Clinical usefulness of phase angle as an indicator of muscle wasting and malnutrition in inpatients with cardiovascular diseases.

Background and Objectives: Extracellular water is increased in patients with edema, such as those with chronic heart failure, and it is difficult to assess skeletal muscle mass with the skeletal muscle mass index when extracellular water is high. We investigated the relationship between phase angle and physical function, nutritional indices, and sarcopenia in patients with cardiovascular diseases, including chronic heart failure. Methods and Study Design: In 590 patients with cardiovascular diseases (372 men), handgrip strength, gait speed, and anterior mid-thigh muscle thickness by ultrasound were measured, and the skeletal muscle mass index, phase angle, and the extracellular water: total body water ratio were measured with a bioelectrical impedance analyzer, and presence of sarcopenia was evaluated. Results: Phase angle, but not the skeletal muscle mass index, was correlated with serum albumin (r = 0.377, p < 0.001) and hemoglobin values in women. Multivariate regression analysis showed that at the extracellular water: total body water ratio below 0.4, both phase angle and skeletal muscle mass index were independent determinants of handgrip strength and log mid-thigh muscle thickness in men, after adjustment for age and presence of chronic heart failure. In contrast, for the ratio of 0.4 or greater, after adjustment for age and presence of chronic heart failure, phase angle was a stronger independent determinant of handgrip strength and log mid-thigh muscle thickness than the skeletal muscle mass index in men. Conclusions: Phase angle is a good marker of muscle wasting and malnutrition in patients with cardiovascular disease, including chronic heart failure.

Type I diabetes suppresses intracellular calcium ion increase normally evoked by heat stress in rat skeletal muscle.

Heat stress, via its effects on muscle intracellular Ca2+ concentrations ([Ca2+]i), has been invoked as a putative therapeutic countermeasure to type 1 diabetes-induced muscle atrophy. Using a circulation- and neurally intact in vivo muscle preparation, we tested the hypothesis that impaired muscle Ca2+ homeostasis in type 1 diabetic rats is due to attenuated heat stress tolerance mediated via transient receptor potential vanilloid 1 (TRPV1). Male Wistar rats were randomly assigned to one of the following four groups: 1) healthy control 30°C (CONT 30°C); 2) CONT 40°C; 3) diabetes 30°C (DIA 30°C); and 4) DIA 40°C. The temperature of 40°C was selected because it exceeds the TRPV1 activation threshold. Spinotrapezius muscles of Wistar rats were exteriorized in vivo and loaded with the fluorescent Ca2+ probe Fura-2 AM. [Ca2+]i was estimated over 20 min using fluorescence microscopy (340/380 nm ratio) in quiescent muscle held at the required temperature, using a calibrated heat source applied to the ventral muscle surface. Western blotting was performed to determine the protein expression levels of TRPV1 in spinotrapezius muscle. After 20 min of heat stress, the CONT 40°C condition induced a 12.3 ± 5% [Ca2+]i (P < 0.05) elevation that was markedly absent in the DIA 40°C or other conditions. Thus, no significant differences were found among DIA 40°C, DIA 30°C, and CONT 30°C. TRPV1 protein expression was decreased by 42.0 ± 9% in DIA compared with CONT (P < 0.05) and, unlike CONT, heat stress did not increase TRPV1 phosphorylation. In conclusion, diabetes suppresses TRPV1 protein expression and function and inhibits the elevated myocyte [Ca2+]i evoked normally by heat stress. These results suggest that capsaicin or other therapeutic strategies to increase Ca2+ accumulation via TRPV1 might be more effective than hyperthermic therapy for type 1 diabetic patients.

Effects of switching from clopidogrel to prasugrel at the chronic phase after coronary stenting on antiplatelet action and vascular endothelial function: Switch-Pras study.

