Endothelial cellular senescence is inhibited by liver X receptor activation with an additional mechanism for its atheroprotection in diabetes.

Senescence of vascular endothelial cells leads to endothelial dysfunction and contributes to the progression of atherosclerosis. Liver X receptors (LXRs) are nuclear receptors whose activation protects against atherosclerosis by transcriptional regulation of genes important in promoting cholesterol efflux and inhibiting inflammation. Here we found that LXR activation with specific ligands reduced the increase in senescence-associated (SA) ß-gal activity, a senescence marker, and reversed the decrease in telomerase activity, a replicative senescence marker, in human endothelial cells under high glucose. This effect of LXR activation was associated with reduced reactive oxygen species and increased endothelial NO synthase activity. A series of experiments that used siRNAs indicated that LXRß mediates the prevention of endothelial cellular senescence, and that sterol regulatory element binding protein-1, which was up-regulated as a direct LXRß target gene, may act as a brake of endothelial cellular senescence. Although oral administration of the LXR ligand led to severe fatty liver in diabetic rats, concomitant therapy with metformin avoided the development of hepatic steatosis. However, the preventive effect of the LXR ligand on SA ß-gal-stained cells in diabetic aortic endothelium was preserved even if metformin was coadministered. Taken together, our studies demonstrate that an additional mechanism, such as the regulation of endothelial cellular senescence, is related to the antiatherogenic properties of LXRs, and concomitant treatment with metformin may provide a clinically useful therapeutic strategy to alleviate an LXR activation-mediated adverse effects on liver triglyceride metabolism.

Oral supplementation with a combination of L-citrulline and L-arginine rapidly increases plasma L-arginine concentration and enhances NO bioavailability.

BACKGROUND: Chronic supplementation with L-citrulline plus L-arginine has been shown to exhibit anti-atherosclerotic effects. However, the short-term action of this combination on the nitric oxide (NO)-cGMP pathway remains to be elucidated. The objective of the present study was to investigate the acute effects of a combination of oral L-citrulline and L-arginine on plasma L-arginine and NO levels, as well as on blood circulation. METHODS: Rats or New Zealand white rabbits were treated orally with L-citrulline, or L-arginine, or a combination of each at half dosage. Following supplementation, plasma levels of L-arginine, NOx, cGMP and changes in blood circulation were determined sequentially. RESULTS: L-Citrulline plus L-arginine supplementation caused a more rapid increase in plasma L-arginine levels and marked enhancement of NO bioavailability, including plasma cGMP concentrations, than with dosage with the single amino acids. Blood flow in the central ear artery in rabbits was also significantly increased by L-citrulline plus L-arginine administration as compared with the control. CONCLUSION: Our data show for the first time that a combination of oral L-citrulline and L-arginine effectively and rapidly augments NO-dependent responses at the acute stage. This approach may have clinical utility for the regulation of cardiovascular function in humans.

Metabolic predictors of ischemic heart disease and cerebrovascular attack in elderly diabetic individuals: difference in risk by age.

