Inflammatory biomarkers at different stages of Sarcopenia in older women.

In recent years, studies have found that Sarcopenia alters inflammatory biomarkers. However, the behavior of inflammatory biomarkers at different stages of Sarcopenia is not well understood. This study aimed to compare a broad panel of inflammatory biomarkers in older women at different stages of Sarcopenia. The study included 71 Brazilian community-dwelling older women. Muscle Strength was assessed by using handgrip strength (Jamar dynamometer). The Short Physical Performance Battery (SPPB) was performed to assess the physical performance, and body composition was assessed by DEXA. Sarcopenia was diagnosed and classified according to the EWGSOP2 criteria. Blood was drawn, and inflammatory biomarkers associated with Sarcopenia (IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, TNF, adiponectin, leptin, resistin, BDNF, sTNFr-1 and sTNFr-2) was analysed. After diagnosis and classification of sarcopenia, 45% of women did not present Sarcopenia (NS, N = 32), 23.9% were diagnosed with Sarcopenia Probable (SP, N = 17), 19,7% with Sarcopenia Confirmed (SC, N = 14), and 11.3% with Severe Sarcopenia (SS, N = 8). The analysis of inflammatory biomarkers revealed that the more advanced the stage of Sarcopenia, the higher the levels of BDNF, IL-8, sTNFr-1, and sTNFr-2. The assessment of BDNF, IL-8, sTNFr-1, and sTNFr-2 levels may be an adjuvant tool in diagnosis and severity classification of Sarcopenia in older Brazilian women.

Accuracy of handgrip and respiratory muscle strength in identifying sarcopenia in older, community-dwelling, Brazilian women.

Certain cut-off points for sarcopenia screening and diagnosis are arbitrary and based on European populations, with normative references often obtained from healthy young adults. Although respiratory skeletal muscle strength tests represent low-cost clinical measures commonly performed in clinical practice by health professionals, a gap remains regarding whether respiratory skeletal muscle strength tests are adequate and sensitive measures for sarcopenia screening. This study aimed to verify the value of handgrip and respiratory muscle strength as possible discriminators to identify sarcopenia and to establish cut-off points for sarcopenia screening in community-dwelling, Brazilian women. In a cross-sectional study, 154 community-dwelling, Brazilian women (65-96 years) were assessed for appendicular skeletal muscle mass, handgrip (HGS), and respiratory muscular strength, including maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP). The data were analyzed using the ROC curve and the Youden Index determined cut-off points. Statistical significance was set at 5%. 88 participants (57%) were sarcopenic. MEP (OR 0.98 [95%CI 0.97, 1.00], p = 0.023) and HGS (OR 0.82 [95% CI 0.75, 0.90], p < 0.001) were independent factors for sarcopenia in older. The optimal cut-off points for identifying sarcopenia were ≤ 77 cmH2O for MEP (AUC = 0.72), and ≤ 20 kg for HGS (AUC = 0.80). Simple muscular strength tests, including HGS and MEP, may be considered in the identification of sarcopenia in older, community-dwelling, Brazilian women. Future work is still needed to assess external validation of the proposed cut-offs before the clinical application.

Adiponectin Is a Contributing Factor of Low Appendicular Lean Mass in Older Community-Dwelling Women: A Cross-Sectional Study.

Inflammation is a chronic, sterile, low-grade inflammation that develops with advanced age in the absence of overt infection and may contribute to the pathophysiology of sarcopenia, a progressive and generalized skeletal muscle disorder. Furthermore, a series of biomarkers linked to sarcopenia occurrence have emerged. To aid diagnostic and treatment strategies for low muscle mass in sarcopenia and other related conditions, the objective of this work was to investigate potential biomarkers associated with appendicular lean mass in community-dwelling older women. This is a cross-sectional study with 71 older women (75 ± 7 years). Dual-energy X-ray absorptiometry was used to assess body composition. Plasmatic blood levels of adipokines (i.e., adiponectin, leptin, and resistin), tumor necrosis factor (TNF) and soluble receptors (sTNFr1 and sTNFr2), interferon (INF), brain-derived neurotrophic factor (BDNF), and interleukins (IL-2, IL-4, IL-5, IL-6, IL-8, and IL-10) were determined by enzyme-linked immunosorbent assay. Older women with low muscle mass showed higher plasma levels of adiponectin, sTNFr1, and IL-8 compared to the regular muscle mass group. In addition, higher adiponectin plasma levels explained 14% of the lower appendicular lean mass. High adiponectin plasmatic blood levels can contribute to lower appendicular lean mass in older, community-dwelling women.

