Hemoglobin as a possible biochemical index of hypertension-induced vascular damage

Factors influencing new-onset hypertension in elderly patients with obstructive sleep apnea: A multicenter cohort study

Investigating the influencing factors of new-onset hypertension in the elderly with obstructive sleep apnea (OSA). 450 Chinese older patients with OSA who were non-hypertensive at baseline were enrolled. All patients had undergone polysomnography monitoring in the multicenter study. The primary endpoint was incident hypertension. Kaplan-Meier survival analysis was performed, and multivariate Cox proportional hazards models were generated to determine the factors influencing new-onset hypertension. A total of 176 (39.1%) patients developed hypertension. The hypertension group had older age, higher hemoglobin (Hb) level and apnea-hypopnea index (AHI) values than the non-hypertension group (all p < 0.05). During the median 33-month follow-up period, multivariate Cox analysis showed age (hazard ratio (HR) = 1.039, 95% confidence interval (95% CI): 1.016-1.062), AHI (HR = 1.015, 95% CI: 1.007-1.023) and Hb level (HR = 1.016, 95% CI: 1.008-1.025) were independent predictors of new-onset hypertension. However, continuous positive airway pressure (CPAP; HR = 0.508, 95% CI: 0.271-0.951) reduced the risk of developing hypertension. Notably, the subgroup analysis demonstrated that the plasma glucose level (HR = 1.168, 95% CI: 1.029-1.326) was a risk factor for male patients. Besides length of time with the pulse oxygen saturation less than 90% (Tsat90; HR = 1.005, 95% CI: 1.003-1.007), body mass index (BMI; HR = 1.170, 95% CI: 1.043-1.311), and dyslipidemia (HR = 2.335, 95% CI: 1.144-4.766) had statistically significant effects on the incidence of hypertension in certain subgroups. Although this study lacked analysis of items such as living habits and medication, it did show age, AHI, Hb and CPAP affected the development of hypertension in elderly OSA patients. These findings suggested that targeted interventions in specific populations may be more effective in preventing hypertension.

HbA1c and height loss among Japanese workers: A retrospective study

Evaluating the risk of height loss could be an efficient way to evaluate endothelial health, which might be associated with all-cause and cardiovascular mortality. Diabetes is an established risk factor both for intervertebral disk degeneration and osteoporosis-related fractures, which are major risk factors for height loss among adults. Therefore, hemoglobin A1c (HbA1c), as an indicator of the presence of diabetes, could be positively associated with height loss. A retrospective study of 10,333 workers aged 40 to 74 years was conducted. Height loss was defined as being in the highest quintile of height decrease per year. HbA1c in the normal range was positively associated with height loss. The known cardiovascular risk factors-adjusted odds ratio (OR) and 95% confidence interval (CI) for height loss with a 1-standard deviation (SD) increase in HbA1c (0.38% for both men and women) was 1.06 (1.02, 1.10) for men and 1.15 (1.07, 1.23) for women, respectively. When limit those analysis among those without diabetes, the magnitude was slightly higher; the fully adjusted OR and 95% CI for height loss with a 1-SD increase in HbA1c was 1.19 (1.11, 1.28) for men and 1.32 (1.20, 1.44) for women, respectively. Even when HbA1c is within the normal range, higher HbA1c is a significant risk factor for height loss among workers.

Short- and medium-term air pollution exposure, plasmatic protein levels and blood pressure in children

Exposure to air pollution influences children's health, however, the biological mechanisms underlying these effects are not completely elucidated. We investigated the association between short- and medium-term outdoor air pollution exposure with protein profiles and their link with blood pressure in 1170 HELIX children aged 6-11 years. Different air pollutants (NO₂, PM₁₀, PM_2.5, and PM_2.5abs) were estimated based on residential and school addresses at three different windows of exposure (1-day, 1-week, and 1-year before clinical and molecular assessment). Thirty-six proteins, including adipokines, cytokines, or apolipoproteins, were measured in children's plasma using Luminex. Systolic and diastolic blood pressure (SBP and DBP) were measured following a standardized protocol. We performed an association study for each air pollutant at each location and time window and each outcome, adjusting for potential confounders. After correcting for multiple-testing, hepatocyte growth factor (HGF) and interleukin 8 (IL8) levels were positively associated with 1-week home exposure to some of the pollutants (NO₂, PM₁₀, or PM_2.5). NO₂ 1-week home exposure was also related to higher SBP. The mediation study suggested that HGF could explain 19% of the short-term effect of NO₂ on blood pressure, but other study designs are needed to prove the causal directionality between HGF and blood pressure.

