Associations of lipid accumulation product, visceral adiposity index, and triglyceride-glucose index with subclinical organ damage in healthy Chinese adults

Background and aims

Obesity is an independent risk factor for cardiovascular disease development. Here, we aimed to examine and compare the predictive values of three novel obesity indices, lipid accumulation product (LAP), visceral adiposity index (VAI), and triglyceride-glucose (TyG) index, for cardiovascular subclinical organ damage.

Methods

A total of 1,773 healthy individuals from the Hanzhong Adolescent Hypertension Study cohort were enrolled. Anthropometric, biochemical, urinary albumin-to-creatinine ratio (uACR), brachial-ankle pulse wave velocity (baPWV), and Cornell voltage-duration product data were collected. Furthermore, the potential risk factors for subclinical organ damage were investigated, with particular emphasis on examining the predictive value of the LAP, VAI, and TyG index for detecting subclinical organ damage.

Results

LAP, VAI, and TyG index exhibited a significant positive association with baPWV and uACR. However, only LAP and VAI were found to have a positive correlation with Cornell product. While the three indices did not show an association with electrocardiographic left ventricular hypertrophy, higher values of LAP and TyG index were significantly associated with an increased risk of arterial stiffness and albuminuria. Furthermore, after dividing the population into quartiles, the fourth quartiles of LAP and TyG index showed a significant association with arterial stiffness and albuminuria when compared with the first quartiles, in both unadjusted and fully adjusted models. Additionally, the concordance index (C-index) values for LAP, VAI, and TyG index were reasonably high for arterial stiffness (0.856, 0.856, and 0.857, respectively) and albuminuria (0.739, 0.737, and 0.746, respectively). Lastly, the analyses of continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI) demonstrated that the TyG index exhibited significantly higher predictive values for arterial stiffness and albuminuria compared with LAP and VAI.

Conclusion

LAP, VAI, and, especially, TyG index demonstrated utility in screening cardiovascular subclinical organ damage among Chinese adults in this community-based sample. These indices have the potential to function as markers for early detection of cardiovascular disease in otherwise healthy individuals.

Associations of SGLT2 genetic polymorphisms with salt sensitivity, blood pressure changes and hypertension incidence in Chinese adults

Sodium-glucose cotransporter 2 (SGLT2) inhibitors lowers blood pressure (BP) and exert a salutary effect on the salt sensitivity of BP. This study aimed to examine the associations of SGLT2 genetic variants with salt sensitivity, longitudinal BP changes and the risk of incident hypertension in Baoji Salt-Sensitive Study. A total of 514 participants were recruited when the cohort was established in 2004, and 333 participants received a dietary intervention that consisted of a 3-day usual diet followed sequentially by a 7-day low-salt diet and a 7-day high-salt diet. The cohort was then followed up for 14 years to evaluate the longitudinal BP changes and development of hypertension. We found that SGLT2 SNP rs3813007 was significantly associated with the systolic BP (SBP) responses to the low-salt diet. Over the 14 years of follow-up, SNPs rs3116149 and rs3813008 were significantly associated with the longitudinal SBP changes, and SNPs rs3116149, rs3813008, rs3813007 in SGLT2 were significantly associated with incidence of hypertension. Furthermore, gene-based analyses revealed that SGLT2 was significantly associated with hypertension incidence. Our study suggests that SGLT2 genetic polymorphisms may be involved in salt sensitivity and development of hypertension.

Sex differences in impact of cumulative systolic blood pressure from childhood to adulthood on albuminuria in midlife: a 30-year prospective cohort study

BACKGROUND AND OBJECTIVES

Albuminuria is recognized as being a predictor of cardiovascular and renal disease. We aimed to identify the impact of the long-term burden and trends of systolic blood pressure on albuminuria in midlife, as well as to explore sex differences concerning this relationship.

METHODS

This longitudinal study consisted of 1,683 adults who had been examined 4 or more times for blood pressure starting in childhood, with a follow-up time period of 30 years. The cumulative effect and longitudinal trend of blood pressure were identified by using the area under the curve (AUC) of individual systolic blood pressure measurement with a growth curve random effects model.

RESULTS

Over 30 years of follow-up, 190 people developed albuminuria, including 53.2% males and 46.8% females (aged 43.39 ± 3.13 years in the latest follow-up). The urine albumin-to-creatinine ratio (uACR) values increased as the total and incremental AUC values increased. Additionally, women had a higher albuminuria incidence in the higher SBP AUC groups than men do (13.3% for men vs. 33.7% for women). Logistic regression showed that the ORs of albuminuria for males and females in the high total AUC group were 1.34 (0.70-2.60) and 2.94 (1.50-5.74), respectively. Similar associations were found in the incremental AUC groups.

CONCLUSIONS

Higher cumulative SBP was correlated with higher uACR levels and a risk of albuminuria in middle age, especially in women. The identification and control of cumulative SBP levels from an early age may assist in reducing the incidences of renal and cardiovascular disease for individuals in later life.

Early-Life Cardiovascular Risk Factor Trajectories and Vascular Aging in Midlife: A 30-Year Prospective Cohort Study

BACKGROUND

Vascular aging, as assessed by structural and functional arterial properties, is an independent predictor of cardiovascular outcomes. We aimed to explore the associations of individual cardiovascular risk factors from childhood to midlife and their accumulation over a 30-year span with vascular aging in midlife.

METHODS

Using data from the ongoing cohort of Hanzhong Adolescent Hypertension study, 2180 participants aged 6 to 18 years at baseline were followed for over 30 years. Distinct trajectories of systolic blood pressure (SBP), body mass index (BMI), and heart rate from childhood to midlife were identified by group-based trajectory modeling. Vascular aging was assessed by carotid intima media thickness or brachial-ankle pulse wave velocity.

RESULTS

We identified 4 distinct SBP trajectories, 3 distinct BMI trajectories, and 2 distinct heart rate trajectories from childhood to midlife. Persistently increasing SBP, high-increasing BMI, and high-stable heart rate were all shown to have a positive association with brachial-ankle pulse wave velocity in midlife. For carotid intima-media thickness, similar associations were observed for persistently increasing SBP and high-increasing body mass index. After further adjustment for SBP, body mass index and heart rate at the time of vascular assessment in 2017, associations were also observed for cardiovascular risk factor trajectories accumulation with brachial-ankle pulse wave velocity (β, 0.656 [95% CI, 0.265-1.047]) and with carotid intima media thickness (β, 0.045 [95% CI, 0.011-0.079]) in adulthood.

