Higher plasma renin activity is a risk factor for total mortality in older Japanese individuals: the Takahata study

Association of Aldosterone with Mortality in the General Population

INTRODUCTION

Aldosterone excess is linked to cardiovascular events and mortality as well as to low-grade inflammation in the context of metabolic diseases. Whether mildly elevated aldosterone levels in the general population promote cardiovascular risk is still under debate. We analyzed the association of plasma aldosterone concentrations with incident cardiovascular events, cardiovascular and all-cause mortality as well as with biomarkers of subclinical inflammation in the population-based KORA F4 study.

METHODS

Plasma aldosterone concentrations were measured with an in-house immunoflurometric assay. The analyses included 2935 participants (n=1076 for selected biomarkers of subclinical inflammation) with a median follow-up of 8.7 (8.2; 9.1) years. The associations were estimated using Cox proportional hazard and linear regression models adjusted for renin, sex, age, body mass index, arterial hypertension, diabetes, estimated glomerular filtration rate, low- and high-density lipoprotein cholesterol, physical activity, smoking, use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, diuretics and calcium channel blockers.

RESULTS

Aldosterone was significantly associated with all-cause mortality (hazard ratio per standard deviation increase: 1.20; 95% confidence interval 1.04-1.37), but not with cardiovascular mortality, incident cardiovascular events, or with biomarkers of subclinical inflammation.

CONCLUSIONS

Aldosterone was associated with all-cause mortality in the population-based KORA F4 study, but the previously described associations of excess aldosterone with cardiovascular complications and biomarkers of subclinical inflammation could not be shown.

The renin-angiotensin-aldosterone system, neurohumoral axis and cardiovascular mortality in LURIC

Although neurohormones and Renin-Angiotensin-Aldosterone-System (RAAS) components are important predictors of cardiovascular mortality (CVM), their importance for predicting outcomes in patients with/without RAAS-blockers and different degrees of arterial stiffness is less understood. We therefore analyzed long-term data from the Ludwigshafen Risk and Cardiovascular Health (LURIC) study in 3316 patients subdivided according to pulse pressure (PP) and RAAS-blocker use. Patients on RAAS-inhibition had higher renin and noradrenaline, lower aldosterone and aldosterone/renin quotient (ARQ). Renin and noradrenaline significantly predicted CVM in patients without RAAS-blocker (HR = 1.17, 1.15) and in patients receiving angiotensin-converting-enzyme (ACE) inhibitors (HR = 1.17, 1.29), whereas aldosterone predicted CVM only in patients receiving ACE-inhibitors (HR = 1.13). CVM was predicted independently from PP by renin, noradrenaline and angiotensin II. Independently from RAAS inhibition renin decreased and ARQs increased with rising PP. Furthermore, noradrenaline increased with PP, but only without ACE-inhibition. The HR for CVM in the ACE-inhibitor group were 1.29, 1.28, 1.29 for renin in the first, second and third PP quartiles and 1.22, and 1.19 for aldosterone in the second and fourth quartile. Furthermore, we showed that noradrenaline predicts CVM in all PP quartiles in patients with ACE-inhibition. In the RAAS-blocker-free group, the HR for renin for CVM were 1.36 and 1.18 in the third and fourth PP quartiles, but neither aldosterone nor noradrenaline were predictive for CVM within the PP quartiles. Renin and noradrenaline are strong predictors of CVM regardless of RAAS blockade, whereas aldosterone is predictive only in the ACE-inhibitor group. Catecholamines but not renin are associated with rising PP.

Associations of Frequency of Laughter With Risk of All-Cause Mortality and Cardiovascular Disease Incidence in a General Population: Findings From the Yamagata Study

Background

Positive and negative psychological factors are associated with mortality and cardiovascular disease. This study prospectively investigated associations of daily frequency of laughter with mortality and cardiovascular disease in a community-based population.

Methods

This study included 17,152 subjects ≥40 years old who participated in an annual health check in Yamagata Prefecture. Self-reported daily frequency of laughter was grouped into three categories (≥1/week; ≥1/month but <1/week; <1/month). Associations of daily frequency of laughter with increase in all-cause mortality and cardiovascular disease incidence were determined using Cox proportional hazards modeling.

Results

During follow-up (median, 5.4 years), 257 subjects died and 138 subjects experienced cardiovascular events. Kaplan-Meier analysis revealed that all-cause mortality and cardiovascular disease incidence were significantly higher among subjects with a low frequency of laughter (log-rank P < 0.01). Cox proportional hazard model analysis adjusted for age, gender, hypertension, smoking, and alcohol drinking status showed that risk of all-cause mortality was significantly higher in subjects who laughed <1/month than in subjects who laughed ≥1/week (hazard ratio [HR] 1.95; 95% confidence interval [CI], 1.16–3.09). Similarly, risk of cardiovascular events was higher in subjects who laughed ≥1/month but <1/week than in subjects who laughed ≥1/week (HR 1.62; 95% CI, 1.07–2.40).

