White blood cell count and hypertension incidence. The NHANES I Epidemiologic Follow-up Study

Components of the Complete Blood Count as a Risk Predictor for Incident Hypertension in a Large Taiwanese Population Follow-up Study

BACKGROUND

Previous studies investigating the relationship between hypertension (HT) and hematological parameters report inconsistent results, and most them included a small number of participants or only conducted a cross-sectional analysis of 1 or 2 hematological factors. Moreover, no large cohort follow-up studies have investigated this topic. The aim of this longitudinal study was to explore associations between components of the complete blood count (CBC) and incident HT using data from a large Taiwanese biobank.

METHODS AND RESULTS

Hematological parameters including white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin, hematocrit (HCT), and platelet count were evaluated. We included 21,293 participants who did not have HT at baseline and followed them for a mean period of 3.9 years. During follow-up, 3,002 participants with new-onset HT (defined as incident HT) were identified. Univariable analysis revealed that high WBC count, high RBC count, high hemoglobin, high HCT, and low platelet count were associated with incident HT. Multivariable analysis after adjusting potential confounding factors found high WBC count (odds ratio [OR], 1.057; 95% confidence interval [CI], 1.028 to 1.087; P<0.001) and high HCT (OR, 1.023; 95% CI, 1.010 to 1.036; P<0.001) were still significantly associated with incident HT.

CONCLUSIONS

High WBC count and high HCT were associated with incident HT.

Clinical features and next-generation sequencing landscape of essential thrombocythemia, prefibrotic primary myelofibrosis, and overt fibrotic primary myelofibrosis: a Chinese monocentric retrospective study

OBJECTIVE

Since prefibrotic primary myelofibrosis (pre-PMF) was recognized as a separate entity in the 2016 revised classification of MPN differed from essential thrombocythemia (ET) or overt fibrotic primary myelofibrosis (overt PMF), it has been a subject of debate among experts due to its indefinite diagnosis.

METHODS

We retrospectively reviewed the clinical parameters, haematologic information, and genetic mutations of patients who were diagnosed with myeloproliferative neoplasms (MPNs) according to the WHO 2016 criteria in China, including 56 ET patients, 19 pre-PMF patients, and 43 overt PMF patients.

RESULTS

Pre-PMF patients exhibited higher leukocyte counts [14.2(6.0-28.1) × 10⁹/L vs 9.6(4.0-55.0) × 10⁹/L, P = 0.003], LDH values [307(233-479)U/L vs 241(129-1182)U/L, P < 0.001], onset ages [67(32-76) years vs 50(16-79) years, P = 0.006], a higher frequency of splenomegaly(47.4% vs 16.7%, P = 0.018) and hypertension (57.9 vs 23.2%, P = 0.005) than ET patients. On the other hand, pre-PMF patients had higher platelet counts [960(500-2245) × 10⁹/L vs 633(102-1720) × 10⁹/L, P = 0.017], haemoglobin levels [152(115-174)g/L vs 119(71-200)g/L, P = 0.003], lower LDH values [307(233-479)U/L vs 439(134-8100)U/L, P = 0.007] and a lower frequency of splenomegaly(47.4 vs 75.6%, P = 0.031) than overt PMF patients. Next-generation sequencing landscape was performed in 50 patients, revealed the frequency of EP300 mutations was significantly increased in pre-PMF patients compared with ET and overt PMF patients (60 vs 10 vs 15.79%, P = 0.033), and WT1 was more often overexpressed (WT1/ABL1 copies ≥ 1.0%) in patients with overt PMF than in those with ET or pre-PMF(54.55 vs 16.67 vs 17.65%, P = 0.009). In terms of outcome, male sex, along with symptoms including MPN10, anaemia (haemoglobin < 120 g/L), thrombocytopenia (platelet count < 100 × 10⁹/L), leucocytosis (leukocyte counts > 13 × 10⁹/L), high LDH value (> 350U/L), splenomegaly, WT1 overexpression(WT1/ABL1 copies ≥ 1.0%), KMT2A, ASXL1 and TP53 mutations, indicated a poor prognosis for PMF patients.

CONCLUSION

The results of this study indicated that a comprehensive evaluation of BM features, clinical phenotypes, haematologic parameters, and molecular profiles is needed for the accurate diagnosis and treatment of ET, pre-PMF, and overt PMF patients.

Association of mitochondrial DNA copy number with cardiometabolic diseases

Mitochondrial DNA (mtDNA) is present in multiple copies in human cells. We evaluated cross-sectional associations of whole blood mtDNA copy number (CN) with several cardiometabolic disease traits in 408,361 participants of multiple ancestries in TOPMed and UK Biobank. Age showed a threshold association with mtDNA CN: among younger participants (<65 years of age), each additional 10 years of age was associated with 0.03 standard deviation (s.d.) higher level of mtDNA CN (P = 0.0014) versus a 0.14 s.d. lower level of mtDNA CN (P = 1.82 × 10^-13) among older participants (≥65 years). At lower mtDNA CN levels, we found age-independent associations with increased odds of obesity (P = 5.6 × 10^-238), hypertension (P = 2.8 × 10^-50), diabetes (P = 3.6 × 10^-7), and hyperlipidemia (P = 6.3 × 10^-5). The observed decline in mtDNA CN after 65 years of age may be a key to understanding age-related diseases.

Blood Lead, Systemic Inflammation, and Blood Pressure: Exploring Associations and Mediation Effects in Workers Exposed to Lead

Relationships of lead exposure with blood pressure and blood lead with inflammation have been previously established yet, but the conclusions are still controversial. The objective of our study was to investigate the role of systemic inflammation in the relationships between blood lead concentration and blood pressure. We quantified the levels of blood lead and white blood cell count in 505 lead-exposed workers with 842 observations. Associations between blood lead, white blood cell count, and blood pressure were evaluated by using linear mixed models. We further performed mediation analysis to investigate the role of white blood cell count in the associations between blood lead concentration and blood pressure. We observed that each 1% increase of blood lead levels was significantly positively associated with a 0.9%, 1.7%, and 1.1% increases in systolic blood pressure, white blood cell count, and blood platelet count, respectively. Also, we found that the levels of white blood cell count were positively correlated with diastolic blood pressure and systolic blood pressure in a dose-response manner. Mediation analysis showed that the levels of white blood cell significantly mediated the associations between concentration of blood lead and systolic blood pressure. Collectively, our findings suggest that blood lead was positively associated with systolic blood pressure and that systemic inflammation might play a key role in this association.

Role of Inflammatory Biomarkers in the Prevalence and Incidence of Hypertension Among HIV-Positive Participants in the START Trial

BACKGROUND

The association between hypertension (HTN) and inflammatory biomarkers (interleukin-6 [IL-6] and high-sensitivity C-reactive protein [hsCRP]) in HIV-positive persons with CD4+ count >500 cells/mm3 is unknown.