CONCLUSIONS

Longitudinal exposure to individual cardiovascular risk factors from childhood to midlife and cardiovascular risk factor accumulation were associated with an increased risk of vascular aging in midlife. Our study lends support for early targeting of risk factors in order to prevent cardiovascular disease later in life.

Associations of genetic variations in NEDD4L with salt sensitivity, blood pressure changes and hypertension incidence in Chinese adults

Neural precursor cell expressed developmentally downregulated 4-like (NEDD4L), a member of the E3 ubiquitin-protein ligases, encoded by NEDD4L gene, was found to be involved in in salt sensitivity by regulating sodium reabsorption in salt-sensitive rats. The authors aimed to explore the associations of NEDD4L genetic variants with salt sensitivity, blood pressure (BP) changes and hypertension incidence in Chinese adults. Participants from 124 families in Northern China in the Baoji Salt-Sensitive Study Cohort in 2004, who received the chronic salt intake intervention, including a 7-day low-salt diet (3.0 g/day) and a 7-day high-salt diet (18 g/day), were analyzed. Besides, the development of hypertension over 14 years was evaluated. NEDD4L single nucleotide polymorphism (SNP) rs74408486 was shown to be significantly associated with systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure (MAP) responses to low-salt diet, while SNPs rs292449 and rs2288775 were significantly associated with pulse pressure (PP) response to high-salt diet. In addition, SNP rs4149605, rs73450471, and rs482805 were significantly associated with the longitudinal changes in SBP, DBP, MAP, or PP at 14 years of follow-up. SNP rs292449 was significantly associated with hypertension incidence over the 14-year follow-up. Finally, this gene-based analysis found that NEDD4L was significantly associated with longitudinal BP changes and the incidence of hypertension over the 14-year follow-up. This study indicated that gene polymorphism in NEDD4L serve an important function in salt sensitivity, longitudinal BP change and development of hypertension in the Chinese population.

Early life body mass index trajectories and albuminuria in midlife: A 30-year prospective cohort study

BACKGROUND

Albuminuria is a marker of vascular dysfunction and is associated with chronic renal and cardiovascular diseases. Data on the association between the longitudinal patterns of weight change early in life and albuminuria later in life are limited. We aimed to identify the body mass index (BMI) trajectory across a 30-year span and evaluate its association with middle-age albuminuria.

METHODS

Of the 4623 participants aged 6-18-year-old recruited by Hanzhong Adolescent Hypertension Study cohort in northern China from March 10, 1987 to June 3, 2017, a total of 1,825 participants followed up with 6 visits over 30 years were enrolled. Group-based trajectory modeling was used to identify distinct BMI trajectories in longitudinal analyses. Albuminuria was defined as a urinary albumin-to-creatinine ratio (uACR) ≥ 30 mg/g.

FINDINGS

Three distinct BMI trajectories were identified: low-increasing (n = 671, 36.8%), moderate-increasing (n = 940, 51.5%), and high-increasing (n = 214, 11.7%); male participants exhibited a steeper increase in BMI than females. The uACR was increased linearly from the low- to high-increasing group. A total of 201 individuals developed albuminuria, with an incidence of 11.0%. Compared with the low-increasing group, the odds ratio (OR) of albuminuria in middle age was 2.13(95% confidence interval [CI]: 1.26 to 3.61) for the high-increasing group after full adjustment for age, sex, smoking, alcohol consumption, marital status, systolic blood pressure, diabetes, and hyperlipidemia. The unadjusted ORs of the high-increasing BMI group were 5.08 (2.76-9.37) for males and 3.45 (1.78-6.69) for females, and the association remained significant in males in the fully adjusted models.

INTERPRETATION

Higher BMI trajectories are associated with higher uACR and an increased risk of albuminuria in middle age, especially in males. Identifying long-term BMI trajectories from an early age may assist in predicting the risk of renal diseases and cardiovascular disease later in life.

FUNDING

This work was supported by the National Natural Science Foundation of China (81600327, 82070437, 81870319, 82070549, and 82170437), Natural Science Basic Research Program of Shaanxi Province (2021JM-257 and 2021JM-588), Institutional Foundation of the First Affiliated Hospital of Xi'an Jiaotong University (2019QN-06 and 2021ZXY-14), the Clinical Research Award of the First Affiliated Hospital of Xi'an Jiaotong University of China (XJTU1AF-CRF-2019-004, XJTU1AF2021CRF-021, and XJTU1AFCRF-2017-021), Research Incubation Fund of Xi'an People's Hospital (FZ-61), Grants from the Major Chronic Non-communicable Disease Prevention and Control Research Key Project of the Ministry of Science and Technology of China (2017YFC1307604 and 2016YFC1300104).

Associations of Long-Term Visit-to-Visit Blood Pressure Variability With Subclinical Kidney Damage and Albuminuria in Adulthood: a 30-Year Prospective Cohort Study

BACKGROUND

Recent evidence indicates that long-term visit-to-visit blood pressure variability (BPV) may be associated with risk of cardiovascular disease. We, therefore, aimed to determine the potential associations of long-term BPV from childhood to middle age with subclinical kidney damage (SKD) and albuminuria in adulthood.

METHODS

Using data from the ongoing cohort of Hanzhong Adolescent Hypertension study, which recruited children and adolescents aged 6 to 18 years at baseline, we assessed BPV by SD and average real variability (ARV) for 30 years (6 visits). Presence of SKD was defined as estimated glomerular filtration rate between 30 and 60 mL/min per 1.73 m² or elevated urinary albumin-to creatinine ratio at least 30 mg/g. Albuminuria was defined as urinary albumin-to creatinine ratio ≥30 mg/g.

RESULTS

During 30 years of follow-up, of the 1771 participants, 204 SKD events occurred. After adjustment for demographic, clinical characteristics, and mean BP during 30 years, higher SD_SBP , ARV_SBP , SD_DBP , ARV_DBP , SD_MAP , ARV_MAP , and ARV_PP were significantly associated with higher risk of SKD. When we used cumulative exposure to BP from childhood to adulthood instead of mean BP as adjustment factors, results were similar. In addition, greater long-term BPV was also associated with the risk of albuminuria. Long-term BPV from childhood to middle age was associated with higher risk of SKD and albuminuria in adulthood, independent of mean BP or cumulative exposure to BP during follow-up.

