Validation of genetic classifiers derived from mouse and human tumors to identify molecular subtypes of colorectal cancer

Colorectal cancer (CRC) is a leading cause of cancer death in the United States. Standard treatment for advanced-stage CRC for decades has included 5-fluorouracil-based chemotherapy. More recently, targeted therapies for metastatic CRC are being used based on the individual cancer's molecular profile. In the past few years, several different molecular subtype schemes for human CRC have been developed. The molecular subtypes can be distinguished by gene expression signatures and have the potential to be used to guide treatment decisions. However, many subtyping classification methods were developed using mRNA expression levels of hundreds to thousands of genes, making them impractical for clinical use. In this study, we assessed whether an immunohistochemical approach could be used for molecular subtyping of CRCs. We validated two previously published, independent sets of immunohistochemistry classifiers and modified the published methods to improve the accuracy of the scoring methods. In addition, we evaluated whether protein and genetic signatures identified originally in the mouse were linked to clinical outcomes of patients with CRC. We found that low DDAH1 or low GAL3ST2 protein levels in human CRCs correlate with poor patient outcomes. The results of this study have the potential to impact methods for determining the prognosis and therapy selection for patients with CRC.

Height Loss in Old Age and Fracture Risk Among Men in Late Life: A Prospective Cohort Study

To assess the association of height loss in old age with subsequent risk of hip and any clinical fracture in men late in life while accounting for the competing risk of mortality, we used data from 3491 community-dwelling men (mean age 79.2 years). Height loss between baseline and follow-up (mean 7.0 years between examinations) was categorized as <1 cm (referent group), ≥1 to <2 cm, ≥2 to <3 cm, and ≥3 cm. Men were contacted every 4 months after the follow-up examination to ask about fractures (confirmed by radiographic reports) and ascertain vital status (deaths verified by death certificates). Competing risk methods were used to estimate absolute probabilities of fracture outcomes by height loss category and calculate adjusted risks of fracture outcomes by height loss. During an average of 7.8 years, 158 (4.5%) men experienced a hip fracture and 1414 (40.5%) died before experiencing this event. The absolute 10-year probability of fracture events accounting for the competing risk of death increased with greater height loss. For example, the hip fracture probability was 2.7% (95% confidence interval [CI] 1.9-3.8%) among men with height loss <1 cm increasing to 11.6% (95% CI 8.0-16.0%) among men with height loss ≥3 cm. After adjustment for demographics, fall history, multimorbidity, baseline height, weight change, and femoral neck bone mineral density and considering competing mortality risk, men with height loss ≥3 cm versus <1 cm had a nearly twofold (subdistribution hazard ratio [HR] = 1.94, 95% CI 1.06-3.55) higher risk of hip fracture and a 1.4-fold (subdistribution HR = 1.42, 95% CI 1.05-1.91) increased risk of any clinical fracture. Height loss ≥3 cm in men during old age was associated with higher subsequent risk of clinical fractures, especially hip fractures, even after accounting for the competing risk of death and traditional skeletal and non-skeletal risk factors. © 2021 American Society for Bone and Mineral Research (ASBMR).

Joint Associations of Prevalent Radiographic Vertebral Fracture and Abdominal Aortic Calcification With Incident Hip, Major Osteoporotic, and Clinical Vertebral Fractures

Prevalent vertebral fractures (PVFx) and abdominal aortic calcification (AAC) are both associated with incident fractures and can be ascertained on the same lateral spine images, but their joint association with incident fractures is unclear. Our objective was to estimate the individual and joint associations of PVFx and AAC with incident major osteoporotic, hip, and clinical vertebral fractures in 5365 older men enrolled in the Osteoporotic Fractures in Men (MrOS) Study, using Cox proportional hazards and Fine and Gray subdistribution hazards models to account for competing mortality. PVFx (Genant SQ grade 2 or 3) and 24-point AAC score were ascertained on baseline lateral spine radiographs. Self-reports of incident fractures were solicited every 4 months and confirmed by review of clinical radiographic reports. Compared with men without PVFx and AAC-24 score 0 or 1, the subdistribution hazard ratio (SHR) for incident major osteoporotic fracture was 1.38 (95% confidence interval [CI] 1.13-1.69) among men with AAC-24 score ≥2 alone, 1.71 (95% CI 1.37-2.14) for men with PVFx alone, and 2.35 (95% CI 1.75-3.16) for men with both risk factors, after accounting for conventional risk factors and competing mortality. Wald statistics showed improved prediction model performance by including both risk factors compared with including only AAC (chi-square = 17.3, p < .001) or including only PVFx (chi-square = 8.5, p = .036). Older men with both PVFx and a high level of AAC are at higher risk of incident major osteoporotic fracture than men with either risk factor alone. Assessing prevalent radiographic vertebral fracture and AAC on the same lateral spine images may improve prediction of older men who will have an incident major osteoporotic fracture, even after accounting for traditional fracture risk factors and competing mortality. © 2021 American Society for Bone and Mineral Research (ASBMR).

Multidimensional sleep health and subsequent health-care costs and utilization in older women

STUDY OBJECTIVES

Determine the association of poor multidimensional sleep health with health-care costs and utilization.

METHODS

We linked 1,459 community-dwelling women (mean age 83.6 years) participating in the Study of Osteoporotic Fractures Year 16 visit (2002-2004) with their Medicare claims. Five dimensions of sleep health (satisfaction, daytime sleepiness, timing, latency, and duration) were assessed by self-report. The number of impaired dimensions was expressed as a score (range 0-5). Total direct health-care costs and utilization were ascertained during the subsequent 36 months.

RESULTS

Mean (SD) total health-care costs/year (2017 dollars) increased in a graded manner across the sleep health score ranging from $10,745 ($15,795) among women with no impairment to up to $15,332 ($22,810) in women with impairment in three to five dimensions (p = 0.01). After adjustment for age, race, and enrollment site, women with impairment in three to five dimensions vs. no impairment had greater mean total costs (cost ratio [CR] 1.34 [95% CI = 1.13 to 1.60]) and appeared to be at higher risk of hospitalization (odds ratio (OR) 1.31 [95% CI = 0.96 to 1.81]). After further accounting for number of medical conditions, functional limitations, and depressive symptoms, impairment in three to five sleep health dimensions was not associated with total costs (CR 1.02 [95% CI = 0.86 to 1.22]) or hospitalization (OR 0.91 [95% CI = 0.65 to 1.28]). Poor multidimensional sleep health was not related to outpatient costs or risk of skilled nursing facility stay.

CONCLUSIONS

Older women with poor sleep health have higher subsequent total health-care costs largely attributable to their greater burden of medical conditions, functional limitations, and depressive symptoms.

Self-reported poor sleep on multiple dimensions is associated with higher total health care costs in older men

STUDY OBJECTIVES

To estimate the association of self-reported poor sleep in multiple dimensions with health care costs in older men.

METHODS

Participants were 1,413 men (mean [SD] age 76.5 [5.7] years) enrolled in both the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) study and Medicare Fee-for-Service. Poor sleep was characterized at the baseline MrOS Sleep visit on five dimensions (satisfaction, daytime sleepiness, timing, latency, and duration). Health care costs and utilization were ascertained over 3 years of follow-up using Medicare Claims.

