Influences of smoking on central blood pressure in hypertensive subjects

Background/Introduction

Smoking is known to induce systemic vascular damage, leading to cardiovascular diseases. Recent studies demonstrated that central blood pressure has a greater impact on cardiovascular events than brachial blood pressure.

Purpose

We investigated influences of habitual smoking on central systolic blood pressure (CSBP) in hypertensive subjects.

Methods

A total of 5630 subjects (male = 2622, 51.7±12.0 year-old at baseline), who visited our hospital for a physical check-up at least twice during the last 10 years and underwent CSBP measurement at each visit, were enrolled, and they were divided into three groups; normotensive (n=4634), non-treated hypertensive (n=91) and treated hypertensive subjects (n=905). Then, the influences of smoking on the average and yearly changes of CSBP (median follow-up 5 years) were analyzed. Brachial blood pressure (oscillometer) and radial artery pressure waveforms (tonometer) were recorded using an automated device, and the pressure corresponding to the second systolic peak of radial pressure waveforms was taken as CSBP (HEM-9000AI, Omron Healthcare, Kyoto). Hypertension was defined as brachial BP ≥140/90mmHg or the use of antihypertensive medications. A yearly change in CSBP was calculated in each subject by linear regression analysis using longitudinal data.

Results

The average CSBP was higher in habitual smokers than in non-smokers when analyzed in normotensive (109.1±11.7 vs. 107.6±12.8 mmHg, p<0.001) and non-treated hypertensive subjects (150.7±14.8 vs. 142.8±16.7 mmHg, p<0.05), whereas in hypertensive subjects under medication the average CSBP was lower in smokers than in non-smokers (124.6±12.4 vs. 127.8±13.6 mmHg, p<0.01). Smoking status did not affect yearly changes of CSBP in normotensive (habitual smokers vs. non-smokers; 1.38±6.00 vs. 1.44±6.04 mmHg/year), treated hypertensive (−0.16±7.08 vs. −0.66±8.24 mmHg/year), and non-treated hypertensive subjects (4.09±15.1 vs. −0.53±10.3 mmHg/year).

Conclusions

Habitual smoking increases CSBP, however, antihypertensive medications counteract the unfavorable effects of smoking on CSBP. These results imply a new pathway underlying the development of cardiovascular diseases in smokers. Unfavorable changes in the cardiovascular system caused by smoking may quite slowly progress that short period of observation in the present study could not have detected enhanced yearly increases of CSBP by smoking.

Funding Acknowledgement

Type of funding sources: None.

Relationship between year-to-year blood pressure variability and target organ damage in the general population

Background/Introduction

Visit-to-visit blood pressure variability (BPV) is a strong predictor of cardiovascular events as well as target organ damage (TOD) in hypertension. However, effects of year-to-year BPV on the development of TOD have not been investigated in the general population.

Purpose

The present study was designed to investigate a possible relationship between year-to-year BPV and TOD in the general population.

Methods

Consecutive 5542 subjects (male=3771, 58.6±10.7 yea-old) who visited our hospital for an annual physical check-up for 5 years in a row during 2008 and 2013 were enrolled. The average, standard deviation (SD), coefficient of variation (CV), and average real variability (ARV) of systolic blood pressure (SBP) were calculated using data during the period. Other baseline data were obtained in 2013; left ventricular hypertrophy (LVH; Sokolow-Lyon voltage >3.8 mV and/or Cornell product >2440 mm ms) and kidney impairment (estimated glomerular filtration rate; eGFR<60) were taken as TOD. Then, subjects without TOD at baseline (2013) (n=3801, male=2584, 57.4±10.4 yea-old) were followed up until 2019 (median = 5 years) and the impact of BPV on the development of TOD was investigated.

Results

The average, SD, CV and ARV of SBP were 123.8 mmHg, 8.04 mmHg, 6.50%, and 9.19 mmHg, respectively. At baseline, these parameters were higher in subjects with TOD than those without TOD (Table 1-A). During the follow-up of subjects without TOD at baseline, LVH and kidney impairment developed in 425 and 623 subjects (24.7 and 35.8 per 1000 person-year), respectively. In retrospective analysis, the average, SD, and ARV were higher in subjects with than without future TOD (Table 1-B). Although some indices of year-to-year BPV predicted future development of TOD in univariate Cox-hazard analysis, only the average of SBP predicted incident TOD after adjustment.

Conclusions

Year-to-year BPV is a marker of the incident TOD in the general population. However, these indices do not independently predict the onset of TOD and, thus, there may be unknown pathway that links TOD and BPV.

Funding Acknowledgement

Type of funding sources: None. Table 1. BP variability and TODTable 2. Cox-hazard analyses

Effect of advancing age on dietary salt intakes: a 10-year follow-up study

Background/Introduction

The National Nutrition Survey in Japan indicated that dietary salt intake of the Japanese is gradually decreasing for the last several decades, while salt intakes are higher in elderly than young people. There is no survey on the alteration of salt intakes with advancing age in individuals.

Purpose

The present study investigated effects of aging on salt intakes in individuals.

Methods

A total of 2600 subjects (men; 1787, age; 30 to 79 years-old at 2008) who participated in our physical check-up program both in 2008 and 2018 were enrolled. Individual dietary salt intakes in 2008 and 2018, which were estimated using a spot urine by a previously reported method, were compared.

Results

The mean age and salt intakes at 2008 were 53.9±10.0 years and 12.2±3.2 g/day in men and 54.4±9.2 years and 8.3±2.1 g/day in women, respectively. Salt intake increased to 13.2±3.3 g/day in men and 8.8±2.2 g/day in women during the 10 years. Salt intakes were higher in hypertensive than normotensive subjects both at 2008 and 2018, but changes of blood pressure category were not associated with those of salt intakes during the 10 years (table). Changes in salt intakes in each decade are shown in Figure. Salt intakes in each decade increased with advancing age both in men and women until their 70s. Salt intakes in people in their 60s and 70s at 2018 were higher than those at 2008. Similar results were obtained in subjects without any anti-hypertensive medications (n=1667) (data not shown).

