The high prevalence of falls and the enormous impact they have on the elderly population is a cause for concern. We aimed to develop a walking-monitor gait pattern (G-STRIDE) for older adults based on a 6-axis inertial measurement (IMU) with the application of pedestrian dead reckoning algorithms and tested its structural and clinical validity. A cross-sectional case–control study was conducted with 21 participants (11 fallers and 10 non-fallers). We measured gait using an IMU attached to the foot while participants walked around different grounds (indoor flooring, outdoor floor, asphalt, etc.). The G-STRIDE consisted of a portable inertial device that monitored the gait pattern and a mobile app for telematic clinical analysis. G-STRIDE made it possible to measure gait parameters under normal living conditions when walking without assessing the patient in the outpatient clinic. Moreover, we verified concurrent validity with convectional outcome measures using intraclass correlation coefficients (ICCs) and analyzed the differences between participants. G-STRIDE showed high estimation accuracy for the walking speed of the elderly and good concurrent validity compared to conventional measures (ICC = 0.69; p < 0.000). In conclusion, the developed inertial-based G-STRIDE can accurately classify older people with risk to fall with a significance as high as using traditional but more subjective clinical methods (gait speed, Timed Up and Go Test).

The mechanisms underlying the relationship between the vascular complications of diabetes and the glycaemic control are not well understood. We tested whether glycaemic control influences the functioning of the nitric oxide system in type 1 diabetic patients and the role for oxidative stress. The changes in the forearm blood flow after the infusion in the brachial artery of NG-monomethyl-l-arginine, methacholine, methacholine plus superoxide dismutase, and nitroprusside were evaluated using strain gauge plethysmography in 14 healthy subjects and 24 patients with type 1 diabetes (12 with HbA(1c) < 7.5%; 12 with HbA(1c) > or = 7.5%). After adjusting insulin treatment, the vascular studies were repeated in the initially poorly controlled patients (HbA(1c) > or = 7.5%). Compared with healthy people, impaired vascular responses to NG-monomethyl-l-arginine (P = 0.0001), methacholine (P = 0.007) and nitroprusside (P = 0.0015) were found in the patients with type 1 diabetes and a poor glycaemic control (HbA(1c) >/= 7.5%), but not in subjects with good control (HbA(1c) < 7.5%). Superoxide dismutase improved the responses to methacholine only in those patients with poor control (P = 0.0037). After the adjustment of the insulin treatment in poorly-controlled patients, the responses improved and the effect of superoxide dismutase disappeared only in the patients that achieved good control (n = 9), but not in those who remained poorly-controlled (n = 3). In patients with diabetes type 1, glycaemic control determines the functioning of the NO system by a reversible mechanism involving superoxide anions. This finding provides an explanation of the relationship between glycaemic control and vascular complications in diabetes.

Background Different methods have been proposed to study skeletal muscle mass in sarcopenia diagnosis, although all have inherent drawbacks. The aim of this study was to evaluate the utility of muscle ultrasound in muscle assessment by studying its correlation with dual-energy x-ray absorptiometry (DXA) and calf circumference (CC), cut-off values for ultrasound-based detection of low muscle mass, and the correlation with muscle performance. Methods Fifty-seven participants older than 70 years, underwent a muscle ultrasound study, DXA, calf circumference (CC) and functional assessment. Ultrasound measurements were taken in the femoral quadriceps (transverse plane) and in the medial gastrocnemius (transverse and longitudinal planes). Muscle function was assessed by gait speed, Short Physical Performance Battery (SPPB) and grip strength. Results Median age was 78.9 years (IQR 74.9–81.9), and 33 were women (57.9%). We found good correlation between muscle thickness of gastrocnemius muscle in transverse and longitudinal plane and appendicular lean mass measured by DXA (r=0.546 and r=0.689 respectively) and good correlations between muscle thickness of gastrocnemius in transverse and longitudinal plane with CC (r=0.651 and r=0.447 respectively). The thickness of gastrocnemius medialis optimal cut-off points for low muscle mass were 18,5mm in the transverse plane (Sensitivity: 77,8%, Specificity: 77,1%), and 17.3mm in the longitudinal plane (Sensitivity: 100%, Specificity: 68.8%). Muscle thickness was also significantly correlated with gait speed, SPPB and grip strength. Conclusions Measures of gastrocnemius medialis thickness obtained by ultrasound are reliable and correlate well with DXA and CC values and muscle performance.