RESULTS

Median (interquartile range [IQR]) annualized total health care costs (2018 US dollars) rose from $3,616 (IQR 1,523-7,875) for those with no impaired sleep dimensions to $4,416 (IQR 1,854-11,343) for men with two impaired sleep dimensions and $5,819 (IQR 1,936-15,569) for those with at least three impaired sleep dimensions. After multivariable adjustment, the ratio of total health care costs (CR) was significantly higher for men with two (1.24, 95% confidence interval [CI] 1.03- to 1.48) and men with at least three impaired sleep dimensions (1.78, 95% CI 1.42 to 2.23) vs. those with no impaired sleep dimensions. After excluding 101 men who died during the 3-year follow-up period, these associations were attenuated and not significant (CR 1.22, 95% CI 0.98 to 1.53 for men ≥3 impaired sleep dimensions vs. none).

CONCLUSIONS

Self-reported poor sleep on multiple dimensions is associated with higher subsequent total health care costs in older men, but this may be due to higher mortality and increased health care costs toward the end of life among those with poor sleep health.

Implications of Frailty among Men with Implantable Cardioverter Defibrillators

OBJECTIVES

Frailty is associated with adverse outcomes, but little is known of the impact of frailty on patients with implantable cardioverter defibrillators (ICDs). This study sought to determine the prevalence of frailty, based on quantitative assessment, and assessed its potential impact on outcomes among community-dwelling men with ICDs.

METHODS

A total of 124 ICD-treated men presenting for a routine device clinic appointment between May and October 2016 underwent frailty assessment consisting of three components: shrinking (weight loss ≥5% during the past year), weakness (inability to rise from a chair without using their arms), and self-reported poor energy level. Patients who had no components were considered robust, those with 1 component were intermediate stage, and those with ≥2 components were deemed frail.

RESULTS

Mean age was 70.4 (±9.7) years. Of the 124 men, 31 (25%) were considered to be frail, 65 (52%) were intermediate, and 28 (23%) were robust. Frail men were older and were more likely to have symptomatic heart failure, chronic kidney disease, and hypertension (P < 0.05 for all) compared with nonfrail men. During a follow-up of 16 months, frail men were significantly more likely to die compared with nonfrail men (29% vs 5.4%, P < 0.0003). The incidence of appropriate ICD shocks (16.1% vs 6.5%) or hospitalizations (38.7% vs 23.7%) tended to be higher among frail versus nonfrail patients, but neither reached statistical significance (P = 0.10).

CONCLUSIONS

Almost one-fourth of men with ICD are frail. Almost one-third of frail ICD patients died within 16 months. It may be useful to assess frailty in patients with ICD.

Hospitalization-Associated Change in Gait Speed and Risk of Functional Limitations for Older Adults

BACKGROUND

Hospitalization-associated functional decline is a common problem for older adults, but it is unclear how hospitalizations affect physical performance measures such as gait speed. We sought to determine hospitalization-associated change in gait speed and likelihood of new limitations in mobility and activities of daily living (ADLs).

METHODS

We used longitudinal data over 5 years from the Health, Aging and Body Composition Study, a prospective cohort of black and white community-dwelling men and women, aged 70-79 years, who had no limitations in mobility (difficulty walking 1/4 mile or climbing 10 steps) or ADLs (transferring, bathing, dressing, and eating) at baseline. Gait speed, and new self-reported limitations in mobility and ADLs were assessed annually. Selected participants (n = 2,963) had no limitations at the beginning of each 1-year interval. Hospitalizations were self-reported every 6 months and verified with medical record data. Generalized estimating equations were used to examine hospitalization-associated change in gait speed and odds of new limitations over each 1-year interval. Fully adjusted models included demographics, hospitalization within the past year, health conditions, symptoms, body mass index, and health-related behaviors.

RESULTS

In fully adjusted models, any hospitalization was associated with decrease in gait speed (-0.04 m/s; 95% confidence interval [CI]: -0.05 to -0.03) and higher odds of new limitations in mobility or ADLs (odds ratio = 1.97, 95% CI: 1.70-2.28), and separately with increased odds of new mobility limitation (odds ratio = 2.22, 95% CI: 1.90-2.60) and new ADL limitations (odds ratio = 1.84, 95% CI: 1.53-2.21). Multiple hospitalizations within a year were associated with gait speed decline (-0.06 m/s; 95% CI: -0.08 to -0.04) and greater odds of new limitations in mobility or ADLs (odds ratio = 2.96, 95% CI: 2.23-3.95).

CONCLUSIONS

Functionally independent older adults experienced hospitalization-associated declines in gait speed and new limitations in mobility and ADLs.

Frailty Phenotype and Healthcare Costs and Utilization in Older Men

OBJECTIVES

To determine the association of the frailty phenotype with subsequent healthcare costs and utilization.

DESIGN

Prospective cohort study (Osteoporotic Fracture in Men [MrOS]).

SETTING

Six US sites.

PARTICIPANTS

A total of 1,514 community-dwelling men (mean age = 79.3 years) participating in the MrOS Year 7 (Y7) examination linked with their Medicare claims data.

MEASUREMENTS

At Y7, the frailty phenotype was operationalized using five components and categorized as robust, pre-frail, or frail. Multimorbidity and a frailty indicator (approximating the deficit accumulation index) were derived from claims data. Functional limitations were assessed by asking about difficulty performing instrumental activities of daily living. Total direct healthcare costs and utilization were ascertained during 36 months following Y7.

RESULTS

Mean of total annualized costs (2018 dollars) was $5,707 (standard deviation [SD] = 8,800) among robust, $8,964 (SD = 18,156) among pre-frail, and $20,027 (SD = 27,419) among frail men. Compared with robust men, frail men (cost ratio [CR] = 2.35; 95% confidence interval [CI] = 1.88-2.93) and pre-frail men (CR = 1.28; 95% CI = 1.11-1.48) incurred greater total costs after adjustment for demographics, multimorbidity, and cognitive function. Associations of phenotypic pre-frailty and frailty with higher total costs were somewhat attenuated but persisted after further consideration of functional limitations and a claims-based frailty indicator. Each individual frailty component was also associated with higher total costs. Frail vs robust men had higher odds of hospitalization (odds ratio [OR] = 2.62; 95% CI = 1.75-3.91) and skilled nursing facility (SNF) stay (OR = 3.36; 95% CI = 1.83-6.20). A smaller but significant effect of the pre-frail category on SNF stay was present.

CONCLUSION

Phenotypic pre-frailty and frailty were associated with higher subsequent total healthcare costs in older community-dwelling men after accounting for a claims-based frailty indicator, functional limitations, multimorbidity, cognitive impairment, and demographics. Assessment of the frailty phenotype or individual components such as slowness may improve identification of older community-dwelling adults at risk for costly extensive care.

The Association Between Objectively Measured Physical Activity and Subsequent Health Care Utilization in Older Men

BACKGROUND

To examine the associations between objective physical activity measures and subsequent health care utilization.

METHODS

We studied 1,283 men (mean age 79.1 years, SD 5.3) participating in the Osteoporotic Fractures in Men Study. Participants wore a SenseWear® Pro Armband monitor for 1 week. Data was summarized as daily (i) step counts, (ii) total energy expenditure, (iii) active energy expenditure, and (iv) activity time (sedentary, ≥ light, ≥ moderate). The outcome measures of 1-year hospitalizations/duration of stay from Medicare data were analyzed with a two-part hurdle model. Covariates included age, clinical center, body mass index, marital status, depressive symptoms, medical conditions, cognitive function, and prior hospitalization.