BACKGROUND: High LDL-cholesterol (LDL-C) and glucose levels are risk factors for ischemic heart disease (IHD) in middle-aged diabetic individuals; however, the risk among the elderly, especially the very elderly, is not well known. The aim of this study was to identify factors that predict IHD and cerebrovascular attack (CVA) in the elderly and to investigate their differences by age. METHODS: We performed a prospective cohort study (Japan Cholesterol and Diabetes Mellitus Study) with 5.5 years of follow-up. A total of 4,014 patients with type 2 diabetes and without previous IHD or CVA (1,936 women; age 67.4 ± 9.5 years, median 70 years; <65 years old, n = 1,261; 65 to 74 years old, n = 1,731; and ≥ 75 years old, n = 1,016) were recruited on a consecutive outpatient basis from 40 hospitals throughout Japan. Lipids, glucose, and other factors related to IHD or CVA risk, such as blood pressure (BP), were investigated using the multivariate Cox hazard model. RESULTS: One hundred fifty-three cases of IHD and 104 CVAs (7.8 and 5.7/1,000 people per year, respectively) occurred over 5.5 years. Lower HDL-cholesterol (HDL-C) and female gender were correlated with IHD in patients ≥75 years old (hazard ratio (HR):0.629, P < 0.01 and 1.132, P < 0.05, respectively). In contrast, systolic BP (SBP), HbA1C, LDL-C and non-HDL-C were correlated with IHD in subjects <65 years old (P < 0.05), and the LDL-C/HDL-C ratio was correlated with IHD in all subjects. HDL-C was correlated with CVA in patients ≥75 years old (HR: 0.536, P < 0.01). Kaplan-Meier estimator curves showed that IHD occurred more frequently in patients <65 years old in the highest quartile of the LDL-C/HDL-C ratio. In patients ≥75 years old, IHD and CVA were both the most frequent among those with the lowest HDL-C levels. CONCLUSIONS: IHD and CVA in late elderly diabetic patients were predicted by HDL-C. LDL-C, HbA1C, SBP and non-HDL-C are risk factors for IHD in the non-elderly. The LDL-C/HDL-C ratio may represent the effects of both LDL-C and HDL-C. These age-dependent differences in risk are important for developing individualized strategies to prevent atherosclerotic disease. TRIAL REGISTRATION: UMIN-CTR, UMIN00000516.

Dose-dependent modulatory effects of insulin on glucose-induced endothelial senescence in vitro and in vivo: a relationship between telomeres and nitric oxide.

The elderly are prone to postprandial hyperglycemia that increases their cardiovascular risk. Although insulin therapy is necessary to treat diabetes, high plasma concentrations of insulin may cause the development of atherosclerosis and accelerate endothelial senescence. We assumed that high glucose causes stress-induced premature senescence and replicative senescence and examined the regulatory role of insulin in endothelial senescence and functions under different glucose conditions. Exposure of human endothelial cells to high glucose (22 mM) for 3 days increased senescence-associated-ß-galactosidase activity, a senescence marker, and decreased telomerase activity, a replicative senescence marker. Physiological concentrations of insulin preserved telomere length and delayed endothelial senescence under high-glucose conditions. The effect of insulin under high-glucose conditions was associated with reduced reactive oxygen species and increased nitric oxide (NO). Small interfering RNA targeting endothelial NO synthase reduced the antisenescence effects of insulin. Physiological concentrations of insulin also reversed high glucose-induced increases in p53 and vascular cell adhesion molecule-1 and decreases in senescence marker protein-30. On the other hand, when insulin was given at any concentrations under normal glucose or at high concentrations under high glucose, its ability to promote cellular senescence was unrelated to endothelial NO. Finally, streptozotocin-induced diabetes showed more senescent cells in the aortic endothelium of aged rats compared with age-matched control and insulin-treated animals. Conclusively, the regulatory effects of insulin on endothelial senescence were modulated by the glucose environment. These data may help explain insulin's complicated roles in atherosclerosis in the elderly.

Age, gender, insulin and blood glucose control status alter the risk of ischemic heart disease and stroke among elderly diabetic patients.