Compared to clopidogrel, prasugrel has a lower incidence of ischemic events following percutaneous coronary intervention (PCI) because of an early reduction during the acute phase in P2Y12 reaction units (PRU). The objective of this study was to compare the antiplatelet effect and vascular endothelial function of both drugs during the chronic phase after PCI. Patients who had undergone PCI and were confirmed to have no restenosis by follow-up coronary angiography under dual anti-platelet therapy with clopidogrel (75 mg/day) and aspirin (100 mg/day) were randomized to either continue clopidogrel or switch to prasugrel (3.75 mg/day). At baseline, prior to randomization we determined the CYP2C19 genotype. At the baseline and 24 weeks after randomization, the P2Y12 reactivity unit (PRU) was measured using the VerifyNow™ P2Y12 assay. Endothelial function was evaluated by flow-mediated vasodilation (FMD) and reactive hyperemia peripheral arterial tonometry (RH-PAT), while and circulating CD34+/CD133+/CD45low progenitor cells were measured by flow cytometric analysis. Serum high-sensitivity C-reactive protein (hsCRP) level was also measured. The PRU was reduced significantly in the prasugrel group (P = 0.0008), especially in patients who were intermediate or poor metabolizers based on the CYP2C19 genotype (P < 0.0001). This reduction was not observed in the clopidogrel group. The number of CD34+/CD133+/CD45low cells increased in the clopidogrel group (P = 0.008), but not in the prasugrel group. The hsCRP, FMD and reactive hyperemia index measured by RH-PAT did not change in either group. Prasugrel is potentially better than clopidogrel for preventing thrombotic events, although clopidogrel may have an advantage over prasugrel in terms of preventing atherosclerotic events. Proper use of thienopyridine drugs based on the CYP2C19 genotype has promising clinical potential.

Vascular Endothelial Dysfunction and Autonomic Nervous Hyperactivity among Premenopausal Women with Cold-Sensitivity Constitution (Hiesho).

The cold-sensitivity constitution (CSC), termed "Hiesho" in Japanese, is a woman-specific cold sense of peripheral sites. The etiology of and criteria for CSC are not yet well established. We defined CSC as temperature gradient > 6˚C between body surface and core, and investigated the autonomic nervous activity by measuring heart rate variability and the vascular endothelial function by determining reactive hyperemia index (RHI) in 43 healthy premenopausal women, aged 18-47 years. Twenty five women had CSC during both the follicular and luteal phases of their menstrual cycles (sustained-CSC group), 8 women did not show CSC during both phases (non-CSC group), and the remaining 10 women showed CSC in either menstrual phase (occasional CSC). To identify the pathophysiological bases of CSC, we compared the sympathetic nervous activity and vascular endothelial function between sustained-CSC and non-CSC. We thus found that sympathetic nervous activity was higher among the sustained-CSC group (p = 0.042) during the follicular phase, compared with the non-CSC group, while the RHI was similar in both groups. Furthermore, the sympathetic nervous activity was similar between the sustained-CSC women aged ≥ 40 years (n = 10) and those aged < 40 years (n = 15) during either menstrual phase, whereas the RHI of the women aged < 40 years was lower during the follicular phase (p = 0.045), compared with the women aged ≥ 40 years. In conclusion, CSC is associated with sympathetic nervous hyperactivity in premenopausal women, and vascular endothelial dysfunction is also involved in CSC among younger women.

Is blood flow-restricted training effective for rehabilitation of a pianist with residual neurological symptoms in the upper limbs? A case study.

[Purpose] We investigated whether blood flow-restricted training known as KAATSU training, was effective for rehabilitation of a pianist with residual neurological symptoms in the upper limbs. [Participant and Methods] A pianist with residual neurological symptoms in the upper body played "Revolutionary Etude" under two conditions: piano performance with (Piano-blood flow-restricted) and without (Piano-control) the restriction of blood flow to the upper limbs. In the Piano-blood flow-restricted exercise, a pressure of 130-170 mmHg was applied around the most proximal portion of both arms. The changes in upper limb circumference and muscle strength were measured before, immediately after, and 15 min after the performance. The impression of the piano performance was recorded after the Piano-blood flow-restricted exercise. [Results] Immediately after the piano performance, the forearm and upper arm circumferences had increased significantly in both arms, and the change was greater in the Piano-blood flow-restricted than in the Piano-control condition. The handgrip strength for the right arm also showed greater changes in the former than the latter. However, there were no significant differences between the two conditions regarding the handgrip strength of the left arm. [Conclusion] There is a high possibility that blood flow-restricted training is effective for rehabilitation of the pianist with residual neurological symptoms in the upper limbs.