RESULTS

Each 1 SD = 3,092 step increase in daily step count was associated with a 34% (95% confidence interval [CI]: 19%-46%) lower odds of hospitalization in base model (age and center) and 21% (95% CI: 4%-35%) lower odds of hospitalization in fully adjusted models. Similar but smaller associations held for other physical activity measures, but these associations were not significant in fully adjusted models. Among those hospitalized, higher step count was associated with shorter total duration of acute/postacute care stays in the base model only. There was a fourfold significant difference (from model-based estimates) in predicted care days comparing those with 2,000 versus 10,000 daily steps in the base model, but only a twofold difference (not significant) in the full model.

CONCLUSION

Daily step count is an easily determined measure of physical activity that may be useful in assessment of future health care burden in older men.

Abdominal aortic calcification (AAC) and ankle-brachial index (ABI) predict health care costs and utilization in older men, independent of prevalent clinical cardiovascular disease and each other

BACKGROUND AND AIMS

Abdominal aortic calcification (AAC) and low ankle-brachial index (ABI) are markers of multisite atherosclerosis. We sought to estimate their associations in older men with health care costs and utilization adjusted for each other, and after accounting for CVD risk factors and prevalent CVD diagnoses.

METHODS

This was an observational cohort study of 2393 community-dwelling men (mean age 73.6 years) enrolled in the Osteoporotic Fractures in Men (MrOS) study and U.S. Medicare Fee for Service (FFS). AAC was scored on baseline lateral lumbar spine X-rays using a 24-point scale. ABI was measured as the lowest ratio of arm to right or left ankle blood pressure. Health care costs, hospital stays, and SNF stays were identified from Medicare FFS claims over 36 months following the baseline visit.

RESULTS

Men with AAC score ≥9 (n = 519 [21.7% of analytic cohort]) had higher annualized total health care costs of $1473 (95% C.I. 293, 2654, 2017 U S. dollars) compared to those with AAC score 0-1, after multivariable adjustment. Men with ABI <0.90 (n = 154 [6.4% of analytic cohort]) had higher annualized total health care costs of $2705 (95% CI 634, 4776) compared to men with normal ABI (≥0.9 and < 1.4), after multivariable adjustment.

CONCLUSIONS

High levels of AAC and low ABI in older men are associated with higher subsequent health care costs, after accounting for clinical CVD risk factors, prevalent CVD diagnoses, and each other. Further investigations of whether preventing progression of peripheral vascular disease and calcification reduces subsequent health care costs are warranted.

Association of sleep-disordered breathing with total healthcare costs and utilization in older men: the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) study

STUDY OBJECTIVES

To determine the associations of sleep-disordered breathing (SDB) with subsequent healthcare costs and utilization including inpatient and post-acute care facility stays among community-dwelling older men.

METHODS

Participants were 1,316 men (mean age 76.1 [SD = 5.7] years) in the Outcomes of Sleep Disorders in Older Men (MrOS sleep) study (from December 2003 to March 2005), who were enrolled in a Medicare Fee-For-Service plan. Primary SDB measures including apnea hypopnea index (AHI) and oxygen desaturation index (ODI) were collected using in-home level 2 polysomnography. Incident healthcare costs and utilization were determined from claims data in the subsequent 3-year period post-MrOS sleep visit.

RESULTS

Five hundred and twenty-nine (40.2%) men had at least one hospitalization in the 3-year period. Compared with those without sleep apnea (AHI < 5/hour), men with moderate to severe sleep apnea (AHI ≥ 15/hour) had a higher odds of all-cause hospitalization (odds ratio [OR] adjusted for age and site 1.43, 95% confidence interval [CI]: 1.07-1.90). This association was slightly attenuated after further adjustment for traditional prognostic factors including education, body mass index, comorbid medical conditions, and health status (OR = 1.36; 95% CI: 1.01-1.83). Similar associations were observed for ODI. However, measures of SDB were not related to subsequent healthcare costs (total or outpatient) or odds of post-acute skilled nursing facility stay.

CONCLUSIONS

Older men with SDB have an increased risk of hospitalization, not entirely explained by the greater prevalence of comorbid conditions, but not higher subsequent total healthcare costs. These findings indicate a need to evaluate the impact of SDB treatment on subsequent healthcare utilization.

Effects of Mobility and Multimorbidity on Inpatient and Postacute Health Care Utilization

Background

This study examines effects of mobility and multimorbidity on hospitalization and inpatient and postacute care (PAC) facility days among older men.

Methods

Prospective study of 1,701 men (mean age 79.3 years) participating in Osteoporotic Fractures in Men (MrOS) Study Year 7 (Y7) examination (2007-2008) linked with their Medicare claims. At Y7, mobility ascertained by usual gait speed and categorized as poor, intermediate, or good. Multimorbidity quantified by applying Elixhauser algorithm to inpatient and outpatient claims and categorized as none, mild-moderate, or high. Hospitalizations and PAC facility stays ascertained during 12 months following Y7.

Results

Reduced mobility and greater multimorbidity burden were independently associated with a higher risk of inpatient and PAC facility utilization, after accounting for each other and traditional indicators. Adjusted mean total facility days per year were 1.13 (95% confidence interval [CI] = 0.74-1.40) among men with good mobility increasing to 2.43 (95% CI = 1.17-3.84) among men with poor mobility, and 0.67 (95% CI = 0.38-0.91) among men without multimorbidity increasing to 2.70 (95% CI = 1.58-3.77) among men with high multimorbidity. Men with poor mobility and high multimorbidity had a ninefold increase in mean total facility days per year (5.50, 95% CI = 2.78-10.87) compared with men with good mobility without multimorbidity (0.59, 95% CI = 0.37-0.95).

Conclusions

Among older men, mobility limitations and multimorbidity were independent predictors of higher inpatient and PAC utilization after considering each other and conventional predictors. Marked combined effects of reduced mobility and multimorbidity burden may be important to consider in clinical decision-making and planning health care delivery strategies for the growing aged population.

Depressive Symptoms and Total Healthcare Costs: Roles of Functional Limitations and Multimorbidity

OBJECTIVES

Depressive symptoms can be both a cause and a consequence of functional limitations and medical conditions. Our objectives were to determine the association of depressive symptoms with subsequent total healthcare costs in older women after accounting for functional limitations and multimorbidity.

DESIGN

Prospective cohort study (Study of Osteoporotic Fractures [SOF]).

SETTING

Four US sites.

PARTICIPANTS

A total of 2508 community-dwelling women (mean age = 79.4 years) participating in the SOF year 10 (Y10) examination linked with their Medicare claims data.

MEASUREMENTS

At Y10, depressive symptoms were measured using the 15-item Geriatric Depression Scale (GDS) and functional limitations were assessed by number (range = 0-5) of impairments in performing instrumental activities of daily living. Multimorbidity was ascertained by the Elixhauser method using claims data for the 12 months preceding the Y10 examination. Total direct healthcare costs, outpatient costs, acute hospital stays, and skilled nursing facility during the 12 months following the Y10 examination were ascertained from claims data.

