Balance impairment in kidney transplant recipients without concurrent peripheral neuropathy.

Kidney transplant recipients (KTRs) present with compromised functional capacity, low levels of physical activity, muscle atrophy, and peripheral nerve dysfunction that may result in high postural instability. This study aimed to compare the static balance control of 19 KTRs with 19 healthy adults (HA). All participants completed the Romberg test on a stabilometric platform with eyes open (EO), eyes closed (EC) and during a dual task (DT) condition. Centre of pressure (COP) measures (COP velocity (COPv) and sway area (SA)), as well as position-based outcomes such as anterior-posterior (AP) and medio-lateral (ML) ranges of COP displacements were recorded. Independent ANCOVA revealed an overall lower performance of KTRs compared to HA (p<0.05) with the EC condition exhibiting the worst relative performance for KTRs, suggesting a poorer capacity of relying on proprioceptive information when maintaining the upright posture. The addition of a cognitive task did not further worsen balance performance in KTRs. As impaired postural control is one of the main predictors of falls in elderly subjects, these data might also indicate that this constitutes an equivalent risk factor for falling in middle-aged KTRs.

Cdc2-like kinase 2 in the hypothalamus is necessary to maintain energy homeostasis.

OBJECTIVE: To investigate whether the Cdc2-like kinase 2 (CLK2) is expressed in hypothalamic neurons and if it is, whether the hypothalamic CLK2 has a role in the regulation of energy balance. SUBJECTS: Swiss mice on chow or high-fat diet (HFD) and db/db mice on chow diet were used to address the role of CLK2 in the hypothalamus. RESULTS: Hypothalamic CLK2Thr343 phosphorylation, which induces CLK2 activity, is regulated in vivo by refeeding, insulin and leptin, in a PI3K (phosphoinositide 3-kinase)-dependent manner. The reduction of CLK2 expression in the hypothalamus, by chronic pharmacological inhibition with TG003 or by chronic knockdown with small interfering RNA was sufficient to abolish the anorexigenic effect of insulin and leptin, to increase body weight, fat mass, food intake and to decrease energy expenditure in mice on chow. In contrast, CLK2Thr343 phosphorylation in the hypothalamus in response to insulin, leptin or refeeding was impaired in mice on HFD or in db/db mice. Chronic CLK2 inhibition in the hypothalamus was associated with a slight increase in the fasting blood glucose levels, reduction in PEPCK (phosphoenolpyruvate carboxykinase) expression in the liver and enhanced glucose production from pyruvate, suggesting a regulation of hepatic glucose production. Further, overexpressing CLK2 in the mediobasal hypothalami of mice on HFD or in db/db mice by adenovirus partially reversed the obese phenotype. CONCLUSIONS: Thus, our results suggest that protein CLK2 integrates some important hypothalamic pathways, and may be a promising molecule for new therapeutic approaches for obesity and diabetes.

Pioglitazone treatment increases food intake and decreases energy expenditure partially via hypothalamic adiponectin/adipoR1/AMPK pathway.

INTRODUCTION: Thiazolidinediones (TZDs) enhanced body weight (BW) partially by increased adipogenesis and hyperphagia. Neuronal PPARγ knockout mice on high-fat diet (HFD) are leaner because of enhanced leptin response, although it could be secondary to their leanness. Thus, it still is an open question how TZDs may alter energy balance. Multiple factors regulate food intake (FI) and energy expenditure (EE), including anorexigenic hormones as insulin and leptin. Nonetheless, elevated hypothalamic AMPK activity increases FI and TZDs increase AMPK activity in muscle cells. Thus, the aim of the present study was to investigate whether Pioglitazone (PIO) treatment alters hypothalamic insulin and leptin action/signaling, AMPK phosphorylation, and whether these alterations may be implicated in the regulation of FI and EE. METHODS: Swiss mice on HFD (2 months) received PIO (25 mg kg(-1) per day-gavage) or vehicle for 14 days. AMPK and AdipoR1 were inhibited via Intracerebroventricular injections using Compound C (CompC) and small interference RNA (siRNA), respectively. Western blot, real-time PCR and CLAMS were done. RESULTS: PIO treatment increased BW, adiposity, FI, NPY mRNA and decreased POMC mRNA expression and EE in HFD mice. Despite higher adiposity, PIO treatment improved insulin sensitivity, glucose tolerance, decreased insulin and increased adiponectin serum levels. This result was associated with, improved insulin and leptin action/signaling, decreased α2AMPK(Ser491) phosphorylation and elevated Acetyl-CoA carboxylase and AMPK(Thr172) phosphorylation in hypothalamus. The inhibition of hypothalamic AMPK with CompC was associated with decreased adiposity, FI, NPY mRNA and EE in PIO-treated mice. The reduced expression of hypothalamic AdipoR1 with siRNA concomitantly with PIO treatment reverted PIO induced obesity development, suggesting that adiponectin may be involved in this effect. CONCLUSIONS: These results demonstrated that PIO, despite improving insulin/leptin action in hypothalamus, increases FI and decreases EE, partially, by activating hypothalamic adiponectin/AdipoR1/AMPK axis. Suggesting a novel mechanism in the hypothalamus by which TZDs increase BW.

Effects of a Pilates exercise program on muscle strength, postural control and body composition: results from a pilot study in a group of post-menopausal women.

Participation in exercise programs is heartily recommended for older adults since the level of physical fitness directly influences functional independence. The aim of this present study was to investigate the effects of supervised Pilates exercise training on the physical function, hypothesizing that a period of Pilates exercise training (PET) can increase overall muscle strength, body composition, and balance, during single and dual-task conditions, in a group of post-menopausal women. Twenty-five subjects, aged 59 to 66 years old, were recruited. Eligible participants were assessed prior and after 3 months of PET performed twice per week. Muscular strength was evaluated with handgrip strength (HGS) test, 30-s chair sit-to-stand test (30CST), and abdominal strength (AST) test. Postural control and dual-task performance were measured through a stabilometric platform while dynamic balance with 8 ft up and go test. Finally, body composition was assessed by means of dual-energy X-ray absorptiometry. Statistically significant improvements were detected on HGS (+8.22%), 30CST (+23.41%), 8 ft up and go test (-5.95%), AST (+30.81%), medio-lateral oscillations in open eyes and dual-task condition (-22.03% and -10.37%). Pilates was effective in increasing upper body, lower body, and abdominal muscle strength. No changes on body composition were detected. Results on this investigation indicated also that 12-week of mat Pilates is not sufficient to determine a clinical meaningful improvement on static balance in single and dual-task conditions.