Assessment of Skeletal Muscle Mass in Older People: Comparison Between 2 Anthropometry-Based Methods and Dual-Energy X-ray Absorptiometry.

OBJECTIVES: Sarcopenia is a common geriatric syndrome, whose diagnosis implies the assessment of muscle mass. Dual-energy x-ray absorptiometry (DXA) is the reference method for clinical practice, but it is not universally available. We compared DXA with 2 anthropometry-based methods to assess muscle mass in older adults. DESIGN: Cross-sectional. SETTING: Ambulatory patients. PARTICIPANTS: 148 (87 female and 61 male) white older adults. MEASUREMENTS: Mid-arm muscle circumference (MAMC), whole skeletal muscle mass estimated by the Lee's formula (eTSMM), and relative skeletal muscle index (RSMI). RESULTS: Men and women did not differ for MAMC and RSMI, whereas eTSMM was higher (P < .001) in men. MAMC and eTSMM correlated with RSMI, in the whole sample as in men and women separately (P < .001). According to the McNemar test, the frequencies of older men and women with low muscle mass identified by eTSMM did not differ from those detected by RSMI (P = .066) at variance with MAMC. Using EWGSOP (European Working Group on Sarcopenia in Older People) criteria for RSMI as standard reference, the receiver operating characteristic (ROC) curves provided redefined cut-offs of reduced muscle mass: 18.6 cm in women and 22.3 cm in men for MAMC, and 17.7 kg in women and 28.3 kg in men for eTSMM. The areas under the ROC curves (AUCs) for MAMC were 0.882 in women (sensitivity 89%, specificity 84%) and 0.826 in men (sensitivity 94%, specificity 67%). The AUCs for eTSMM were 0.8913 in women (sensitivity 95%, specificity 81%) and 0.878 in men (sensitivity 97%, specificity 67%). No significant difference was found between the ROC curves of MAMC and eTSMM in both sexes. CONCLUSION: Two simple anthropometric methods, possibly used in every clinical setting, could be valuable screening tools for low muscle mass in older subjects.

Assessment of thoracic ultrasound in complementary diagnosis and in follow up of community-acquired pneumonia (cap).

BACKGROUND: Chest X-ray (CXR) is the primary diagnostic tool for community-acquired pneumonia (CAP). Some authors recently proposed that thoracic ultrasound (TUS) could valuably flank or even reliably substitute CXR in the diagnosis and follow-up of CAP. We investigated the clinical utility of TUS in a large sample of patients with CAP, to challenge the hypothesis that it may be a substitute for CXR. METHODS: Out of 645 consecutive patients with a CXR-confirmed CAP diagnosed in the emergency room of our hospital over a three-years period, 510 were subsequently admitted to our department of Internal Medicine. These patients were evaluated by TUS by a well-trained operator who was blinded of the initial diagnosis. TUS scans were performed both at admission and repeated at day 4-6th and 9-14th during stay. RESULTS: TUS identified 375/510 (73.5%) of CXR-confirmed lesions, mostly located in posterior-basal or mid-thoracic areas of the lungs. Pleural effusion was detected in 26.9% of patients by CXR and in 30.4% by TUS. TUS documented the change in size of the consolidated areas as follows: 6.3 ± 3.4 cm at time 0, 2.5 ± 1.8 at 4-6 d, 0.9 ± 1.4 at 9-14 d. Out of the 12 patients with delayed CAP healing, 7 of them turned out to have lung cancer. CONCLUSIONS: TUS allowed to detect lung consolidations in over 70% of patients with CXR-confirmed CAP, but it gave false negative results in 26.5% of cases. Our longitudinal results confirm the role of TUS in the follow-up of detectable lesions. Thus, TUS should be regarded as a complementary and monitoring tool in pneumonia, instead of a primary imaging modality.

Assessment of trabecular bone score (TBS) in overweight/obese men: effect of metabolic and anthropometric factors.

The "trabecular bone score" (TBS) indirectly explores bone quality, independently of bone mineral density (BMD). We investigated the effects of anthropometric and metabolic parameters on TBS in 87 overweight/obese men. We assessed BMD and TBS by DXA, and some parameters of glucose metabolism, sex-and calciotropic hormone levels. Regression models were adjusted for either age and BMI, or age and waist circumference, or age and waist/hip ratio, also considering BMI >35 (y/n) and metabolic syndrome (MS) (y/n). Correlations between TBS and parameters studied were higher when correcting for waist circumference, although not significant in subjects with BMI >35. The analysis of covariance showed that the same model always had a higher adjusted r-square index. BMD at lumbar spine and total hip, fasting glucose, bioavailable testosterone, and sex hormone-binding globulin are the only covariates having a significant effect (p < 0.05) on the variations of TBS. The presence of MS negatively affected only the association between TBS and BMD at total hip. We did not find any significant effect of BMI >35 on TBS values or significant interaction terms between each covariate and either BMI >35 or the presence of MS. Obesity negatively affected TBS, despite unchanged BMD. Alterations of glucose homeostasis and sex hormone levels seem to influence this relationship, while calciotropic hormones have no role. The effect of waist circumference on TBS is more pronounced than that of BMI.