RESULTS

Annualized mean (SD) total healthcare costs were $4654 ($9075) in those with little or no depressive symptoms (GDS score = 0-1), $7871 ($14 534) in those with mild depressive symptoms (GDS score = 2-5), and $9010 ($15 578) in those with moderate to severe depressive symptoms (GDS score = 6 or more). After adjustment for age, site, self-reported functional limitations, and multimorbidity, the magnitudes of these incremental costs were partially attenuated (cost ratio = 1.34 [95% confidence interval {CI} = 1.14-1.59] for those with mild depressive symptoms, and cost ratio = 1.29 [95% CI = 0.99-1.69] for those with moderate to severe depressive symptoms vs women with little or no depressive symptoms).

CONCLUSION

Depressive symptoms were associated with higher subsequent healthcare costs attributable, in part, to greater functional limitations and multimorbidity among those with symptoms. Importantly, even mild depressive symptoms were associated with higher healthcare costs. J Am Geriatr Soc 67:1596-1603, 2019.

Impact of Competing Risk of Mortality on Association of Cognitive Impairment With Risk of Hip Fracture in Older Women

Previous studies examining the association of cognitive impairment and dementia with fracture outcomes in older adults have usually used standard approaches that did not take into account the competing risk of mortality. However, ignoring mortality may not provide accurate estimates of risk of fracture because dementia in older adults strongly predicts death, making mortality a competing risk. A total of 1491 women (mean age 87.6 years) participating in the prospective Study of Osteoporotic Fractures (SOF) Year 20 exam were cognitively assessed and followed to ascertain vital status (deaths verified by death certificates) and hip fractures (confirmed by radiographic reports). Cognitive status was categorized as normal, mild cognitive impairment (MCI), or dementia, based on a standardized evaluation. Absolute probability of hip fracture by category of cognitive function was estimated using traditional Kaplan-Meier method and cumulative incidence function accounting for competing mortality risk. Risk of hip fracture by cognitive function category was determined using conventional Cox proportional hazards regression and subdistribution hazards models with death as a competing risk. During an average follow-up of 5.6 years, 139 (9.3%) women experienced a hip fracture and 990 (66.4%) died before experiencing this outcome. Among women with dementia, the risk of hip fracture was 11.7% (95% confidence interval [CI] 7.3-17.2) at 5 years and 18.6% (95% CI 9.1-30.9) at 10 years using traditional survival analysis versus 7.9% (95% CI 5.1-11.6) at 5 years and 8.8% (95% CI 5.8-12.8) at 9.8 years using a competing risk approach. Results were similar for women with MCI. Women with MCI and dementia have a higher risk of hip fractures than women with normal cognition. However, not taking into account the competing risk of mortality significantly overestimates the risk of hip fracture in women in the ninth and tenth decades of life with cognitive impairment. © 2018 American Society for Bone and Mineral Research.

Central Obesity and Visceral Adipose Tissue Are Not Associated With Incident Atherosclerotic Cardiovascular Disease Events in Older Men

Background Visceral adipose tissue ( VAT ) and other measures of central obesity predict incident atherosclerotic cardiovascular disease ( ASCVD ) events in middle-aged individuals, but these associations are less certain in older individuals age 70 years and older. Our objective was to estimate the associations of VAT and the android-gynoid fat mass ratio, another measure of central obesity, with incident ASCVD events among a large cohort of older men. Methods and Results Two thousand eight hundred ninety-nine men (mean [ SD ] age 76.3 [5.5] years) enrolled in the Outcomes of Sleep Disorders in Older Men study had rigorous adjudication of incident ASCVD events (myocardial infarction, coronary heart disease death, or fatal or nonfatal stroke). We used proportional hazards models to estimate the hazard ratios for incident ASCVD per SD increase of VAT or android-gynoid fat mass ratio (measured at baseline with dual-energy absorptiometry), adjusted for age, race, education, systolic blood pressure, smoking status, oxidized low-density lipoprotein level, treatment for hypertension, statin use, aspirin use, presence of diabetes mellitus, and study enrollment site. Over a mean ( SD ) follow-up period of 7.9 (3.4) years, 424 men (14.6%) had an incident ASCVD event. Neither VAT nor android-gynoid fat mass ratio were associated with incident ASCVD events, either unadjusted or after multivariable-adjustment (hazard ratios [95% confidence interval ] per SD increase 1.02 [0.92-1.13] and 1.05 [0.95-1.17], respectively). Conclusions Central adipose tissue, as measured by VAT or android-gynoid fat mass ratio, was not associated with incident ASCVD events in this study of older men.

Association of High-resolution Peripheral Quantitative Computed Tomography (HR-pQCT) bone microarchitectural parameters with previous clinical fracture in older men: The Osteoporotic Fractures in Men (MrOS) study

High-resolution peripheral quantitative computed tomography (HR-pQCT) assesses both volumetric bone mineral density (vBMD) and trabecular and cortical microarchitecture. However, studies of the association of HR-pQCT parameters with fracture history have been small, predominantly limited to postmenopausal women, often performed limited adjustment for potential confounders including for BMD, and infrequently assessed strength or failure measures. We used data from the Osteoporotic Fractures in Men (MrOS) study, a prospective cohort study of community-dwelling men aged ≥65 years, to evaluate the association of distal radius, proximal (diaphyseal) tibia and distal tibia HR-pQCT parameters measured at the Year 14 (Y14) study visit with prior clinical fracture. The primary HR-pQCT exposure variables were finite element analysis estimated failure loads (EFL) for each skeletal site; secondary exposure variables were total vBMD, total bone area, trabecular vBMD, trabecular bone area, trabecular thickness, trabecular number, cortical vBMD, cortical bone area, cortical thickness, and cortical porosity. Clinical fractures were ascertained from questionnaires administered every 4 months between MrOS study baseline and the Y14 visit and centrally adjudicated by masked review of radiographic reports. We used multivariate-adjusted logistic regression to estimate the odds of prior clinical fracture per 1 SD decrement for each Y14 HR-pQCT parameter. Three hundred forty-four (19.2%) of the 1794 men with available HR-pQCT measures had a confirmed clinical fracture between baseline and Y14. After multivariable adjustment, including for total hip areal BMD, decreased HR-pQCT finite element analysis EFL for each site was associated with significantly greater odds of prior confirmed clinical fracture and major osteoporotic fracture. Among other HR-pQCT parameters, decreased cortical area appeared to have the strongest independent association with prior clinical fracture. Future studies should explore associations of HR-pQCT parameters with specific fracture types and risk of incident fractures and the impact of age and sex on these relationships.

Weight loss in men in late life and bone strength and microarchitecture: a prospective study

Weight loss in men in late life was associated with lower bone strength. In contrast, weight gain was not associated with a commensurate increase in bone strength. Future studies should measure concurrent changes in weight and parameters of bone strength and microarchitecture and evaluate potential causal pathways underlying these associations.

INTRODUCTION

Our aim was to determine associations of weight loss with bone strength and microarchitecture.