CONCLUSIONS

Identifying long-term BPV from early age may assist in predicting kidney disease and cardiovascular disease in later life.

Associations of Renalase With Blood Pressure and Hypertension in Chinese Adults

Objective

Renalase, a novel secretory flavoprotein with amine oxidase activity, is secreted into the blood by the kidneys and is hypothesized to participate in blood pressure (BP) regulation. We investigated the associations of renalase with BP and the risk of hypertension by examining renalase single nucleopeptide polymorphism (SNPs), serum renalase levels, and renal expression of renalase in humans.

Methods

① Subjects (n = 514) from the original Baoji Salt-Sensitive Study cohort were genotyped to investigate the association of renalase SNPs with longitudinal BP changes and the risk of hypertension during 14 years of follow-up. ② Two thousand three hundred and ninety two participants from the Hanzhong Adolescent Hypertension Study cohort were used to examine the association of serum renalase levels with hypertension. Renalase expression in renal biopsy specimens from 193 patients were measured by immunohistochemistry. ③ Renalase expression was compared in hypertensive vs. normotensive patients.

Results

① SNP rs7922058 was associated with 14-year change in systolic BP, and rs10887800, rs796945, rs1935582, rs2296545, and rs2576178 were significantly associated with 14-year change in diastolic BP while rs1935582 and rs2576178 were associated with mean arterial pressure change over 14 years. In addition, SNPs rs796945, rs1935582, and rs2576178 were significantly associated with hypertension incidence. Gene-based analysis found that renalase gene was significantly associated with hypertension incidence over 14-year follow-up after adjustment for multiple measurements. ② Hypertensive subjects had higher serum renalase levels than normotensive subjects (27.2 ± 0.4 vs. 25.1 ± 0.2 μg/mL). Serum renalase levels and BPs showed a linear correlation. In addition, serum renalase was significantly associated with the risk of hypertension [OR = 1.018 (1.006–1.030)]. ③ The expression of renalase in human renal biopsy specimens significantly decreased in hypertensive patients compared to non-hypertensive patients (0.030 ± 0.001 vs. 0.038 ± 0.004).

Conclusions

These findings indicate that renalase may play an important role in BP progression and development of hypertension.

Association of body mass index changes from childhood to adulthood with dyslipidemia in adults: Hanzhong adolescent cohort study

BACKGROUND

Dyslipidemia is a disorder of lipid metabolism and associated with insulin resistance. The relationship between longitudinal body mass index (BMI) changes from childhood to adulthood and long-term dyslipidemia was explored in this study.

METHODS

We assessed the longitudinal relationship between BMI changes since childhood and dyslipidemia among 1738 participants in rural areas of Hanzhong City, Shaanxi. All participants were initially examined between the ages of 6 and 15 years in 1987 and were reexamined in 1995, 2013 and 2017; the total follow-up duration was 30 years. Anthropometric measurements and blood biochemistry indexes were measured.

RESULTS

We found that gradual progression of normal weight to overweight (OR = 1.65; 95% CI = 1.27, 2.15) or persistent overweight (OR = 2.45; 95% CI = 1.52, 3.96) from childhood to adulthood was associated with an increased risk of dyslipidemia in adulthood. And these risks were largely disappeared if the overweight or obesity during childhood was resolved by adulthood. The higher the BMI in adulthood and the younger the age at which overweight begins, the higher the risk of dyslipidemia.

CONCLUSIONS

Early weight loss and any degree of weight loss from childhood to adulthood can help improve dyslipidemia in adulthood. We further emphasize the importance of weight management and control in public health primary prevention.

Associations of Serum Uromodulin and Its Genetic Variants With Blood Pressure and Hypertension in Chinese Adults

Background: Uromodulin, also named Tamm Horsfall protein, has been associated with renal function and regulation of sodium homeostasis. We aimed to examine the associations of serum uromodulin levels and its genetic variants with longitudinal blood pressure (BP) changes and hypertension incidence/risk. Methods: A total of 514 participants from the original Baoji Salt-Sensitive Study cohort were genotyped to examine the associations of genetic variations in uromodulin gene with the longitudinal BP changes and the incidence of hypertension over 8 years of follow-up. In addition, 2,210 subjects from the cohort of Hanzhong Adolescent Hypertension Study were used to investigate the relationships between serum uromodulin levels and the risk of hypertension. Results: SNPs rs12917707 and rs12708631 in the uromodulin gene were significantly associated with the longitudinal BP changes over 8 years of follow-up. SNP rs12708631 was significantly associated with the incidence of hypertension over 8 years. In addition, gene-based analyses supported the associations of uromodulin gene with the longitudinal BP changes and hypertension incidence in Baoji Salt-Sensitive Study cohort. Furthermore, serum uromodulin levels in the hypertensive subjects were lower than in the normotensive subjects (25.5 ± 1.1 vs. 34.7 ± 0.7 ng/mL). Serum uromodulin levels decreased gradually as BP levels increased (34.6, 33.2, 27.8, and 25.0 ng/mL for subjects with normotension, high-normal, grade 1 hypertension, and grade 2 hypertension, respectively). Serum uromodulin was significantly associated with the lower risk of hypertension [0.978 (0.972-0.984)] in Hanzhong Adolescent Hypertension Study cohort. Conclusion: This study shows that uromodulin is associated with blood pressure progression and development of hypertension.

Association of Genetic Variants of Klotho with BP Responses to Dietary Sodium or Potassium Intervention and Long-Term BP Progression

OBJECTIVES

Klotho (KL) plays pivotal roles in the progression of salt-sensitive hypertension. Salt-sensitive hypertension was associated with KL genotypes. We aimed to explore the association of common genetic variants of KL with individual blood pressure (BP) responses to sodium and potassium through a dietary intervention study as well as long-term BP progression.

METHODS

We conducted family-based dietary interventions among 344 participants from 126 families in rural villages of northern China in 2004. Subjects sequentially underwent a baseline diet, a low-salt diet (51.3 mmol/day Na), a high-salt diet (307.8 mmol/day Na), and a high-salt + potassium supplementation diet (307.8 mmol/day Na + 60 mmol/day K). After dietary intervention, we followed up with these participants in 2009 and 2012. The associations between 6 single-nucleotide polymorphisms (SNPs) of KL and phenotypes were analyzed through a linear mixed-effects model.