METHODS

We studied HTN in participants of the Strategic Timing of AntiRetroviral Treatment (START) trial of immediate vs. deferred antiretroviral therapy (ART) in HIV-positive, ART naive adults with CD4+ count > 500 cells/mm3. HTN was defined as having a systolic blood pressure (BP) ≥140 mmHg, a diastolic BP ≥90 mmHg, or using BP-lowering therapy. Logistic and discrete Cox regression models were used to study the association between baseline biomarker levels with prevalent and incident HTN.

RESULTS

Among 4,249 participants with no history of cardiovascular disease, the median age was 36 years, 55% were nonwhite, and the prevalence of HTN at baseline was 18.9%. After adjustment for race, age, gender, body mass index (BMI), diabetes, smoking, HIV RNA and CD4+ levels, associations of IL-6 and hsCRP with HTN prevalence were not significant (OR per twofold higher:1.10, 95% confidence interval [CI]: 0.99, 1.20 for IL-6 and 1.05, 95% CI: 0.99, 1.10 for hsCRP). Overall incidence of HTN was 6.8 cases/100 person years. In similarly adjusted models, neither IL-6 (Hazard ratios [HR] per twofold higher IL-6 levels: 0.97, 95% CI: 0.88, 1.08) nor hsCRP (HR per twofold higher hsCRP levels: 0.97, 95% CI: 0.92, 1.02) were associated with risk of incident HTN. Associations did not differ by treatment group. Age, race, gender, and BMI were significantly associated with both the prevalence and incidence of HTN.

CONCLUSIONS

Traditional risk factors and not baseline levels of IL-6 or hsCRP were associated with the prevalence and incidence of HTN in START.

C-reactive protein and incident hypertension in a worksite population of Japanese men

Inflammation plays a key role in the pathogenesis of cardiovascular diseases via the development of atherosclerosis. Here, we evaluated the impact of serum C-reactive protein (CRP) and the white blood cell (WBC) count on the risk of hypertension in middle-aged Japanese men at a work site. We evaluated a total of 2991 Japanese male workers without hypertension who ranged in age from 18 to 64 years (mean age 40.4 ± 0.2 years) at a worksite in 2010. The hazard ratio (HR) for incident hypertension was estimated according to quartile levels of serum high-sensitivity CRP (hs-CRP) or WBC count. These men were followed up for 5 years from 2010 to 2015. During the follow-up period, 579 (19.4%) subjects developed hypertension. In a multivariable analysis, the risk of incident hypertension was significantly increased with higher hs-CRP levels: HR 1.00 (reference) for the lowest quartile, 1.39 (1.04-1.85) for the 2nd quartile, 1.46 (1.08-1.98) for the 3rd quartile, and 1.57 (1.17-2.11) for the highest quartile. In contrast, the WBC count was not associated with a greater risk of incident hypertension after multivariable adjustment. These findings suggest that higher levels of serum hs-CRP, but not the WBC count, are associated with the future incidence of hypertension in middle-aged Japanese men.

White blood cell count and the incidence of hyperuricemia: insights from a community-based study

Hyperuricemia (HUA) is a risk factor for chronic kidney disease (CKD). The relationship between HUA and white blood cell (WBC) count remains unknown. A sampling survey for CKD was conducted in Sanlin community in 2012 and 2014. CKD was defined as proteinuria in at least the microalbuminuric stage or an estimated GFR of 60 mL/(min∙1.73 m²). HUA was defined as serum uric acid > 420 μmol/L in men and > 360 μmol/L in women. This study included 1024 participants. The prevalence of HUA was 17.77%. Patients with HUA were more likely to have higher levels of WBC count, which was positively associated with HUA prevalence. This association was also observed in participants without CKD, diabetes mellitus, hyperlipidemia, or obesity. Multivariate logistic regression analysis showed that WBC count was independently associated with the risk for HUA in male and female participants. Compared with participants without HUA, inflammatory factors such as high-sensitivity C-reactive protein, tumor necrosis factor-α, and interleukin 6 increased in participants with HUA. Hence, WBC count is positively associated with HUA, and this association is independent of conventional risk factors for CKD.

Value of neutrophil to lymphocyte ratio as a predictor of mortality in patients undergoing aortic valve replacement

Background

Neutrophil to lymphocyte ratio (NLR) has been studied as a measure of inflammation and as a prognosticating factor in various medical conditions including neoplastic, inflammatory and cardiovascular. The prognostic role of NLR in predicting mortality in patients with aortic stenosis undergoing surgical aortic valve replacement (AVR) has not been studied. The aim of our study is to explore the utility of NLR as a predictor of both, short and long-term mortality, in patients undergoing surgical AVR.

Methods

Consecutive patients with aortic stenosis admitted for AVR to our institution were evaluated for study inclusion. Of the 335 patients admitted from January 2007 to September 2011, 234 met study inclusion criteria. Patients were divided into two groups depending on their initial preoperative NLR level with a cutoff value of 3. Three-year vital status was accessed with electronic medical records and Social Security Death Index. Survival analysis, stratified by NLR, was used to evaluate the predictive value of preoperative NLR levels.

Results

Patients with NLR ≥3, when compared to those with NLR <3, had a significantly higher short-term (9.40% vs. 0, P=0.0006), 6-month (19.54% vs. 0.95%, P<0.0001), and 3-year mortality (27.35% vs. 3.78%, P<0.0001). After adjustment for baseline characteristics, co-morbidities, symptomatology, echocardiographic findings, and blood tests, NLR level remained a significant independent predictor of 3-year mortality; Hazard ratios (HRs) increased by a factor of 1.18 (1.05-1.33, P=0.0068) and patients with a NLR ≥3 had 4.77 fold increase in 3-year mortality (1.48-15.32, P=0.0090).

Conclusions

NLR is an independent predictor of short-term and long-term mortality in patients with aortic stenosis undergoing AVR surgery, especially those with NLR ≥3. We strongly suggest the use of NLR as a tool to risk stratify patients with aortic stenosis undergoing AVR surgery.

Joint Effect of Cigarette Smoking and Body Mass Index on White Blood Cell Count in Korean Adults

Background

White blood cell count is an independent risk factor for cardiovascular disease. Several lifestyle and metabolic factors such as cigarette smoking and obesity are known to be associated with an elevated white blood cell count. However, the joint effect of cigarette smoking and obesity on white blood cell count has not yet been fully described.

Methods

We explored the joint effect of cigarette smoking and obesity on white blood cell count using multiple logistic regression analyses after adjusting for confounding variables in a population-based, cross-sectional study of 416,065 Korean adults.

