Osteoporosis and sarcopenia in older adults

The percentage of individuals older than 65 years of age is increasing. In 2008, approximately 506 million individuals worldwide were older than 65. This number is expected to double and reach 14% of the world’s population by year 2040. With this increase, a higher number of older men and women are expected to experience deterioration in their bones and muscles leading to osteoporosis and sarcopenia respectively. Therefore, understanding the burden that osteoporosis and sarcopenia represent in older men and women could have major public health implications. We studied the importance of areal and volumetric bone mineral density (vBMD) in fracture risk prediction in older men. We found that low areal BMD (aBMD) and (vBMD) were both associated with multiple sites of fracture. Nonetheless, low vBMD was not found to be a better predictor of major osteoporotic fractures (Hip, spine wrist, shoulder) compared to aBMD, except at the spine. Subsequently, in the same cohort of older men, we found that low appendicular lean mass was positively associated with central and peripheral bone skeletal size, density and strength parameters that have been previously related to fractures. On the other hand, grip strength was only associated with site specific radial strength and geometric parameters. There was no association between leg power and the skeletal size, density and strength of older men after adjusting for appendicular lean mass and grip strength. These findings highlight the more important role of the mechanical load of the muscles on bones, compared to the muscle strength and power. Finally, we were interested in examining whether sarcopenia with or without osteoporosis is associated with an increased risk of non-spine fractures. In this third paper, we demonstrated that men with both sarcopenia and low BMD are at a much higher risk for non-spine fractures compared to men with either one or neither condition. On the other hand, low BMD with or without sarcopenia in older women was associated with an increased risk of fractures, suggesting that low BMD is the driving force of non-spine fractures in older women. Future research should investigate further the crosstalk between muscle and bones. There are currently multiple sarcopenia definitions. Therefore, a consensus on the definition for sarcopenia should be reached, so that diagnostic and therapeutic tools can be developed. Furthermore, dual-energy X-ray absorptiometry (DXA) remains the gold standard diagnostic tool for fracture risk assessment

Association of Serum Klotho with Loss of Bone Mineral Density and Fracture Risk in Older Adults

ObjectivesKlotho deficiency has been previously linked to aging-like phenotypes such as osteoporosis, cognitive impairment, and sarcopenia. Low serum klotho was shown to be related to grip strength and disability. Nonetheless, no previous study has explored the association between serum klotho and fractures. The purpose of this report is to examine the relationship of serum klotho with bone mineral density (BMD) loss and fractures in older adults.DesignThe Health, Aging, and Body Composition (Health ABC) Study is a longitudinal cohort study of 3,075 community-dwelling older adults.SettingUS clinical centers.ParticipantsTwo thousand seven hundred and seventy six well-functioning black and white adults aged 70 to 79 years with serum klotho measurements were followed up for a median of 5 years.MeasurementsPercent annualized BMD change and fracture risk were compared across klotho quartiles. A Poisson distribution was used to calculate age-adjusted fracture incidence rates, and Cox proportional hazards models for multivariable-adjusted hazard ratios.ResultsThe annualized percent changes in hip, femoral neck, and vertebral BMD were similar across klotho quartiles. Participants experienced 507 nonspine fractures, 203 hip fractures, and 135 vertebral fractures. The Incidence rate (IR) of nonspine fractures was 17 per 1,000 person-years. The most frequent site was hip (IR = 6 per 1,000 person-years) and the IR of vertebral fractures was 3 per 1,000 person-years. There was no association between the lowest quartile of plasma klotho and nonspine (hazard ratio (HR) = 1.19, 95% confidence interval (CI) = 0.86-1.65), hip (HR = 1.34, 95% CI = 0.79-2.27), or vertebral fractures (HR = 1.17, 95% CI = 0.65-2.11).ConclusionAlthough klotho gene is a susceptible gene for reduced BMD, klotho blood concentration does not appear to be a predictor of bone loss or fracture risk in well-functioning older adults

Frailty and Risk of Cardiovascular Diseases in Older Persons: The Age, Gene/Environment Susceptibility-Reykjavik Study