RESULTS

SNPs rs211247 and rs1207568 were positively correlated with the BP response to high-salt diet in the dominant model after adjusting for confounders (β = 1.670 and 2.163, p = 0.032 and 0.005, respectively). BPs rs526906 and rs525014 were in a haplotype block. Block rs526906-rs525014 was positively correlated with diastolic BP response to potassium and potassium sensitivity in the additive model (β = 0.845, p = 0.032). In addition, regression analysis indicated that rs211247 was associated with long-term systolic BP alterations after 8 years of follow-up in the recessive model (β = 20.47, p = 0.032).

CONCLUSIONS

Common variants of the KL gene might modify individual BP sensitivity to sodium or potassium and influence the long-term progression of BP, suggesting a potential role in the development of salt-sensitive hypertension. Thus, KL may be a new early intervention target for salt-sensitive hypertension.

Associations of corin genetic polymorphisms with salt sensitivity, blood pressure changes, and hypertension incidence in Chinese adults

Corin, a transmembrane serine protease that can cleave pro‐atrial natriuretic peptide (Pro‐ANP) into smaller bioactive molecule atrial natriuretic peptide, has been shown to be involved in the pathophysiology of hypertension, cardiac hypertrophy. We sought to examine the associations of corin genetic variations with salt sensitivity, blood pressure (BP) changes and hypertension incidence. We studied participants of the original Baoji Salt‐Sensitive cohort, recruited from 124 families from seven Chinese villages in 2004 who sequentially received a usual baseline salt diet, a 7‐day low salt diet (3 g/day) and a 7‐day high salt diet (18 g/day), respectively. They were followed up for 8 years (in 2009, 2012) to evaluate the development of hypertension. Corin SNP rs3749584 was significantly associated with diastolic BP (DBP) and mean arterial pressure (MAP) response to low‐salt diet, while rs4695253, rs17654278 were associated with pulse pressure (PP) response to low‐salt diet. SNPs rs4695253, rs12509275, rs2351783, rs2271036, rs2271037 were significantly associated with systolic BP (SBP), DBP, and MAP responses to high‐salt diet. In addition, SNPs rs12641823, rs6834933, rs2271036, and rs22710367 were significantly associated with the longitudinal changes in SBP, DBP, MAP, or PP over 8 years of follow‐up. SNP rs73814824 was significantly associated with the incidence of hypertension over 8 years. Gene‐based analysis showed that corin gene was significantly associated with longitudinal BP changes and hypertension incidence after 8‐year follow‐up. This study suggests that corin may play a role in salt sensitivity, BP progression, and development of hypertension.

Associations of plasma uromodulin and genetic variants with blood pressure responses to dietary salt interventions

Uromodulin, also named Tamm Horsfall protein, have been associated with renal function and sodium homeostasis regulation. The authors sought to examine the effects of salt intake on plasma and urinary uromodulin levels and the association of its genetic variants with salt sensitivity in Chinese adults. Eighty patients from our natural population cohort were maintained sequentially either on a usual diet for 3 days, a low-salt diet (3.0 g) for 7 days, and a high-salt diet (18.0 g) for an additional 7 days. In addition, the authors studied 514 patients of the Baoji Salt-Sensitive Study, recruited from 124 families who received the same salt intake intervention, and investigated the association of genetic variations in uromodulin gene with salt sensitivity. Plasma uromodulin levels were significantly lower on a high-salt diet than on a baseline diet (28.3 ± 4.5 vs. 54.9 ± 8.8 ng/ml). Daily urinary excretions of uromodulin were significantly decreased on a high-salt diet than on a low-salt diet (28.7 ± 6.7 vs. 157.2 ± 21.7 ng/ml). SNPs rs7193058 and rs4997081 were associated with the diastolic blood pressure (DBP), mean arterial pressure (MAP) responses to the high-salt diet. In addition, several SNPs in the uromodulin gene were significantly associated with pulse pressure (PP) response to the low-salt intervention. This study shows that dietary salt intake affects plasma and urinary uromodulin levels and that uromodulin may play a role in the pathophysiological process of salt sensitivity in the Chinese populations.

Risk factors for electrocardiographic left ventricular hypertrophy in a young Chinese general population: the Hanzhong adolescent cohort study

Background

Electrocardiographic left ventricular hypertrophy (ECG-LVH) is a common manifestation of preclinical cardiovascular disease. The present study aimed to investigate risk factors for ECG-LVH and its prevalence in a cohort of young Chinese individuals.

Methods

(1) A total of 1515 participants aged 36–45 years old from our previously established cohort who were followed up in 2017 were included. Cross-sectional analysis was used to examine risk factors for ECG-LVH and its prevalence. (2) A total of 235 participants were recruited from the same cohort in 2013 and were followed up in 2017. Longitudinal analysis was used to determine the predictors of LVH occurrence over the 4-year period. We used multivariable logistic regression models to calculate OR and 95% CIs and to analyze risk factors for ECG-LVH.

Results

In the cross-sectional analysis, the prevalence of LVH diagnosed by the Cornell voltage-duration product in the overall population and the hypertensive population was 4.6% and 8.8%, respectively. The logistic regression results shown that female sex [2.611 (1.591–4.583)], hypertension [2.638 (1.449–4.803)], systolic blood pressure (SBP) [1.021 (1.007–1.035)], serum uric acid (SUA) [1.004 (1.001–1.006)] and carotid intima-media thickness (CIMT) [67.670 (13.352–342.976)] were significantly associated with the risk of LVH (all P < 0.05). In the longitudinal analysis, fasting glucose [1.377 (1.087–1.754)], SBP [1.046 (1.013–1.080)] and female sex [1.242 (1.069–1.853)] were independent predictors for the occurrence of LVH in the fourth year of follow-up.

Conclusions

Our study suggested that female sex, hypertension, SBP, SUA and CIMT were significantly associated with the risk of LVH in young people. In addition, fasting glucose, SBP and female sex are independent predictors of the occurrence of LVH in a young Chinese general population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-01966-y.

Long-term burden of higher body mass index from childhood on adult cardiometabolic biomarkers: A 30-year cohort study

BACKGROUND AND AIMS

Data are limited regarding the association between long-term burden of higher body mass index (BMI) from childhood and cardiometabolic biomarkers.