Results

Cigarette smoking and body mass index have a dose-response relationship with a higher white blood cell count, but no synergistic interaction is observed between them (men, P for interaction=0.797; women, P for interaction=0.311). Cigarette smoking and body mass index might have an additive combination effect on high white blood cell count. Obese male smokers were 2.36 times more likely and obese female smokers 2.35 times more likely to have a high white blood cell count when compared with normal body mass index non-smokers.

Conclusion

Cigarette smoking and body mass index are independently associated with an elevated white blood cell count in both men and women.

Comparative Assessment of Some White Blood Cell and Platelet Parameters among Normotensive and Hypertensive Subjects in Port Harcourt, Nigeria

Background

Reports comparing the values of white blood cells (WBCs) and platelet parameters among normotensive, newly diagnosed hypertensive, and known hypertensive participants in Nigeria are relatively scarce. This study sought to compare these hematologic parameters of normotensive and hypertensive participants in the Southeastern Nigeria.

Materials and Methods

Fifty participants each of normotensive, newly diagnosed hypertensive, and known hypertensive and age- and sex-matched individuals were recruited into the study. Using an automated hematology analyzer, the following hematological parameters were determined in all participants: total WBC; neutrophil, lymphocyte and platelet counts; percentage value of neutrophil and lymphocytes; mean platelet volume (MPV); platelet distribution width; and total lymphocyte count.

Results

Significantly higher total WBCs and (absolute) neutrophil counts and lower percentage lymphocyte were observed among known hypertensive male participants, whereas percentage neutrophil was significantly higher among known hypertensive female participants. Platelet count and MPV were significantly higher in hypertensive male participants compared to their normotensive counterparts. MPV was found to be significantly lower in hypertensive female participants compared to normotensive females.

Conclusion

The present study reports significantly higher leukocytes, platelet counts, and MPV among hypertensive males and lower MPV among hypertensive females. Regular assessment of hematological parameters may perhaps be useful indicators of the prognosis of hypertension among the study population.

Proteolytic receptor cleavage in the pathogenesis of blood rheology and co-morbidities in metabolic syndrome. Early forms of autodigestion

Abnormal blood rheological properties seldom occur in isolation and instead are accompanied by other complications, often designated as co-morbidities. In the metabolic syndrome with complications like hypertension, diabetes and lack of normal microvascular blood flow, the underlying molecular mechanisms that simultaneously lead to elevated blood pressure and diabetes as well as abnormal microvascular rheology and other cell dysfunctions have remained largely unknown. In this review, we propose a new hypothesis for the origin of abnormal cell functions as well as multiple co-morbidities. Utilizing experimental models for the metabolic disease with diverse co-morbidities we summarize evidence for the presence of an uncontrolled extracellular proteolytic activity that causes ectodomain receptor cleavage and loss of their associated cell function. We summarize evidence for unchecked degrading proteinase activity, e.g. due to matrix metalloproteases, in patients with hypertension, Type II diabetes and obesity, in addition to evidence for receptor cleavage in the form of receptor fragments and decreased extracellular membrane expression levels. The evidence suggest that a shift in blood rheological properties and other co-morbidities may in fact be derived from a common mechanism that is due to uncontrolled proteolytic activity, i.e. an early form of autodigestion. Identification of the particular proteases involved and the mechanisms of their activation may open the door to treatment that simultaneously targets multiple co-morbidities in the metabolic syndrome.

Increased Neutrophil to Lymphocyte Ratio in Patients With Resistant Hypertension

Resistant hypertension (RHT) is an important disease that causes an increase in cardiovascular risk, yet its etiology remains unclear. The authors aimed to investigate neutrophil/lymphocyte ratio (NLR) as an inflammation marker in patients with RHT. A total of 150 patients were included in the study and grouped according to their office and ambulatory blood pressure measurements. They were classified as having normotension (NT), controlled hypertension (CHT), or RHT. The RHT group had a significantly higher NLR than the CHT group (P=.03), and NLRs of both hypertension groups were significantly higher than those in the NT group (P<.001, for both). NLR and neutrophil count were found to be independent correlates for RHT in multivariate analysis (P<.001). NLR and neutrophil count are increased in RHT patients than both CHT and NT patients. This finding, which is defined for the first time in patients with RHT, may imply the importance of inflammation in blood pressure control.

Use of white blood cell counts to predict metabolic syndrome in the elderly: a 4 year longitudinal study

BACKGROUND

The white blood cell (WBC) count was one of the first inflammatory markers associated with metabolic syndrome (MetS). Recently, two longitudinal studies have demonstrated a cause and effect relationship between MetS and WBC counts among middle-aged adults. However, no study has used WBC cutoff values to predict MetS in the elderly.

METHODS

Subjects who underwent routine health checkups, and were above 60 years of age, were enrolled. All subjects were followed-up until they developed MetS or until 4 years from the date of entry, whichever came earlier. Of the 4539 subjects eligible for enrollment, 3428 subjects comprised the study group and 1111 subjects comprised the validation group.

RESULTS

WBC counts were significantly different between subjects with and without MetS in both genders. Using the ROC curve, WBC cutoff values of 5.7 × 10(3)/µl in males and 5.0 × 10(3)/µl in females were associated with the increased risk of developing MetS (all p values <0.001). Using these WBC cutoff values, the hazard ratio (HR) for females was significant in both the study group and validation group. However, the HR for males failed significance in the validation group. Kaplan-Meier plots and κ coefficients confirmed that the WBC cutoff value could predict development of MetS in women but not in men.

CONCLUSIONS

The association between WBC count and MetS was gender specific. A WBC cutoff value greater than 5.0 10(3)/µl may predict the development of MetS in elderly women.

In prehypertension leukocytosis is associated with body mass index but not with blood pressure or incident hypertension

BACKGROUND

Previous studies reported increased white blood cell counts (WBCCs), an inflammatory marker, in hypertension, prehypertension and metabolic syndrome. Evidence suggests that inflammation precedes blood pressure (BP) elevation and may contribute to incident hypertension. Angiotensin receptor blockers (ARBs) may reduce inflammation. We analyzed WBCC trends in TRial Of Preventing HYpertension (TROPHY) to determine if this inflammatory marker predicted incident hypertension in prehypertensive individuals and whether randomized assignment to the ARB candesartan (391 individuals) for 2 years, lowered WBCC compared with placebo-treated controls (381 individuals).

METHODS

A new analysis of TROPHY trial data.