Flow-Mediated Vasodilation and Reactive Hyperemia Index in Heart Failure with Reduced or Preserved Ejection Fraction.

Vascular endothelial dysfunction is part of the underlying pathophysiology of heart failure. However, there are no reports in which vascular endothelial function of both conduit arteries and microvasculature was assessed in patients with heart failure. This study was aimed to assess vascular endothelial function separately in heart failure with reduced (HFrEF) and preserved ejection fraction (HFpEF). We performed simultaneous measurement of both flow-mediated vasodilation for endothelial function of conduit arteries and reactive hyperemia-peripheral arterial tonometry for that of microvasculature in 88 consecutive patients with chronic heart failure. In 55 patients with ischemic heart disease as an underlying cause of heart failure, flow-mediated vasodilation value was comparable between the two groups of HFrEF (left ventricular ejection fraction < 50%, n = 31) and HFpEF (left ventricular ejection fraction ≥ 50%, n = 24). Reactive hyperemia index measured by reactive hyperemia peripheral arterial tonometry, however, was lower in HFrEF patients compared to HFpEF patients (P = 0.014). In contrast, among 33 patients with non-ischemic heart disease, the degree of flow-mediated vasodilation was lower in HFpEF patients (n = 18) compared with HFrEF patients (n = 15) (P = 0.009), while reactive hyperemia index was comparable between the two groups. The clinical and pathophysiological significance of endothelial function in heart failure differs between conduit artery and microvasculature, and these differences may contribute to the underlying pathophysiology of HFpEF and HFrEF, as well as in ischemic heart disease and non-ischemic heart disease.

Echocardiographic surrogates of right atrial pressure in pulmonary hypertension.

Right atrial pressure (RAP), a representative parameter of right heart failure, is very important for prognostic evaluation and risk assessment in pulmonary hypertension. However, its measurement requires invasive cardiac catheterization. In this study, we determined the most accurate echocardiographic surrogate of catheterization-based RAP. In 23 patients with pulmonary hypertension, a total of 66 cardiac catheterization procedures were performed along with 2-dimensional echocardiography. We evaluated tricuspid E/A, E', A' and E/E', and estimated RAP by the respirophasic variation of the inferior vena cava diameter (eRAP-IVCd) as possible surrogates of catheterization-based RAP. In simple linear regression analysis, E/A (R = 0.452, P = 0.0001) and eRAP-IVCd (R = 0.505, P < 0.0001) were positively correlated with catheterization-based RAP, whereas A' (R = - 0.512, P < 0.0001) was negatively correlated with RAP. In multiple regression analysis, A' was the most significant independent predictor of catheterization-based RAP (R = - 0.375, P = 0.0007). In 16 patients who had multiple measurements, there were a total of 43 measurements before and after medication changes. The absolute change in catheterization-based RAP was negatively correlated with the percent change in A'. Receiver operating characteristic curve analysis indicated that the optimal cut-off value of A' to predict a catheterization-based RAP > 10 mmHg was 11.3 cm/s (area under the curve = 0.782, sensitivity = 0.70, specificity = 0.78). In 20 measurements of 20 patients with left heart failure, catheterization-based RAP was not correlated with any of 5 echocardiographic parameters. However, it was closely correlated with catheterization-based pulmonary capillary wedge pressure. The echocardiographic parameter, A', was the best surrogate of catheterization-based RAP in patients with pulmonary hypertension.

Short physical performance battery for middle-aged and older adult cardiovascular disease patients: implication for strength tests and lower extremity morphological evaluation.

