Publications by authors named "John A Robbins"

Unlabelled: This study examined if the amino acids phenylalanine or tyrosine contribute to risk of hip fracture or frailty in older adults. We determined that neither phenylalanine nor tyrosine are important predictors of hip fracture or frailty. We suggest advice on protein intake for skeletal health consider specific amino acid composition.

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Article Synopsis
  • Researchers developed a protein-based risk score for predicting hip fractures using an aptamer-based proteomic platform that showed promise in initial studies.
  • The risk score demonstrated strong predictive capabilities and improved fracture discrimination when validated in additional health study cohorts and in a UK Biobank cohort.
  • While the proteomic risk score outperformed existing tools, including the FRAX assessment, its clinical usefulness beyond current methods and the modest improvement in prediction need further evaluation.
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Hip fractures are associated with significant disability, high cost, and mortality. However, the exact biological mechanisms underlying susceptibility to hip fractures remain incompletely understood. In an exploratory search of the underlying biology as reflected through the circulating proteome, we performed a comprehensive Circulating Proteome Association Study (CPAS) meta-analysis for incident hip fractures.

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Amino acids are the building blocks of proteins, and sufficient protein intake is important for skeletal health. We utilized stored serum from the Cardiovascular Health Study in 1992-1993 to examine the relationship between levels of the essential amino acid tryptophan (trp) and its oxidized and nonoxidized metabolites to risk for incident hip fractures and mortality over 12 years of follow-up. We included 131 persons who sustained a hip fracture during this time period and 131 without a hip fracture over these same 12 years of follow-up; 58% female and 95% White.

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  • * They measured 25 immune cell types in nearly 2,000 participants and found specific associations: in women, more natural killer (NK) cells seemed to lower the risk of hip fractures, while higher levels of Th17 cells increased the risk; for men, more γδ T cells were linked to a lower risk.
  • * However, when combining data from both sexes, no clear associations between immune cell types and hip fracture risk were found, highlighting potential differences in men and women regarding immune responses and fracture risk.
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Background: Type 2 diabetes is a major public health concern in the United States and worldwide. The dietary inflammatory index (DII) and the energy-adjusted DII (E-DII) are tools that assess dietary inflammation. Previous evidence suggests that obesity can modify the association between inflammation and disease.

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Importance: The best approach to identify younger postmenopausal women for osteoporosis screening is uncertain. The Fracture Risk Assessment Tool (FRAX), which includes self-identified racial and ethnic information, and the Osteoporosis Self-assessment Tool (OST), which does not, are risk assessment tools recommended by US Preventive Services Task Force guidelines to identify candidates for bone mineral density (BMD) testing in this age group.

Objective: To compare the ability of FRAX vs OST to discriminate between younger postmenopausal women who do and do not experience incident fracture during a 10-year follow-up in the 4 racial and ethnic groups specified by FRAX.

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Objective: Branched chain amino acids (BCAA) are building blocks for protein, an essential component of bone. However, the association of plasma levels of BCAA with fractures in populations outside of Hong Kong or with hip fractures in particular is not known. The purpose of these analyses was to determine the relationship of BCAA including valine, leucine, and isoleucine and total BCAA (SD of the sum of Z-scores for each BCAA) with incident hip fractures and bone mineral density (BMD) of the hip and lumbar spine in older African American and Caucasian men and women in the Cardiovascular Health Study.

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Background: Comorbidities like coronary heart disease are common among older people who sustain an osteoporotic hip fracture. However, their impact on short- and long-term mortality post-hip fracture is not well quantified.

Methods: We examined 4092 and 1173 older adults without and with prevalent coronary heart disease, respectively.

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Objective: Advancing age is a powerful risk factor for hip fractures. The biological mechanisms through which aging impacts the risk of hip fractures have not been well studied.

Methods: Biological factors associated with "advancing age" that help to explain how aging is associated with the risk of hip fractures are reviewed.

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Unlabelled: Endothelial dysfunction underlies the development of atherosclerotic vascular disease, which in turn is associated with osteoporotic fractures. Here, we examined the association of two markers of endothelial dysfunction with incident hip fracture risk in older adults but found no statistically significant associations between them.

Purpose/introduction: Endothelial dysfunction underlies the development of atherosclerotic vascular disease.

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Background: To evaluate the association between the dietary inflammatory index (DII) and incident cardiovascular disease (CVD) in Hispanic women from the Women's Health Initiative (WHI), and to determine if body mass index (BMI) interacted with the DII scores.

Methods: Secondary analysis of baseline dietary data and long-term CVD outcomes among 3,469 postmenopausal women who self-identified as Hispanic enrolled in WHI. DII scores were calculated from self-administered food frequency questionnaires.