RESULTS

In the total population, baseline BMI correlated with WBCC (r = 0.185, P < 0.0001), neutrophils (r = 0.135, P < 0.001) and lymphocytes (r = 0.204, P < 0.0001). Baseline triglycerides also correlated significantly with inflammatory markers. Despite a wide range of home BP (HBP) values, HBP did not correlate with baseline WBCC counts. After 2 years, candesartan decreased placebo corrected HBP by -5.5/-2.5 mmHg, (P < 0.0001), but WBCC, neutrophil and lymphocyte counts were not different in placebo and in candesartan groups. Baseline WBCC, neutrophils and lymphocyte counts did not predict incident hypertension in the placebo group.

CONCLUSION

In TROPHY, candesartan lowered BP but did not alter WBCC. Baseline WBCC did not predict incident hypertension. Our findings do not support the hypothesis that inflammation contributes to incident hypertension or that ARB treatment suppresses inflammation. The significant independent association of WBCC with baseline BMI and triglycerides is consistent with the evidence that obesity and insulin resistance are associated with inflammation. The findings highlight the importance of effective lifestyle modification in prehypertension to reduce inflammatory cardio-metabolic risk and suppress transition to hypertension.

Nicotine exposure, blood pressure, and inflammation in tobacco smokers and chewers in a rural community in Nepal

Tobacco consumption is high amongst the people of Xxx. This study was carried out in 2011 in a rural community of Xxx, to compare pathological parameters associated with tobacco use in relation to nicotine metabolism between smokers, chewers, and a control group. A total of 216 volunteers provided blood and urine samples for testing nicotine metabolites, C-reactive protein, and cell counts. Data were analyzed using ANOVA, correlation, and t-tests using STATA. Differences in blood pressure amongst the groups indicate a role of smoking in preventing a rise in BP with age, likely attributable to a different mechanism of metabolism of tobacco constituents.

Increasing sleep duration to lower beat-to-beat blood pressure: a pilot study

Strong evidence has accumulated over the last several years, showing that low sleep quantity and/or quality plays an important role in the elevation of blood pressure. We hypothesized that increasing sleep duration serves as an effective behavioral strategy to reduce blood pressure in prehypertension or type 1 hypertension. Twenty-two participants with prehypertension or stage 1 hypertension, and habitual sleep durations of 7 h or less, participated in a 6-week intervention study. Subjects were randomized to a sleep extension group (48 ± 12 years, N = 13) aiming to increase bedtime by 1 h daily over a 6-week intervention period, or to a sleep maintenance group (47 ± 12 years, N = 9) aiming to maintain habitual bedtimes. Both groups received sleep hygiene instructions. Beat-to-beat blood pressure was monitored over 24 h, and 24-h urine and a fasting blood sample were collected pre- and post-intervention. Subjects in the sleep extension group increased their actigraphy-assessed daily sleep duration by 35 ± 9 min, while subjects in the sleep maintenance condition increased slightly by 4 ± 9 min (P = 0.03 for group effect). Systolic and diastolic beat-to-beat blood pressure averaged across the 24-h recording period significantly decreased from pre- to post-intervention visit in the sleep extension group by 14 ± 3 and 8 ± 3 mmHg, respectively (P < 0.05). Though the reduction of 7 ± 5 and 3 ± 4 mmHg in the sleep maintenance group was not significant, it did not differ from the blood pressure reduction in the sleep extension group (P = 0.15 for interaction effect). These changes were not paralleled by pre- to post-intervention changes in inflammatory or sympatho-adrenal markers, nor by changes in caloric intake. While these preliminary findings have to be interpreted with caution due to the small sample size, they encourage future investigations to test whether behavioral interventions designed to increase sleep duration serve as an effective strategy in the treatment of hypertension.

CXCL5 polymorphisms are associated with variable blood pressure in cardiovascular disease-free adults

Objective

Leukocyte count has been associated with blood pressure, hypertension, and hypertensive complications. We hypothesized that polymorphisms in the CXCL5 gene, which encodes the neutrophilic chemokine ENA-78, are associated with blood pressure in cardiovascular disease (CVD)-free adults and that these polymorphisms are functional.

Methods and results

A total of 192 community-dwelling participants without CVD or risk equivalents were enrolled. Two CXCL5 polymorphisms (−156 G > C (rs352046) and 398 G > A (rs425535)) were tested for associations with blood pressure. Allele-specific mRNA expression in leukocytes was also measured to determine whether heterozygosity was associated with allelic expression imbalance. In −156 C variant carriers, systolic blood pressure (SBP) was 7 mmHg higher than in −156 G/G wild-type homozygotes (131 ± 17 vs. 124 ± 14 mmHg; P = 0.008). Similarly, diastolic blood pressure (DBP) was 4 mmHg higher in −156 C variant carriers (78 ± 11 vs. 74 ± 11 mmHg; P = 0.013). In multivariate analysis of SBP, age, sex, body mass index, and the −156 G > C polymorphism were identified as significant variables. Age, sex, and the −156 G > C SNP were further associated with DBP, along with white blood cells. Allelic expression imbalance and significantly higher circulating ENA-78 concentrations were noted for variant carriers.

Conclusion

CXCL5 gene polymorphisms are functional and associated with variable blood pressure in CVD-free individuals. The role of CXCL5 as a hypertension- and CVD-susceptibility gene should be further explored.

Effect of interval training program on white blood cell count in the management of hypertension: A randomized controlled study

OBJECTIVE

Elevated white blood cell (WBC) count is considered to be prospectively and positively associated with cardiovascular diseases, particularly hypertension. Also, the positive role of exercise in the management of hypertension has been well and long established. However the relationship between WBC count and hypertensive management particularly in the nonpharmacological technique is ambiguous and unclear. Therefore the purpose of the present study was to determine the effect of interval training program on WBC count and cardiovascular parameters in male hypertensive patients.

MATERIALS AND METHODS

A total of 245 male patients with mild to moderate (systolic blood pressure (SBP) between 140 mmHg and 179 mmHg and diastolic blood pressure (DBP) between 90 mmHg and 109 mmHg) essential hypertension were age matched and grouped into experimental and control groups. The experimental (n=140; 58.90±7.35 years) group involved in an 8-week interval training (60-79% HR max reserve) program of between 45 minutes to 60 minutes, while the age-matched controls hypertensive (n=105; 58.27±6.24 years) group remain sedentary during this period. Cardiovascular parameters (SBP, DBP, and VO(2) max) and WBC count were assessed. Student's t and Pearson correlation tests were used in data analysis.

RESULTS

Findings of the study revealed a significant effect of the interval training program on VO2max, SBP, and DBP and WBC count at P<0.05 and VO2max is negatively related to the WBC count (r=-0.339) at P<0.01.

CONCLUSIONS

It was concluded that the interval training program is an effective adjunct nonpharmacological management of hypertension and the therapeutic effect of exercise programs may be mediated through suppression of inflammatory (WBC count) reaction.

