The Bone, Exercise, Alendronate, and Caloric Restriction (BEACON) trial design and methods.

Background: Among older adults living with obesity, intentional weight loss (WL) improves prognosis of many comorbidities. However, concomitant decline in bone mineral density (BMD) limits overall benefit of WL by increasing osteoporotic fracture risk. Identification of intervention strategies to maximize body fat loss, while minimizing harm to the musculoskeletal system, is an important area of clinical research.

New Human Leukocyte Antigen (HLA) Antibody Formation and Creatinine Elevation With Abaloparatide in Kidney Transplant Recipient.

A 39-year-old female with a history of kidney transplant presented to the endocrinology clinic for osteoporosis evaluation after sustaining an ankle fracture from a fall. Her kidney transplant regimen (mycophenolate mofetil 360 mg twice a day, tacrolimus 0.5 mg every morning and 0.

Bone Turnover Markers After Six Nights of Insufficient Sleep and Subsequent Recovery Sleep in Healthy Men.

Purpose: The goal of this study was to determine the bone turnover marker (BTM) response to insufficient and subsequent recovery sleep, independent of changes in posture, body weight, and physical activity.

Methods: Healthy men (N = 12) who habitually slept 7-9 h/night were admitted to an inpatient sleep laboratory for a baseline 8 h/night sleep opportunity followed by six nights of insufficient sleep (5 h/night). Diet, physical activity, and posture were controlled.

Acute catabolic bone metabolism response to exercise in young and older adults: A narrative review.

Exercise is recommended for cardiometabolic benefits and to preserve or improve bone health, especially for older adults at increased risk of fracture. However, exercise interventions have modest benefits on areal bone mineral density (aBMD), and exercise can lead to bone loss in young athletes under certain conditions. In this narrative review, we discuss evidence for a disruption in calcium homeostasis during exercise that may diminish the skeletal benefits of exercise.

Maintaining serum ionized calcium during brisk walking attenuates the increase in bone resorption in older adults.

Background: Endurance exercise can cause a decrease in serum ionized calcium (iCa) and increases in parathyroid hormone (PTH) and bone resorption, reflected by serum carboxy-terminal collagen crosslinks (CTX). We developed a calcium clamp to prevent the decrease in iCa during exercise, which attenuated increases in PTH and CTX during vigorous cycling in young men. The goal was to determine whether this occurs in older adults during brisk walking.

Bone turnover marker responses to sleep restriction and weekend recovery sleep.

Background: Prior data demonstrated three weeks of sleep restriction and concurrent circadian disruption uncoupled bone turnover markers (BTMs), indicating decreased bone formation and no change or increased bone resorption. The effect of insufficient sleep with or without ad libitum weekend recovery sleep on BTMs is unknown.

Methods: BTMs were measured in stored serum from 20 healthy adults randomized to one of three study groups consisting of a control group (N = 3 men; 9 h/night) or one of two nocturnal sleep restriction groups in an inpatient laboratory environment.

Sleep disruptions and bone health: what do we know so far?

Purpose Of Review: This review briefly summarizes the growing body of literature addressing the skeletal consequences of sleep and circadian disruption.

Recent Findings: The most recent data in the field suggest that the diurnal variation in bone turnover markers are because of endogenous circadian rhythmicity linked to clock genes in all bone cells; in a small human intervention study, cumulative sleep restriction with concurrent circadian disruption negatively alter bone turnover markers in a way that could explain the lower BMD and increased fracture risk identified in some prior night shift work studies; abnormal sleep duration and obstructive sleep apnea are associated with low BMD and increased fracture risk in some but not all studies.

Summary: Normal physiology and some animal and human intervention studies suggest that sleep and circadian disruptions, such as night shift work, abnormal sleep durations and obstructive sleep apnea are detrimental to skeletal health.

Bone Mineral Density in Different Menopause Stages is Associated with Follicle Stimulating Hormone Levels in Healthy Women.