Frailty is a risk factor for cardiovascular diseases (CVD), but the studies available have not considered the presence of subclinical atherosclerotic disease as potential confounders. We investigated the association between frailty and the onset of CVD independently of subclinical atherosclerotic disease. For this reason, a sample of 3818 older participants participating in the Age, Gene/Environment Susceptibility-Reykjavik Study without CVD at baseline was followed for a median of 8.7 years. Frailty was defined as the presence of 653 among five Fried's criteria (unintentional weight loss, low physical activity level, weakness, exhaustion, and slow gait speed). Incident CVD was defined as onset of coronary artery disease, heart failure, stroke, and CVD-related mortality identified using hospital, medical, and death records. Subclinical atherosclerotic disease was evaluated as the maximum value of carotid intima media thickness, presence of carotid plaque (moderate or high), and total coronary calcifications (CACs). At baseline, frail participants (n\u2009=\u2009300) were more frequently obese, diabetic, and had a greater presence of metabolic syndrome than the nonfrail (n\u2009=\u20093518). Frail participants also showed a higher presence of carotid plaques and CACs. Using a Cox's regression analysis, adjusted for clinical, biochemical, and subclinical atherosclerosis estimates, frailty increased the risk of CVD (hazard ratio [HR]\u2009=\u20091.35; 95% confidence interval [CI]: 1.05-1.74), with results stronger for women than men (HR\u2009=\u20091.51, p\u2009=\u20090.006 and 1.19, p\u2009=\u20090.44, respectively). Among Fried's criteria, exhaustion was the only criterion significantly associated with the onset of new CVD events (HR\u2009=\u20091.30; 95% CI: 1.00-1.73). In conclusion, frailty was associated with the onset of CVD in older people even after adjusting for subclinical atherosclerotic disease

Anchoring of a large set of markers onto a BAC library for the development of a draft physical map of the grapevine genome

International audienceFive hundred and six EST-derived markers, 313 SSR markers and 26 BAC end-derived or SCAR markers were anchored by PCR on a subset of a Cabernet Sauvignon BAC library representing six genome equivalents pooled in three dimensions. In parallel, the 12,351 EST clusters of the grapevine UniGene set (build #11) from NCBI were used to design 12,125 primers pairs and perform electronic PCR on 67,543 nonredundant BAC-end sequences. This in silico experiment yielded 1,140 positive results concerning 638 different markers, among which 602 had not been already anchored by PCR. The data obtained will provide an easier access to the regulatory sequences surrounding important genes (represented by ESTs). In total, 1,731 islands of BAC clones (set of overlapping BAC clones containing at least one common marker) were obtained and 226 of them contained at least one genetically mapped anchor. These assigned islands are very useful because they will link the genetic map and the future fingerprint-based physical map and because they allowed us to indirectly place 93 ESTs on the genetic map. The islands containing two or more mapped SSR markers were also used to assess the quality of the integrated genetic map of the grapevine genome

Associations of Quadriceps Torque Properties with Muscle Size, Attenuation, and Intramuscular Adipose Tissue in Older Adults

To access publisher's full text version of this article click on the hyperlink belowBACKGROUND: Atrophy and fatty infiltration of muscle with aging are associated with fractures and falls, however, their direct associations with muscle function are not well described. It was hypothesized that participants with lower quadriceps muscle attenuation, area, and greater intramuscular adipose tissue (IMAT) will exhibit slower rates of torque development (RTD) and lower peak knee extension torques. METHODS: Data from 4,842 participants (2,041 men, 2,801 women) from the Age Gene/Environment Susceptibility Reykjavik Study (mean age 76 ± 0.1 years) with complete thigh computed tomography and isometric knee testing. Regression models were adjusted for health, behavior, and comorbidities. Muscle attenuation was further adjusted for muscle area and IMAT; muscle area adjusted for IMAT and attenuation; and IMAT adjusted for muscle area and attenuation. Standardized betas (β) indicate association effect sizes. RESULTS: In the fully-adjusted models, attenuation (men β = 0.06, 95% CI: 0.01, 0.11; women β = 0.07, 95% CI: 0.03, 0.11) and muscle area (men β = 0.13, 95% CI: 0.07, 0.19; women β = 0.10, 95% CI: 0.06, 0.15) were associated with knee RTD. Attenuation (men β = 0.12, 95% CI: 0.08, 0.16; women β = 0.12, 95% CI: 0.09, 0.16) and muscle area (men β = 0.38, 95% CI: 0.33, 0.43; women β = 0.33, 95% CI: 0.29, 0.37) were associated with peak torque. CONCLUSIONS: These data suggest that muscle attenuation and area are independently associated with RTD and peak torque; and that area and attenuation demonstrate similar contributions to RTD.National Institutes of Health National Institute on Aging Intramural Research Program Hjartavernd (the Icelandic Heart Association) Althingi (the Icelandic Parliament