Carotid artery stiffness, high-density lipoprotein cholesterol and inflammation in men with pre-hypertension

Low circulating levels of high-density lipoprotein cholesterol (HDL-C) are associated with increased risk for cardiovascular events. HDL-C has a variety of poorly understood atheroprotective effects, including altering lipid metabolism and reducing inflammation. Increased arterial stiffness is an important predictor of subsequent cardiovascular risk. Therefore, in this study, we sought to determine whether HDL-C levels are associated with carotid arterial stiffness. In addition, we examined potential correlates of this association, such as inflammatory factors, cardiorespiratory fitness and body fat percentage. Carotid artery beta-stiffness was measured by ultrasound in 47 (23 years old) healthy pre-hypertensive men. Low HDL-C was defined as <1.0 mmol l(-1). Body fat was measured by air displacement plethysmography. Cardiorespiratory fitness was measured using a maximal exercise test, with metabolic gas analysis and inflammatory markers consisting of C-reactive protein (CRP), white blood cell (WBC) count and absolute neutrophil count. Men with a low HDL-C had significantly higher carotid artery stiffness, CRP, WBC count, neutrophil count, body fat, fasting glucose and lower cardiorespiratory fitness (P<0.05). Co-varying for cardiorespiratory fitness, % body fat and glucose had no effect on group differences in carotid artery stiffness. Co-varying for inflammatory markers resulted in groups having similar carotid artery stiffness. Pre-hypertensive men with low HDL-C have a higher carotid artery stiffness when compared with those with higher HDL-C. The detrimental effects of low HDL-C on large artery stiffness in pre-hypertensive men may be mediated by inflammation and not by cardiorespiratory fitness or body fat levels.

The associations of total and differential white blood cell counts with obesity, hypertension, dyslipidemia and glucose intolerance in a Korean population

Although many studies have reported an association between total white blood cell count and metabolic syndrome, relatively few reports are available on the association between differential white blood cell counts and metabolic syndrome. The medical records of 15,654 subjects (age, median 46, range 14-90 yr; 8,380 men and 7,274 women) who visited the Center for Health Promotion were investigated. It was found that as total white blood cell (WBC) and differential WBC counts increased the frequencies of diabetes, hypertension, obesity, dyslipidemia, and metabolic syndrome also increased. Moreover, these significant relationships persisted after adjusting for age, gender, smoking, alcohol intake, educational background, and household income. The odds ratios (95% CI) for metabolic syndrome was 2.64 (2.30- 3.04) in the highest quartile of total WBC count, with corresponding figures of 2.14 (1.88-2.44) for neutrophils, 2.32 (2.03-2.64) for lymphocytes, 1.56 (1.37-1.78) for monocytes, 1.36 (1.20-1.54) for basophils, and 1.82 (1.59-2.08) for eosinophils versus the lowest quartiles of the appropriate total and differential counts, respectively, after adjusting for the variables mentioned above. These independent associations were also observed by subgroup analyses according to the smoking status. Our data suggest that even within normal ranges, total WBC count and the differential WBC counts are associated with the presence of metabolic syndrome.

Revision in Reference Ranges of Peripheral Total Leukocyte Count and Differential Leukocyte Percentages Based on a Normal Serum C-Reactive Protein Level

BACKGROUND/PURPOSE

A higher total leukocyte count is a predictor of all-cause mortality and cardiovascular morbidity. The currently used reference range for peripheral total leukocyte count is wide (4.5-11.0 x 10(9)/L) and is associated with a low sensitivity in identifying non-infectious chronic diseases. We attempt to revise it based on a normal serum C-reactive protein (CRP) level.

METHODS

Study subjects were participants in a health check program at our hospital between 2000 and 2002. Those whose leukocyte analysis had been checked with the Sysmex Cell Counter NE-9000 were enrolled.

RESULTS

Significantly positive relationships between CRP level and total leukocyte count, neutrophil percentage, and monocyte percentage were found in all subjects (n = 14,114; p < 0.0001). In contrast, CRP level had a significantly inverse correlation with lymphocyte percentage (p < 0.0001). A proposed new reference range for total leukocyte count was estimated based on the data in the normal CRP level group (CRP < 0.1 mg/dL; n = 4839). To rest on the essence of statistics that the range of [mean +/- 2 standard deviations] contains approximately the middle 95% of observations in a sampled population, a new reference range for total leukocyte count was accordingly estimated to be 3.11-8.83 x 10(9)/L.

CONCLUSION

In view of the abundant evidence showing that a higher peripheral total leukocyte count is harmful to health, a down-correction of its upper reference range from the currently used 11.0 x 10(9)/L to the proposed 8.83 x 10(9)/L, based on a normal CRP level, should allow more abnormal health conditions to be identified and promote the usefulness of peripheral leukocyte analysis.

Incidence of hypertension and risk of cardiovascular events among ethnic Chinese: report from a community-based cohort study in Taiwan

BACKGROUND

Hypertension confers risk on cardiovascular events; however, less is known concerning hypertension incidence among ethnic Chinese. The effect of prehypertension on new onset of hypertension and cardiovascular events is also unknown.

OBJECTIVES

To investigate the incidence of hypertension, risk factors and cardiovascular events in Taiwan.

DESIGN

A prospective community-based cohort design.

SETTING AND PARTICIPANTS

The Chin-Shan Community Cardiovascular Cohort consisted of 1703 men and 1899 women aged 35 years old and above, of homogeneous Chinese ethnicity, from 1990 to 2005.

MAIN OUTCOME MEASURES

Hypertension incidence rates, cardiovascular events.

RESULTS

The patterns of adjusted cumulative incidence probability were curvilinear, increasing from 1% in the first period to 27% in the fourth period in normotensive subjects. The patterns among pre-hypertensives were from 4% in the first period to 59% in the fourth period. Women had an 18% lower risk of developing hypertension than men. The survival curves were distinctly different for different blood pressure categories (P < 0.001). Baseline blood pressure categories played important roles in predicting cardiovascular risks; the hazard risks of prehypertension and hypertension increased from 1.73 to 4.52, compared with baseline normotensive subjects.

CONCLUSION

The hypertension incidence rates among ethnic adult Chinese were high and were associated with obesity and metabolic syndrome status. Furthermore, the baseline prehypertension elicited significant risk of cardiovascular events in the community.

Association of peripheral total and differential leukocyte counts with metabolic syndrome and risk of ischemic cardiovascular diseases in patients with type 2 diabetes mellitus

BACKGROUND

There is increasing evidence that leukocytes play a central role in obesity, glucose intolerance, type 2 diabetes mellitus (T2DM), and cardiovascular diseases, but the role of differential leukocytes in metabolic syndrome (MetS) and atherosclerosis is largely unknown. The aim of this study was to examine the relationship between the component features of MetS and peripheral leukocyte counts and to explore whether leukocyte counts are associated with clustering of MetS and macrovascular diseases in patients with T2DM.