[Purpose] To examine if the SPPB is higher with healthy subjects than outpatients, which was higher than inpatients and if the SPPB can be validated assessment tool for strength tests and lower extremity morphological evaluation in cardiovascular disease patients. [Subjects and Methods] Twenty-four middle aged and older adults with cardiovascular disease were recruited from inpatient and outpatient facilities and assigned to separate experimental groups. Twelve age-matched healthy volunteers were assigned to a control group. SPPB test was used to assess balance and functional motilities. The test outcomes were compared with level of care (inpatient vs. outpatient), physical characteristics, strength and lower extremity morphology. [Results] Total SPPB scores, strength tests (knee extensor muscle strength), and lower extremity morphological evaluation (muscle thickness of anterior and posterior mid-thigh and posterior lower-leg) were greater in healthy subjects and outpatients groups compared with inpatients. To predict total Short Physical Performance Battery scores, the predicted knee extension and anterior mid-thigh muscle thickness were calculated. [Conclusion] The SPPB is an effective tool as the strength tests and lower extremity morphological evaluation for middle-aged and older adult cardiovascular disease patients. Notably, high knee extensor muscle strength and quadriceps femoris muscle thickness are positively associated with high SPPB scores.

Repetitive restriction of muscle blood flow enhances mTOR signaling pathways in a rat model.

Skeletal muscle is a plastic organ that adapts its mass to various stresses by affecting pathways that regulate protein synthesis and degradation. This study investigated the effects of repetitive restriction of muscle blood flow (RRMBF) on microvascular oxygen pressure (PmvO2), mammalian target of rapamycin (mTOR) signaling pathways, and transcripts associated with proteolysis in rat skeletal muscle. Eleven-week-old male Wistar rats under anesthesia underwent six RRMBF consisting of an external compressive force of 100 mmHg for 5 min applied to the proximal portion of the right thigh, each followed by 3 min rest. During RRMBF, PmvO2 was measured by phosphorescence quenching techniques. The total RNA and protein of the tibialis anterior muscle were obtained from control rats, and rats treated with RRMBF 0-6 h after the stimuli. The protein expression and phosphorylation of various signaling proteins were determined by western blotting. The mRNA expression level was measured by real-time RT-PCR analysis. The total muscle weight increased in rats 0 h after RRMBF, but not in rats 1-6 h. During RRMBF, PmvO2 significantly decreased (36.1 ± 5.7 to 5.9 ± 1.7 torr), and recovered at rest period. RRMBF significantly increased phosphorylation of p70 S6-kinase (p70S6k), a downstream target of mTOR, and ribosomal protein S6 1 h after the stimuli. The protein level of REDD1 and phosphorylation of AMPK and MAPKs did not change. The mRNA expression levels of FOXO3a, MuRF-1, and myostatin were not significantly altered. These results suggested that RRMBF significantly decreased PmvO2, and enhanced mTOR signaling pathways in skeletal muscle using a rat model, which may play a role in diminishing muscle atrophy under various conditions in human studies.

Effect of a cardiac rehabilitation program on exercise oscillatory ventilation in Japanese patients with heart failure.

Although exercise oscillatory ventilation has emerged as a potent independent risk factor for adverse prognosis in heart failure, it is not well known whether cardiac rehabilitation can improve oscillatory ventilation. In this study, we investigated the magnitude of oscillations in ventilation before and after cardiac rehabilitation in chronic heart failure patients with exercise oscillatory ventilation. Cardiac rehabilitation (5-month program) was performed in 26 patients with chronic heart failure who showed an oscillatory ventilation pattern during cardiopulmonary exercise testing (CPX). After the 5-month rehabilitation program was completed, the patients again underwent CPX. To determine the magnitude of oscillations in ventilation, the amplitude and cycle length of the oscillations were calculated and compared with several other parameters, including biomarkers that have established prognostic value in heart failure. At baseline before cardiac rehabilitation, both oscillation amplitude (R = 0.625, P < 0.01) and cycle length (R = 0.469, P < 0.05) were positively correlated with the slope of minute ventilation vs. carbon dioxide production. Plasma BNP levels were positively correlated with amplitude (R = 0.615, P < 0.01) but not cycle length (R = 0.371). Cardiac rehabilitation decreased oscillation amplitude (P < 0.01) but failed to change cycle length. The change in amplitude was positively correlated with the change in BNP levels (R = 0.760, P < 0.01). Multiple regression analysis showed that only the change in amplitude was an independent predictor of the change in BNP levels (R = 0.717, P < 0.01). A 5-month cardiac rehabilitation program improves exercise oscillatory ventilation in chronic heart failure patients by reducing the oscillation amplitude. This effect is associated with a reduction of plasma BNP levels, potentially contributing to an improvement of heart failure.

