Across aging, adipose tissue (AT) changes its quantity and distribution: AT becomes dysfunctional with an increase in production of inflammatory peptides, a decline of those with anti-inflammatory activity and infiltration of macrophages. Adipose organ dysfunction may lead to age-related metabolic alterations. Aging is characterized by an increase in adiposity and a decline in brown adipose tissue (BAT) depots and activity, and UCP1 expression. There are many possible links to age-associated involution of BAT, including the loss of mitochondrial function, impairment of the sympathetic nervous system, age-induced alteration of brown adipogenic stem/progenitor cell function and changes in endocrine signals. Aging is also associated with a reduction in beige adipocyte formation. Beige adipocytes are known to differentiate from a sub-population of progenitors resident in white adipose tissue (WAT); a defective ability of progenitor cells to proliferate and differentiate has been hypothesized with aging. The loss of beige adipocytes with age may be caused by changes in trophic factors in the adipose tissue microenvironment, which regulate progenitor cell proliferation and differentiation. This review focuses on possible mechanisms involved in the reduction of BAT and beige activity with aging, along with possible targets for age-related metabolic disease therapy.

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Objective: This study aimed to determine whether multiple weight cycles in adulthood are an independent predictor of lower muscle mass and reduced strength, with potential implication for sarcopenia in adults with obesity. Methods: A total of 60 males and 147 females with obesity were included, with a mean BMI of 37.9 ± 6.0 kg/m 2 and a mean age of 52.6 ± 12.4 years. Muscle strength was evaluated with handgrip and appendicular skeletal muscle mass was measured with dual-energy x-ray absorptiometry. Results: Participants were categorized into the following three groups: non-weight cyclers, mild weight cyclers, and severe weight cyclers. From a binary logistic regression that considered muscle mass categories as a dependent variable and weight cycling categories, age, and sex as independent variables, severe weight cyclers showed a 3.8-times increased risk of low muscle mass (95% CI: 1.42-10.01). Considering handgrip strength categories as a dependent variable and weight cycling categories, age, sex, and BMI as independent variables, severe weight cycling was associated with an increased risk of low muscle mass (about 6.3 times, 95% CI: 1.96-20.59). Severe weight cyclers showed a 5.2-times greater risk of developing sarcopenia. Conclusions: In adults with obesity, weight cycling is associated with lower muscle mass and strength and a greater likelihood of developing sarcopenic obesity.

Background The endothelium plays a key role in the maintenance of vascular health and represents a potential physiological target for dietary and other lifestyle interventions designed to reduce the risk of cardiovascular diseases (CVD) including stroke or coronary heart disease. Objective To conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) investigating the effects of the Mediterranean dietary pattern (MedDiet) on endothelial function. Methods Medline, Embase, and Scopus databases were searched from inception until January 2019 for studies that met the following criteria: 1) RCTs including adult participants, 2) interventions promoting the MedDiet, 3) inclusion of a control group, and 4) measurements of endothelial function. A random-effects meta-analysis was conducted. Metaregression and subgroup analyses were performed to identify whether effects were modified by health status (i.e., healthy participants versus participants with existing comorbidities), type of intervention (i.e., MedDiet alone or with a cointervention), study duration, study design (i.e., parallel or crossover), BMI, and age of participants. Results Fourteen articles reporting data for 1930 participants were included in the meta-analysis. Study duration ranged from 4 wk to 2.3 y. We observed a beneficial effect of the MedDiet on endothelial function [standardized mean difference (SMD): 0.35; 95% CI: 0.17, 0.53; P <0.001; I2 = 73.68%]. MedDiet interventions improved flow-mediated dilation (FMD)—the reference method for noninvasive, clinical measurement of endothelial function—by 1.66% (absolute change; 95% CI: 1.15, 2.17; P <0.001; I2 = 0%). Effects of the MedDiet on endothelial function were not modified by health status, type of intervention, study duration, study design, BMI, or age of participants (P >0.05). Conclusions MedDiet interventions improve endothelial function in adults, suggesting that the protective effects of the MedDiet are evident at early stages of the atherosclerotic process with important implications for the early prevention of CVD. This study has the PROSPERO registration number: CRD42018106188.