METHODS

1872 subjects with T2DM who enrolled in a diabetes disease management program were studied. The definition of MetS was modified from that outlined by the criteria of NCEP-ATP III. Areas under the receiver-operating characteristic curve and odds ratios at various intervals of the WBC counts were computed.

RESULTS

The peripheral total leukocyte, monocyte, and neutrophil cell counts are increased parallel to the clustering of components of MetS. When white cell counts were analyzed per quartile and as continuous variables after adjustment for age, sex, and other known risk factors with multiple regression analysis, peripheral total leukocyte, monocyte, neutrophils, and lymphocyte counts were independently and significantly associated with specific features of clustering of MetS and prevalence of ischemic cardiovascular diseases. Leukocyte counts, especially neutrophil/lymphocyte ratio, in addition with MetS is associated with the risk of ischemic cardiovascular diseases.

CONCLUSION

Our results indicate that differential leukocyte counts are associated with MetS and that peripheral leukocytes may play a role in the pathogenesis of macrovascular complications in patients with T2DM.

Plasma levels of complement C3 is associated with development of hypertension: a longitudinal cohort study

Hypertension has been associated with raised plasma levels of complement factor 3 and 4 (C3 and C4). The nature of this association is unclear. This population-based longitudinal study explored whether C3 or C4 is associated with development of hypertension. Blood pressure and plasma levels of C3 and C4 were determined in 2178 healthy men, aged 35-50 years, initially without treatment for hypertension. Incidence of hypertension and blood pressure increase over 15.7 (+/-2.2) years follow-up was studied in relation to C3 and C4 at baseline. Among men with initially normal blood pressure (<160/95 mm Hg), incidence of hypertension (>or=160/95 mm Hg or treatment) was 32, 42, 37 and 47%, respectively, for men with C3 in the first, second, third and fourth quartile (trend: P=0.001). This relationship remained significant after adjustment for confounding factors. Among men without blood pressure treatment, systolic BP increase (mean+standard error, adjusted for age, initial blood pressure and follow-up time) was 17.5+0.8, 19.6+0.9, 19.8+0.8 and 20.8+0.8 mm Hg, respectively, in the C3 quartiles (trend: P=0.004). C3 was not associated diastolic blood pressure at follow-up. Although C4 was associated with blood pressure at the baseline examination, there was no relationship between C4 and development of hypertension or future blood pressure increase. It is concluded that C3 in plasma is associated with future blood pressure increase and development of hypertension.

Exaggerated Blood Pressure Response to Exercise is Associated With Inflammatory Markers

PURPOSE

An exaggerated blood pressure (EBP) response to exercise has been shown to be a predictor of future hypertension and risk of cardiovascular mortality. Although EBP is associated with endothelial dysfunction and increased left ventricular hypertrophy, the underlying mechanisms are not fully understood. Inflammatory markers, C-reactive protein (CRP) and white blood cells (WBCs), were predictive of future hypertension. The objective of this study was to examine the hypothesis that increasing levels of CRP and WBCs would be related to an EBP response during exercise.

METHODS

Inflammatory markers were compared in 43 males with an EBP (systolic blood pressure [SBP] >or=210 mm Hg) response during maximal treadmill testing to an age and resting SBP-matched group of 42 males with a normal blood pressure response to exercise.

RESULTS

There were significant group differences in maximal SBP and diastolic blood pressure (DBP), exercise induced increases in SBP and DBP (P <.01), and WBCs (P <.01), but CRP did not differ between groups (P =.39). White blood cells were significantly associated with maximal SBP (r = 0.31), and the exercise-induced increase in SBP (r = 0.34). However, CRP did not correlate with the maximal blood pressure response to exercise (r = 0.11, P =.33). In a stepwise multiple regression analysis, WBC was independently associated with the exercise-induced increase in SBP (beta = 0.256, P =.011).

CONCLUSIONS

These results suggest that inflammation may be associated with an EBP response during exercise testing.

Association of white blood cell count with systolic blood pressure within the normotensive range

Hypertension and inflammation promote cardiovascular disease (CVD). Even high normal systolic blood pressure (SBP) is associated with increased CVD risk. We assessed the relationship of elevated SBP within the normotensive range and white blood cell (WBC) count. This is a cross-sectional study of 3484 white asymptomatic individuals (mean age: 43+/-8 years, 79% males) without hypertension with SBP<140 mm Hg. White blood cell count >or=75th percentile (8.35 x 10(9) cells/l) was considered cutoff for elevated WBC. Subjects were classified into three levels of SBP (first: <120 mm Hg, n=1,176, 34%; second: 120-129 mm Hg, n=1,654, 47%; third: 130-139 mm Hg, n=654, 19%). Mean WBC count increased linearly across SBP categories (first: 6.14+/-1.54, second: 6.20+/-1.52, third: 6.41+/-1.62, P=0.02 for trend). There was a linear increase in prevalence of elevated WBC across higher SBP categories (22, 24 and 28%, P=0.02). As compared to those with SBP<120 mm Hg, in multivariate linear regression analyses (adjusting for age, gender, smoking status, diabetes, body mass index, physical activity, cholesterol/high-density lipoprotein cholesterol ratio) WBC count was significantly higher among participants with SBP 130-139 mm Hg (regression coefficient: 2.64, 95% confidence interval: 1.04-4.24, P=0.001). Odds ratio for prevalence of elevated WBC with SBP<120 mm Hg as reference group was 1.14 (0.92-1.41) for SBP 120-129 mm Hg and 1.50 (1.15-1.92) for SBP 130-139 mm Hg. In conclusion, Higher SBP within the normotensive range is also associated with elevated WBC count. Further studies are needed to clarify the role of inflammation in high normal SBP and associated CVD risk.

Association of lymphocyte sub-populations with clustered features of metabolic syndrome in middle-aged Japanese men

To examine the relationship between altered cellular immune status and clustered features of the metabolic syndrome, we measured body mass index (BMI), serum concentrations of high-density lipoprotein-cholesterol, triglycerides, fasting plasma glucose, and blood pressure levels as well as differential leukocyte counts and lymphocyte sub-populations among 439 apparently healthy Japanese men aged 35-60 years. The components of the metabolic syndrome were defined based on the following criteria: BMI >/=25.0 kg/m(2), fasting plasma glucose >/=6.11 mmol/l, systolic blood pressure >/=130 mmHg and/or diastolic blood pressure >/=85 mmHg, high-density lipoprotein (HDL)-cholesterol <1.03 mmol/l, and fasting triglyceride >/=1.69 mmol/l. Counts of total leukocyte, total lymphocyte, CD3 + T cell, CD4 + T cell, and CD4 + CD45RO + T cell significantly correlated with the number of components of the metabolic syndrome (0, 1, 2, and 3+) after adjustment for age and smoking status. These findings were more evident among smokers than among non-smokers. The counts of total leukocytes, total lymphocytes and more specifically memory (CD4 + CD45RO + T) cells were elevated with clustered features of the metabolic syndrome in middle-aged men, which suggest the involvement of altered cellular immune status in the pathogenesis of atherosclerosis.