METHODS

We used data from 1723 community-dwelling men (mean age 84.5 years) who attended the MrOS study Year (Y) 14 exam and had high-resolution peripheral quantitative computed tomography (HR-pQCT) scans at ≥ 1 skeletal sites (distal tibia, distal radius, or diaphyseal tibia). Weight change from Y7 to Y14 exams (mean 7.3 years between exams) was classified as moderate weight loss (loss ≥ 10%), mild weight loss (loss 5 to < 10%), stable weight (< 5% change), or weight gain (gain ≥ 5%). Mean HR-pQCT parameters (95%CI) were calculated by weight change category using linear regression models adjusted for age, race, site, health status, body mass index, limb length, and physical activity. The primary outcome measure was estimated failure load.

RESULTS

There was a nonlinear association of weight change with failure load at each skeletal site with different associations for weight loss vs. weight gain (p < 0.03). Failure load and total bone mineral density (BMD) at distal sites were lower with greater weight loss with 7.0-7.6% lower failure loads and 4.3-5.8% lower BMDs among men with moderate weight loss compared to those with stable weight (p < 0.01, both comparisons). Cortical, but not trabecular, BMDs at distal sites were lower with greater weight loss. Greater weight loss was associated with lower cortical thickness at all three skeletal sites.

CONCLUSION

Weight loss in men in late life is associated with lower peripheral bone strength and total BMD with global measures reflecting cortical but not trabecular parameters.

Frailty as a Risk Factor for Cardiovascular Versus Noncardiovascular Mortality in Older Men: Results From the MrOS Sleep (Outcomes of Sleep Disorders in Older Men) Study

Background

Frailty is associated with greater mortality; however, whether frail patients primarily die of cardiovascular disease (CVD) or non‐CVD causes is unknown.

Methods and Results

We assessed the cause of death in relation to frailty status, measured at baseline, among 3135 community‐dwelling older men in the MrOS Sleep (Outcomes of Sleep Disorders in Older Men) study. Absolute probability and risk of CVD mortality associated with frailty status were estimated with traditional methods that used censoring and newer methods that considered non‐CVD mortality as a competing risk. Of the 3135 men (mean age: 76.4±5.6 years), 475 (15.2%) were frail. During an average follow‐up of 9.2 years, 1275 (40.7%) men died, including 445 (34.9%) from CVD and 828 (64.9%) from non‐CVD causes (2 deaths unadjudicated). Both CVD and non‐CVD mortality risk increased with frailty. Cumulative absolute probability of CVD death at 10 years among frail men was 23.8% (20.2–27.6%) using the competing risk method versus 32.5% (27.3–37.8%) using the traditional Kaplan–Meier method (41.5% [95% confidence interval, 36.9–45.9%] and 48.6% [95% confidence interval, 43.6–53.4%], respectively, for non‐CVD mortality). The multivariable‐adjusted risk of CVD death among frail versus robust men was 1.38 (95% confidence interval, 0.99–1.92) using the competing risk method versus 1.84 (95% confidence interval, 1.35–2.51) using the traditional Cox proportional hazards method.

Conclusions

Among community‐dwelling older men, ≈35% of the deaths were due to CVD. Frail men were at increased risk of CVD death, but ignoring the competing risk of non‐CVD mortality overestimated their long‐term probability and relative risk of CVD death.

Associations of recent weight loss with health care costs and utilization among older women

The association of weight loss with health care costs among older women is uncertain. Our study aim was to examine the association of objectively measured weight change with subsequent total health care (THC) costs and other health care utilization among older women. Our study population included 2,083 women (mean age 80.2 years) enrolled in the Study of Osteoporotic Fractures and U.S. Medicare Fee for Service. Weight loss and gain were defined, respectively, as ≥5% decrease and ≥5% increase in body weight, and weight maintenance as <5% change in body weight over a period of 4.5 years. THC costs, outpatient costs, hospitalizations, and skilled nursing facility [SNF] utilization were estimated from Medicare claims for 1 year after the period during which weight change was measured. The associations of weight change with THC and outpatient costs were estimated using generalized linear models with gamma variance and log link functions, and with hospitalizations and SNF utilization using logistic models. Adjusted for age and current body mass index (BMI), weight loss compared with weight maintenance was associated with a 35% increase in THC costs ($2148 [95% CI, 745 to 3552], 2014 U.S. dollars), a 15% increase in outpatient costs ($329 [95% C.I. −1 to 660]), and odds ratios of 1.42 (95% CI, 1.14 to 1.76) for ≥1 hospital stay and 1.45 (95% CI, 1.03 to 2.03) for ≥1 SNF stay. These associations did not vary by BMI category. After additional adjustment for multi-morbidity and functional status, associations of weight loss with all four outcomes were no longer significant. In conclusion, ≥5% weight loss among older women is not associated with increased THC and outpatient costs, hospitalization, and SNF utilization, irrespective of BMI category after accounting for multi-morbidity and impaired functional status that accompany weight loss.

Predictors of change of trabecular bone score (TBS) in older men: results from the Osteoporotic Fractures in Men (MrOS) Study

Among older men, characteristics that predict longitudinal changes in trabecular bone score (TBS) are different from characteristics that predict changes in bone mineral density (BMD). Most notably, weight loss is strongly associated with concomitant loss in BMD but with concomitant increases in TBS, when measured on Hologic densitometers.

INTRODUCTION

Our objective was to compare and contrast predictors of changes in TBS, total hip BMD, and lumbar spine BMD.

METHODS

Our study population was 3969 Osteoporotic Fractures in Men (MrOS) cohort participants (mean age 72.8 years) with repeat measures of TBS, lumbar spine and total hip BMD, body mass index (BMI) less than 37 kg/m², and no use of bisphosphonate or glucocorticoid medications. TBS was scored (Med-Imaps Software version 2.1) and BMD measured on Hologic densitometers.

RESULTS

One thousand four hundred forty-four men had a TBS decrease > 0.04 units (estimated least significant change for TBS), 795 men had a TBS increase > 0.04 units, and 1730 men had TBS change ≤ 0.04 units over mean follow-up of 4.6 years. Older age was not associated with TBS change, but was associated with greater decline in lumbar spine and total hip BMD. Compared to stable weight, > 10% weight loss was strongly associated with an increase in TBS [effect size = 1.24 (95% CI 1.12, 1.36)] and strongly associated with a decrease in total hip BMD [- 1.16 (95% CI - 1.19, - 1.03)]. Other predictors discordant for longitudinal changes of TBS and BMD included baseline BMI, walk speed, and ACE inhibitor use.

CONCLUSIONS

Predictors of changes in TBS are different from predictors of changes in lumbar spine and total hip BMD. At least when assessed on Hologic densitometers, weight loss is associated with subsequent declines in spine and total hip BMD but subsequent increase in TBS. Faster walk speed may protect against loss of hip BMD, but is not associated with longitudinal changes of TBS.

High dairy protein intake is associated with greater bone strength parameters at the distal radius and tibia in older men: a cross-sectional study

Dairy protein but not plant protein was associated with bone strength of the radius and tibia in older men. These results are consistent with previous results in women and support similar findings related to fracture outcomes. Bone strength differences were largely due to thickness and area of the bone cortex.

INTRODUCTION

Our objective was to determine the association of protein intake by source (dairy, non-dairy animal, plant) with bone strength and bone microarchitecture among older men.