METHODS AND RESULTS

A total of 1553 individuals aged 6-15 years, who were examined 4 or more times for BMI since childhood and followed for 30 years were included in our analysis. Total area under the curve (AUCt) and incremental AUC (AUCi) were calculated as the long-term burden and trends of BMI. Cardiometabolic biomarkers including serum uric acid (SUA), fasting blood-glucose (FBG), and triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C) were obtained from venous blood samples. The results showed a positive association of BMI AUCt and AUCi with cardiometabolic biomarkers. After adjusting for demographic variables, the AUCt and AUCi of BMI were significantly associated with a higher level of SUA (β = 3.71; 2.87), FBG (β = 0.09; 0.09), and TG/HDL-C (β = 0.14; 0.11). We performed further studies after dividing subjects into four groups according to AUCt and AUCi of BMI by quartiles. Compared with the lowest quartile group, the highest quartile group had significantly increased risk ratios of hyperuricemia (RR = 2.01; 1.74), type 2 diabetes mellitus (RR = 8.18; 3.96), and high-risk TG/HDL-C (RR = 4.05; 3.26).

CONCLUSION

Our study identifies all subjects' BMI growth curve from childhood and indicates that the long-term burden of higher BMI significantly increases the cardiometabolic risk, and the impact of excessive body weight on cardiometabolic health originates in early life. We emphasize the importance of weight control from childhood for cardiometabolic health.

Predictive Role of Child-To-Adult Blood Pressure Trajectories for Incident Metabolic Syndrome: 30-Year Hanzhong Adolescent Hypertension Study

OBJECTIVE

The relationship between child-to-adult blood pressure (BP) trajectories and metabolic syndrome (MetS) is unknown. We aimed to determine the predictive role of BP trajectories for incident MetS and its components.

METHODS

The prospective Hanzhong Adolescent Hypertension study began in 1987 and included 2692 participants free of MetS at baseline with at least 3 BP measurements available from 1987 to 2017.

RESULTS

The systolic BP (SBP) trajectory patterns were grouped as normal (class 1, 18.7%), high normal (class 2, 60.3%), prehypertensive (class 3, 13.1%), stage 1 hypertensive (class 4, 5.7%), and stage 2 hypertensive (class 5, 2.2%). Compared with those in the normal group, individuals in classes 2 to 5 had significantly higher risks of MetS (all Ps < .05), and those with hypertension had more than an 8-fold higher risk of MetS (both P < .05). The fully adjusted risk ratios (RRs) of central obesity increased significantly in a stepwise manner as the SBP trajectory group increased from class 1 to class 5 (P < .05). Compared with those with a normal SBP trajectory, participants in the prehypertensive group and stage 1 and stage 2 hypertensive groups had significantly higher RRs for high-risk triglycerides after full adjustment (RR = 1.89 [1.22-2.94]; RR = 3.61 [2.16-6.02]; and RR = 3.22 [1.52-6.84], respectively).

CONCLUSION

Our study suggests that BP trajectories are predictive of incident MetS outcomes. Early detection of hypertension or modest elevations in BP is crucial. The stage of hypertension based on SBP level showed a greater association with central obesity.

Identification of Candidate Biomarkers for Salt Sensitivity of Blood Pressure by Integrated Bioinformatics Analysis

In the current study, we aimed to identify potential biomarkers for salt sensitivity of blood pressure (SSBP), which may provide a novel insight into the pathogenic mechanisms of salt-sensitive hypertension. Firstly, we conducted weighted gene coexpression network analysis (WGCNA) and selected a gene module and 60 hub genes significantly correlated to SSBP. Then, GO function and KEGG signaling pathway enrichment analysis and protein-protein interaction (PPI) network analysis were performed. Furthermore, we identified a five-gene signature with high connectivity degree in the PPI network and high AUC of ROC curves, which may have high diagnosis value for SSBP. Moreover, through combining two gene screening methods, we identified 23 differentially expressed circRNAs and selected the top 5% circRNAs (1 circRNA) with the highest connectivity degree in the coexpression network as hub circRNA highly associated with SSBP. Finally, we carried out RT-qPCR to validate the expression of five hub genes, and our results showed that the expression of HECTD1 (P = 0.017), SRSF5 (P = 0.003), SRSF1 (P = 0.006), HERC2 (P = 0.004), and TNPO1 (P = 0.002) was significantly upregulated in the renal tissue in salt-sensitive rats compared to salt-resistant rats, indicating that these five hub genes can serve as potential biomarkers for SSBP.

Effect of metabolically healthy obesity on the development of arterial stiffness: a prospective cohort study

Background

Metabolically healthy obesity (MHO) has been reported to be associated with the development of vascular damage by the carotid intima-media thickness, but the relationship between metabolic health and obesity phenotypes and arterial stiffness is still unknown. Our hypothesized that different metabolic health and obesity phenotypes might be associated with the development of arterial stiffness, and that subjects in MHO phenotype might not have increased risks of arterial stiffness compared with those in metabolically healthy nonobesity phenotype (MHNO), while metabolic unhealthy individuals might have increased risks of arterial stiffness.

Methods

A prospective cohort of 2076 participants (aged 36-48 years) who were enrolled in the Hanzhong Adolescent Hypertension Cohort Study in 2017 was analyzed in a cross-sectional analysis. A subgroup of 202 participants from 2005 to 2017 was selected by an isometric sampling method and was included in the final longitudinal analysis.

Results

We identified four metabolic health and obesity phenotypes for both the cross-sectional and longitudinal analyses as follows: MHNO, metabolically unhealthy nonobesity (MUNO), MHO, and metabolically unhealthy obesity (MUO). In the cross-sectional analysis, individuals with the MHO phenotype had the lowest brachial-ankle pulse wave velocity (baPWV) levels of the four phenotypes (P < 0.001), and participants with the MHO phenotype had a similar risk of arterial stiffness after fully adjustment [odds ratio (OR) = 0.99 (0.61-1.60)] as the MUNO subjects. Subjects with metabolically unhealthy status had a significantly higher risk of arterial stiffness than the MHNO individuals, particularly females (P < 0.005). In the longitudinal analysis, subjects with the MUNO and MUO phenotypes had a significantly higher risk of arterial stiffness than the MHNO individuals after adjustment for age and sex [OR = 5.21 (2.26-12.02), OR = 3.32 (1.18-9.32), respectively].

Conclusions

The MHO phenotype did not significantly increase the progression of arterial stiffness. Metabolically unhealthy individuals (MUNO, MUO), regardless of obesity status, showed a worse effect for the development of arterial stiffness, particularly females.