Conclusions

The observational follow-up study revealed that salt intakes in each individual increased after the interval of 10 years in both men and women. The results suggest that the sense of taste changes with advancing age in young adults as well as elderly persons, which may be related with alterations of lifestyle.

Age difference in changes of salt intake

Funding Acknowledgement

Type of funding source: None

What is the optimal blood pressure level for kidney in the general population?

Background/Introduction

Hypertension induces kidney dysfunction, and vice versa. Furthermore, kidney dysfunction can be a risk factor for cardiovascular diseases as well as end-stage of kidney disease. Although blood pressure (BP) control is necessary to prevent deterioration of kidney function, strict BP control may deteriorate kidney function.

Purpose

The present observational study investigated effects of BP levels on the incidence of chronic kidney disease (CKD) in the general population.

Methods

A total of 12,753 subjects with normal kidney function (estimated glomerular filtration rate [eGFR] ≥60 mL/min per 1.73 m2) (male 7,707, mean age 51.8 years) who visited our hospital for an annual physical check-up from April 2010 to March 2018 were enrolled. After baseline examination, subjects were followed up until March 2019 (median 1769 days) with the endpoint being the development of CKD (eGFR<60 mL/min per 1.73 m2). The modified MDRD formula for Japanese was used to calculate eGFR. Hypertension was defined as BP ≥140/90mmHg or the use of antihypertensive medication.

Results

During the follow-up period, 1,604 subjects developed CKD (26.9 per 1,000 person-years) with the incidence being more frequent in hypertensive (n=3,098) than normotensive (n=9,655) subjects at enrollment (44.2 vs. 21.5 per 1,000 person-years, respectively; hazard ratio [95% confidence interval] from multivariate Cox proportional analysis 1.205 [1.061–1.369]). Hazard ratio of systolic BP at baseline was 1.006 [1.002–1.010] in a multivariate Cox proportional hazard regression model adjusted for possible risk factors. The incidence was lower in subjects without hypertension throughout the follow-up period (normotension group, n=7,866) than those who were diagnosed as having hypertension at least once during the period (hypertension group, n=4,887) (23.1 vs. 32.3 per 1,000 person-years, p<0.001). In the normotension group, subjects with average BP <120/80mmHg had lower incidence of CKD than in those with BP ≥120/80mmHg (17.2 vs. 36.1 per 1,000 person-years, p<0.001). In contrast, in the hypertension group, the incidences of CKD in subjects with average BP <120/80, 120–139/80–89 and ≥140/90mmHg were 34.3, 25.8, and 54.4 per 1,000 person-years, respectively (p<0.001). Moreover, in hypertensive subjects under medication (n=2,002) with average BP <120/80, 120–139/80–89 and ≥140/90mmHg, the incidence of CKD was 65.5, 41.3, and 64.3 per 1,000 person-years, respectively (p<0.01).

Conclusions

The incidence of CKD was higher in hypertensive than in normotensive subjects. The lower BP was associated with the lower incidence of CKD in normotensive subjects, while strict BP control may increase the risk of CKD in hypertensive subjects.

Funding Acknowledgement

Type of funding source: None

Excessive salt intake is a significant predictor for future development of metabolic syndrome in the general population

Background/Introduction

Dietary salt consumption is one of the most important modifiable factors in our lifestyle and restriction of dietary salt results in the reduction of blood pressure in previous studies. Excessive salt intake causes cardiovascular diseases independently of its effects on blood pressure. Since metabolic syndrome also increases a risk of cardiovascular disease, there may be some association between salt intake and metabolic syndrome.

Purpose

The present study was designed to investigate a possible relationship between salt intake and future development of metabolic syndrome in the general population.

Methods

Consecutive 12,256 subjects without metabolic syndrome (male=7,053, 52.1±12.3 year-old) who visited our hospital for an annual physical check-up from April 2010 to March 2018 were enrolled. After baseline examination, subjects were followed up until March 2019 (median 1,582 days) with the endpoint being the development of metabolic syndrome. Metabolic syndrome was diagnosed according to the Japanese criteria (2005). Individual salt intake was estimated using a spot urine by a previously reported method.

Results

Salt intake was 11.9±3.0 g/day in male and 8.2±2.1 g/day in female subjects at baseline. During the follow-up period, 1,669 subjects developed metabolic syndrome (29.9 per 1,000 person-year) with the incidence being more frequent in male than female subjects (41.8 vs. 14.2 per 1,000 person-year). Non-adjusted hazard ratio (HR) (95% confidence interval [CI]) of salt intake for the development of metabolic syndrome was 1.157 (1.142–1.173). In analysis where subjects were divided into gender-specific quartiles according to the baseline salt intake, Kaplan-Meyer curve analysis revealed that the incidence of metabolic syndrome were increased across the quartiles (20.6, 25.0, 32.4, and 42.7 per 1,000 person-years; logrank p<0.001). Multivariate Cox proportional hazard analysis adjusted for age, gender, body mass index, systolic blood pressure, heart rate, serum creatinine, uric acid, fasting plasma glucose, low-density lipoprotein cholesterol, triglyceride, hemoglobin and current smoking habit at baseline revealed that salt intake predicted the new onset of metabolic syndrome (HR: 1.036, 95% CI: 1.019–1.054).

Conclusions

Excessive salt intake is significantly associated with the new development of metabolic syndrome in the general population. The results suggest that salt restriction prevents metabolic syndrome as well as hypertension leading to cardiovascular diseases.