Diverse contribution of bone marrow-derived late-outgrowth endothelial progenitor cells to vascular repair under pulmonary arterial hypertension and arterial neointimal formation.

AIMS: It is still controversial whether bone marrow (BM)-derived endothelial progenitor cells (EPCs) can contribute to vascular repair and prevent the progression of vascular diseases. We aimed to characterize BM-derived EPC subpopulations and to evaluate their therapeutic efficacies to repair injured vascular endothelium of systemic and pulmonary arteries. METHODS AND RESULTS: BM mononuclear cells of Fisher-344 rats were cultured under endothelial cell-conditions. Early EPCs appeared on days 3-6. Late-outgrowth and very late-outgrowth EPCs (LOCs and VLOCs) were defined as cells forming cobblestone colonies on days 9-14 and 17-21, respectively. Among EPC subpopulations, LOCs showed the highest angiogenic capability with enhanced proliferation potential and secretion of proangiogenic proteins. To investigate the therapeutic effects of these EPCs, Fisher-344 rats underwent wire-mediated endovascular injury in femoral artery (FA) and were concurrently injected intraperitoneally with 60mg/kg monocrotaline (MCT). Injured rats were then treated with six injections of one of three EPCs (1×10(6) per time). After 4weeks, transplanted LOCs, but not early EPCs or VLOCs, significantly attenuated neointimal lesion formation in injured FAs. Some of CD31(+) LOCs directly replaced the injured FA endothelium (replacement ratio: 11.7±7.0%). In contrast, any EPC treatment could neither replace MCT-injured endothelium of pulmonary arterioles nor prevent the progression of pulmonary arterial hypertension (PAH). LOCs modified protectively the expression profile of angiogenic and inflammatory genes in injured FAs, but not in MCT-injured lungs. CONCLUSION: BM-derived LOCs can contribute to vascular repair of injured systemic artery; however, even they cannot rescue injured pulmonary vasculature under MCT-induced PAH.

Effect of low-load resistance exercise with and without blood flow restriction to volitional fatigue on muscle swelling.

PURPOSE: The effects on muscle swelling were compared between low-load resistance exercise to exhaustion with (BFR) and without blood flow restriction (NBFR). METHODS: Ten young men [aged 27 (SD 5) years, standing height 1.74 (SD 0.05) m, body mass 70.3 (SD 4.3) kg] performed 20 % of one repetition maximal dumbbell curl exercise to exhaustion (four sets, rest intervals were 30 s for BFR and/or 3 min for NBFR, respectively). One arm was randomly chosen for BFR exercise and the other arm performed NBFR exercise. During the BFR exercise session, an elastic cuff was worn proximally on the testing arm at 160 mmHg. Electromyography (EMG) signals were recorded from surface electrodes placed on the biceps brachii muscle and analyzed for integrated EMG (iEMG). Biceps brachii muscle thickness (MTH) was measured using B-mode ultrasound. RESULTS: The total number of exercise repetitions was greater (p < 0.01) in NBFR (221 ± 67 reps) than in BFR (111 ± 36 reps). During the exercise session, iEMG for biceps brachii muscles increased (p < 0.01) during BFR and NBFR (3.94 and 4.45 times of baseline value). Immediately after the exercise, MTH sharply increased (p < 0.01) with BFR and NBFR (1.21 and 1.20 times of baseline value). These results demonstrate that both BFR and NBFR exercises lead to pronounced muscle activation and muscle swelling. CONCLUSION: Low-load resistance exercise to exhaustion is an effective method for promoting muscle swelling regardless of BFR. Furthermore, our data indicate that the increase in muscle swelling for both NBFR and BFR is maintained even 60 min after the exercise.

Effects of methylglyoxal on human cardiac fibroblast: roles of transient receptor potential ankyrin 1 (TRPA1) channels.