Conclusion

Daily frequency of laughter represents an independent risk factor for all-cause mortality and cardiovascular disease in a Japanese general population.

Cognitive impairment, brain ischemia and shorter telomeres are predictors of mortality in the Japanese elderly: A 13-year prospective community-based study

OBJECTIVE

To examine whether cognitive impairment, deep white matter hyperintensity (DWMH) on brain MRI, and shorter telomere length would be predictors of mortality in community-dwelling Japanese elderly.

METHODS

We followed 259 individuals (74% of all the residents at age 70) from age 70 to 83 years. The mean observation period was 133 ± 34 months. The key clinical characteristics examined included DWMH on brain MRI and cognitive function. Telomere length was also measured in 81 subjects. Both univariate and multivariate analyses were performed.

RESULTS

Of the 259 subjects, 69 subjects (30 men, 39 women; 26.6%) died during the follow-up period. Cognitive impairment, smoking habits, diabetes mellitus, and moderate to severe DWMH were significant predictors of total mortality in univariate analysis. However, only cognitive impairment and moderate to severe DWMH remained as significant independent predictors of death in multivariate analysis. The rate of mortality increased with additional number of risk factors (cognitive impairment and DWMH). The total mortality of subjects with both cognitive impairment and DWMH was 71.4%. The median telomere length was 7.8 kb in the deceased and 8.2 kb in the living subjects. The deceased subjects had significantly shorter telomere length (P = .0025) than the living subjects. Telomere length with moderate to severe DWMH was higher than without moderate to severe DWMH on brain MRI (P = .017).

CONCLUSIONS

The present study revealed that cognitive impairment, DWMH, and shorter telomere length were significant predictors of total mortality in the community-dwelling Japanese elderly. Furthermore, the combination of cognitive impairment and DWMH increased the mortality rate, as compared with a single risk factor. It is also clarified that a significant difference was present in telomere length by severity of DWMH.

Presence of Myocardial Damage Predicts Future Development of Hypertension in a Normotensive Japanese General Population: The Yamagata (Takahata) Study

BACKGROUND

A modest rise in blood pressure (BP) reportedly increases cardiovascular mortality despite not reaching obvious hypertension, suggesting that target organ damages are latently induced by slight BP rising. The goal of this study was to determine whether presence of subclinical myocardial damage can predict the future development of hypertension in the normotensive general population.

METHODS AND RESULTS

The cohort study was conducted with subjects who participated in a community-based annual health check. Normotensive subjects without prior cardiovascular diseases at baseline were eligible for analyses (n = 524, mean age 58 ± 9 years; 53% women). We measured heart-type fatty acid binding protein (H-FABP) at baseline as a biomarker of ongoing myocardial damage. Longitudinal changes in BP were examined during median follow-up period of 6.2 years, and we investigated the association between the baseline H-FABP level and longitudinal BP changes.

RESULTS

During the follow-up, 177 subjects (34%) developed hypertension. In multivariate Cox proportional hazard analysis adjusted for potential confounders including age and baseline BP, presence of myocardial damage was significantly associated with the development of hypertension (hazard ratio 1.80, 95% confidence interval, 1.26-2.54; P = 0.0014). Furthermore, relative risk of myocardial damage for incident hypertension was higher in younger subjects and lower BP category.

CONCLUSIONS

Presence of subclinical myocardial damage was independently associated with the future development of hypertension in the normotensive general population.

Serum uric acid is not independently associated with plasma renin activity and plasma aldosterone in hypertensive adults

BACKGROUND AND AIMS

In experimental investigations conducted in rats, raising serum uric acid (SUA) levels resulted in the stimulation of intrarenal renin expression. Studies in humans exploring the association of SUA with plasma renin activity (PRA) yielded conflicting results. Moreover, little is known about the relationship of SUA with plasma aldosterone concentration (PAC). The study aimed to assess the relationship between SUA levels, PRA, and PAC and the influence of age, gender, body mass index (BMI), and hyperuricemia on these relationships in subjects with essential hypertension (EH).

METHODS AND RESULTS

We enrolled 372 hypertensive patients (mean age 45 ± 12 years, men 67%) with uncomplicated EH that was not pharmacologically treated. The study population was divided in tertiles according to SUA levels. While PRA did not differ significantly across the three tertiles, PAC was higher in subjects belonging to the uppermost tertile of SUA than those in the lower ones (p = 0.0429); however, this difference lost statistical significance after adjustment for age, sex, BMI, and serum creatinine. Univariate correlation analyses showed significant associations of SUA with PRA (r = 0.137; p = 0.008) and PAC (r = 0.179; p < 0.001). However, these relationships were not significant after correcting for confounding factors in multiple linear regression analyses. We did not observe statistically significant effect modification by gender, age, BMI, and hyperuricemia.