Although estradiol (E) has been believed to be the most critical factor in the menopause-associated decrease in bone mineral density (BMD), the role of increasing follicle stimulating hormone (FSH) during menopause is relatively unclear. We determined the extent to which hip and lumbar spine BMD differ among the stages of menopause in healthy women, and whether BMD is associated with FSH and E levels. A cross-sectional study of 141 healthy women classified as premenopausal (Pre; 38 ± 6 yrs; mean ± SD, = 30), early perimenopausal (EPeri; 50 ± 3yrs, = 31), late perimenopausal (LPeri; 50 ± 4yrs, = 30), early postmenopausal (EPost; 55 ± 3yrs, = 24), or late postmenopausal (LPost; 62 ± 4 yrs, = 26), was conducted.

Sleep Restriction With Circadian Disruption Negatively Alter Bone Turnover Markers in Women.

Purpose: The purpose of this work is to determine whether an uncoupling of bone turnover markers (BTMs) occurs in women exposed to the combination of sleep restriction with circadian disruption (SRCD), as previously reported in men.

Methods: Four bone biomarkers (N-terminal propeptide of type I procollagen [P1NP] and osteocalcin = bone formation; C-telopeptide [CTX] = bone resorption; sclerostin = bone formation inhibitor) were measured in bihourly samples over 24 hours at baseline and after approximately 3 weeks of sleep restriction (~5.6 hours of sleep/24 hours) with concurrent circadian disruption (SRCD, recurring 28-hour "day" in dim light).

Bone Biomarker Response to Walking under Different Thermal Conditions in Older Adults.

Unlabelled: Endurance exercise can cause a decrease in serum ionized calcium (iCa) and increases in parathyroid hormone (PTH) and c-terminal telopeptide of type I collagen (CTX), which may be due to Ca loss in sweat.

Purpose: This study aimed to determine whether exercise in a warm environment exaggerates the decrease in iCa and increases in PTH and CTX compared with a cool environment in older adults.

Methods: Twelve women and men 61-78 yr old performed two identical 60-min treadmill bouts at ~75% of maximal heart rate under warm and cool conditions.

Circadian Rhythm of Vascular Function in Midlife Adults.

Objective- Adverse cardiovascular events occur more frequently in the morning than at other times of the day. Vascular endothelial function (VEF)-a robust cardiovascular risk marker-is impaired during this morning period. We recently discovered that this morning impairment in VEF is not caused by either overnight sleep or the inactivity that accompanies sleep.

Dermal Calcium Loss Is Not the Primary Determinant of Parathyroid Hormone Secretion during Exercise.

Introduction: Exercise can cause a decrease in serum ionized calcium (iCa) concentration, which stimulates parathyroid hormone (PTH) secretion and activates bone resorption. We postulated that dermal Ca loss during cycling exercise is the major determinant of the serum iCa, PTH, and bone resorption (C-terminal telopeptide of type 1 collagen [CTX]) responses.

Methods: To investigate this, women (n = 13) and men (n = 12) age 18 to 45 yr performed the same exercise bout under cool (18°C) and warm (26°C) conditions.

Maintenance of Serum Ionized Calcium During Exercise Attenuates Parathyroid Hormone and Bone Resorption Responses.

Exercise can cause a decrease in serum ionized calcium (iCa) and increases in parathyroid hormone (PTH) and bone resorption. We used a novel intravenous iCa clamp technique to determine whether preventing a decline in serum iCa during exercise prevents increases in PTH and carboxy-terminal collagen crosslinks (CTX). Eleven cycling-trained men (aged 18 to 45 years) underwent two identical 60-min cycling bouts with infusion of Ca gluconate or saline.

The importance of the circadian system & sleep for bone health.

Adequate sleep timed appropriately during the circadian night is important for numerous biological processes and systems. New evidence suggests that both sleep timing and duration may be important for optimal bone health as well. This review examines the diurnal variation of bone turnover markers (BTMs) and the importance of circadian clock genes in regulating bone mass.

Bone Turnover Markers After Sleep Restriction and Circadian Disruption: A Mechanism for Sleep-Related Bone Loss in Humans.