Funding Acknowledgement

Type of funding source: None

Arterial stiffness could reflect increased cardiac load and reduced pulmonary function in the general population

Background

Pulmonary function is known to decrease with age and reduced pulmonary function has been reported to be associated with all-cause mortality and cardiovascular death. The association between pulmonary impairment and atherosclerosis was reported previously but has not been investigated sufficiently in the general population.

Purpose

We hypothesized that arterial stiffness could reflect increase of cardiac load and reduced pulmonary function. The present study aimed to investigate whether increased cardiac load and reduced pulmonary function could affect arterial stiffness in the general population.

Methods

Subjects undergoing their health check-up were enrolled. Plasma B-type natriuretic peptide (BNP) levels and serum high-sensitivity cardiac troponin I (hs-cTnI) levels were measured to evaluate cardiac load and myocardial damage. Radial augmentation index (rAI) was measured to investigate arterial stiffness using HEM-9000AI device. Subjects with an ST-T segment abnormality on the electrocardiogram, renal insufficiency, cancer, active inflammatory disease, or a history of cardiovascular events and pulmonary disease were excluded. Pulmonary function was assessed using spirometry by calculating forced vital capacity (FVC) as a percentage of predicted value (FVC%-predicted), forced expiratory volume in 1 second (FEV1) as a percentage of predicted value (FEV1%-predicted), and the ratio of FEV1 to FVC (FEV1/FVC).

Results

A total of 1100 subjects aged 57 years were enrolled and their median values of BNP and hs-cTnI were 15.5 and 2.3 pg/ml. The levels of rAI were significantly associated with the levels of BNP after adjustment for possible confounders in multivariate regression analysis, but were not with the levels of hs-TnI. While the parameters of pulmonary function were inversely associated with the levels of rAI and hs-cTnI after adjustment for possible confounders in the multivariate regression analysis, but not with the levels of BNP. The other multivariate regression analyses where BNP, hs-cTnI, parameters of pulmonary function, and the other possible factors were simultaneously included as independent variables revealed that the BNP levels and the FVC%-predicted or FEV1%-predicted, besides age, gender, smoking status, body mass index, blood pressure, heart rate, creatinine, fasting plasma glucose, and triglyceride, were significantly associated with the levels of rAI.

Conclusions

The significant associations of rAI with BNP and pulmonary function were revealed in the general population. These findings support that arterial stiffness could reflect increased cardiac load and reduced pulmonary function, in apparently healthy individuals.

Funding Acknowledgement

Type of funding source: None

1415Dose antihypertensive medication improve accelerated age-dependent decline of GFR in hypertension?

Background/Introduction

An impairment of kidney function is a risk not only for end stage renal disease but also for cardiovascular events. Hypertension is known to accelerate an age-dependent decline in glomerular filtration rate (GFR).

Purpose

Effects of antihypertensive medications on yearly changes of estimate GFR (eGFR) in hypertensive patients were investigated.

Methods

Consecutive 5110 subjects (male=3196, 52.3±11.3 year-old) who participated in our physical check-up program during 2010 and 2012 were enrolled and followed up for 5 years. The average and the yearly change of eGFR during the 5 years were calculated in each individual and the both values were compared in hypertensive and normotensive subjects. Effect of antihypertensive medication on eGFR was also investigated. The modified Modification of Diet in Renal Disease study formula for the Japanese population was used for calculating eGFR.

Results

In hypertensive subjects (n=1408), the baseline and the average of eGFR were smaller (74.8±14.6 vs. 80.4±13.6, p<0.001 and 72.1±13.2 vs. 77.9±11.9 mL/min per 1.73 m2, p<0.001, respectively) and the yearly decline of eGFR was greater (0.96±1.41 vs. 0.84±1.19 mL/min per 1.73 m2 per year, p<0.01) than in normotensive subjects (n=3702). The baseline and the average of eGFR were smaller in hypertensive patients with (n=1234) than without (n=174) antihypertensive medication (74.3±14.6 vs. 78.3±13.8, p<0.001 and 71.7±13.2 vs. 74.9±12.7 mL/min per 1.73 m2, p<0.01, respectively). Although the yearly decline of eGFR in hypertensive patients with medication tended to be smaller than the decline in those without medication (0.94±1.41 vs. 1.09±1.42 mL/min per 1.73 m2 per year), this did not reach a statistical significance (p=0.213). Neither the number, classes of antihypertensive medications nor systolic blood pressure during the follow-up period did affect the average or yearly decline of eGFR in hypertensive patients.

Conclusions

As compared to normotensive subjects, eGFR was reduced and a yearly decrease in eGFR during the 5 years was accelerated in hypertensive patients. Although antihypertensive medication may reduce an accelerated age-dependent decline of kidney function in hypertension, observational period in this study was too short to clarify such beneficial effects of antihypertensive medications.

P5301Impacts of lifestyle behavior and shift Work on visceral fat accumulation and progression of atherosclerosis in middle-aged workers

Background

Work style, and particularly shift work, can affect an individual's health through disrupting circadian rhythms. Moreover, lifestyle habits including dietary and exercise routines might be altered by irregular shift hours. We thus hypothesized that an individual's lifestyle including working habits could influence the prevalence of visceral fat obesity and the progression of atherosclerosis.

Purpose

The present study investigated how lifestyle and shift work affect the accumulation of visceral fat and the progression of subclinical atherosclerosis in middle-aged workers.

Methods

This study enrolled employees undergoing their periodic health check-up (n=10883). The Cardio-Ankle Vascular Index (CAVI) was measured to assess arterial stiffness, followed by ultrasound examination and computed tomography imaging to measure carotid intima-media thickness (IMT) and visceral fat area (VFA), respectively. Lifestyle was evaluated by the following items: 1) eating breakfast, 2) nighttime eating, 3) regular exercise, 4) habitual drinking, 5) habitual smoking, 6) sleeping hours, and 7) working hours. With regard to work factors, subjects were categorized into fixed daytime workers or shift workers (including subjects working with an irregular schedule, outside of daytime hours, or at nighttime).