CONCLUSION

SUA levels are weakly associated with PRA and PAC in adults with untreated EH. These relationships were lost after adjustment for age, sex, BMI, and serum creatinine.

Association Between Polymorphisms of ADRBK1 Gene and Plasma Renin Activity in Hypertensive Patients: A Case-Control Study

Background

Renin is the first step of the RAS cascade, which is a major regulator of salt-volume homeostasis. Adrenergic beta receptor kinase 1 (ADRBK1) plays important roles in regulating blood pressure via the epithelial Na⁺ channel (ENaC), which plays an important role in Na⁺ reabsorption in the renal collecting duct. The present case-control study was designed to investigate the potential relationship between polymorphisms of ADRBK1 and plasma renin activity (PRA) in hypertension.

Material/Methods

We recruited 1831 hypertensive and 422 normotensive Han Chinese subjects. Sitting PRA (ng/mL/h) was measured using radioimmunoassay method. Hypertensive patients were classified into 4 renin categories via PRA quartile. Single-nucleotide polymorphisms (SNPs) of the ADRBK1 gene (rs1894111, rs4930416, rs7127431, rs12286664, and rs3730147) were identified via TaqMan polymerase chain reaction.

Results

Comparison of the hypertensive group and the control group showed significant differences in distribution of genotypes and alleles of rs1894111 (P<0.05). Moreover, distribution of the dominant model (CC vs. CT+TT) in rs1894111 was lower in the hypertensive group than in the control group (P<0.05). Subjects were classified into 4 subgroups based on PRA quartile; the dominant model (CC vs. CT+TT) of rs1894111 was significantly lower in the quartile 1 group (the group with the lowest PRA) than in the control group (P<0.05). Logistic regression analysis demonstrated that the dominant model (CC vs. CT+TT) of rs1894111 was significantly different in the hypertensive group (OR=1.590, 95%CI=1.022–2.474, P<0.05), particularly in the quartile 1 group (OR=1.845, 95%CI=1.119–3.042, P<0.05), but not in the quartile 4 group.

Conclusions

The dominant model (CC vs. CT+TT) of rs1894111 polymorphism in the ADRBK1 gene might be associated with low-renin hypertension in Han Chinese.

A Genetic Variant in the Distal Enhancer Region of the Human Renin Gene Affects Renin Expression

Background

The high heritability of plasma renin activity was confirmed in recent investigations. A variation located near the strong enhancer of the human renin gene (REN), C-5312T, has been shown to have different transcription activity levels depending on its allele: the 5312T allele shows transcription levels that are 45% greater than those of the 5312C allele. The purpose of this study was to confirm the hypothesis that variations in the enhancer region of the REN gene are involved in regulating renal expression of renin.

Methods

Sixty-four subjects with biopsy-proven renal diseases were included in this study (male/female: 35/29, age 41.9 ± 20.9 years, SBP/DBP 123.1 ± 23.7/73.4 ± 14.8 mmHg, s-Cr 0.93 ± 0.63 mg/dl). A genetic variant of REN, C-5312T, was assayed by PCR-RFLP and the TaqMan method. Total RNAs from a small part of the renal cortex were reverse-transcribed and amplified for REN and GAPDH with a real-time PCR system.

Results

Logarithmically transformed expression values of the relative ratio of REN to GAPDH (10⁻³) were as follows (mean ± SE): CC (26 cases), 0.016 ± 0.005; CT (33 cases), 0.047 ± 0.021 (p = 0.41 vs. CC); TT (5 cases), 0.198 ± 0.194 (p = 0.011 vs. CC, p < 0.031 vs. CT). Thus, significant differences in REN expression were observed among the genetic variants.

Conclusion

The results suggest that variants in the enhancer region of the human renin gene have an effect on the expression levels of renin in renal tissue; this observation is in good accordance with the results of the transcriptional assay.

Lower aldosterone-renin ratio is a risk factor for total and cancer death in Japanese individuals: the Takahata study

OBJECTIVE

A higher plasma aldosterone-renin ratio (ARR) is an established marker for screening for primary aldosteronism (PA). The association between higher ARR and mortality in a general population has not been fully explored. We here examined whether higher ARR is a risk factor for total and cause-specific mortality in a Japanese population.

SUBJECTS AND METHODS

A population-based, longitudinal study of 1,310 Japanese individuals (age: 63·9 ± 9·8 years) enrolled in the Takahata study between 2004 and 2006 and followed for up to 8 years. The incidence and causes of death were monitored annually until 10 January 2012 (median follow-up: 2691 days).