Influence of height on endothelial maintenance activity: a narrative review

Recent studies have revealed an inverse association between height and cardiovascular disease. However, the background mechanism of this association has not yet been clarified. Height has also been reported to be positively associated with cancer. Therefore, well-known cardiovascular risk factors, such as increased oxidative stress and chronic inflammation, are not the best explanations for this inverse association because these risk factors are also related to cancer. However, impaired blood flow is the main pathological problem in cardiovascular disease, while glowing feeding vessels (angiogenesis) are the main characteristic of cancer pathologies. Therefore, endothelial maintenance activity, especially for the productivity of hematopoietic stem cells such as CD34-positive cells, could be associated with the height of an individual because this cell contributes not only to the progression of atherosclerosis but also to the development of angiogenesis. In addition, recent studies have also revealed a close connection between bone marrow activity and endothelial maintenance; bone marrow-derived hematopoietic stem cells contribute towards endothelial maintenance. Since the absolute volume of bone marrow is positively associated with height, height could influence endothelial maintenance activity. Based on these hypotheses, we performed several studies. The aim of this review is not only to discuss the association between height and bone marrow activity, but also to describe the potential mechanism underlying endothelial maintenance. In addition, this review also aims to explain some of the reasons that implicate hypertension as a major risk factor for stroke among the Japanese population. The review also aims to clarify the anthropological reasons behind the high risk of atherosclerosis progression in Japanese individuals with acquired genetic characteristics.

Risk factors of the progression to hypertension and characteristics of natural history during progression: A national cohort study

Background

Although the high disease burden that results from cardiovascular complications of hypertension, factors related to the progression to hypertension in the normotensive population are not actively reported. The purpose of this study was to estimate the rate of the progression to hypertension and to reveal the associated risk factors.

Methods

The study included normotensive participants from the National Health Insurance Service-National Health Screening Cohort, and contained a 10% sample of all adults who received a national health screening test in either 2002 or 2003. At the end of the study in 2015, the patients were divided into two groups based on whether or not they progressed to hypertension. Cox proportional hazard modeling was performed to identify risk factors for progression. Subgroup analysis using logistic regression was employed to reveal factors influencing the different natural history of the progression.

Results

Among the 75,335 included participants, the progression rate to hypertension was 66.39% (50,013), with an adjusted incidence rate of 8.62 per 100 person-year in the aged 40–64 group and 12.68 in the aged 65 or above group. Age, BMI, hemoglobin, and family history of hypertension and other diseases were related to the progression. Among the progression group, 78.21% (39,116) participants skipped a pre-hypertensive status; this group consisted of older females with lower pulse pressure and more alcohol consumption compared to people who had pre-hypertensive status before the progression.

Conclusion

Substantial risk factors for the progression to hypertension should be carefully managed even in normotensive participants who receive health screening tests.

Short stature-related single-nucleotide polymorphism (SNP) activates endothelial repair activity in elderly Japanese

Background

Hypertension and atherosclerosis are bidirectionally related, while platelet count could serve as an indicator of endothelial repair. Therefore, high platelet counts could be associated with hypertension by indicating more intense endothelial repair activity. Furthermore, short stature has been shown to constitute a risk of atherosclerosis. Since inflammation-related single-nucleotide polymorphism (SNP (rs3782886)) is reportedly associated with myocardial infarction and short stature, rs3782886 could be associated with a high platelet count and thus more intense endothelial repair activity.

Methods

We conducted a cross-sectional study of 988 elderly Japanese who participated in a general health check-up. Short stature was defined as a height of at or under the 25th percentile of the study population, and high platelet count as the highest tertiles of the platelet levels.

Results

High platelet counts were found to be independently and positively associated with hypertension while rs3782886 was independently associated with high platelet levels and short stature. The classical cardiovascular risk factor-adjusted odds ratio (OR) and 95% confidence interval (CI) of high platelet count for hypertension was 1.34 (1.02, 1.77). With non-minor homo of the rs3782886 as the reference group, the adjusted OR and 95% CI for high platelet count and short stature of minor home were 2.40 (1.30, 4.42) and 2.21 (1.16, 4.21), respectively.