Trial registration

NCT02734472. Registered 12 April 2016 - Retrospectively registered, http:www.clinicaltrials.gov.

The predictive value of repeated blood pressure measurements in childhood for cardiovascular risk in adults: the Hanzhong Adolescent Hypertension Study

There is currently a lack of strong evidence linking childhood elevated blood pressure to long-term cardiovascular risk in adulthood. Repeated observations of abnormal blood pressure in childhood may enhance the prediction of cardiovascular risk in adulthood compared with a single observation. The study included 1738 individuals in rural areas of Hanzhong City, Shaanxi, who had been followed for 30 years since baseline (1987, at which time participants were aged 6-15 years). According to four independent measurements of blood pressure in 1987, 1989, 1992, and 1995, childhood elevated blood pressure was defined as 2 in-person examinations with blood pressure values above the 90th percentile. Arterial stiffness and left ventricular hypertrophy in adulthood were assessed by brachial-ankle pulse wave velocity and the Cornell product index, respectively. Childhood elevated blood pressure was associated with an increased risk of adult hypertension (OR, 2.01; 95% CI, 1.53-2.65), arterial stiffness (OR, 1.69; 95% CI, 1.32-2.16) and left ventricular hypertrophy (OR, 1.86; 95% CI, 1.13-3.05) (all P < 0.05). Cardiovascular risk in adults increased with increasing childhood blood pressure levels. In addition, two abnormal childhood blood pressure observations predicted an increased likelihood of hypertension in adulthood (0.77 for 2 versus 0.70 for 1 observation, P < 0.001). Our study provides strong evidence that elevated blood pressure in childhood predicts cardiovascular risk in adults. The prediction was enhanced by two observations of abnormal blood pressure in childhood compared with a single measurement. We emphasize the importance of childhood blood pressure monitoring and control in the prevention of cardiovascular diseases.

Body Mass Index Trajectories in Early Life Is Predictive of Cardiometabolic Risk

OBJECTIVE

To identify distinct body mass index (BMI) trajectories across the life-course and explore the effects of BMI trajectories on the adult cardiovascular disease outcomes using a dataset with 30 years of follow-up in northern China.

STUDY DESIGN

A total of 2839 participants aged 6-18 years whose BMIs were measured 3-6 times during the Hanzhong Adolescent Hypertension Study were included in our analysis. Latent mixture modeling was used to clarify distinct BMI trajectories in longitudinal analyses.

RESULTS

Three groups with distinct trajectories in BMI were identified by the latent mixed models: a low-increasing group (n = 1324 [36.64%]), a moderate-increasing group (n = 1178 [16.89%]), and a high-increasing group (n = 337 [39.46%]). Compared with the participants in the low-increasing group, the risk ratios of hypertension, type 2 diabetes mellitus, high-risk triglycerides, and high-risk high-density lipoprotein cholesterol were more than 3.0 in the high-increasing group (all P < .001) after being fully adjusted. Increased risks existed in high brachial-ankle pulse wave velocity for the high-increasing group compared with the low-increasing group (RR, 2.75; 95% CI, 1.94-3.91; P < .001). Additionally, participants in the moderate-increasing group had a 2.31-fold increased risks of left ventricular hypertrophy (95% CI, 1.25-4.30; P = .008).

CONCLUSIONS

Our study indicates that BMI trajectories from childhood to adulthood vary and that an elevated BMI trajectory in early life is predictive of an increased the risk of developing cardiovascular disease risks.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02734472.

[The correlation between blood pressure response to cold pressor test and long-term blood pressure changes]

Objective: The aim of the study was to investigate the correlation between blood pressure response to cold pressor test (CPT) and follow-up blood pressure after 8 years in subjects, and to evaluate the predictive value of CPT for long-term blood pressure levels. Methods: A total of 365 individuals from eight natural villages were enrolled by stratified cluster sampling from Mei County, Shaanxi Province in 2004. Baseline characteristics of subjects were collected and CPTs were conducted. Subjects were followed up in 2009 and 2012, respectively. According to the maximal change of systolic response (SR), the area under the curve (AUC) of systolic blood pressure change (AUC-SBP), the maximal change of diastolic response (DR) and the AUC of diastolic blood pressure change (AUC-DBP) in CPT, the individuals were divided into four quartile groups by above parameters, respectively: group Ⅰ (P(25)), group Ⅱ (P(50)), group Ⅲ (P(75)) and group Ⅳ (P(100)). The correlation between blood pressure response to CPT and the follow-up blood pressure was analyzed. Results: (1) There were no significant differences in baseline blood pressure levels and prevalence of hypertension among four quartile groups no matter it was grouped on SR, DR, AUC-SBP or AUC-DBP. (2) The prevalence of hypertension in each group from lowest (P(25)) to highest (P(100)) in 2012 was 25.64%, 30.67%, 38.03%, 55.74% on SR grouping (P<0.01), and 27.5%, 29.17%, 38.46%, 57.35% on AUC-SBP grouping (P<0.05), respectively. (3) There were no significant differences in the prevalence of hypertension among four groups in 2012 (P>0.05) either on DR or on AUC-DBP grouping. (4) The random effects model analysis showed that the correlation coefficient between SR, AUC-SBP and long-term systolic blood pressure increase were 1.91 (P<0.05) and 1.44 (P<0.05), respectively, and the correlation coefficient between DR, AUC-DBP and long-term diastolic blood pressure increase were 0.82 (P<0.05) and 0.78 (P>0.05), respectively. Age, male, body mass index, and fasting blood glucose were independent risk factors for long-term blood pressure elevation, and age, body mass index and fasting blood glucose positively correlated with changes in long-term blood pressure (all P<0.05). Conclusion: Individual systolic blood pressure response to CPT can be used as a predictor of long-term hypertension.

Association of uric acid in serum and urine with subclinical renal damage: Hanzhong Adolescent Hypertension Study

BACKGROUND AND OBJECTIVES

The aim of the study was to examine the associations of uric acid (UA) in blood and urine with subclinical renal damage (SRD) and its progression in a Chinese cohort.

METHODS

1) 2342 participants from our previously established cohort who were followed up in 2017 were included. Cross-sectional analysis was used to examine the relationships between serum and urinary UA and the risk of SRD. 2) A total of 266 participants were recruited from the same cohort in 2013, and followed up in 2017. Longitudinal analysis was used to determine the relationships of serum and urinary UA with progression of SRD, which was defined as urinary albumin-to-creatinine ratio (uACR) progression or estimated glomerular filtration rate (eGFR) decline.