Assessment of fracture risk by the FRAX algorithm in men and women with and without type 2 diabetes mellitus: a cross-sectional study.

BACKGROUND: The FRAX algorithm is a diffuse tool to assess fracture risk, but it has not been clinically applied in European patients with diabetes. We investigated FRAX-estimated fracture risk in patients with type 2 diabetes mellitus (DM), compared with concomitantly enrolled control subjects. METHODS: In our multicentric cross-sectional study, we assessed the FRAX scores of 974 DM and 777 control subjects from three Italian diabetes outpatient clinics, and in DM. We tested the association between parameters and complications of the disease and FRAX scores. RESULTS: DM had significantly lower FRAX-estimated probability of both major osteoporotic fracture (MOF) and hip fracture (HF) than control subjects (6.35 ± 5.07% versus 7.75 ± 6.93%, p < 0.001, and 2.17 ± 3.07% versus 2.91 ± 4.56%, p = 0.023, respectively). When grouping by gender, such differences were found only in men. In DM, the frequency of previous fracture was higher than in control subjects (29.88% versus 20.46%, p < 0.001). In diabetic patients, age, sex, body mass index, HbA1c and hypoglycaemia are significantly associated with FRAX scores; gender-specific regression models differed. Among DM, the tree-based regression (classification and regression tree (CART)) analysis identified groups of patients with different mean FRAX scores. In female DM aged > 65 years with or without obesity, MOF > 20% was found in 5.66% and 13.53% and H > 3% in 40.57% and 63.91% of patients, respectively. CONCLUSIONS: Patients with DM had mean FRAX scores lower than control subjects, despite the higher number of previous fractures. Some features and complications of DM did associate with FRAX scores. Among DM patients, the CART analysis identified subgroups with higher FRAX scores. However, despite its potential utility, concerns still remain for using FRAX in DM patients.

Evolutionary imprint of activation: the design principles of VSDs.

Voltage-sensor domains (VSDs) are modular biomolecular machines that transduce electrical signals in cells through a highly conserved activation mechanism. Here, we investigate sequence-function relationships in VSDs with approaches from information theory and probabilistic modeling. Specifically, we collect over 6,600 unique VSD sequences from diverse, long-diverged phylogenetic lineages and relate the statistical properties of this ensemble to functional constraints imposed by evolution. The VSD is a helical bundle with helices labeled S1-S4. Surrounding conserved VSD residues such as the countercharges and the S2 phenylalanine, we discover sparse networks of coevolving residues. Additional networks are found lining the VSD lumen, tuning the local hydrophilicity. Notably, state-dependent contacts and the absence of coevolution between S4 and the rest of the bundle are imprints of the activation mechanism on the VSD sequence ensemble. These design principles rationalize existing experimental results and generate testable hypotheses.

Impact of fractures on health care in a major university hospital in Rome.

BACKGROUND AND AIMS: The aim of the study was to investigate the impact of fractures (i.e., hip, Colles, humeral and vertebral fractures), compared with that of other common diseases requiring hospitalization, on health care in the main hospital in Rome (Italy). METHODS: Hospital discharge forms, filled in according to the 9th International Classification of Diseases, were examined from 1996 to 1999. Data on fractures were compared with those related to other diseases which occupy a considerable proportion of hospital operating time in Italy: coronary heart disease (CHD), cerebrovascular disorders (CVD), diabetes mellitus (DM), chronic obstructive pulmonary disease (COPD) and breast cancer (BC). RESULTS: In all groups of patients, the mean age of females was significantly higher (p<0.0001) than that of males. Male patients with hip fractures had hospital stays significantly longer than females (p<0.0001), whereas women with Colles fractures had significantly (p<0.02) longer stays. When patients were divided according to age (i.e., over or under 60 years), mean hospital stays did not differ between younger and older patients in all groups except Colles fractures (p<0.001). Hip fractures in older patients showed striking in-hospital mortality. Throughout the study period, hip fractures accounted for the highest overall and per-patient costs. The number of female patients with fractures (and, obviously, breast cancer) was higher, while the opposite applied to the other disorders. Male patients with fractures, CHD and CVD were significantly younger than females (p<0.0001). When the percentage of deaths was added to that of patients discharged to other institutions, fractures showed the poorest outcome of any hospitalization event. Per-patient costs were remarkably higher for CHD, followed by fractures. CONCLUSIONS: Fractures represent a growing but often underestimated burden for hospital care in Italy; further studies are needed on this issue.