BACKGROUND: We analyzed the effects of insulin therapy, age and gender on the risk of ischemic heart disease (IHD) and cerebrovascular accident (CVA) according to glycemic control. METHODS AND RESULTS: We performed a prospective cohort study (Japan Cholesterol and Diabetes Mellitus Study) of type 2 diabetes patients (n = 4014) for 2 years. The primary endpoint was the onset of fatal/non-fatal IHD and/or CVA, which occurred at rates of 7.9 and 7.2 per 1000 person-years, respectively. We divided diabetic patients into four groups based on age (≤ 70 and > 70) and hemoglobin A1C levels (≤ 7.0 and > 7.0%). Multiple regression analysis revealed that IHD was associated with high systolic blood pressure and low HDL-C in patients under 70 years of age with fair glycemic control and was associated with low diastolic blood pressure in the older/fair group. Interestingly, insulin use was associated with IHD in the older/poor group (OR = 2.27, 95% CI = 1.11-5.89; p = 0.026) and was associated with CVA in the older/fair group (OR = 2.09, 95% CI = 1.06-4.25; p = 0.028). CVA was associated with lower HDL-C and longer duration of diabetes in younger/poor glycemic control group. Results by stepwise analysis were similar. Next, patients were divided into four groups based on gender and diabetic control(hemoglobinA1C < or > 7.0%). Multiple regression analysis revealed that IHD was associated with high systolic blood pressure in male/fair glycemic control group, age in male/poor control group, and short duration of diabetic history in females in both glycemic control groups. Interestingly, insulin use was associated with IHD in the male/poor group(OR = 4.11, 95% CI = 1.22-8.12; p = 0.018) and with CVA in the female/poor group(OR = 3.26, 95% CI = 1.12-6.24; p = 0.02). CVA was associated with short duration of diabetes in both female groups. CONCLUSIONS: IHD and CVA risks are affected by specific factors in diabetics, such as treatment, gender and age. Specifically, insulin use has a potential role in preventing IHD but may also be a risk factor for CVA among the diabetic elderly, thus revealing a need to develop improved treatment strategies for diabetes in elderly patients. The Japan Cholesterol and Diabetes Mellitus Study was formulated to evaluate them(Umin Clinical Trials Registry, clinical trial reg. no. UMIN00000516; http://www.umin.ac.jp/ctr/index.htm).

The effects of selective estrogen receptor modulator treatment following hormone replacement therapy on elderly postmenopausal women with osteoporosis.

OBJECTIVES: A comparison between the atheroprotective and osteoprotective effects of the selective estrogen receptor modulator (SERM) raloxifene and those of hormone replacement therapy (HRT) has not been made in elderly women. METHODS: A randomized prospective controlled trial was performed in a cohort of 32 elderly Japanese women with osteoporosis receiving HRT (estriol plus medroxyprogesterone) for more than 1 year. In 16 randomly selected subjects, HRT was changed to raloxifene therapy (60mg/day, 71.4±3.4 years, SERM group). The other 16 patients were continued on HRT (71.8±2.9 years, HRT group). As a control group, 14 subjects were enrolled, did not take any medications and were age-matched to experimental patients (72.5±3.3 years, control group). Plasma lipids, TNFα, adiponectin, NO metabolites (NOx:NO2(-) and NO3(-)), cyclicGMP and bone-mineral density (BMD) were evaluated at baseline and at 26 and 52 weeks after enrollment. RESULTS: SERM (Raloxifene) increased high-density-lipoprotein cholesterol levels and tended to decrease low-density-lipoprotein cholesterol levels (P=0.058) compared with baseline. Adiponectin, NOx and cGMP levels were significantly increased after 6 months compared with baseline or the HRT group. TNFα was decreased by raloxifene. In control subjects, no significant changes were observed in any of these markers. Bone-mineral density was higher at baseline in the raloxifene and HRT groups than in the control group, and BMD increased 12 months after baseline in the HRT and control group. CONCLUSION: SERM improved BMD and endothelial function in elderly postmenopausal women with osteoporosis who had received HRT, and these effects were comparable to or slightly stronger than those of HRT. Changes in adiponectin and TNFα may underlie the improvements in endothelial function, such as NO signaling.

Relationship between blood coagulability and sense of burden among caregivers of patients with dementia.

AIM: This study aimed to examine the relationship between blood coagulability and sense of burden among caregivers of patients with senile dementia of the Alzheimer type. METHODS: A cross-sectional study was carried out involving healthy older caregivers who lived with their patients with senile dementia of the Alzheimer type. We evaluated the Zarit Burden Interview score, levels of von Willebrand factor antigen, D-dimer, thrombin-antithrombin III complex, tissue plasminogen activator/plasminogen activator inhibitor type 1 complex, number of chronic diseases, body mass index and number of medications. A linear regression model was used to estimate adjusted associations. RESULTS: Thrombin-antithrombin III complex levels were higher in female caregivers than in male caregivers (P = 0.07). Headaches were significantly more frequent in female caregivers than in male caregivers, as assessed by a visual analog scale (P < 0.01). The number of chronic diseases and body mass index were positively associated with levels of tissue plasminogen activator/plasminogen activator inhibitor type 1 complex (P < 0.05). Similarly, the number of medications was positively associated with levels of D-dimer (P < 0.05). However, the Zarit Burden Interview score was not associated with blood coagulability (P > 0.05). CONCLUSIONS: The present study found that the number of chronic diseases and body mass index were associated with blood coagulability, and that female caregivers were more prone to headaches and higher blood coagulability than male caregivers. These findings highlight the essential nature of health management during caregiving. The impact of caregiver burden on blood coagulability is likely to differ depending on the long-term or short-term psychological stress associated with caregiving conditions. Geriatr Gerontol Int 2019; 19: 804-808.