Context: Sleep abnormalities are associated with low bone mineral density. Underlying mechanisms are unknown.

Objective: Investigate the impact of sleep restriction with circadian disruption on bone biomarkers.

Free 25-Hydroxyvitamin D: Impact of Vitamin D Binding Protein Assays on Racial-Genotypic Associations.

Context: Total 25-hydroxyvitamin D (25OHD) is a marker of vitamin D status and is lower in African Americans than in whites. Whether this difference holds for free 25OHOD (f25OHD) is unclear, considering reported genetic-racial differences in vitamin D binding protein (DBP) used to calculate f25OHD.

Objectives: Our objective was to assess racial-geographic differences in f25OHD and to understand inconsistencies in racial associations with DBP and calculated f25OHD.

Associations of 25-Hydroxyvitamin D and 1,25-Dihydroxyvitamin D With Bone Mineral Density, Bone Mineral Density Change, and Incident Nonvertebral Fracture.

Relationships between 1,25-dihydroxyvitamin D (1,25(OH)2 D) and skeletal outcomes are uncertain. We examined the associations of 1,25(OH)2 D with bone mineral density (BMD), BMD change, and incident non-vertebral fractures in a cohort of older men and compared them with those of 25-hydroxyvitamin D (25OHD). The study population included 1000 men (aged 74.

Obstructive sleep apnea and metabolic bone disease: insights into the relationship between bone and sleep.

Obstructive sleep apnea (OSA) and low bone mass are two prevalent conditions, particularly among older adults-a section of the U.S. population that is expected to grow dramatically over the coming years.

Higher 25(OH)D2 is associated with lower 25(OH)D3 and 1,25(OH)2D3.

Context: Despite common use of supplemental vitamin D2 in clinical practice, the associations of serum vitamin D2 concentrations with other vitamin D metabolites and total vitamin D are unclear.

Objective: The aim of the study was to measure vitamin D2 and D3 levels and examine their associations with each other and with total vitamin D.

Design: We performed a cross-sectional analysis of 679 randomly selected participants from the Osteoporotic Fractures in Men Study.

Nicotine-substitute gum-induced milk alkali syndrome: a look at unexpected sources of calcium.

Objective: This report describes a 64-year-old woman with recurrent hypercalcemia. Her laboratory evaluation was consistent with milk-alkali syndrome. It was eventually discovered that the source of the excessive calcium consumption was nicotine-replacement chewing gum and carbonated water.

Expression of the Bcl-2 apoptotic marker in cats diagnosed with inflammatory bowel disease and gastrointestinal lymphoma.

Immunolabeling for the critical lymphocyte survival factor, Bcl-2, of intestinal biopsies from cats with histologic evidence of inflammatory bowel disease (IBD) or gastrointestinal (GI) lymphoma was evaluated to determine if expression differed significantly between these two disease processes. Immunolabeling for Bcl-2 was performed on small intestinal endoscopic or full thickness biopsy sections from 55 cats. Diagnosis of IBD, T-cell lymphoma or B-cell lymphoma was established previously.

What every hospitalist should know about the post-bariatric surgery patient.

Obesity is a growing worldwide epidemic, increasingly addressed through surgical options for weight loss. Benefits of these operations, such as weight loss and improvement or reversal of obesity-related comorbidities, are well established; however, postoperative complications do occur. This article will evaluate common causes for hospital admissions in the post-bariatric surgery population as they relate to the hospitalist who is often responsible for their care.

An outpatient-based clinical program for diabetes prevention: an update.

Objective: To update outcomes of the Diet-Exercise-Activity-Lifestyle (DEAL) program, a clinic-based diabetes prevention intervention.

Methods: Changes in weight, fasting blood glucose, and 2-hour glucose after a 75-g oral glucose tolerance test were evaluated in patients who enrolled in the DEAL program between January 2007 and August 2009.

Results: The 221 qualified participants had a mean age of 62 years, weight of 87.