Cardiac fibroblasts contribute to the pathogenesis of cardiac remodeling. Methylglyoxal (MG) is an endogenous carbonyl compound produced under hyperglycemic conditions, which may play a role in the development of pathophysiological conditions including diabetic cardiomyopathy. However, the mechanism by which this occurs and the molecular targets of MG are unclear. We investigated the effects of MG on Ca(2+) signals, its underlying mechanism, and cell cycle progression/cell differentiation in human cardiac fibroblasts. The conventional and quantitative real-time RT-PCR, Western blot, immunocytochemical analysis, and intracellular Ca(2+) concentration [Ca(2+)]i measurement were applied. Cell cycle progression was assessed using the fluorescence activated cell sorting. MG induced Ca(2+) entry concentration dependently. Ruthenium red (RR), a general cation channel blocker, and HC030031, a selective transient receptor potential ankyrin 1 (TRPA1) antagonist, inhibited MG-induced Ca(2+) entry. Treatment with aminoguanidine, a MG scavenger, also inhibited it. Allyl isothiocyanate, a selective TRPA1 agonist, increased Ca(2+) entry. The use of small interfering RNA to knock down TRPA1 reduced the MG-induced Ca(2+) entry as well as TRPA1 mRNA expression. The quantitative real-time RT-PCR analysis showed the prominent existence of TRPA1 mRNA. Expression of TRPA1 protein was confirmed by Western blotting and immunocytochemical analyses. MG promoted cell cycle progression from G0/G1 to S/G2/M, which was suppressed by HC030031 or RR. MG also enhanced α-smooth muscle actin expression. The present results suggest that methylglyoxal activates TRPA1 and promotes cell cycle progression and differentiation in human cardiac fibroblasts. MG might participate the development of pathophysiological conditions including diabetic cardiomyopathy via activation of TRPA1.

Developmental changes in the protective effect of exogenous brain-derived neurotrophic factor and neurotrophin-3 against ototoxic drugs in cultured rat vestibular ganglion neurons.

We examine developmental changes in the responsiveness of rat vestibular ganglion neurons (VGNs) to two neurotrophic factors (NTFs), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) and investigate the protective effects of these NTFs against ototoxic drugs during postnatal development in dissociated cultures. VGNs were obtained from rats on postnatal days (P) 1, 3, 7 and 14. BDNF facilitated neuronal survival as well as neurite sprouting of VGNs obtained from younger rats (P1 and P3), whereas these effects were not observed in older rats (P7 and P14). BDNF was also effective in facilitating neurite extension in VGNs at each of the postnatal ages. NT-3 also facilitated neuronal survival and neurite extension of VGNs from younger rats but these effects were significantly smaller than those of BDNF (p < 0.05). The protective effects of BDNF and NT-3 against ototoxic drugs, gentamicin and cisplatin, were also age-dependent: they were effective for neuronal survival, neurite sprouting and neurite extension in VGNs from younger rats, whereas these effects tended to disappear in VGNs from older rats. Analysis of the changes in the expression of the receptors of NTFs revealed that expression of TrkB and TrkC proteins and their mRNA did not change during the developmental period, whereas expression of p75(NTR) protein was down-regulated together with that of p75(NTR) mRNA during the developmental period. Developmental changes in the responsiveness to exogenous NTFs in VGNs, which is not caused by the changes of their receptors but probably caused by changes in the intracellular signaling pathways, should be taken into consideration in the prevention of neuronal degeneration caused by ototoxic drugs.

Effects of detraining after blood flow-restricted low-intensity training on muscle size and strength in older adults.

BACKGROUND: Although blood flow-restricted low-intensity resistance training (BFR-RT) increases muscle size and strength in older adults, the effect of detraining on muscle adaptation is unclear. METHODS: We investigated the effects of 24 weeks of detraining on thigh muscle cross-sectional area (CSA) and one-repetition maximum strength (1-RM) in older adults who had previously participated in 12 weeks of training (BFR-RT, 20-30 % 1-RM, knee extension and leg press) or non-BFR training. RESULTS: Both 1-RM and relative dynamic strengths (1-RM divided by quadriceps femoris (QF) muscle CSA) were higher at both post-training and detraining than at pre-training for the BFR-RT group (p < 0.05). QF muscle CSA was higher at only post-training than at pre-training for the BFR-RT group (p < 0.01). CONCLUSION: Increased muscle strength following 12 weeks of training with BFR-RT was well preserved at 24 weeks of detraining, which is due mainly to neural adaptation in older adults.