Efficacy of HMG-CoA reductase inhibitors in the prevention of cerebrovascular attack in 1016 patients older than 75 years among 4014 type 2 diabetic individuals.

BACKGROUND/OBJECTIVES: HMG-CoA reductase inhibitors (statins) reduce ischemic heart disease (IHD) in middle-aged diabetic individuals, and LDL-cholesterol (LDL-C) is a risk factor. However, their preventive effects on cerebrovascular attack (CVA) have not been identified in elderly, especially in elderly ≥ 75 years (late elderly), who account for approximately 30% of diabetic individuals in Japan. Randomized controlled studies of statins for late elderly are difficult to carry out, because many co-morbidities in elderly disrupt randomized controlled conditions. METHODS: We performed a prospective cohort study (Japan Cholesterol and Diabetes Mellitus Study) with 5.5 years of follow-up since 2004. A total of 4014 type 2 diabetic patients without previous IHD or CVA (n=1936 women; age = 67.4 ± 9.5 years; ≥ 75 years: n = 1016) were enrolled, while 405 patients were registered as sub-cohort patients. We recorded detailed information on medications and laboratory data after every change in medication in patients of sub-cohort and suffered from IHD or CVA. We subdivided statin-users into prevalent, new and non-users. RESULTS: A total of 104 CVAs occurred during 5.5-years. Plasma HDL-C level was inversely correlated with CVA in patients ≥ 65 years. In case-control study, among patients who were not prescribed statins, CVA increased in age-dependent manner. CVA incidence was lower in prevalent and new statin-users than in non-users (hazard ratio [HR]:0.46, 0.523), especially in late elderly (HR: 0.51, 0.21). Statins reduced CVAs mainly due to a direct effect and partially due to the effects of HDL-C and glucose metabolism. No significant differences were observed between statins. CONCLUSION: Statins prevented CVA in middle-aged, elderly and late elderly diabetic patients via a direct effect. This study is the first to demonstrate the usefulness of observational studies for statistically analyzing agents' effects on late elderly.

Importance of high-density lipoprotein cholesterol levels in elderly diabetic individuals with type IIb dyslipidemia: A 2-year survey of cardiovascular events.

AIM: The risk factors for ischemic heart disease (IHD) or cerebrovascular accident (CVA) in elderly diabetic individuals with type IIb dyslipidemia are not fully known. Therefore, we investigated the relationship between lipid levels and IHD and CVA in diabetic individuals with type IIb dyslipidemia. METHOD: The Japan Cholesterol and Diabetes Mellitus Study is a prospective cohort study of 4014 type 2 diabetic patients (1936 women; age 67.4 ± 9.5 years). The primary end-points were the onset of IHD or CVA. Lipid and glucose levels, and other factors were investigated in relation to the occurrence of IHD or CVA. A total of 462 participants were included in the group of patients with type IIb dyslipidemia. RESULTS: The 462 diabetic participants with type IIb dyslipidemia were divided into those who were aged <65 years, 65-74 years and >75 years (n=168, 190 and 104, respectively). High-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol/HDL-C were significantly associated with the risk of cardiovascular events in diabetic individuals with type IIb dyslipidemia who were aged <65 years, and HDL-C and diastolic blood pressure was significantly associated with cardiovascular events in patients aged 65-74 years. Non-HDL-C was not significantly associated with the risk of cardiovascular events. Multiple regression analysis showed that lower HDL-C was significantly associated with the risk of cardiovascular events in diabetic individuals with type IIb dyslipidemia who were aged <65 years and 65-74 years. CONCLUSIONS: Lower HDL-C was an important risk factor for cardiovascular events in diabetic individuals with type IIb dyslipidemia who were aged <75 years.