RESULTS

In cross-sectional analysis, higher levels of uACR were associated with higher levels of serum uric acid (SUA) and urinary uric acid/creatinine ratio (uUA/Cre). Lower eGFR was associated with higher levels of SUA and fractional excretion of uric acid (FEUA) but lower uUA/Cre levels in all subjects. In addition, the multivariate-adjusted odds ratios for SRD compared with non-SRD were 3.574 (2.255-5.664) for uUA/Cre. Increasing uUA/Cre levels were associated with higher risk of SRD. In longitudinal analysis, 4-year changes of uUA/Cre and SUA were significantly associated with eGFR decline.

CONCLUSIONS

This study suggested that urinary UA excretion was significantly associated with the risk of SRD in Chinese adults. Furthermore, 4-year changes of serum and urinary UA were associated with SRD progression. These findings suggest that UA, especially urinary UA, may be used as a simple, noninvasive marker for early detection of decreased renal function in otherwise healthy subjects.

LncRNA TNK2-AS1 regulated ox-LDL-stimulated HASMC proliferation and migration via modulating VEGFA and FGF1 expression by sponging miR-150-5p

Long non‐coding RNAs (lncRNAs) have been indicated for the regulatory roles in cardiovascular diseases. This study determined the expression of lncRNA TNK2 antisense RNA 1 (TNK2‐AS1) in oxidized low‐density lipoprotein (ox‐LDL)‐stimulated human aortic smooth muscle cells (HASMCs) and examined the mechanistic role of TNK2‐AS1 in the proliferation and migration of HASMCs. Our results demonstrated that ox‐LDL promoted HASMC proliferation and migration, and the enhanced proliferation and migration in ox‐LDL‐treated HASMCs were accompanied by the up‐regulation of TNK2‐AS1. In vitro functional studies showed that TNK2‐AS1 knockdown suppressed cell proliferation and migration of ox‐LDL‐stimulated HASMCs, while TNK2‐AS1 overexpression enhanced HASMC proliferation and migration. Additionally, TNK2‐AS1 inversely regulated miR‐150‐5p expression via acting as a competing endogenous RNA (ceRNA), and the enhanced effects of TNK2‐AS1 overexpression on HASMC proliferation and migration were attenuated by miR‐150‐5p overexpression. Moreover, miR‐150‐5p could target the 3’ untranslated regions of vascular endothelial growth factor A (VEGFA) and fibroblast growth factor 1 (FGF1) to regulate FGF1 and VEGFA expression in HASMCs, and the inhibitory effects of miR‐150‐5p overexpression in ox‐LDL‐stimulated HASMCs were attenuated by enforced expression of VEGFA and FGF1. Enforced expression of VEGFA and FGF1 also partially restored the suppressed cell proliferation and migration induced by TNK2‐AS1 knockdown in ox‐LDL‐stimulated HASMCs, while the enhanced effects of TNK2‐AS1 overexpression on HASMC proliferation and migration were attenuated by the knockdown of VEGFA and FGF1. Collectively, our findings showed that TNK2‐AS1 exerted its action in ox‐LDL‐stimulated HASMCs via regulating VEGFA and FGF1 expression by acting as a ceRNA for miR‐150‐5p.

Association between urinary sodium excretion and uric acid, and its interaction on the risk of prehypertension among Chinese young adults

High uric acid (UA) level and high salt intake are reportedly associated with cardiovascular disease. This study investigated the association between UA and urinary sodium excretion, as well as its interaction on the risk of prehypertension. A total of 1869 participants without hypertension were recruited from a previously established cohort in Shaanxi Province, China. The participants were classified as normotensive or prehypertensive on the basis of their blood pressure. Increasing quartiles of sodium excretion were associated with high urinary UA/creatinine levels in prehypertensive participants. Estimated sodium excretion positively correlated with urinary UA/creatinine excretions in the prehypertensive group. In addition, the multivariate-adjusted odds ratios for prehypertension compared with normotension were 1.68 (1.27–2.22) for sodium excretion and 1.71 (1.21–2.42) for serum UA. Increasing sodium excretion and serum UA were associated with higher risk of prehypertension. Compared with the lowest quartiles, the highest sodium excretion and serum UA quartiles entailed 3.48 times greater risk of prehypertension. Sodium excretion is associated with urinary UA excretion in prehypertensive participants. The present study shows that high levels of salt intake and serum UA simultaneously are associated with a higher risk of prehypertension.

Effect of Salt Intervention on Serum Levels of Fibroblast Growth Factor 23 (FGF23) in Chinese Adults: An Intervention Study

Background

Fibroblast growth factor 23 (FGF23), a prominent regulator of phosphate and calcium metabolism, regulates sodium excretion in distal tubules through sodium-chloride cotransporter. This effect regulates blood pressure. Salt intake exerts effects on serum levels of FGF23 in mice. The aim of this study was to explore whether salt intervention affects serum concentrations of FGF23 in Chinese adults.

Material/Methods

We enrolled 44 participants from Lantian, a rural community of Shaanxi, China. All participants were maintained on a three-day normal diet, which was sequentially followed by a seven-day low-Na⁺ diet and seven-day high-Na⁺ diet. Serum FGF23 concentrations were assessed by ELISA.

Results

Serum FGF23 concentrations elevated during low-salt diet compared with levels at baseline (66.20±44.21 pg/mL versus 86.77±53.74 pg/mL, p<0.05) and remarkably decreased when changed from low to high salt intake (86.77±53.74 pg/mL versus 49.26±42.67 pg/mL, p<0.001). Responses of FGF23 to salt intervention were more prominent in normotensive, older than 60 years, BMI <24 kg/m² and salt-resistant individuals. Furthermore, a significant inverse correlation was observed between 24-hour urinary sodium and serum concentrations of FGF23 after adjusting age, sex, BMI and hypertension status.

Conclusions

Dietary salt intervention significantly affects serum FGF23 in Chinese adults.

The Relationships of the Fractional Excretion of Uric Acid with Brachial-Ankle Pulse Wave Velocity and Ankle Brachial Index in Chinese Young Adults

BACKGROUND/AIMS

Elevated serum uric acid (UA) was intimately correlated with vascular stiffness and abnormal ankle brachial index (ABI) in various populations. These correlations lost significance after adjustment for estimated glomerular filtration rate (eGFR), indicating that the association of UA and brachial-ankle pulse wave velocity (baPWV) or ABI might be driven by kidney function. UA is predominantly eliminated through the kidneys, and metabolic disorders can influence the clearance of UA. In this study, we aimed to explore the putative correlation between FEUA and baPWV or ABI to determine to what extent the associations with UA were affected by renal function.