Associations between White Blood Cell Count and Risk for Cerebrovascular Disease Mortality: NHANES II Mortality Study, 1976–1992

PURPOSE

To examine associations between elevated white blood cell count (WBC) and cerebrovascular disease (CeVD) mortality independent of cigarette smoking and by gender.

METHODS

We used Cox regression analyses of data from 8459 adults (3982 men; 4477 women) aged 30 to 75 years in the NHANES II Mortality Study (1976-1992) to estimate the relative risk of death from CeVD across quartiles of WBC.

RESULTS

During 17 years of follow-up, there were 192 deaths from CeVD (93 men; 99 women). Compared with those with WBC (cells/mm(3))<5700, adults with WBC>8200 were at increased risk of CeVD mortality (relative risk [RR], 2.1; 95% confidence interval [CI], 1.2-3.7) after adjustment for smoking and other cardiovascular disease risk factors. Similar results were observed among never smokers (RR, 2.0; 95% CI, 1.0-3.8). The adjusted relative risk of CeVD mortality comparing those with WBC>8200 to those with WBC<5700 was 1.5 (95% CI, 0.7-3.5) among men and 2.7 (95% CI, 1.4-5.0) among women.

CONCLUSIONS

Elevated WBC may predict CeVD mortality even after considering the effects of smoking and other cardiovascular disease risk factors.

[Telomerase activity in peripheral blood leukocytes from patients with essential hypertension]

BACKGROUND AND OBJECTIVE

Primary or secondary activation of the immune mechanisms that lead to proliferation and dysfunction of specific cellular groups appears to be involved in the pathogenesis and complications of essential hypertension. In view of the evidence that, on one hand, telomeric length determines the replicative capacity and life span of cells and, on the other hand, idiopathic hypertensive patients have peripheral white cell replicative disorders, we decided to investigate the relationship between the influence of telomerase activity in peripheral leukocytes as an indirect marker of telomeric length and the presence of arterial hypertension.

PATIENTS AND METHOD

Telomerase activity in peripheral white blood cells was measured in healthy individuals, in effectively treated hypertensive patients and in a non-well controlled hypertensive group. White blood cells were separated through a density gradient, then lysed and their DNA amplified by a polimerase chain reaction (PCR). Telomerase activity was determined with an ELISA specific kit.

RESULTS

The white blood cell count was higher in the hypertensive than the control group (p < 0.05). Telomerase activity was positive in all three groups but higher in patients under 45 year-old with bad controlled hypertension as compared with healthy individuals and patients under 45 year-old with well controlled hypertension (p < 0.05); in the latter group, telomerase activity was significantly lower than in the other groups (p < 0.05).

CONCLUSIONS

Our results indicate that there exists a relationship between telomerase activity in peripheral leukocytes, the proliferation of these white blood cells and the presence of essential arterial hypertension.

White blood cell count as a risk factor for hypertension; a study of Japanese male office workers

OBJECTIVE

To investigate the association of white blood cell (WBC) count with risk of hypertension.

DESIGN

Cross-sectional and longitudinal studies.

SETTING

A work site in Japan.

PARTICIPANTS

A total of 3776 Japanese male office workers aged 23-49 years were enrolled in this study; 2900 hypertension-free [systolic blood pressure (SBP) < 140 mm Hg, diastolic blood pressure (DBP) < 90 mm Hg, no medication for hypertension, and no past history of hypertension] men were followed up over a 4-year period.

MAIN OUTCOME MEASURES

Blood pressure levels and the incidence of hypertension (SBP > or = 140 mm Hg and/or DBP > or = 90 mm Hg or medication for hypertension) according to WBC count at study entry.

RESULTS

After controlling for potential predictors of hypertension, SBP and DBP levels increased in a dose-dependent manner among both never-smokers and ex-smokers as WBC count increased. Among current smokers, only SBP level increased progressively with WBC count level. The multivariate-adjusted relative risk for development of hypertension compared with the first WBC count quintile was 1.29, 1.21, 1.67, and 1.92 among never-smokers (P for trend = 0.002): and 1.34, 1.46, 1.84, and 1.97 among ex-smokers (P for trend = 0.030) with the second, third, fourth, and fifth quintiles, respectively. Among current smokers, the respective multivariate-adjusted relative risks for hypertension relative to the first WBC count quintile were 0.91, 0.97, 1.08, and 0.84 (P for trend = 0.999).

CONCLUSIONS

WBC count is an important risk factor for hypertension, and the increased risk for hypertension associated with WBC count is more pronounced in non-smokers.

Polymorphonuclear integrins, membrane fluidity, and cytosolic Ca(2+) content after activation in essential hypertension

The purpose of this research was to obtain further information about the role of polymorphonuclear leukocytes in essential hypertension. These cells could be involved in the pathogenesis of organ injury. Thirty subjects (14 men and 16 women) with essential hypertension were enrolled. In these subjects we determined, at baseline and after in vitro activation with 4-phorbol 12-myristate 13-acetate and N:-formyl-methionyl-leucyl-phenylalanine, the polymorphonuclear leukocyte membrane fluidity, obtained by labeling the cells with 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3, 5-hexatriene, cytosolic Ca(2+) concentration, obtained by marking the cells with Fura 2-AM, and integrin pattern (CD11a, CD11b, CD11c, and CD18), by using the indirect immunofluorescence with a flow cytometer. At baseline there was no difference in membrane fluidity between normal subjects and hypertensives, whereas hypertensives showed an increase in cytosolic Ca(2+) content and an increase of the phenotypical expression of CD11a, CD11b, and CD18. In normal subjects and in hypertensives, after activation, no variation was found in membrane fluidity and cytosolic Ca(2+) content. In normal subjects, after activation, we observed a significant increase of the expression of all adhesion molecules, whereas in hypertensives we found an increase of the expression of CD11b, CD11c, and CD18 but also a decrease of CD11a. The behavior of the polymorphonuclear leukocyte integrin profile may have several explanations, and in particular, the trend of CD11a after chemotactic activation may be related to its cleavage or to an altered integrin phosphorylation/dephosphorylation balance hypothetically present in this clinical condition.