METHODS

We used data from 1016 men (mean 84.3 years) who attended the Year 14 exam of the Osteoporotic Fractures in Men (MrOS) study, completed a food frequency questionnaire (500-5000 kcal/day), were not taking androgen or androgen agonists, and had high-resolution peripheral quantitative computed tomography (HR-pQCT) scans of the distal radius and distal or diaphyseal tibia. Protein was expressed as percentage of total energy intake (TEI); mean ± SD for TEI = 1548 ± 607 kcal/day and for total protein = 16.2 ± 2.9%TEI. We used linear regression with standardized HR-pQCT parameters as dependent variables and adjusted for age, limb length, center, education, race/ethnicity, marital status, smoking, alcohol intake, physical activity level, corticosteroids use, supplement use (calcium and vitamin D), and osteoporosis medications.

RESULTS

Higher dairy protein intake was associated with higher estimated failure load at the distal radius and distal tibia [radius effect size = 0.17 (95% CI 0.07, 0.27), tibia effect size = 0.13 (95% CI 0.03, 0.23)], while higher non-dairy animal protein was associated with higher failure load at only the distal radius. Plant protein intake was not associated with failure load at any site.

CONCLUSION

The association between protein intake and bone strength varied by source of protein. These results support a link between dairy protein intake and skeletal health, but an intervention study is needed to evaluate causality.

Which Sleep Health Characteristics Predict All-Cause Mortality in Older Men? An Application of Flexible Multivariable Approaches

Study Objectives

Sleep is multidimensional, with domains including duration, timing, continuity, regularity, rhythmicity, quality, and sleepiness/alertness. Individual sleep characteristics representing these domains are known to predict health outcomes. However, most studies consider sleep characteristics in isolation, resulting in an incomplete understanding of which sleep characteristics are the strongest predictors of health outcomes. We applied three multivariable approaches to robustly determine which sleep characteristics increase mortality risk in the osteoporotic fractures in men sleep study.

Methods

In total, 2,887 men (mean 76.3 years) completed relevant assessments and were followed for up to 11 years. One actigraphy or self-reported sleep characteristic was selected to represent each of seven sleep domains. Multivariable Cox models, survival trees, and random survival forests were applied to determine which sleep characteristics increase mortality risk.

Results

Rhythmicity (actigraphy pseudo-F statistic) and continuity (actigraphy minutes awake after sleep onset) were the most robust sleep predictors across models. In a multivariable Cox model, lower rhythmicity (hazard ratio, HR [95%CI] =1.12 [1.04, 1.22]) and lower continuity (1.16 [1.08, 1.24]) were the strongest sleep predictors. In the random survival forest, rhythmicity and continuity were the most important individual sleep characteristics (ranked as the sixth and eighth most important among 43 possible sleep and non-sleep predictors); moreover, the predictive importance of all sleep information considered simultaneously followed only age, cognition, and cardiovascular disease.

Conclusions

Research within a multidimensional sleep health framework can jumpstart future research on causal pathways linking sleep and health, new interventions that target specific sleep health profiles, and improved sleep screening for adverse health outcomes.

Sleep Disturbances and Risk of Hospitalization and Inpatient Days Among Older Women

Study Objectives

Determine the associations of sleep disturbances with hospitalization risk among older women.

Methods

One thousand eight hundred and twenty-seven women (mean age 83.6 years) participating in Study of Osteoporotic Fractures Year 16 (Y16) examination (2002-2004) linked with Medicare and/or HMO claims. At Y16 examination, sleep/wake parameters were measured by actigraphy (total sleep time [TST], sleep efficiency [SE], sleep latency [SL], and wake after sleep onset [WASO]) and subjective sleep measures (sleep quality [Pittsburgh Sleep Quality Index] and daytime sleepiness [Epworth Sleepiness Scale]) were assessed by questionnaire. Measures except TST were dichotomized based on clinical thresholds. Incident hospitalizations were determined from claims data.

Results

Nine hundred and seventy-six women (53%) had ≥1 hospitalization in the 3 years after the Year 16 examination. Reduced SE (odds ratio [OR] = 2.39, 95% confidence interval [CI] 1.69-3.39), prolonged SL (OR = 1.41, 95% CI 1.11-1.78), greater WASO (OR = 1.57, 95% CI 1.28-1.93), shorter TST (OR = 1.98, 95% CI 1.42-2.77) and poorer sleep quality (OR = 1.33, 95% CI 1.07-1.65) were each associated with a higher age and site-adjusted odds of hospitalization; associations were attenuated after multivariable adjustment for traditional prognostic factors with the OR for reduced SE (OR = 1.60, 95% CI 1.08-2.38) and shorter TST (OR = 1.63, 95% CI 1.12-2.37) remaining significant. Among women who were hospitalized, greater WASO (rate ratio [RR] = 1.20, 95% CI 1.04-1.37) and poorer sleep quality (RR = 1.18, 95% CI 1.02-1.35) were each associated with a greater age and site-adjusted RR of inpatient days, but associations did not persist after multivariate adjustment.

Conclusions

Older women with sleep disturbances have an increased risk of hospitalization partially attributable to demographics, poorer health status, and comorbidities.

Subclonal diversity arises early even in small colorectal tumours and contributes to differential growth fates

OBJECTIVE AND DESIGN

The goal of the study was to determine whether the mutational profile of early colorectal polyps correlated with growth behaviour. The growth of small polyps (6-9 mm) that were first identified during routine screening of patients was monitored over time by interval imaging with CT colonography. Mutations in these lesions with known growth rates were identified by targeted next-generation sequencing. The timing of mutational events was estimated using computer modelling and statistical inference considering several parameters including allele frequency and fitness.

RESULTS

The mutational landscape of small polyps is varied both within individual polyps and among the group as a whole but no single alteration was correlated with growth behaviour. Polyps carried 0-3 pathogenic mutations with the most frequent being in APC, KRAS/NRAS, BRAF, FBXW7 and TP53. In polyps with two or more pathogenic mutations, allele frequencies were often variable, indicating the presence of multiple populations within a single tumour. Based on computer modelling, detectable mutations occurred at a mean polyp size of 30±35 crypts, well before the tumour is of a clinically detectable size.

CONCLUSIONS

These data indicate that small colon polyps can have multiple pathogenic mutations in crucial driver genes that arise early in the existence of a tumour. Understanding the molecular pathway of tumourigenesis and clonal evolution in polyps that are at risk for progressing to invasive cancers will allow us to begin to better predict which polyps are more likely to progress into adenocarcinomas and which patients are at greater risk of developing advanced disease.

Abstract 2915: The timing of mutational burst events impact the growth of tumors in the colon

Basic and clinical scientists believe that benign polyps in the colon progress to cancers through the slow, stepwise accumulation of mutations. Interestingly, only a small percentage of all tumors progress, whereas a significant number remain static in size, regress, or resolve completely. The mechanisms underlying these differential fates are unknown, and mechanisms of tumor evolution during this premalignant phase are still under investigation and continued debate. We previously reported that sub-clonal diversity arises early in small human adenomas and contributes to the growth of tumors in the colon. An emerging hypothesis is that colorectal tumors form and progress via a process of punctuated equilibrium, where multiple copy number alterations and mutational events happen simultaneously in a burst-like fashion. In this study, we prospectively test this concept using a mouse model in which tumor induction is spatially and temporally controlled via a non-surgical delivery of adenovirus expressing CRE recombinase and a temporally controlled mutational burst via administration of the carcinogen Azoxymethane. Tumors are induced at a similar rate regardless the timing of the burst relative to tumor induction with a mean tumor incidence of 62% at three weeks post induction. However, tumor growth may be affected by the timing of the burst. Animals that had a mutational burst event prior to tumor induction or those that had a late mutational burst event had a lower average in vivo growth rate compared to controls and those with an early burst event, but the average in vivo tumor size was comparable across all groups. Taken together, these preliminary data provide evidence that the timing of a mutational burst event contributes to tumor growth. This prospective experiment is being extended through computer modeling and statistical inference to compare in silico mutational landscapes to a cohort of colon polyps removed from patients at normal screening. The findings will provide new insights into the earliest stages of tumorigenesis.