Pathophysiological roles of the serum acylcarnitine level and acylcarnitine/free carnitine ratio in patients with cardiovascular diseases.

Introduction: L-carnitine exerts protective effects, such as maintaining mitochondrial functions and decreasing reactive oxygen species, while acylcarnitine (AC) is linked to the development of heart failure and atherosclerosis. Hypothesis: Serum carnitines play important pathophysiological roles in cardiovascular diseases. Methods: Pre-operative biochemical data were obtained from 117 patients (71 men, average age 69.9 years) who underwent surgery for cardiovascular diseases. Measurements included pre-operative biochemical data including estimated glomerular filtration rate (eGFR), physical functions, skeletal muscle mass index (SMI) measured by bioelectrical impedance analysis, anterior thigh muscle thickness (MTh) measured by ultrasound, and routine echocardiography. Carnitine components were measured with the enzyme cycling method. Muscle wasting was diagnosed based on the Asian Working Group for Sarcopenia criteria. Results: Plasma brain natriuretic peptide (BNP) level was correlated with serum free carnitine (FC) and AC level, and the acylcarnitine/free carnitine ratio (AC/FC). AC/FC was elevated with stage of chronic kidney disease. In multivariate analysis, log (eGFR) and log (BNP) were extracted as independent factors to define log (serum AC) (eGFR: ß = 0.258, p = 0.008; BNP: ß = 0.273, p = 0.011), even if corrected for age, sex and body mass index. AC/FC was negatively correlated with hand-grip strength (r = -0.387, p = 0.006), SMI (r = -0.314, p = 0.012), and anterior thigh MTh (r = -0.340, p = 0.014) in men. Conclusions: A significant association between serum AC level and AC/FC, and chronic kidney disease and heart failure exists in patients with cardiovascular diseases who have undergone cardiovascular surgery. Skeletal muscle loss and muscle wasting are also linked to the elevation of serum AC level and AC/FC.

Physiological Role of Serum Growth Differentiation Factor-15 (GDF-15) Level and Iron Metabolism in Community-Dwelling Older Adults.

Background Anemia is common in older adults and, together with heart failure and chronic kidney disease, forms a vicious cycle, whereas diseases such as chronic inflammation and cancer are associated with the anemia of chronic disease (ACD). Researchers have linked growth differentiation factor-15 (GDF-15) to a variety of conditions such as cardiovascular disease, inflammation, cancer, and kidney disease, and have reported hepcidin as a biomarker for iron regulation in ACD. Therefore, anemia, GDF-15, and hepcidin have significance in aging physiology. Hypothesis GDF-15 and hepcidin play important physiological roles in community-dwelling older adults. This study sought to explore the relationship between these biomarkers and anemia, inflammation, or other health outcomes. Methods This was a prospective study of 73 community-dwelling older adults (six men and 67 women, mean age of 76.3 years). Their serum iron level, percentage transferrin saturation (TSAT), high-sensitivity C-reactive protein (hs-CRP), and estimated glomerular filtration rate (eGFR) were measured. Enzyme-linked immunosorbent assays were used to assess their serum GDF-15, ferritin, and hepcidin levels. The participants' grip strength and walking speed were measured. The skeletal muscle mass index (SMI) of each participant was determined by bioelectrical impedance analysis. Results The GDF-15 level was significantly inversely correlated with serum iron, ferritin, and hepcidin levels; percentage TSAT; the eGFR; and gait speed. Serum hepcidin was positively correlated with levels of ferritin, albumin, and hemoglobin. Handgrip strength, SMI, and hs-CRP were not correlated with either GDF-15 or hepcidin levels. After adjusting for age, sex, and body mass index (BMI), multivariate analysis identified the log GDF-15 and serum iron level (log GDF-15: ß=-0.248, iron: ß=0.296) as significant factors determining hemoglobin levels, whose findings have significance due to novel results. Multivariate analysis identified eGFR and levels of hemoglobin and hepcidin as significant factors associated with log GDF-15 (eGFR: ß=-0.406, hemoglobin: ß=-0.269, hepcidin: ß=-0.235). Similarly, ferritin and albumin levels were identified as significant factors associated with hepcidin levels (ferritin: ß=0.590, Alb: ß=0.277). Conclusions Anemia in community-dwelling older adults was determined not only by increasing serum iron levels but also by decreasing GDF-15 levels. Also, the increasing GDF-15 level was determined by a decreasing hepcidin level as well as the presence of anemia and renal dysfunction, and the decreasing hepcidin level was determined by decreasing stored iron and decreasing albumin levels. Serum GDF-15 and hepcidin could potentially inform diagnostic or treatment strategies for anemia or age-related health conditions.