Plasma hydrogen peroxide production in hypertensives and normotensive subjects at genetic risk of hypertension

BACKGROUND

Oxygen free radicals may play roles in hypertension both in arteriolar constriction and in formation of lesions.

OBJECTIVE

To quantify free radical production in blood plasma of genetic hypertensives.

DESIGN

Hydrogen peroxide levels were measured, because it is one of the most stable reactive oxygen species.

METHODS

An electrode technique was used to determine plasma hydrogen peroxide levels after blockade of endogenous catalase with sodium azide. This method was validated by an independent spectrophotometric technique.

RESULTS

Members of the essential hypertensive group (n=21) had higher plasma hydrogen peroxide levels (3.16+/-0.14 versus 2.50+/-0.16 micromol/l, P=0.005) than did members of the normotensive group (n=29). Furthermore, within the normotensive group, those with a family history of hypertension (n=15) exhibited higher hydrogen peroxide levels (2.83+/-0.27 versus 2.14< or =0.13 micromol/l, P=0.03) than did those without such a family history (n=14). Plasma hydrogen peroxide levels in these 50 subjects were correlated to their mean arterial pressures (r=0.54, P < 0.001). When hypertensives were grouped with normotensives without a family history of hypertension, the correlation improved (r=0.70, P< 0.001). Statistical analysis (two-way analysis of variance) revealed that a family history of hypertension was a better predictor of plasma hydrogen peroxide production than was blood pressure status (P=0.003 versus P=0.093). Further investigations showed that superoxide is produced in plasma and that one of its sources is xanthine oxidase.

CONCLUSIONS

Hydrogen peroxide is produced in blood plasma and elevation of its level could constitute a pathogenic factor in vascular organ damage attendant upon systemic hypertension.

Reflections on telomeres, growth, aging, and essential hypertension

Here we review the "telomere hypothesis of cellular aging." We propose that this hypothesis is relevant to our understanding of the roles of genetics as well as growth and development in the etiology of essential hypertension and its cardiovascular complications. Elements of this hypothesis and the speculations that we make can be directly tested using tissues (cells) obtained from human beings.

Na+/H+ exchange in hypertension and in diabetes mellitus--facts and hypotheses

An enhancement of Na+/H+ exchange (NHE) in blood cells of selected patients with essential hypertension and with diabetic nephropathy has been described by various investigators. Recent studies have shown that enhanced NHE activity persists in immortalized lymphoblasts from these patients after prolonged cell culture and, thus, appears to be under genetic control. Available evidence strongly argues against a mutation in the encoding gene or an overexpression of the NHE. Immortalized cells from hypertensive patients with enhanced NHE activity display two-fold enhanced agonist-induced rises of the cytosolic free Ca2+ concentration and the underlying reason was identified as an increased activation of pertussis toxin (PTX)-sensitive G proteins. The molecular mechanism(s) of this phenomenon have not yet been elucidated. It appears likely that similar changes contribute to the enhanced NHE activity phenotype in diabetic nephropathy, although experimental evidence for this is still lacking. An enhanced activation of PTX-sensitive G proteins could explain many of the hitherto unexplained phenomena in essential hypertension, e.g. inheritance, increased vasoconstriction, hypertrophy of remodeling of arterial blood vessels and the heart, enhanced platelet aggregation etc. In diabetes the same defect could provide the basis for the susceptibility to nephropathy, e.g. by enhancing the deleterious effects of autocrine and paracrine growth factors. Thus, the experimental approach of immortalizing blood cells from patients with essential hypertension and diabetic nephropathy has opened new horizons in the identification of genetically fixed abnormalities in intracellular signal transduction which could contribute to both pathologies and which can now be studied without the confounding influences of the diabetic or hypertensive in vivo milieu.

Enhanced immunoglobulin formation of immortalized B cells from hypertensive patients

Increased immunoglobulin levels and leukocyte counts have frequently been reported in essential hypertension. The underlying mechanisms, however, have remained obscure. Enhanced Na(+)-H+ exchanger activity is another frequently observed abnormality in essential hypertension that persists in immortalized B lymphoblasts and coincides with enhanced proliferation. We investigated the capacity of B lymphoblasts from essential hypertensive patients to synthesize and secrete immunoglobulins. Six B cell lines from essential hypertensive patients with enhanced Na(+)-H+ exchanger phenotype and six cell lines from normotensive subjects were studied. Lymphocyte markers were visualized by immunostaining. Immunoglobulin secretion was analyzed by enzyme-linked immunosorbent assay. These cell lines did not differ with respect to B cell markers. In response to 100 nmol/L platelet-activating factor, cells from hypertensive patients proliferated distinctly more quickly and their cell number increased by 3.9 +/- 0.4-fold (mean +/- SD) within 4 days, whereas the number of cells from normotensive subjects increased by only 2.6 +/- 0.1-fold. Furthermore, platelet-activating factor induced average increases in IgM and IgG formation of 13.3- and 5.4-fold, respectively, in lymphoblasts from hypertensive patients, which was significantly higher than increases in cells from normotensive subjects (1.4- and 1.2-fold, respectively). Thus, lymphoblasts from hypertensive patients proliferate more quickly and secrete more immunoglobulins in response to a physiological stimulus in vitro. This may contribute to the raised immunoglobulin levels and leukocyte counts reported in vivo.

Properties of circulating leukocytes in spontaneously hypertensive rats

The factors responsible for predisposition to progressive organ injury and vascular complications in arterial hypertension are uncertain. Recent evidence shows that leukocytes participate in cardiovascular conditions for which hypertension is a risk factor. Therefore, there is a need to define the properties of circulating leukocytes in hypertensives. There are about twice as many circulating leukocytes in spontaneous hypertensive rats (SHRs) compared with their normotensive controls, the Wistar-Kyoto rats (WKYs). The SHR neutrophils are viscoelastic and similar to neutrophils in WKYs but exhibit lower deformability in short-term elastic deformation. Mature SHRs have elevated levels of spontaneous pseudopod formation. Mild stimulation with N-formyl-Met-Leu-Phe or platelet-activating factor (10(-8) M) results in a significantly enhanced level of neutrophil pseudopod formation in SHRs but not in WKYs. SHRs exhibit higher levels of spontaneous superoxide formation. Alkaline phosphatase content of individual circulating neutrophils in SHRs is on average lower while plasma levels of alkaline phosphatase in the same samples are elevated in the SHRs. Spontaneous degranulation of SHR neutrophils is also detectable with myeloperoxidase measurements. Such activity of circulating leukocytes poses a significant risk for vascular cytotoxicity in the hypertensive rats.