Citation Format: Chelsie K. Sievers, Tien N. Vo, Perry J. Pickhardt, Bryan D. Pooler, Kristina A. Matkowskyj, Dawn M. Albrecht, Quincy Rosemarie, Michael A. Newton, Richard B. Halberg. The timing of mutational burst events impact the growth of tumors in the colon [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2915. doi:10.1158/1538-7445.AM2017-2915

Association of Trabecular Bone Score (TBS) With Incident Clinical and Radiographic Vertebral Fractures Adjusted for Lumbar Spine BMD in Older Men: A Prospective Cohort Study

The association of trabecular bone score (TBS) with incident clinical and radiographic vertebral fractures in older men is uncertain. TBS was estimated from baseline spine dual-energy X-ray absorptiometry (DXA) scans for 5831 older men (mean age 73.7 years) enrolled in the Osteoporotic Fractures in Men (MrOS) study. Cox proportional hazard models were used to determine the association of TBS (per 1 SD decrease) with incident clinical vertebral fractures. Logistic regression was used to determine the association between TBS (per 1 SD decrease) and incident radiographic vertebral fracture among the subset of 4309 men with baseline and follow-up lateral spine radiographs (mean 4.6 years later). We also examined whether any associations varied by body mass index (BMI) category. TBS was associated with a 1.41-fold (95% confidence interval [CI] 1.23 to 1.63) higher aged-adjusted odds of incident radiographic fracture, and this relationship did not vary by BMI (p value = 0.22 for interaction term). This association was no longer significant with further adjustment for lumbar spine bone mineral density (BMD; odds ratio [OR] = 1.11, 95% CI 0.94 to 1.30). In contrast, the age-adjusted association of TBS with incident clinical vertebral fracture was stronger in men with lower BMI (≤ median value of 26.8 kg/m² ; hazard ratio [HR] = 2.28, 95% CI 1.82 to 2.87) than in men with higher BMI (> median; HR = 1.60, 95% CI 1.31 to 1.94; p value = 0.0002 for interaction term). With further adjustment for lumbar spine BMD, the association of TBS with incident clinical vertebral fracture was substantially attenuated in both groups (HR = 1.30 [95% CI 0.99 to 1.72] among men with lower BMI and 1.11 [95% CI 0.87 to 1.41] among men with higher BMI). In conclusion, TBS is not associated with incident clinical or radiographic vertebral fracture after consideration of age and lumbar spine BMD, with the possible exception of incident clinical vertebral fracture among men with lower BMI. © 2017 American Society for Bone and Mineral Research.

Association of Increased Urinary Albumin With Risk of Incident Clinical Fracture and Rate of Hip Bone Loss: the Osteoporotic Fractures in Men Study

Prior studies suggest that increased urine albumin is associated with a heightened fracture risk in women, but results in men are unclear. We used data from Osteoporotic Fractures in Men (MrOS), a prospective cohort study of community-dwelling men aged ≥65 years, to evaluate the association of increased urine albumin with subsequent fractures and annualized rate of hip bone loss. We calculated albumin/creatinine ratio (ACR) from urine collected at the 2003-2005 visit. Subsequent clinical fractures were ascertained from triannual questionnaires and centrally adjudicated by review of radiographic reports. Total hip BMD was measured by DXA at the 2003-2005 visit and again an average of 3.5 years later. We estimated risk of incident clinical fracture using Cox proportional hazards models, and annualized BMD change using ANCOVA. Of 2982 men with calculable ACR, 9.4% had ACR ≥30 mg/g (albuminuria) and 1.0% had ACR ≥300 mg/g (macroalbuminuria). During a mean of 8.7 years of follow-up, 20.0% of men had an incident clinical fracture. In multivariate-adjusted models, neither higher ACR quintile (p for trend 0.75) nor albuminuria (HR versus no albuminuria, 0.89; 95% CI, 0.65 to 1.20) was associated with increased risk of incident clinical fracture. Increased urine albumin had a borderline significant, multivariate-adjusted, positive association with rate of total hip bone loss when modeled in ACR quintiles (p = 0.06), but not when modeled as albuminuria versus no albuminuria. Macroalbuminuria was associated with a higher rate of annualized hip bone loss compared to no albuminuria (-1.8% more annualized loss than in men with ACR <30 mg/g; p < 0.001), but the limited prevalence of macroalbuminuria precluded reliable estimates of its fracture associations. In these community-dwelling older men, we found no association between urine albumin levels and risk of incident clinical fracture, but found a borderline significant, positive association with rate of hip bone loss. © 2016 American Society for Bone and Mineral Research.

Comparison of Associations of DXA and CT Visceral Adipose Tissue Measures With Insulin Resistance, Lipid Levels, and Inflammatory Markers

Visceral adipose tissue (VAT) measured by computed tomography (CT) is related to insulin resistance, lipids, and serum inflammatory markers. Our objective was to compare the strength of the associations of VAT measured using dual-energy X-ray absorptiometry (DXA-VAT) and CT (CT-VAT) with insulin resistance, serum lipids, and serum markers of inflammation. For 1117 men aged 65 and older enrolled in the Osteoporotic Fractures in Men Study, the cross-sectional associations of DXA-VAT and CT-VAT with homeostasis model assessment of insulin resistance (homa2ir), C-reactive protein, and high-density lipoprotein (HDL) cholesterol were estimated with regression models and compared using a Hausman test. Adjusted for age and body mass index, DXA-VAT was moderately associated with homa2ir (effect size 0.38, 95% confidence interval [CI]: 0.28-0.47) and modestly associated with HDL cholesterol (DXA effect size -0.29, 95% CI: -0.38 to -0.21). These associations were significantly greater than those for CT-VAT with homa2ir (0.30, 95% CI: 0.24-0.37; p value for effect size difference 0.03) and CT-VAT with HDL cholesterol (-0.22, 95% CI: -0.29 to -0.15; p value for difference 0.005). Neither DXA-VAT nor CT-VAT was associated with C-reactive protein after adjustment for age and body mass index (DXA-VAT effect size 0.14, 95% CI: -0.04 to 0.32; CT-VAT effect size 0.08, 95% CI: -0.08 to 0.25; p value for difference 0.35). DXA-VAT has similar or greater associations with insulin resistance and HDL cholesterol as does CT-VAT in older men, confirming the concurrent validity of DXA-VAT. Investigations of how well DXA measurements of VAT predict incident cardiovascular disease events are warranted.