Results

Among all subjects enrolled, 6820 subjects were fixed daytime workers and 4063 subjects were shift workers. Most of the employees engaged in fixed daytime work were clerical workers, while the employees engaged in shift work were mainly physical workers in this company. Fixed daytime workers had significantly greater VFA than shift workers, but the prevalence of metabolic syndrome, CAVI values, and carotid IMT were similar between groups. Reduced regular exercise, long sleeping hours, and fixed daytime work were independently associated with visceral fat accumulation by both multivariate regression and logistic regression analyses. However, the logistic regression analysis with the presence of metabolic syndrome as the endpoint revealed that skipping breakfast, reduced regular exercise, long sleeping hours, and short working hours were independent determinants of metabolic syndrome. On the other hand, univariate and multivariate regression analysis showed that habitual smoking, but not shift work, were significantly associated with CAVI and carotid IMT. Logistic regression analysis with the endpoint of carotid atherosclerosis (presence of plaque) showed that habitual smoking was an independent determinant of carotid atherosclerosis.

Conclusions

Reduced regular exercise, long sleeping hours, and fixed daytime work were significantly associated with visceral fat accumulation, while habitual smoking has a consistent association with the progression of atherosclerosis. These findings support the concept that unhealthy lifestyles should be modified before considering intervention in work styles.

P1545Predictve factor for major adverse cardiovascular events in health check-up participants

Background/Introduction

Health check-up has been carried out for individual health management. One of its main objectives is the early detection and prevention of major adverse cardiovascular event (MACE).

Purpose

We investigated predictive factors for MACE among clinical test items in health check-up program.

Methods

A total of 13522 subjects (male=8140, 52.8±12.3 year-old at baseline), who visited our hospital for a health check-up between 2008 and 2015, were enrolled. After the baseline examination, they were followed up until December 2016 (median 1827 days) with the endpoint being the incident of MACE. The outcome was confirmed using a questionnaire at health check-up, medical record, telephone, or letter. Possible association between MACE and clinical test items including gender, age, waist circumference, blood pressure, kidney function, fasting plasma glucose, lipid profile, hemoglobin, electrocardiogram (ECG), smoking habit and alcohol consumption was investigated.

Results

During the follow-up period, MACE occurred in 196 subjects (3.03 per 1000 person-year), with the incidence being more frequent in male than female subjects (4.07 vs. 1.42 per 1000 person-year). Multivariate Cox-hazard analysis demonstrated that male gender (hazard ratio [HR] = 2.457, 95% confidence intervals [CI] = 1.498–4.028), age (HR = 1.056, 95% CI = 1.040–1.071), waist circumference (HR = 1.023, 95% CI = 1.004–1.042), systolic blood pressure (HR = 1.015, 95% CI = 1.005–1.024), hemoglobin (HR = 0.868, 95% CI = 0.758–0.994) and Sokolow–Lyon voltage in the ECG (HR = 1.227, 95% CI = 1.033–1.458) were significant predictors for MACE. However, in a model where B-type natriuretic peptide (BNP) was also added as an independent variable, BNP (HR = 2.593, 95% CI = 1.602–4.196) was the strongest predictor for MACE.

Conclusions

In participants underwent health check-up, systolic blood pressure and hemoglobin as well as age and gender were the risk factors of MACE. Appropriate control of blood pressure and treatment of anemia may be useful for the prevention of MACE. Measurement of BNP may give us additional important information associated with future MACE.

Abnormality in sarcoplasmic reticulum-dependent arterial contraction in responses to caffeine and noradrenaline in spontaneously hypertensive rats

We studied caffeine- and noradrenaline-induced contraction in tail arteries from 4-week-old male SHR and age- and sex-matched WKY. After the sarcoplasmic reticulum Ca2+ had been depleted by the Ca(2+)-free EGTA (0.1 mmol/l) solution, the caffeine (10 mmol/l)-induced contractions in a low-Ca2+ (0.5 mmol/l) solution were smaller in SHR than in WKY. After the sarcoplasmic reticulum had been loaded with Ca2+ in physiological Ca2+ (2.5 mmol/l) solution, caffeine- and noradrenaline (10(-5) mol/l)-induced contractions in a Ca(2+)-free EGTA solution were smaller in SHR than in WKY. The Ca2+ concentration-tension relationship in skinned arterial fibres was similar in WKY and SHR. These data suggest that the ability of the sarcoplasmic reticulum to take up Ca2+ and store Ca2+ is decreased in SHR. The decreased take up and store of Ca2+ may increase cytosolic Ca2+, which elevates arterial resistance and develops hypertension in gene hypertension.

REG Iα gene expression is linked with the poor prognosis of lung adenocarcinoma and squamous cell carcinoma patients via discrete mechanisms

The aim of the present study was to evaluate the effects of the REG Iα and REG Iβ genes on lung cancer cell lines, and thereafter, the expression of REG family genes (REG Iα, REG Iβ, REG III, HIP/PAP and REG IV) in lung cancer in relation to patient prognosis was evaluated. Lung adenocarcinoma (AD) and squamous cell carcinoma (SCC) cell lines expressing REG Iα or REG Iβ (HLC-1 REG Iα/Iβ and EBC-1 REG Iα/Iβ) were established, and cell number, cell invasive activity, and anchorage-independent cell growth were compared with these variables in the control cells. The expression levels of REG family genes were evaluated by real-time RT-PCR in surgically resected lung cancers, and disease-specific survival (DSS) curves were generated. The HLC-1 REG Iα/Iβ cell line showed significant increases in cell number and anchorage-independent cell growth compared with the control cells. EBC-1 REG Iα/Iβ cells showed significant increases in cell invasive activity and anchorage-independent cell growth as compared with the control cells. Except for the REG Iβ gene, expression of other REG family genes was observed in the surgically resected samples; however, DSS was significantly worse only in stage I patients who were positive for REG Iα expression than in patients who were negative for REG Iα expression. The effects of REG Iα on AD and SCC cells were different in the in vitro study, and a correlation between REG Iα expression and patient prognosis was noted in the in vivo study. Therefore, overexpression of REG Iα is a risk factor for poor prognosis caused by discrete mechanisms in AD and SCC patients.