Prior aerobic physical training modulates neuropeptide expression and central thermoregulation after ovariectomy in the rat.

This study compared the effects of aerobic physical training and estradiol (E2) replacement on central pathways involved with thermoregulation in ovariectomized rats. Rats were assigned to untrained ovariectomized treated with placebo (UN-OVX), untrained ovariectomized treated with E2 (E2-OVX), and trained ovariectomized (TR-OVX) groups. Tail skin temperature (TST), internal temperature (Tint), and basal oxygen consumption (VO2) were recorded. Neuronal activity, brain expression of Kiss1, NKB and Prodyn, and central norepinephrine (NE) levels were measured. UN-OVX had the highest TST. Compared to UN-OVX rats, TR-OVX and E2-OVX had lower Fos expression in the paraventricular and arcuate (ARC) nuclei, and lower double labeling for Tyrosine Hydroxylase and Fos in the brainstem. Compared to UN-OVX, only TR-OVX group exhibited lower kisspeptin (Kiss1), neurokinin B (NKB), and prodynorphin expression in the ARC and higher central NE levels. Aerobic physical training before menopause may prevent the heat dissipation imbalance induced by reduction of E2, through central NE release, modulation of Kiss1, NKB and prodynorphin expression in neurons from ARC nucleus.

The superior beneficial effects of exercise training versus hormone replacement therapy on skeletal muscle of ovariectomized rats.

Previous studies have highlighted the positive effects of Estradiol (E2) replacement therapy and physical exercise on skeletal muscle during menopause. However, the comparison effects of exercise training (ET) and estradiol replacement therapy during menopause on skeletal muscle have not been investigated to date. This study aimed to compare the effects of endurance exercise training versus E2 replacement therapy on mitochondrial density, redox status, and inflammatory biomarkers in the skeletal muscle of ovariectomized rats. Thirty female Wistar rats (12-week-old) were randomly assigned into three groups: Untrained ovariectomized rats (UN-OVX, n = 10); untrained ovariectomized rats treated with estradiol replacement therapy (E2-OVX); and, trained ovariectomized rats (TR-OVX). After ovariectomy, the E2-OVX rats were treated subcutaneously with E2 (implanted Silastic® capsule containing 360 µg of 17ß-estradiol/mL) while the TR-OVX group performed an exercise training protocol (50-70% of maximal running speed on a treadmill, 60 min/day, 5 days/week for 8 weeks). After euthanasia, the soleus muscle was processed for histological and biochemical evaluations. Only exercise prevented the reduction of maximal oxygen consumption and increased mechanical efficiency (ME). While mitochondrial muscle density, total antioxidant capacity (FRAP), catalase (CAT) activity, and interleukin 10 levels were higher in TR-OVX, only OVX-E2 presented higher CAT activity and lower interleukin 6 levels. Endurance exercise training compared with E2 replacement therapy maintains the aerobic capacity improving the ME of OVX rats. In addition, only endurance exercise training raises the skeletal muscle mitochondrial content and tends to balance the redox and inflammatory status in the skeletal muscle of OVX rats.

Does endurance training prior to ovariectomy protect against myocardial contractility dysfunction in rats?

BACKGROUND: Endurance training prevents cardiac dysfunction induced by menopause, but to date, no studies compared the effects of endurance training prior to menopause versus estrogen replacement therapy during menopause on heart function of rats. METHODS: Female Wistar rats aged three months were randomly assigned into three groups: Untrained ovariectomized rats (UN-OVX), untrained ovariectomized rats treated with estradiol (UN-OVX-E2), and ovariectomized rats previously exercised (EX-OVX). The endurance training protocol consisted of running on a treadmill at 60-70% of maximal aerobic capacity, 60 min per day, five days per week, for eight weeks. Estradiol replacement therapy consisted of silastic capsules containing the hormone for twelve days. After euthanasia, hearts were harvested, weighed and cardiac function was evaluated by the Langendorff technique. RESULTS: Both cardiac contractility and relaxation indexes improved similarly in the EX-OVX and UN-OVX-E2 rats compared to UN-OVX. CONCLUSION: Our findings reveal similar beneficial effects between endurance training previously to menopause and estradiol replacement therapy during menopause on cardiac function of rats.