The Association Between Protein Intake by Source and Osteoporotic Fracture in Older Men: A Prospective Cohort Study

Dietary protein is a potentially modifiable risk factor for fracture. Our objectives were to assess the association of protein intake with incident fracture among older men and whether these associations varied by protein source or by skeletal site. We studied a longitudinal cohort of 5875 men (mean age 73.6 ± 5.9 years) in the Osteoporotic Fractures in Men (MrOS) study. At baseline, protein intake was assessed as percent of total energy intake (TEI) with mean intake from all sources = 16.1%TEI. Incident clinical fractures were confirmed by physician review of medical records. There were 612 major osteoporotic fractures, 806 low-trauma fractures, 270 hip fractures, 193 spine fractures, and 919 non-hip non-spine fractures during 15 years of follow-up. We used Cox proportional hazards models with age, race, height, clinical site, TEI, physical activity, marital status, osteoporosis, gastrointestinal surgery, smoking, oral corticosteroids use, alcohol consumption, and calcium and vitamin D supplements as covariates to compute hazard ratios (HRs) with 95% confidence intervals (CIs), all expressed per unit (SD = 2.9%TEI) increase. Higher protein intake was associated with a decreased risk of major osteoporotic fracture (HR = 0.92; 95% CI, 0.84 to 1.00) with a similar association found for low-trauma fracture. The association between protein and fracture varied by protein source; eg, increased dairy protein and non-dairy animal protein were associated with a decreased risk of hip fracture (HR = 0.80 [95% CI, 0.65 to 0.98] and HR = 0.84 [95% CI, 0.72 to 0.97], respectively), whereas plant-source protein was not (HR = 0.99 [95% CI, 0.78 to 1.24]). The association between protein and fracture varied by fracture site; total protein was associated with a decreased risk of hip fracture (HR = 0.84 [95% CI, 0.73 to 0.95]), but not clinical spine fracture (HR = 1.06 [95% CI, 0.92 to 1.22]). In conclusion, those with high protein intake (particularly high animal protein intake) as a percentage of TEI have a lower risk of major osteoporotic fracture. © 2016 American Society for Bone and Mineral Research.

The Association Between Trabecular Bone Score and Lumbar Spine Volumetric BMD Is Attenuated Among Older Men With High Body Mass Index

Trabecular bone score (TBS) has been proposed as a dual-energy X-ray absorptiometry (DXA) derived measure of underlying quality of trabecular bone; however, TBS is not considered valid for those with body mass index (BMI) >37 kg/m² . Our objective was to determine the association between TBS and lumbar spine (trabecular) volumetric BMD (LS-VBMD) and to examine whether the association varied by BMI and body composition among older men below this clinical threshold. We used regression models to study 3479 men age ≥65 years enrolled in the Osteoporotic Fractures in Men (MrOS) study who had TBS from spine DXA scans, LS-VBMD from central quantitative computed tomography, measures of trunk fat and lean mass from DXA, and BMI <37 kg/m² . TBS was categorized as normal (n = 925), partially degraded (n = 1747), and degraded (n = 807). TBS was inversely related to BMI, trunk fat mass, and trunk lean mass (all p < 0.001). The relationship between TBS and LS-VBMD was nonlinear with magnitude of effect (slope of regression line using standardized variables) ranging from 0.07 (95% CI, -0.02 to 0.15) among those with degraded TBS up to 0.71 (95% CI, 0.54 to 0.89) among those with normal TBS. The relationship was still nonlinear after adjusting for age, clinical site, and either BMI, trunk lean mass, or trunk fat mass. The magnitude of effect relating TBS and LS-VBMD also decreased with increasing BMI (interaction, p = 0.090) and increasing trunk lean mass (interaction, p = 0.001), but not with increasing trunk fat mass (interaction, p = 0.224). In summary, the strength of the association between TBS and LS-VBMD among older men was variable and dependent on BMI and body composition, particularly trunk lean mass. The clinical utility of TBS among older men may be somewhat limited among men with high BMI or high trunk lean mass. © 2016 American Society for Bone and Mineral Research.

Injectable dual-gelling cell-laden composite hydrogels for bone tissue engineering

The present work investigated the osteogenic potential of injectable, dual thermally and chemically gelable composite hydrogels for mesenchymal stem cell (MSC) delivery in vitro and in vivo. Composite hydrogels comprising copolymer macromers of N-isopropylacrylamide were fabricated through the incorporation of gelatin microparticles (GMPs) as enzymatically digestible porogens and sites for cellular attachment. High and low polymer content hydrogels with and without GMP loading were shown to successfully encapsulate viable MSCs and maintain their survival over 28 days in vitro. GMP incorporation was also shown to modulate alkaline phosphatase production, but enhanced hydrogel mineralization along with higher polymer content even in the absence of cells. Moreover, the regenerative capacity of 2 mm thick hydrogels with GMPs only, MSCs only, or GMPs and MSCs was evaluated in vivo in an 8 mm rat critical size cranial defect for 4 and 12 weeks. GMP incorporation led to enhanced bony bridging and mineralization within the defect at each timepoint, and direct bone-implant contact as determined by microcomputed tomography and histological scoring, respectively. Encapsulation of both GMPs and MSCs enabled hydrogel degradation leading to significant tissue infiltration and osteoid formation. The results suggest that these injectable, dual-gelling cell-laden composite hydrogels can facilitate bone ingrowth and integration, warranting further investigation for bone tissue engineering.

Two or three days of ofloxacin treatment for uncomplicated multidrug-resistant typhoid fever in children

An open randomized comparison of 2 days (Ofx2) versus 3 days (Ofx3) of oral ofloxacin treatment (15 mg/kg/day) was conducted with Vietnamese children between 1 and 15 years of age with suspected typhoid fever. Of 108 children enrolled, 100 were blood culture positive for Salmonella typhi, and 86% of the isolates were multidrug resistant. There were no significant adverse effects. The therapeutic responses were similar in both groups, with mean (+/- standard deviation) fever clearances of 107 +/- 60 h in the Ofx3 group and 100 +/- 64 h in the Ofx2 group (P > 0.2). There were six "clinical" failures in the Ofx2 group and two clinical failures in the Ofx3 group (P > 0.2), in which fever and symptoms persisted for more than 1 week after the start of treatment, but only one of these was culture positive (Ofx3). There was one suspected relapse, and one carrier was identified. Short courses of ofloxacin are simple, inexpensive, safe, and effective for the treatment of uncomplicated multidrug-resistant typhoid fever.

Mechanism of action of a cytotonic enterotoxin produced by Aeromonas hydrophila

In this study, we describe the mechanism of action of a cytotonic enterotoxin produced by two isolates of Aeromonas hydrophila. Isolates SSU and Ah65 are of different origin and both are capable of producing either a cytotoxic enterotoxin or aerolysin. A cytotonic enterotoxin produced by diarrheal isolate SSU, which was purified and characterized in our laboratory, elevated intracellular cAMP and PgE2 levels in cultured Chinese hamster ovary (CHO) cells. Likewise, enterotoxic activity expressed by a cytotonic enterotoxin was detected in the culture filtrate of a fish isolate (Ah65) after cytotoxic activity was neutralized with homologous aerolysin monoclonal antibodies. This cytotonic enterotoxin also elevated intracellular cAMP and PgE2 levels in CHO cells, suggesting a cholera toxin-like mechanism of action for Aeromonas cytotonic enterotoxins.