Short-term effects of L-citrulline supplementation on arterial stiffness in middle-aged men.

BACKGROUND: Nitric oxide (NO) plays a key role in the maintenance of vascular tone, contributing to the functional regulation of arterial stiffness. Although oral L-citrulline could become the effective precursor of L-arginine (substrate for endothelial NO synthase) via the L-citrulline/ L-arginine pathway, little is known about the efficacy of L-citrulline application on arterial stiffness. OBJECTIVE: We examined the short-term effects of L-citrulline supplementation on arterial stiffness in humans. METHODS: In a double-blind, randomized, placebo-controlled parallel-group trial, 15 healthy male subjects (age: 58.3 ± 4.4 years) with brachial-ankle pulse wave velocity (baPWV; index of arterial stiffness >1400 cm/sec) were given 5.6g/day of L-citrulline (n=8) or placebo (n=7) for 7 days. baPWV and various clinical parameters were measured before (baseline) and after oral supplementation of L-citrulline or placebo. RESULTS: Compared with the placebo group, baPWV was significantly reduced in the L-citrulline group (p<0.01). No significant differences in blood pressure (BP) were found between the two groups, and no correlation was observed between BP and baPWV. The serum nitrogen oxide (NOx, the sum of nitrite plus nitrate) and NO metabolic products were significantly increased only in the L-citrulline group (p<0.05). Plasma citrulline, arginine and the ratio of arginine/asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase (arginine/ADMA ratio) were significantly increased in the L-citrulline group compared with the placebo group (p<0.05, p<0.01, p<0.05, respectively). Moreover, there was a correlation between the increase of plasma arginine and the reduction of baPWV (r=-0.553, p<0.05). CONCLUSION: These findings suggest that short-term L-citrulline supplementation may functionally improve arterial stiffness, independent of blood pressure, in humans.

The role of insulin growth factor on atherosclerosis and endothelial function: the effect on hyperlipidemia and aging.

AIMS: Insulin/insulin-like growth factor (IGF-1) signaling is important for a variety of age-related processes. However, whether or not it affects atherosclerosis is unknown. MAIN METHODS: Six groups of 6 male New Zealand white rabbits were treated for 12 weeks under the following conditions: Groups YC and YIGF: Young rabbits (10 weeks old) were fed regular chow w/wo IGF-1(Somazon 0.1 mg/kg/day, s.c.). Groups HC and HIGF: young rabbits were fed HCD (0.5% cholesterol plus regular chow) w/wo IGF-1. Groups OC and OIGF: old rabbits (120 weeks old) were fed regular chow w/wo IGF-1. KEY FINDINGS: Plasma lipid levels, endothelial responses and morphological findings did not differ between groups YIGF and YC. Animals in group HC had increased plasma lipid levels and atheromas. In group HIGF, IGF led to atheromas with increased plasma insulin growth factor binding protein 3 (IBP3), inducible nitric oxide synthase(iNOS) expression and nitrotyrosine staining, macrophage staining, SM1 staining and SM embryo staining compared to HC. Basal nitric oxide (NO) release evaluated by plasma NO metabolites (NOx) and cGMP levels were lowest in the HIGF group. SIGNIFICANCE: Overall, IGF-1 promoted atherosclerosis by affecting endothelial function and aging. These findings indicate that Insulin/IGF1 may contribute to atherogenesis in the elderly.

Depression, quality of life (QoL) and will to live of community-dwelling postmenopausal women in three Asian countries: Korea, China and Japan.