Carbon nanotubes induce bone calcification by bidirectional interaction with osteoblasts

Multi-walled carbon nanotubes (MWCNTs) promote calcification during hydroxyapatite (HA) formation by osteoblasts. Primary cultured osteoblasts are incubated with MWCNTs or carbon black. After culture for 3 weeks, the degree of calcification is very high in the 50 μg mL(-1) MWCNT group. Transmission electron microscopy shows needle-like crystals around the MWCNTs, and diffraction patterns reveal that the peak of the crystals almost coincides with the known peak of HA.

Brachial-ankle pulse wave velocity predicts increase in blood pressure and onset of hypertension

BACKGROUND

The present study was designed to test the hypothesis that brachial-ankle pulse wave velocity (baPWV) predicts longitudinal increases in blood pressure (BP) and new onset of hypertension in individuals with normal BP.

METHODS

baPWV was measured using a semiautomated device in 2,496 participants (27-84 years) without hypertension who visited our hospital for a yearly health check-up. They were followed up for 4 years with the endpoint being development of hypertension.

RESULTS

During the follow-up period (median, 733 days; actual follow-up, 5,215 person-years), hypertension developed in 698 participants (133.8/1,000 person-years). Kaplan-Meier analysis revealed that risk for hypertension was increased across the tertiles of baseline baPWV. The hazard ratio (first tertile as reference) was 2.02 (95% confidence interval (CI) 1.55-2.64) and 3.49 (95% CI 2.66-4.57) in the second and third tertiles, respectively, after adjustment for possible risk factors. Multivariate Cox proportional hazard regression analysis adjusted for known risk factors, where baPWV was used as a continuous variable, also indicated that the baseline value of baPWV independently predicted new onset of hypertension (P < 0.001). Furthermore, baseline baPWV was significantly associated with a longitudinal increase in BP after adjustment for known risk factors in multiple regression analysis (P < 0.001).

CONCLUSION

This study provides the first evidence that baPWV is an independent predictor of longitudinal increases in BP as well as of new onset of hypertension.

Osteogenic activity of bone marrow-derived mesenchymal stem cells (BMSCs) seeded on irradiated allogenic bone

Allogenic bone grafting, a technique used in orthopaedic surgery, has several problems, including low osteogenic activity. To overcome the problem, this study aimed to determine whether in vivo osteogenesis could be enhanced using allogenic irradiated bone grafts after seeding with autologous bone marrow-derived mesenchymal stem cells (BMSCs). The allogenic bone cylinders were extracted from ACI rats and sterilized by irradiation. Donor BMSCs were obtained from fresh Fischer 344 (F344) rat bone marrow by cell culture. The allogenic bone with or without BMSCs were transplanted subcutaneously into syngeneic F344 rats. At 4 weeks after transplantation, high alkaline phosphatase (ALP) activity, bone-specific osteocalcin mRNA expression and newly formed bone were detected in the allogenic bone with BMSCs. The origin of the newly formed bone was derived from cultured donor BMSCs. However, none of these identifiers of osteogenesis were detected in either the fresh or the irradiated allogenic bone without BMSCs. These results indicate the availability of autologous BMSCs to heighten the osteogenic response of allogenic bone. Our present tissue-engineering method might contribute to a wide variety of allogenic bone grafting techniques in clinical settings.

Engineering bioartificial tracheal tissue using hybrid fibroblast-mesenchymal stem cell cultures in collagen hydrogels

We aimed at providing the first in vitro and in vivo proof-of-concept for a novel tracheal tissue engineering technology. We hypothesized that bioartificial trachea (BT) could be generated from fibroblast and collagen hydrogels, mechanically supported by osteogenically-induced mesenchymal stem cells (MSC) in ring-shaped 3D-hydrogel cultures, and applied in an experimental model of rat trachea injury. Tube-shaped tissue was constructed from mixtures of rat fibroblasts and collagen in custom-made casting molds. The tissue was characterized histologically and mechanically. Ring-shaped tissue was constructed from mixtures of rat MSCs and collagen and fused to the tissue-engineered tubes to function as reinforcement. Stiffness of the biological reinforcement was enhanced by induction of osteogeneic differentiation in MSCs. Osteogenic differentiation was evaluated by assessment of osteocalcin (OC) secretion, quantification of calcium (Ca) deposit, and mechanical testing. Finally, BT was implanted to bridge a surgically-induced tracheal defect. A three-layer tubular tissue structure composed of an interconnected network of fibroblasts was constructed. Tissue collapse was prevented by the placement of MSC-containing ring-shaped tissue reinforcement around the tubular constructs. Osteogenic induction resulted in high OC secretion, high Ca deposit, and enhanced construct stiffness. Ultimately, when BT was implanted, recipient rats were able to breathe spontaneously.

Development of a high-specificity enzyme-linked immunosorbent assay (ELISA) system for the quantification and validation of intact rat osteocalcin

Osteocalcin (OC) exhibits hard tissue-specific expression and binding activity to hydroxyapatite. Therefore, measurement of secreted OC is a very useful index for evaluating osteoblastic differentiation in regenerative bone. In the present study, we established a high-specificity sandwich enzyme-linked immunosorbent assay (ELISA) system for the quantification of intact rat OC, which could be useful for validating tissue-engineered bone samples nondestructively and continuously. The range of detection with the sandwich ELISA system was 0.1-100 ng OC/mL of cell culture media or rat sera. No cross-reactivities were detected with OCs from other species, including human, bovine and mouse OCs, and other mammalian sera, which would contain the corresponding endogenous OCs. The intra- and inter-assay coefficients of variation were < or =4.9% and </=5.9%, respectively. Recovery tests only showed variation between 89.4% and 103.7%. Using the newly developed direct sandwich ELISA system, we found that the secreted OC levels from rat bone marrow-derived mesenchymal stem cells during osteogenic differentiation with dexamethasone were significantly higher than those from cells undergoing non-osteogenic or adipogenic differentiation. It was established that this ELISA system would be suitable for quantitative assessment of bone formation by cultured cells with or without scaffolds in rat experimental models.

