Distal radius and tibia bone microarchitecture impairment in female patients with diffuse systemic sclerosis.

Radius and tibia bone microarchitecture, analyzed through a high-resolution peripheral quantitative computed tomography, were significantly impaired in female patients with diffuse systemic sclerosis compared with healthy controls. Acroosteolysis, quality of life-grip strength, hand disability, and disease duration were significantly associated with this bone deterioration. INTRODUCTION: The effect of diffuse systemic sclerosis (dSSc) on the bone is not completely understood. The objective of this study was to analyze the volumetric bone mineral density (vBMD), microarchitecture, and biomechanical parameters at the distal radius and tibia using high-resolution peripheral quantitative computed tomography (HR-pQCT, XtremeCT) in female patients with dSSc and identify clinical and laboratory variables associated with these parameters. METHODS: Thirty-eight women with dSSc and 76 healthy controls were submitted to HR-pQCT at the distal radius and tibia. Clinical and laboratory findings, bone mineral density(BMD), nailfold capillaroscopy (NC), total passive range of motion(ROM), and quality of life (health assessment questionnaire-HAQ) were associated with HR-pQCT (Scanco Medical AG, Brüttisellen, Switzerland) parameters. Multiple linear regression models adjusted for clinical and laboratory variables, ROM and HAQ, were performed. RESULTS: Density, microarchitecture, and biomechanical parameters at the distal radius and tibia were significantly impaired in dSSc patients compared with healthy controls (p < 0.001). Multiple linear regression models showed that lower trabecular density (Tb.vBMD) (radius R2 = 0.561, p = 0.002; and tibia R2 = 0.533, p = 0.005), and lower trabecular number (Tb.N) (tibia R2 = 0.533, p = 0.005) were significantly associated with acroosteolysis. Higher trabecular separation (Tb.Sp) was associated with disease duration and higher HAQ-grip strength (radius R2 = 0.489, p = 0.013), while cortical density (Ct.vBMD) was associated with ROM (radius R2 = 0.294, p = 0.002). CONCLUSION: Bone microarchitecture in patients with dSSc, analyzed through HR-pQCT, showed impairment of trabecular and cortical bone at distal radius and tibia. Variables associated with hand involvement (acroosteolysis, quality of life-grip strength, and ROM) and disease duration may be considered prognostic factors of this bone impairment.

Effect of swimming session duration and repetition on metabolic markers in rats.

The aim of this study was to investigate the profile of metabolites in male rats subjected to 50-60 min of swimming on three protocols: group A, a single 50 min swimming session; group B, one session a day for three days (5 min on day 1, 15 min on day 2 and 30 min on day 3); and group C, one session a day for 5 days, with increasing duration from 5 min on day 1, 15, 30, 45 and 60 min on consecutive days. The interval between sessions was 24 h. Measurements were made after the last swimming session. Controls did not swim. The glycogen content of liver and gastrocnemius and soleus muscle was depleted in the three groups that swam, but blood glucose concentration was significantly increased only in group B. Serum lactate concentrations were greater than the controls in groups A and B. There were significant increases in serum free fatty acid concentrations in all groups that swam. The increases in plasma free fatty acids may have resulted from lipolysis stimulated by endogenous catecholamines in groups A and C, since basal lipolysis measured in vitro was unchanged by swimming. The large increase in basal lipolysis in group B may have contributed to the rise in plasma free fatty acids. Adipocytes from rats in groups A and B were supersensitive to epinephrine, whereas those from group C were not. We conclude that the metabolic alterations were less pronounced after the last of five swimming sessions over 5 days than after a single session, even though session duration and the contribution of the physical component were similar. Glucose mobilization, but probably not utilization, was similar in the three groups that swam. The mechanisms of lipid mobilization from adipose tissue differed, depending on the stress paradigm. The metabolic changes in groups A and B indicated that three daily swimming sessions were insufficient to cause adaptation. The results contrast with previous findings for foot-shock stress, which leads to sensitization rather than adaptation in response to repeated stimuli.