Conclusion

SNP (rs3782886) was shown to be associated with high platelet count and short stature. This result partly explains how a genetic factor can influence the impact of height on endothelial repair.

Association between chronic kidney disease and carotid intima-media thickness in relation to circulating CD34-positive cell count among community-dwelling elderly Japanese men

BACKGROUND AND AIMS

Endothelial injury is well-known as a process that can lead to chronic kidney disease (CKD) and atherosclerosis. Hematopoietic activity is known to be associated inversely with CKD and positively with atherosclerosis. Since bone-derived progenitor cells (CD34-positive cells) contribute to endothelial repair (including the progression of atherosclerosis), understanding the association between CKD and carotid intima-media thickness (CIMT), in relation to circulating CD34-positive cell count, may be an efficient means of clarifying the mechanisms underlying endothelial activity.

METHODS

We conducted a cross-sectional study of 570 elderly Japanese men aged 60-69 years, who underwent a general health check-up. Participants were stratified as per a median circulating CD34-positive cell count (1.01 cells/μL).

RESULTS

Independent of the known cardiovascular risk factors, CIMT was found to be positively associated with CKD in the participants with high circulating CD34-positive cell counts but not in participants with low counts. Odds ratios were 1.40 (1.04, 1.89) for participants with high and 1.01 (0.72, 1.43) for participants with low circulating CD34-positive cell counts after adjustment for known cardiovascular risk factors at 95% confidence intervals for CKD with one standard deviation increment of CIMT.

CONCLUSIONS

A positive association between CIMT and CKD was observed among participants with high circulating CD34-positive cell counts but not among participants with low counts. Endothelial repair activity might determine the association between CKD and CIMT.

Association of hemoglobin concentration with handgrip strength in relation to hepatocyte growth factor levels among elderly Japanese men aged 60-69 years: a cross-sectional study

Background

Hemoglobin concentration reportedly is positively associated with muscle strength, for example, handgrip strength. However, hemoglobin cannot repair muscle directly, but is beneficial only in a supportive role. Since hepatocyte growth factor (HGF) regulates muscle satellite cell production and differentiation, which is stimulated by organ injury, the supportive effect of hemoglobin should thus be stronger for participants with high HGF than for those with low HGF. However, the association between hemoglobin concentration and handgrip strength in relation to HGF levels remains unknown.

Methods

We conducted a cross-sectional study of 255 Japanese elderly men aged 60–69 years who participated in annual health check-ups in 2014–2015. The study population was categorized on the basis of a median value of HGF of 300.6 pg/mL.

Results

Among present study population, 128 participants showed low HGF. For participants with low HGF, hemoglobin concentration showed no significant association with handgrip strength (standardized parameter estimate (β) = 0.03, p = 0.767), but for those with high HGF, hemoglobin concentration was significantly positively associated with handgrip strength (β = 0.23, p = 0.014).

Conclusions

A significant positive association between hemoglobin level and handgrip strength was established for elderly Japanese men aged 60–69 years with high HGF but not for participants with low HGF. Our finding indicates that HGF levels could determine the relationship of hemoglobin concentration with handgrip strength in elderly Japanese men aged 60–69 years. This result can be expected to serve as an effective tool for the clarification of the roles played by HGF and hemoglobin concentration in maintenance of muscle strength.

Hepatocyte growth factor and carotid intima-media thickness in relation to circulating CD34-positive cell levels

Background

Hepatocyte growth factor (HGF) may act as a possible biochemical index for vascular damage, although evidence for the association between HGF and carotid intima-media thickness (CIMT) is limited. Since both HGF and circulating CD34-positive cells play an important role in endothelial repair, circulating CD34-positive cell levels may influence the association between HGF and CIMT.

Methods

We conducted a cross-sectional study of 269 elderly Japanese men aged 60–69 years who had undertaken an annual medical checkup from 2014 to 2015.