Cell sheet transplantation of cultured mesenchymal stem cells enhances bone formation in a rat nonunion model

Orthopedic surgeons have long been troubled by cases involving nonunion of fractured bones. This study aimed to enhance bone union by cell sheet transplantation of mesenchymal stem cells. A nonunion model was made in rat femur, and rat bone marrow cells were cultured in medium containing dexamethasone and ascorbic acid phosphate to create a cell sheet that could be scraped off as a single sheet. Cell sheets were transplanted onto fractured femurs without a scaffold in the model. X-ray and histological analysis were performed at 2, 4 and 8 weeks. Ultrasonography and biomechanical analysis were performed at 8 weeks. X-ray photographs and histological sections showed callus formation around the fracture site in the cell sheet-transplanted group (sheet group). Bone union was obtained in the sheet group at 8 weeks. By contrast, the control group (without sheet transplantation) showed nonunion of the femur. The results of pullout evaluation in the vertical direction of the femur in the sheet group were significantly better than that of the control group. Analysis of the origin of de novo formed bone using the Sry gene, which was used as a marker for donor cells, showed that transplanted cells without scaffolds could survive and differentiate into osteogenic lineage cells in vivo. These results showed that the femoral fracture in our model was completely cured by the transplantation of a cell sheet created by tissue engineering techniques. Thus, we think that cell sheet transplantation can contribute to hard tissue reconstruction in cases involving nonunion, bone defects and osteonecrosis.

The homeobox gene Hex regulates hepatocyte differentiation from embryonic stem cell-derived endoderm

We investigated the role of the hematopoietically expressed homeobox (Hex) in the differentiation and development of hepatocytes within embryonic stem cell (ESC)-derived embryoid bodies (EBs). Analyses of hepatic endoderm derived from Hex(-/-) EBs revealed a dramatic reduction in the levels of albumin (Alb) and alpha-fetoprotein (Afp) expression. In contrast, stage-specific forced expression of Hex in EBs from wild-type ESCs led to the up-regulation of Alb and Afp expression and secretion of Alb and transferrin. These inductive effects were restricted to c-kit(+) endoderm-enriched EB-derived populations, suggesting that Hex functions at the level of hepatic specification of endoderm in this model. Microarray analysis revealed that Hex regulated the expression of a broad spectrum of hepatocyte-related genes, including fibrinogens, apolipoproteins, and cytochromes. When added to the endoderm-induced EBs, bone morphogenetic protein 4 acted synergistically with Hex in the induction of expression of Alb, Afp, carbamoyl phosphate synthetase, transcription factor 1, and CCAAT/enhancer binding protein alpha. These findings indicate that Hex plays a pivotal role during induction of liver development from endoderm in this in vitro model and suggest that this strategy may provide important insight into the generation of functional hepatocytes from ESCs.

Osteocalcin secretion as an early marker of in vitro osteogenic differentiation of rat mesenchymal stem cells

Osteocalcin (OC) is a bone-specific protein synthesized by osteoblasts that represents a good marker for osteogenic maturation. We examined whether in vitro osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (MSCs) could be simply assessed at earlier stages by monitoring OC secretion into the conditioned medium, rather than measuring OC deposition on the extracellular matrix (ECM), using a sandwich enzyme immunoassay system involving a specific anti-rat OC monoclonal antibody. During a 16-day culture, OC was secreted into the medium of MSCs from day 8 and increased substantially until day 16. In contrast, OC deposition on the ECM was low, even at day 13, when calcium deposition was at high levels. The histological expression pattern of OC messenger RNA provided in situ evidence that osteoblastic cells appeared at the early stages of 6 to 9 days and matured over time in vitro. Furthermore, the temporal expression of osteogenesis-specific genes, such as the transcriptional factors core-binding factor 1 and osterix, followed by increases in secretory OC proved the commitment of MSCs to osteoblastic differentiation. These results revealed that biomineralization followed secretion of OC, which may reflect early osteoblastic differentiation of cultured MSCs under osteoinductive conditions. We ascertained the osteogenic differentiation capacity of cultured MSCs in a non-destructive manner by monitoring OC secretion into the culture medium and proved that secretory OC could represent a reliable marker for predicting in vivo osteogenic potential in bone tissue engineering.

Raloxifene: its ossification-promoting effect on female mesenchymal stem cells

BACKGROUND

Raloxifene acts like estrogen in preventing bone loss in postmenopausal women, but it selectively activates biological responses in bone tissue. It has a direct effect on osteoblasts' differentiation and bone formation in bone marrow culture. However, the point at which raloxifene has an effect on bone marrow-derived mesenchymal stem cells (MSCs), regardless of sex difference, is not known. The purpose of this study was to examine the osteogenic effect of raloxifene on MSCs derived from female and male rats and to assess the sex difference of raloxifene with or without osteogenic supplements (OSs) in the regulation of bone formation.

METHODS

Female and male rat bone marrow cells were cultured with or without OSs. In each experimental group, 10-6 M or 10-8 M raloxifene was added. As a control, cells were cultured without raloxifene. Histologically, mineralization was assessed by alizarin red S staining. Biochemically, alkaline phosphatase (ALP) activity, calcium content, and osteocalcin content were assessed.