RESULTS

During the follow-up period, 64 subjects died. Kaplan-Meier analysis showed a significantly increased risk for total and cancer mortality in subjects with lower ARR (log-rank P < 0·001). Cox's proportional hazard model analyses with adjustment for age and gender showed that lower ARR was associated with increased total and cancer mortality in subjects with low (≦72) vs high (>72) ARR (hazard ratios and 95% confidential intervals: 2·56, 1·44-4·56 and 2·78, 1·16-6·65, respectively).

CONCLUSIONS

Lower ARR was a significant and independent risk factor for increased total and cancer mortality in this Japanese population. Subjects with higher ARR were not-at-risk for total death in general. These findings increase the necessity for identifying people with PA from those with higher ARR. People with higher ARR without PA may be at very low risk for total and cancer death.

Determinants of plasma renin activity: role of a human renin gene variant as a genetic factor

The plasma renin activity (PRA) is affected by a number of environmental factors. However, significant heritability has been shown for the activity. A hypothesis that a candidate regulatory single-nucleotide polymorphism, C-5312T, of human renin gene should have a significant effect on PRA was elucidated and updating of independent determinants of PRA was attempted. Cross sectional study. Outpatient study. We enrolled consecutive 810 subjects who had consulted our hospitals for lifestyle-related diseases. Genotypes were assayed with genomic DNA for C-5312T. Among the genetic variants, the difference of PRA was evaluated. Monovariate linear regression analysis was performed to test the correlation between PRA and clinical variables. Finally, stepwise multiple regression analysis was performed to evaluate the independent determinants. On comparing 2 genotype groups, CC/CT and T allele homozygote, the geometric means of PRA were 0.778 and 0.941 ng/ml/h, respectively (F = 5.992, P = 0.015). Monovariate linear regression analysis revealed that a number of variables have a significant correlation with the activity, including urinary salt excretion. A stepwise multivariate regression analysis revealed that renin C-5312T variant (TT) is one of the independent determinants of PRA. Thus, for the first time, a human renin gene variant was associated with a significant increase in PRA as a genetic factor and the independent determinants for the activity were updated including genetic factor.

A lower level of forced expiratory volume in 1 second is a risk factor for all-cause and cardiovascular mortality in a Japanese population: the Takahata study

Chronic obstructive pulmonary disease is a known risk factor for cardiovascular death in Western countries. Because Japan has a low cardiovascular death rate, the association between a lower level of forced expiratory volume in 1 s (FEV1) and mortality in Japan's general population is unknown. To clarify this, we conducted a community-based longitudinal study. This study included 3253 subjects, who received spirometry from 2004 to 2006 in Takahata, with a 7-year follow-up. The causes of death were assessed on the basis of the death certificate. In 338 subjects, airflow obstruction was observed by spirometry. A total of 127 subjects died. Cardiovascular death was the second highest cause of death in this population. The pulmonary functions of the deceased subjects were significantly lower than those of the subjects who were alive at the end of follow-up. The relative risk of death by all causes, respiratory failure, lung cancer, and cardiovascular disease was significantly increased with airflow obstruction. The Kaplan-Meier analysis showed that all-cause and cardiovascular mortality significantly increased with a worsening severity of airflow obstruction. After adjusting for possible factors that could influence prognosis, a Cox proportional hazard model analysis revealed that a lower level of FEV1 was an independent risk factor for all-cause and cardiovascular mortality (per 10% increase; hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.82-0.98; and HR, 0.72; 95% CI, 0.61-0.86, respectively). In conclusion, airflow obstruction is an independent risk factor for all-cause and cardiovascular death in the Japanese general population. Spirometry might be a useful test to evaluate the risk of cardiovascular death and detect the risk of respiratory death by lung cancer or respiratory failure in healthy Japanese individuals.

Renin as a biomarker of cardiovascular disease in clinical practice

The search for novel circulating blood biomarkers as predictors of cardiovascular (CV) risk and prognosis is a continuing field of interest in clinical medicine. Biomarkers from several pathophysiological pathways, including markers of organ damage, of inflammation, of the atherosclerotic process and of the coagulation pathway, have been investigated in the last decades. A particular interest has been raised for neurohormonal factors. The role of the activation of the sympathetic system and the renin-angiotensin-aldosterone system (RAAS) in the development of CV diseases has been extensively explored. Renin is the first limiting step of the RAAS and its role as a biomarker to improve CV risk stratification still remains a topic of debate. Several studies have shown that elevated plasma renin activity is associated with increased morbidity and mortality in patients with CV disease. The aim of this paper is to critically evaluate the evidence on the role of renin as a biomarker of CV risk and prognosis. With the new advances of pharmacological treatment acting on the RAAS, the effect of elevated levels of renin on the prognosis of these patients becomes even more intriguing.