of PAP therapy on survival. RESULTS: Ten-year all-cause cumulative mortality rate was 52.8%; median time to death was 2.7 years. In nonoverlapping asthma, OSA and COPD, mortality rates were 54.2%, 60.4%, and 63.0%, respectively. The overlap syndromes had the following mortality: COPD-OSA 53.2%, asthma-COPD 62.1%, asthma-OSA 63.5%, and triple overlap asthma-COPD-OSA 67.8%. In patients with OSA not on PAP therapy, after adjustment for age, comorbidities, and lung function, risk of death was 1.34 (1.05-1.71) times higher than those undergoing treatment. Similarly, in patients with OSA nonadherent to PAP therapy the adjusted risk of death was 1.78 (1.13-2.82) times higher versus those using it at least 70% of nights and more than 4 hours nightly. CONCLUSIONS: In this large longitudinal cohort of hospitalized veterans with high comorbid burden, asthma, COPD, OSA and their overlap syndromes had very high long-term mortality. In patients with OSA, PAP initiation and superior therapeutic adherence were associated with significantly better survival.

Collagen-like proteins in pathogenic E. coli strains.

The genome sequences of enterohaemorrhagic E. coli O157:H7 strains show multiple open-reading frames with collagen-like sequences that are absent from the common laboratory strain K-12. These putative collagens are included in prophages embedded in O157:H7 genomes. These prophages carry numerous genes related to strain virulence and have been shown to be inducible and capable of disseminating virulence factors by horizontal gene transfer. We have cloned two collagen-like proteins from E. coli O157:H7 into a laboratory strain and analysed the structure and conformation of the recombinant proteins and several of their constituting domains by a variety of spectroscopic, biophysical, and electron microscopy techniques. We show that these molecules exhibit many of the characteristics of vertebrate collagens, including trimer formation and the presence of a collagen triple helical domain. They also contain a C-terminal trimerization domain, and a trimeric α-helical coiled-coil domain with an unusual amino acid sequence almost completely lacking leucine, valine or isoleucine residues. Intriguingly, these molecules show high thermal stability, with the collagen domain being more stable than those of vertebrate fibrillar collagens, which are much longer and post-translationally modified. Under the electron microscope, collagen-like proteins from E. coli O157:H7 show a dumbbell shape, with two globular domains joined by a hinged stalk. This morphology is consistent with their likely role as trimeric phage side-tail proteins that participate in the attachment of phage particles to E. coli target cells, either directly or through assembly with other phage tail proteins. Thus, collagen-like proteins in enterohaemorrhagic E. coli genomes may have a direct role in the dissemination of virulence-related genes through infection of harmless strains by induced bacteriophages.

Preservation of human tear protein structure and function by a novel contact lens multipurpose solution containing protein-stabilizing agents.

OBJECTIVES: Tear film proteins have antimicrobial and other functions that may be lost after denaturation during contact lens wear. A new multipurpose solution has recently become available (Biotrue, Bausch + Lomb Inc., Rochester, NY), which contains protein-stabilizing agents including hyaluronic acid, poloxamine, and sulfobetaine 10, the latter used previously as a laboratory tool to renature proteins. We examine whether this new multipurpose solution formulation can prevent the denaturation of human lactoferrin and lysozyme at physiologic levels in response to a powerful denaturing challenge. METHODS: Human lactoferrin and lysozyme were treated with sodium dodecyl sulfate (SDS) either with or without an investigational version of the new multipurpose solution (without its two disinfectant agents) (investigational multipurpose solution [iMPS]). The structure was assessed by native-polyacrylamide gel electrophoresis (PAGE), differential scanning calorimetry (DSC), and fluorometry; additionally, antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus was measured. RESULTS: The iMPS prevented an SDS-induced shift in the native-PAGE banding position of lactoferrin. The SDS treatment substantially altered the lactoferrin DSC and fluorescence spectra, indicating that the protein had denatured. This change did not occur in the presence of iMPS. Lactoferrin and lysozyme showed antibacterial and bacteriolytic activity, which was abolished after SDS treatment; this loss of activity did not occur for proteins treated with iMPS. CONCLUSIONS: These data clearly show that the iMPS prevents the denaturation of physiologic levels of human lactoferrin and lysozyme by the strongly denaturing surfactant SDS and that stabilized proteins retain their function. We conclude that this solution has the capacity to stabilize the structure and function of tear proteins.

Expression and characterization of Mycobacterium tuberculosis CYP144: common themes and lessons learned in the M. tuberculosis P450 enzyme family.