Results

The median value for circulating CD34-positive cells was 0.93 cells/μL. Among the study population, 135 men showed low circulating CD34-positive cell levels (≤ 0.93 cells/μL). By multivariable linear regression analysis, HGF was found to be significantly positively associated with CIMT only to participants with low circulating CD34-positive cell levels, with a multi-adjusted β of 0.26 (p = 0.005) and 0.002 (0.986) for low and high circulating CD34-positive cell levels, respectively. In addition, a significant interaction was observed between HGF and circulating CD34-positive cell levels (low and high) on CIMT (multivariable p value of 0.049). A positive association exists between HGF and CIMT in elderly Japanese men, limited to participants with low circulating CD34-positive cell levels.

Conclusion

A positive association exists between HGF and CIMT in community-dwelling elderly Japanese men, which is limited to participants with low numbers of circulating CD34-positive cells. Our findings indicate that circulating CD34-positive cell levels could determine the influence of HGF on CIMT in elderly Japanese men.

Evaluation of lipid profiles and hematological parameters in hypertensive patients: Laboratory-based cross-sectional study

INTRODUCTION

Hypertension and dyslipidemia are the two coexisting and synergizing major risk factors for cardiovascular diseases. The cellular constituents of blood affect the volume and viscosity of blood, thus playing a key role in regulating blood pressure. Overweight and obesity are key determinants of adverse metabolic changes including an increase in blood pressure. The aim of this study was to evaluate lipid profiles and hematological parameters in hypertensive patients at Debre Markos Referral Hospital, Northwest Ethiopia.

METHODS

Laboratory-based cross-sectional study was conducted in 100 eligible hypertensive patients at the hospital. The required amount of blood was withdrawn from the patients by healthcare professionals for immediate automated laboratory analyses. Data were collected on socio-demographic factors, anthropometric measurements, blood pressure, lipid profiles, and hematological parameters.

RESULT

The mean serum levels of triglyceride, total cholesterol, and low-density lipoprotein were significantly higher than their respective cut-off values in the hypertensive patients. Besides, 54%, 52%, 35%, and 11% of the hypertensive patients had abnormal low-density lipoprotein, total cholesterol, triglyceride, and high-density lipoprotein levels, respectively. Higher levels of low-density lipoprotein, hemoglobin, and red blood cell count were observed in the hypertensive patients whose blood pressure had been poorly controlled than the controlled ones (p < 0.05). Waist circumference had a significant positive association with the serum levels of total cholesterol and white blood cell count (p < 0.05).

CONCLUSION

Hypertensive patients had a high prevalence of lipid profile abnormalities and poorly controlled blood pressure which synergize in accelerating other cardiovascular diseases. Some hematological parameters such as red blood cell count are also increased as do the severity of hypertension.

Possible mechanism underlying the association between height and vascular remodeling in elderly Japanese men

Height is reported to be inversely associated with cardiovascular disease. And platelets play an important role in vascular remodeling by supporting CD34-positive cells. To clarify the association between height and platelet, we conducted a cross-sectional study of 219 elderly Japanese men. Since hemoglobin concentration is influenced by vascular remodeling activity, an analysis stratified by hemoglobin level was performed. An inverse association was seen between height and platelet count in subjects with a high hemoglobin concentration (≥ 14.5 g/dL), but not in subjects with a low hemoglobin concentration (< 14.5 g/dL). The standardized parameter estimates (β) were β = -0.22, p = 0.019 for subjects with high hemoglobin, and β = -0.01, p = 0.931 for subjects with low hemoglobin. We also found a positive association between platelets and carotid intima media thickness (CIMT) and circulating CD34-positive cells in subjects with high hemoglobin (partial correlation coefficient (r) = 0.21, p = 0.037 and r = 0.40, p =< 0.001), but not in subjects with low hemoglobin (r = 0.04, p = 0.710 and r = 0.06, p = 0.544). In subjects with a high hemoglobin concentration, platelets were inversely associated with height, and positively associated with CIMT and circulating CD34-positive cells. These results indicate that subjects with a short stature activate vascular remodeling to a much greater extent than subjects with a tall stature.