The purpose of this study was to examine the prevalence of screening-detected depression and the association of depression with QoL in community-dwelling postmenopausal women living in three Asian countries. We examined self-reported questionnaires and conducted the study. A total of 698 community-dwelling postmenopausal women living in three Asian countries participated in this study. The mean age was 59.4±6.6 years (±SD) Depressive symptoms were assessed using a 15-item geriatric depression scale (GDS-15). Using the cut-off of 5/6 for the GDS-15, the percentages of subjects with depression were 39.0% of the Korean subjects, 29.2% of the Chinese subjects, and 33.9% of the Japanese subjects. For the assessment of QoL, we used the EQ-5D of the EuroQoL Group. The following five dimensions were assessed: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. The proportions of subjects reporting problems for each dimension were examined. Subjects with depression had significantly lower levels of some dimensions of QoL than those without depression in all three countries. In all three countries, 29.2-39.0% of community-dwelling postmenopausal women had screening-detected depression, which was significantly associated with a lower level of some dimensions of QoL. These results suggest that clinicians should pay more attention to depression in community-dwelling postmenopausal women.

Place of death for the elderly in need of end-of-life home care: a study in Japan.

To investigate factors affecting the place of death of patients receiving home care services, we performed a retrospective cohort study using 252 elderly Japanese patients. During a 3-year period, 40 patients died at home (78.4 ± 12 years olds), and 59 patients died at hospitals (77.6 ± 13.4 years olds). Patient profiles, including their demographic characteristics, comorbidities, as well as formal and informal care levels were evaluated. Patients who died at home received a shorter term of home care, suffered malignancies more often and received visiting nurse services more often than those at hospitals. Age, gender, comorbidities, laboratory data, independency of activity of daily living (ADL), number of family looking after patients, number and dose of prescriptions and number of medical treatments such as decubitus were not different between these groups. Multivariate logistic regression analyses revealed that patients who died at home had an increased likelihood of suffering from malignancy (odds ratio = OR = 2.18, HR: 1.04-3.98, p = 0.049) and an increased likelihood of receiving visiting nurse services (OR = 3.13, HR: 1.08-6.21, p = 0.029) compared to those who died at hospitals. Thus, dying at home may be associated with cases of malignancy compared to other diseases in Japan, and it may be associated with a greater need for home visiting nurses. In conclusion, the nature of the patient's disease and the presence of visiting nurses influenced the decision regarding the patient's place of death. More study is necessary to better understand the end stages of death at home.

Clinical factors such as B-type natriuretic peptide link to factor VII, endothelial NO synthase and estrogen receptor alpha polymorphism in elderly women.

AIMS: This study evaluated the presence of genetic mutations in relation to thrombosis or atherosclerosis in elderly women. MAIN METHODS: This is an observational study of 93 Japanese women with a mean age of 80.9 years recruited from outpatient clinics of Nagoya University and its related hospitals. Ten single nucleotide polymorphisms (SNPs) were studied. Each gene studied acts in or is related to either blood coagulation (factor V Leiden, prothrombin G20210A, factor XIII Val34Leu, factor VII Arg353Gln, MTHFR C677T, beta-fibrinogen G-455A, PAI-1 4G/5G), metabolic syndrome-related pathways (PPARalpha Leu162Val), or endothelium/estrogen system (eNOS Glu298Asp, ERalpha IVS1-401). SNPs were analyzed for their relation to clinical values including lipids, B-type natriuretic peptide (BNP), fasting plasma glucose, tumor necrosis factor-alpha, interleukin-6, cyclic GMP, and nitric oxide metabolites. KEY FINDINGS: Comparisons between the distributions of different genotypes and clinical values showed three relationships. First, factor VII Arg353Gln and HDL-cholesterol (HDL-C) were linked to Arg/Arg carriers at higher levels (P=.049). The HDL-C to LDL-cholesterol ratio supported this link (P=.027). Second, eNOS Glu298Asp and triglycerides were linked to Glu/Glu carriers at higher levels (P=.031). Third, ERalpha IVS1-401 and BNP were related to CC genotype at lower levels (P=.031). Additionally, the last two relations showed that genotype does not influence the demarcation line of biomarkers, but the plasma/serum levels of biomarkers instead. SIGNIFICANCE: Correlations of factor VII Arg353Gln with HDL-C and eNOS Glu298Asp with triglycerides are new findings. Polymorphisms in the endothelium/estrogen system and the heart failure marker BNP are also correlated, with ERalpha IVS1-401 being the first identified marker. SNPs may be helpful for understanding the pathophysiology of atherosclerotic diseases in elderly women.