RESULTS

On histological analysis, mineralized nodules were seen on alizarin red S staining in the groups treated with OS. On the biochemical analysis, OS increased ALP activity, calcium content, and osteocalcin content. Among female groups with OSs, 10-6 M raloxifene significantly increased ALP activity, calcium content, and osteocalcin content compared with the controls. Among male groups, raloxifene had negligible effects.

CONCLUSIONS

10-6 M Raloxifene had no ossification-inducing effect on female MSCs, but it had an ossification-promoting effect; it had no osteogenic effect on male MSCs. Therefore, raloxifene has a sex difference with regard to its osteogenic effect on MSCs. Moreover, combined treatment with raloxifene plus OS has an effect on female MSCs. These results provide a useful insight into the possible influence of raloxifene after MSC transplantation in clinical practice.

Regenerating gene 1α (REG 1α) expression and new treatment strategies in early non-small cell lung cancer

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Background: Regenerating gene (REG) I was originally isolated as an endogenous growth factor from pancreatic islet β cells. REG Iα protein is suggested to be involved in carcinogenesis in various gastroenterologic tissues. In the present study, to elucidate roles for REG Iα in non-small cell lung cancer (NSCLC), we investigated REG Iα expression in NSCLCs, focusing especially on its relationship with prognosis. Methods: We enrolled 70 NSCLCs (adenocarcinoma (AC)(n=48) and squamous cell carcinoma (SCC)(n=22)) who received surgery at Nara Medical University Hospital. Total RNA was extracted from each tumor tissue and corresponding normal lung tissue (NL)(n=70), cDNA was then reverse-transcribed from total RNA, and quantitative real-time reverse transcriptase-polymerase chain reaction was then carried out. The expression level of REG Iα in each sample was normalized with respect to that of β-actin, and the cutoff level was set at average+3SD expression of the 70 NLs. We also examined the relationship between REG 1α expression in the tumor tissue and the prognosis. Results: Six (12.5%) of the 48 ACs and 5 (22.7%) of the 22 SCCs were positive for REG Iα gene, and which is higher than that of NLs (2 of 70: 2.9%). After median follow-up of 26.2 months, 12 patients died due to disease progression. The survival rate among the REG 1α positive patients was significantly worse than among the REG 1α negative patients in ACs (P<0.05), and not significantly but worse in SCCs (P=0.07). In case of stage I, none of REG 1α negative patient died in both ACs and SCCs compared with 4 patients died of positive patients (AC:2, SCC:2), and also the survival rate among the REG 1α positive patients was significantly worse than among the negative patients in ACs (P<0.01) and SCCs (P<0.05). Disease free survival of REG 1α positive patients was also worse than negative patients in ACs (P<0.05) and SCCs (P=0.16). Conclusions: REG Iα expression in NSCLCs may be the risk factor for poor prognosis, and we anticipate that it will enable us to provide more appropriate and individualized treatment to patients of early NSCLC.

No significant financial relationships to disclose.

Bone marrow-derived mesenchymal cells can rescue osteogenic capacity of devitalized autologous bone

In clinical cases, many orthopaedists have been troubled with bone fragility, such as fractures after devitalization therapy for bone tumour, pathological fractures and metastatic tumours. The aim of this study was to determine whether loss of osteogenic capacity of devitalized autologous bones can be rescued using cultured bone marrow-derived mesenchymal cells. A devitalized bone model was produced from rat femur by irradiation and three groups were prepared: intact bone, irradiated bone and irradiated bone combined with cultured mesenchymal cells. Each bone was transplanted subcutaneously into a syngeneic rat. At 2 or 4 weeks after transplantation, biochemical analyses [alkaline phosphatase (ALP) activity and osteocalcin mRNA expression] and histological measurement were performed. Moreover, we verified the origin of newly formed bone, using the sex-determining region Y (sry) gene as a marker to distinguish between donor and recipient. In both intact bone and irradiated bone with mesenchymal cells, ALP activity and osteocalcin mRNA expression were detected and living osteoblasts together with newly formed bone were clearly seen histologically. Furthermore, analysis of the origin of de novo formed bone indicated that newly formed bone in irradiated bone with mesenchymal cells was derived from cultured bone marrow-derived mesenchymal cells. These results proved that the osteogenic capacity of devitalized autologous bone can be rescued using tissue-engineering techniques. This procedure should contribute to various clinical treatments, such as local metastatic tumours, pathological fracture after devitalization therapy and reconstruction after wide-margin tumour resection. The benefits would be applicable to all types of devitalized bone.

Osteogenic matrix sheet-cell transplantation using osteoblastic cell sheet resulted in bone formation without scaffold at an ectopic site

We previously reported that in vivo bone formation could be observed in composites of porous hydroxyapatite (HA) scaffolds and cultured mesenchymal stem cells (MSCs). In the present study, we developed a new method for transplantation of cultured MSCs without the necessity of using a scaffold to form bone tissue. MSCs were culture-expanded and lifted as cell sheet structures. These cell sheets, designated osteogenic matrix sheets, showed positive alkaline phosphatase (ALP) staining, high ALP activities and high osteocalcin (OC) contents, indicating their osteogenic potential. We transplanted these sheets into subcutaneous sites in rats to assess whether they possessed in vivo bone-forming capability. The transplanted sheets showed mineralized matrix together with osteocytes and an active osteoblast lining, indicating new bone formation, at 6 weeks after transplantation. HA scaffolds were also wrapped with the sheets to make HA/sheet composites and implanted into subcutaneous sites in rats. Histological sections of the composites revealed bone formation in the HA pores at 4 weeks after implantation. Our present results indicate that MSCs can be cultured as sheet structures, and the resulting sheets themselves or HA-sheet composites represent osteogenic implants that can be used for hard tissue reconstruction.