Height indicates hematopoietic capacity in elderly Japanese men

Previously, we reported that height is an indicator of the capacity of vascular repair in elderly men, especially hypertensive men. On the other hand, hemoglobin could act as a possible biochemical index of hypertension-induced vascular damage. However, no studies have clarified the correlation between height and hematopoietic activity. We conducted a cross-sectional study of 249 men aged 65-69 undergoing a general health check-up. Reticulocyte was used to evaluate hematopoietic activity. Because hemoglobin concentration should influence hematopoietic activity, analyses stratified by hemoglobin level were performed. Independent of known cardiovascular risk factors and other hematological parameters (white blood cell count), a significant positive correlation was seen between height and reticulocytes for total subjects and subjects with a high hemoglobin concentration (≥14.5 g/dL), but not in subjects with a low hemoglobin concentration (<14.5 g/dL). The standardized parameter estimates (β) were β=0.18, p=0.003 for total subjects, β=0.28, p=0.001 for subjects with a high hemoglobin concentration, and β=0.03, p=0.717 for subjects with low hemoglobin. Independently, height is significantly positively correlated with reticulocyte in elderly Japanese men, particularly in men with a high hemoglobin concentration. These results indicate that subjects with a short stature might have lower hematopoietic capacity than those with a high stature.

Association between high-density lipoprotein-cholesterol and hypertension in relation to circulating CD34-positive cell levels

Background

Although high-density lipoprotein-cholesterol (HDL) level is inversely correlated with cardiovascular events, HDL is also reported to be positively associated with hypertension, which is a known endothelial impairment factor. Since HDL mediates important protective actions on the vascular endothelium by increasing the number of circulating endothelial progenitor cells (CD34-positive cells), the level of circulating CD34-positive cells should influence the association between HDL and hypertension.

Methods

To investigate the association between HDL and hypertension in relation to the level of circulating CD34-positive cells, we conducted a cross-sectional study of 477 elderly men aged 60–69 years who participated in general health checkup.

Results

HDL was found to be significantly positively associated with hypertension in subjects with a high level of circulating CD34-positive cells, while no significant association was observed for subjects with low circulating CD34-positive cells. Known cardiovascular risk factors adjusted odds (ORs) and 95% confidence intervals (CIs) of hypertension for increments of one standard deviation (SD) in HDL (13.8 mg/dL) were 1.44 (1.06, 1.96) for subjects with a high level of circulating CD34-positive cells and 0.87 (0.63, 1.19) for subjects with low circulating CD34-positive cells. We also revealed a significant association between HDL level and CD34-positive cell level on hypertension, with fully adjusted p values for the effect of this interaction on hypertension at 0.022.

Conclusions

Independent of known cardiovascular risk factors, HDL was found to be positively associated with hypertension in subjects with a high level of circulating CD34-positive cells but not for subjects with low circulating CD34-positive cells.

Possible mechanism underlying the association between higher hemoglobin level and hypertension in older Japanese men

AIM

Hemoglobin is reported to be positively associated with hypertension. However, the underlying mechanism of this association is unknown. Recently, bone marrow-derived CD34-positive cells have been reported to play an important role in endothelial repair in conjunction with platelets. As the association between hypertension and endothelial dysfunction is bidirectional, the influence of endothelial repair also might strongly influence the association between hemoglobin and hypertension.

METHODS

To clarify the clinical importance of the hematological parameter on endothelial maintenance in older men, we carried out a cross-sectional study of 222 Japanese men aged 60-69 years undergoing a general health checkup.

RESULTS

For participants with a lower platelet count (≤21.0/μL), hemoglobin was significantly positively associated with hypertension, but not for participants with a higher platelet count (>21.0/μL). The classical cardiovascular risk factor adjusted odds ratio of hypertension for 1-standard deviation increment of hemoglobin (1.0 g/dL) was 2.09 (95% CI: 1.26, 3.48) for participants with a lower platelet count, and 1.07 (95% CI: 0.68, 1.67) for participants with a higher platelet count. We also found that although there was no significant correlation between hemoglobin and circulating CD34-positive cells for participants with a lower platelet count (β = -0.06, P = 0.603), a significant positive correlation was seen for participants with a higher platelet count (β = 0.29, P = 0.004).

CONCLUSIONS

The positive association between hemoglobin and hypertension was limited to participants with a lower platelet count as a result of insufficient endothelial repair. These results represent an efficient tool for clarifying the mechanism of endothelial maintenance that correlates with hypertension. Geriatr Gerontol Int 2017; 17: 2586-2592.