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Objective: The objective of this study was to assess the effect of menopausal hormone therapy (HT) on blood pressure control in postmenopausal women with hypertension.

Methods: The Women's Health Initiative HT clinical trials were double-blinded, randomized, placebo-controlled studies of women aged 50 to 79 years testing the effects of HT (conjugated equine estrogens [CEE, 0.625 mg/d] or CEE + medroxyprogesterone acetate [MPA; 2.

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Objective: The aim of this study was to examine the association between common menopausal symptoms (MS) and long-term cardiovascular disease (CVD) and all-cause mortality.

Methods: In an observational cohort of 80,278 postmenopausal women with no known CVD at baseline from the Women's Health Initiative, we assessed individual MS severity (mild vs none; moderate/severe vs none) for night sweats, hot flashes, waking up several times at night, joint pain or stiffness, headaches or migraines, vaginal or genital dryness, heart racing or skipping beats, breast tenderness, dizziness, tremors (shakes), feeling tired, forgetfulness, mood swings, restless or fidgety, and difficulty concentrating. Outcomes included total CVD events (primary) and all-cause mortality (secondary).

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Background: Hispanics are a heterogeneous population with differences in the prevalence of cardiovascular disease (CVD) and its related risk factors among ethnic sub-groups. This study evaluated the association of genetic admixture and CVD in self-identified Hispanic women from the Women's Health Initiative (WHI).

Methods: Data came from the WHI Observational Study and the Clinical Trial Components conducted among postmenopausal women.

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Background: It is uncertain if lipids or lipoproteins are associated with osteoporotic fractures. In this study, incident hip fracture risk according to conventional lipid levels and lipoprotein levels and sizes was examined.

Methods: We followed 5832 participants aged ≥65 years from the Cardiovascular Health Study for hip fracture for a mean of 13.

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Context: Gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) may adversely affect bone by inducing oxidative stress. Whether this translates into increased fracture risk in older adults is uncertain.

Objective: Determine the associations of plasma TMAO with hip fracture and bone mineral density (BMD) in older adults.

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Unlabelled: Among 1299 older adults with 24-h Holter monitoring data at baseline, followed for approximately 15 years, 190 incident hip fractures occurred. Increased heart rate variability was independently associated with reduced risk of hip fracture among female participants.

Purpose: Autonomic nervous system function modulates bone remodeling in rodent osteoporosis models.

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Background: The locations of subsequent fractures after initial fracture in postmenopausal women are poorly characterized.

Methods: We conducted a prospective analysis of subsequent fractures after initial fracture in Women's Health Initiative (1993-2018) participants who provided follow-up (mean 15.4 years, SD 6.

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Importance: The burden of fractures among postmenopausal women is high. Although nontraumatic fractures are strong risk factors for future fracture, current clinical guidelines do not address traumatic fractures.

Objective: To determine how future fracture risk varies according to whether an initial fracture is traumatic or nontraumatic.

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Low muscle mass (sarcopenia) is a prevalent and major concern in the aging population as well as in patients with chronic kidney disease (CKD). We hypothesized that sarcopenia is an independent predictor of incident and progressive CKD and increased mortality in older men and women (≥65 years) from the Cardiovascular Health Study. Sarcopenia was defined by bioimpedance-estimated skeletal muscle mass index (SMI) as a continuous variable and categorically (normal, class I, and class II).

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Objective: This study evaluated whether vasomotor symptom (VMS) severity and number of moderate/severe menopausal symptoms (nMS) were associated with health outcomes, and whether calcium and vitamin D (CaD) modified the risks.

Methods: The Women's Health Initiative CaD study was a double blind, randomized, placebo-controlled trial, which tested 400 IU of 25-hydroxyvitamin-D and 1,000 mg of calcium per day in women aged 50 to 79 years. This study included 20,050 women (median follow-up of 7 y).

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Background: Little is known about the relationships of dihydrotestosterone (DHT), a more potent androgen than testosterone (T), with bone mineral density (BMD) and fracture risk. Our objectives were to evaluate the relationships of T, DHT and sex hormone binding globulin (SHBG) with BMD, fracture risk, and lean body mass (LBM).

Methods: We evaluated 1128 older men free of cardiovascular disease in a prospective cohort study using data from the Cardiovascular Health Study.

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The ability of the fracture risk assessment tool (FRAX) to discriminate between women who do and do not experience major osteoporotic fractures (MOFs) is suboptimal. Adding common clinical risk factors may improve discrimination. We used data from the Womens Health Initiative, a prospective study of women aged 50 to 79 years at baseline ( = 99,413; = 5722 in BMD subset) enrolled at 40 US clinical centers.

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