Coronary artery disease investigated using 99mTc-tetrofosmin myocardial SPECT

BACKGROUND

Coronary artery disease can be diagnosed from stress and delayed images of myocardial single photon emission computed tomography (SPECT) using technetium-99 m-tetrofosmin (TcTF). However, the negative predictive value of stress SPECT images after a single injection of a low tracer dose remains unknown. Thus, the present study investigates whether normal stress SPECT results predict event-free survival.

MATERIALS AND METHODS

We screened 302 consecutive patients who were randomly assigned to two groups for myocardial ischaemia using either stress SPECT with a low dose of TcTF (296 MBq, TcTF group, n = 150) or stress together with rest SPECT using thallium(201) chloride (TlCl, 111 MBq; TlCl group, n = 152) as the tracer. A total of 80 patients with abnormal SPECT findings were excluded and the remaining 222 with normal results (age, 66.5 +/- 0.7 years; TcTF/TlCl, 112/110) were enrolled in the present study and followed up for 401 +/- 9 days, with the endpoint being ischaemic cardiac events.

RESULTS

The incidence of cardiac events did not differ between the two groups (0.9% and 0.0% in TcTF and TlCl groups, respectively). The cost and duration of TcTF and TlCl SPECT examinations were about 425 and 603 Euros and 50 and 280 min, respectively.

CONCLUSIONS

The negative predictive values of stress SPECT using a low dose of TcTF and of combined stress and rest SPECT using TlCl did not differ and both were clinically acceptable. Thus, stress SPECT using low dose TcTF is useful in screening patients for myocardial ischaemia.

Brain natriuretic peptide detects cardiac abnormalities in mass screening

BACKGROUND

Plasma brain natriuretic peptide (BNP) is elevated in asymptomatic patients with various cardiac abnormalities. We tested the hypothesis that measuring BNP is useful for detecting asymptomatic patients with cardiac abnormalities who are not identified by conventional health check-up programmes.

MATERIALS AND METHODS

From 2001 to 2002, 6189 subjects (women 34.0%; mean age 56.6 years) underwent multiphasic health check-ups in our hospital, of which 4818 without cardiac abnormalities as revealed by the health check-up were enrolled in the present study. Their plasma concentrations of BNP were measured.

RESULTS

Plasma concentrations of BNP were higher than the normal reference upper limit of our hospital (21.3 pg mL(-1)) in 925 of the 4818 subjects. Echocardiography was performed in 471 subjects who were randomly selected from the 925 subjects with elevated BNP. Abnormal findings were detected in 174 subjects, comprising valvular heart disease in 83, systolic dysfunction in 10, diastolic dysfunction in 54, left ventricular hypertrophy in 41, left ventricular enlargement in 11, left atrial enlargement in 13 and paroxysmal atrial fibrillation in 3.

CONCLUSIONS

Since BNP measurement identifies additional subjects with cardiac abnormalities, it is useful for detecting asymptomatic cardiac abnormalities among apparently healthy subjects, and is suitable for use in high-quality mass screening.

Influence of the porosity of hydroxyapatite ceramics on in vitro and in vivo bone formation by cultured rat bone marrow stromal cells

The in vitro and in vivo osteoblastic differentiation of rat bone marrow stromal cells (MSCs) was assessed on hydroxyapatite disks with 3 different porosities: 30%, 50%, and 70% (HA30, HA50, and HA70, respectively). MSCs obtained by 10-day culture of fresh bone marrow cells were subcultured for 2 weeks on 3 kinds of porous HA disks in the presence and absence of dexamethasone (Dex). After 2 weeks of subculture, alkaline phosphatase (ALP) activity and osteocalcin production of MSCs/HA composites with Dex were higher than those without, and increased with increasing porosity. The resultant bone tissue grafts "cultured-bone/HA constructs" were implanted subcutaneously into the backs of syngeneic rats, and harvested 1, 2, and 4 weeks after implantation. At 1 week, only cultured-bone/HA70 constructs exhibited expanded bone formation. At 2 and 4 weeks, active osteoblasts and progressive bone formation were observed morphologically in both cultured-bone/HA50 and HA70 constructs. At 4 weeks, bone tissue was observed even in cultured-bone/HA30 constructs. ALP activity and osteocalcin production also increased with increasing porosity and time after implantation. In this in vivo model, different scaffold porosity with similar crystal morphology of the apatite phase demonstrated marked differences in ability to support osteogenesis by implanted rat MSCs.

Impact of Metabolic Syndrome on Brachial-Ankle Pulse Wave Velocity in Japanese

The aim of this study was to determine the effect of metabolic syndrome on brachial-ankle pulse wave velocity (baPWV) by using the new guidelines for diagnosis of this syndrome in Japan. We examined 525 men and women without a history of cardiovascular disease or cancer, and an ankle-brachial index < 0.9. The baPWV was measured using a device (Form PWV/ABI) that simultaneously monitored bilateral brachial and ankle pressure wave forms. Metabolic syndrome was defined as a waist circumference > or = 85 (90) cm in men (women) and two or more of the following risk factors: hypertension, dyslipidemia, and glucose intolerance diagnosed by a 75 g oral glucose tolerance test. The baPWV showed a significant linear relationship with waist circumference, waist-to-hip ratio, body fat, systolic and diastolic blood pressure, triglycerides, fasting glucose, 2-h-postload glucose, fasting insulin, and glycosylated hemoglobin-A1c, after adjusting for sex and age. These factors were also strongly related to fasting insulin levels. When subjects were classified into six groups based on waist circumference and the number of risk factors for metabolic syndrome (0, 1, and > or =2), we found that more risk factors clearly increased the odds ratios for an elevated baPWV in those subjects in the highest quartile of the baPWV distribution in multivariate logistic models. An increase in odds ratio was observed despite a normal waist circumference and may well have been due to increased fasting insulin and blood pressure levels. An increase in the number of risk factors for metabolic syndrome was highly correlated with an increased baPWV, probably due to insulin resistance.