The current study does not confirm the recently reported usefulness of RTE in presurgical selection of nodules with indeterminate cytology and suggest the need for quantitative analytical assessment of nodule stiffness to improve RTE efficacy.
BACKGROUND:
Experimental evidence suggests a key role of SIRT1 (silent information regulator 1) in age- and metabolic-related vascular dysfunction. Whether these effects hold true in the human microvasculature is unknown. We aimed to investigate the SIRT1 role in very early stages of age- and obesity-related microvascular dysfunction in humans.
METHODS:
Ninety-five subjects undergoing elective laparoscopic surgery were recruited and stratified based on their body mass index status (above or below 30 kg/m
2
) and age (above or below 40 years) and in 4 groups: Young Nonobese, Young Obese, Old Nonobese, and Old Obese. we measured small resistance arteries’ endothelial function by pressurized micromyography before and after incubation with a SIRT1 agonist (SRT1720) and a mitochondria reactive oxygen species scavenger (MitoTEMPO). We assessed vascular levels of mitochondria ROS and nitric oxide availability by confocal microscopy and vascular gene expression of SIRT1 and mitochondrial proteins by qPCR. Chromatin immunoprecipitation assay was employed to investigate SIRT1-dependent epigenetic regulation of mitochondrial proteins.
RESULTS:
Compared with Young Nonobese, obese and older patients showed lower vascular expression of SIRT1 and antioxidant proteins (FOXO3 [forkhead box protein O3] and SOD2) and higher expression of pro-oxidant and aging mitochondria proteins p66
Shc
and Arginase II. Old Obese, Young Obese and Old Nonobese groups endothelial dysfunction was rescued by SRT1720. The restoration was comparable to the one obtained with mitoTEMPO. These effects were explained by SIRT1-dependent chromatin changes leading to reduced p66
Shc
expression and upregulation of proteins involved in mitochondria respiratory chain.
CONCLUSIONS:
SIRT1 is a novel central modulator of the earliest microvascular damage induced by age and obesity. Through a complex epigenetic control mainly involving p66
Shc
and Arginase II, it influences mitochondria ROS levels, NO availability, and the expression of proteins of the mitochondria respiratory chain. Therapeutic modulation of SIRT1 restores obesity- and age-related endothelial dysfunction. Early targeting of SIRT1 might represent a crucial strategy to prevent age- and obesity-related microvascular dysfunction.
OBJECTIVE:To compare and examine relationships between body image (BI), body composition and physical function in overweight and normal weight active older women. METHOD: We measured body mass (BM), body mass index (BMI), waist circumference (WAIST), grip strength (GS), lower limb muscle strength [LLMS], arm curl, balance, step-in-place test (SIPT), usual walk (WALK), fast walking (fastWALK), single chair stand (CHAIRtime) and repeated chair stand (CHAIRreps) in 398 overweight or obese women (67.2 ± 8.5 years; BMI > 27 kg•m 2 ) and 302 women with a BMI < 27 kg•m 2 (67.3 ± 8.5 years). Current (CBI) and ideal body image (IBI), and body dissatisfaction (DS; current -ideal) were determined by participant's responses to standardized silhouettes. RESULTS: Multiple regression analyses verified positive (CBI) and negative associations (DS) for balance in obese category. A positive association with WALK and fastWALK was observed for current (normal weight and obesity categories) and IBI (overweight). There were positive associations for SIPT, arm curl and CHAIRreps. CONCLUSION: Physically active older women showed an elevated prevalence of dissatisfaction regardless of BMI which was mediated by age, and associated with worsened physical function; similar associations were seen for current body image.
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