Utility of growth differentiation factor-15 as a predictor of cardiovascular surgery outcomes: Current research and future directions.

In a world increasingly confronted by cardiovascular diseases (CVDs) and an aging population, accurate risk assessment prior to cardiac surgery is critical. Although effective, traditional risk calculators such as the Japan SCORE, Society of Thoracic Surgeons score, and EuroSCORE II may not completely capture contemporary risks, particularly due to emerging factors such as frailty and sarcopenia. These calculators often focus on regional and ethnic specificity and rely heavily on evaluations based on age and underlying diseases. Growth differentiation factor-15 (GDF-15) is a stress-responsive cytokine that has been identified as a potential biomarker for sarcopenia and a tool for future cardiac risk assessment. Preoperative plasma GDF-15 levels have been associated with preoperative, intraoperative, and postoperative factors and short- and long-term mortality rates in patients undergoing cardiac surgery. Increased plasma GDF-15 levels have prognostic significance, having been correlated with the use of cardiopulmonary bypass during surgery, amount of bleeding, postoperative acute kidney injury, and intensive care unit stay duration. Notably, the inclusion of preoperative levels of GDF-15 in risk stratification models enhances their predictive value, especially when compared with those of the N-terminal prohormone of brain natriuretic peptide, which does not lead to reclassification. Thus, this review examines traditional risk assessments for cardiac surgery and the role of the novel biomarker GDF-15. This study acknowledges that the relationship between patient outcomes and elevated GDF-15 levels is not limited to CVDs or cardiac surgery but can be associated with variable diseases, including diabetes and cancer. Moreover, the normal range of GDF-15 is not well defined. Given its promise for improving patient care and outcomes in cardiovascular surgery, future research should explore the potential of GDF-15 as a biomarker for postoperative outcomes and target therapeutic intervention.

CAN WE DIAGNOSE SARCOPENIA USING ANTERIOR FEMORAL MUSCLE THICKNESS IN PATIENTS WITH CARDIOVASCULAR DISEASE?

Objective: Making the diagnosis of sarcopenia is not always easy and this is especially true for those with cardiovascular disease. The purpose of this study is to investigate whether it is possible to diagnose sarcopenia by using ultrasound-guided measurements of anterior femoral muscle thickness. Methods: We investigated the utility of ultrasound-guided measurements of anterior femoral muscle thickness in 1075 hospitalized patients with cardiovascular disease (675 men). As a comparison, sarcopenia was assessed by skeletal muscle mass index using bioelectrical impedance analysis and the Asia Working Group for Sarcopenia criteria. Results: When the receiver operating characteristic curve using muscle thickness was examined, we found this could be used to make the diagnosis of sarcopenia (men: cutoff value 2.425 cm, area under the curve 0.796; women: cutoff value 1.995 cm, area under the curve 0.746). The prevalence of sarcopenia according to the criteria with skeletal muscle mass index was 34.2% in men and 51.8% in women, while its prevalence according to the cutoff value of muscle thickness was 29.2% in men and 36.7% in women. Conclusion: Ultrasound-guided measurement of the anterior femoral muscle thickness is a simple and useful method to help make the diagnosis of sarcopenia in patients with cardiovascular disease.