CYP144 from Mycobacterium tuberculosis was expressed and purified. CYP144 demonstrates heme thiolate coordination in its ferric form, but the cysteinate is protonated to thiol in both the carbon monoxide-bound and ligand-free ferrous forms (forming P420 in the former). Tight binding of various azole drugs was shown, with affinity for miconazole (K(d)=0.98 µM), clotrimazole (0.37 µM) and econazole (0.78 µM) being highest. These azoles are also the trio with the highest affinity for the essential CYP121 and for the cholesterol oxidase CYP125 (essential for host infection), and have high potency as anti-mycobacterial drugs. Construction of a Mtb gene knockout strain demonstrated that CYP144 is not essential for growth in vitro. However the deletion strain was more sensitive to azole inhibition in culture suggesting an important role for CYP144 in cell physiology and/or in mediating azole resistance. The biophysical and genetic features of CYP144 are compared to those of other characterized Mtb P450s, identifying both commonality in properties (including thiolate protonation in ferrous P450s) and intriguing differences in thermodynamic and spectroscopic features. Our developing knowledge of the Mtb P450s has revealed unusual biochemistry and gene essentiality, highlighting their potential as drug targets in this human pathogen.

Structural effects of fibulin 5 missense mutations associated with age-related macular degeneration and cutis laxa.

PURPOSE: AMD has a complex etiology with environmental and genetic risk factors. Ten fibulin 5 sequence variants have been associated with AMD and two other fibulin 5 mutations cause autosomal-recessive cutis laxa. Fibulin 5 is a 52-kDa calcium-binding epidermal growth factor (cbEGF)-rich extracellular matrix protein that is essential for the formation of elastic tissues. Biophysical techniques were used to detect structural changes in the fibulin 5 mutants and to determine whether changes are predictive of pathogenicity. METHODS: Native PAGE, nonreduced SDS-PAGE, size-exclusion column multiangle laser light scattering, sedimentation velocity, and circular dichroism (CD) were used to investigate the mobility, hydrodynamic radii, folding, and oligomeric states of the fibulin 5 mutants in the absence and presence of Ca(2+). RESULTS: CD showed that all mutants are folded, although perturbations to secondary structure contents were detected. Both cutis laxa mutants increased dimerization. Most other mutants slightly increased self-association in the absence of Ca(2+) but this was also demonstrated by G202R, a polymorphism detected in a control individual. The AMD-associated mutant G412E showed lower-than-expected mobility during native-PAGE, the largest hydrodynamic radius for the monomer form and the highest levels of aggregation in both the absence and presence of Ca(2+). CONCLUSIONS: The results identified structural differences for the disease-causing cutis laxa mutants and for one AMD variant (G412E), suggesting that this may also be pathogenic. Although the other AMD-associated mutants showed no gross structural differences, they cannot be excluded as pathogenic by differences outside the scope of this study-for example, disruption of heterointeractions.

Fibulin 5 forms a compact dimer in physiological solutions.

Fibulin 5 is a 52-kDa calcium-binding epidermal growth factor (cbEGF)-rich extracellular matrix protein that is essential for the formation of elastic tissues. Missense mutations in fibulin 5 cause the elastin disorder cutis laxa and have been associated with age-related macular degeneration, a leading cause of blindness. We investigated the structure, hydrodynamics, and oligomerization of fibulin 5 using small angle x-ray scattering, EM, light scattering, circular dichroism, and sedimentation. Compact structures for the monomer were determined by small angle x-ray scattering and EM, and are supported by close agreement between the theoretical sedimentation of the structures and the experimental sedimentation of the monomer in solution. EM showed that monomers associate around a central cavity to form a dimer. Light scattering and equilibrium sedimentation demonstrated that the equilibrium between the monomer and the dimer is dependent upon NaCl and Ca2+ concentrations and that the dimer is dominant under physiological conditions. The dimerization of fragments containing just the cbEGF domains suggests that intermolecular interactions between cbEGFs cause dimerization of fibulin 5. It is possible that fibulin 5 functions as a dimer during elastinogenesis or that dimerization may provide a method for limiting interactions with binding partners such as tropoelastin.

Serum MUC5AC mucin as a potential marker for cholangiocarcinoma.

Aberrant expression of MUC5AC mucin is obvious in cholangiocarcinoma tissues, however, this mucin has never been detected in the serum. Using immunoblotting marked with antibody vs. MUC5AC core protein, we could detect MUC5AC mucin in the serum of 112 from 179 cholangiocarcinoma patients (62.6% sensitivity), two of the 62 with benign hepatobiliary diseases, six of the 60 with hepato-gastrointestinal cancer, and none in either the 60 active opisthorchiasis or 74 healthy persons. Detection of serum mucin in the serum of cholangiocarcinoma patients corresponded well to the MUC5AC expressed in individual tissues. Serum MUC5AC may be used to enhance the diagnostic accuracy of cholangiocarcinoma.