METHODS

This cross-sectional study enrolled 2351 participants, who underwent general health screening in Hanzhong people's hospital from March to June of 2017. BaPWV and ABI were measured using a volume-plethysmographic apparatus (BP-203RPEII; Nihon Colin, Tokyo, Japan). FEUA was divided into quartiles: Q1:FEUA≤3.07; Q2: 3.07<FEUA≤5.32; Q3: 5.32<FEUA≤9.19; and Q4: FEUA> 9.19.

RESULTS

Lower FEUA predicted a higher prevalence of high baPWV and low ABI (p for trend <0.001). The respective ORs for high baPWV from the first to the third quartiles of FEUA were 1.777(1.323, 2.387); 1.561(1.158, 2.104); and 1.680 (1.250, 2.259). The prevalence of low ABI was greatly elevated with the decrement of FEUA [ORs for the first to third FEUA quartiles were 6.977(2.062, 23.610); 5.123(1.475, 17.790); and 2.685(0.709, 10.171), respectively]. The association of FEUA and ABI was independent of related confounding factors. However, the association between FEUA and baPWV was greatly influenced by corresponding confounders, especially gender. The efficacy of FEUA in the prediction of low ABI was stronger than that of serum UA. However, serum UA was more powerful in the prediction of high baPWV.

CONCLUSION

Kidney function exerted a profound influence on the relationship between UA and baPWV or ABI, revealing complex interactions among cardiovascular risk factors.

Short-Term High-Salt Diet Increases Corin Level to Regulate the Salt-Water Balance in Humans and Rodents

BACKGROUND

Dietary sodium and potassium affect the fluctuation in blood pressure (BP) and renal function. Corin, with its enzymatic activity to convert pro-atrial natriuretic peptide (pro-ANP) to biologically active ANP, regulates BP, cardiac, and renal functions. We investigated whether corin expression responds to a high-salt (HS) diet to regulate salt and water balance.

METHODS

Forty-two volunteers followed 3 sequential diets for 7 days each: a low-salt (LS) diet (3.0 g/day NaCl), a HS diet (18.0 g/day NaCl), followed by an HS diet with K+ supplementation (HS + K+) (18.0 g/day NaCl and 4.5 g/day KCl).

RESULTS

Corin level was higher with the HS diet than the LS and HS + K+ diets and was positively correlated with systolic BP (SBP) and 24-hour urinary Na+ and microalbumin (U-mALB) excretion. In rodents, serum and renal levels of corin were transiently increased with the HS diet and were decreased if the HS diet was continued for up to 7 days. HS loading increased SBP, 24-hour urinary Na+, U-mALB excretion, and the expression of proprotein convertase subtilisin/kexin-6 (PCSK6), a corin activator. Knockdown of PCSK6 or corin in high salt-treated M1-cortical collecting duct (M1-CCD) cells increased the expression of aquaporin 2 (AQP2) and β-epithelial Na+ channel (β-ENaC).

CONCLUSIONS

Short-term HS may induce the PCSK6-corin-ANP-AQP2/β-ENaC pathway in the kidney. Enhanced serum corin level in humans and rodents is positively correlated with HS-induced SBP and 24-hour urinary Na+ and U-mALB excretion, which suggests that corin is involved in the salt-water balance in response to HS intake.

CLINICAL TRIALS REGISTRATION

Public Trials Registry Number NCT02915315.

Effect of Salt Intake on Serum Glucagon-Like Peptide-1 Levels in Normotensive Salt-Sensitive Subjects

BACKGROUND/AIMS

Excess dietary salt is a critical risk factor of salt-sensitive hypertension. Glucagon-like peptide-1 (GLP-1) , a gut incretin hormone, conferring benefits for blood pressure by natriuresis and diuresis. We implemented a randomized trial to verify the effect of altered salt intake on serum GLP-1 level in human beings.

METHODS

The 38 subjects were recruited from a rural community of Northern China. All subjects were sequentially maintained a baseline diet period for 3 days, a low-salt diet period for 7 days (3.0g/day of NaCl) , and a high-salt diet period for additional 7 days (18.0g/day of NaCl).

RESULTS

Serum GLP-1 level increased significantly with the change from the baseline period to the low-salt diet period and decreased with the change from the low-salt to high-salt diet in normotensive salt-sensitive (SS) but not salt-resistant (SR) individuals. There was a significant inverse correlation between the serum GLP-1 level and the MAP in SS subjects. Inverse correlation between the serum GLP-1 level and 24-h urinary sodium excretion was also found among different dietary interventions in SS subjects.

CONCLUSIONS

Our study indicates that variations in dietary salt intake affect the serum GLP-1 level in normotensive salt-sensitive Chinese adults.

Dietary salt blunts vasodilation by stimulating epithelial sodium channels in endothelial cells from salt-sensitive Dahl rats

BACKGROUND AND PURPOSE

Our recent studies show that the reduced activity of epithelial sodium channels (ENaC) in endothelial cells accounts for the adaptation of vasculature to salt in Sprague-Dawley rats. The present study examines a hypothesis that enhanced ENaC activity mediates the loss of vasorelaxation in Dahl salt-sensitive (SS) rats.

EXPERIMENTAL APPROACH

We used the cell-attached patch-clamp technique to record ENaC activity in split-open mesenteric arteries. Western blot and immunofluorescence staining were used to evaluate the levels of aldosterone, ENaC, eNOS and NO. Blood pressure was measured with the tail-cuff method and the artery relaxation was measured with the wire myograph assay.

KEY RESULTS

High-salt (HS) diet significantly increased plasma aldosterone and ENaC activity in the endothelial cells of Dahl SS rats. The endothelium-dependent artery relaxation was blunted by HS challenge in these rats. Amiloride, a potent blocker of ENaC, increased both phosphorylated eNOS and NO and therefore prevented the HS-induced loss of vasorelaxation. As, in SS rats, endogenous aldosterone was already elevated by HS challenge, exogenous aldosterone did not further elevate ENaC activity in the rats fed with HS. Eplerenone, a mineralocorticoid receptor antagonist, attenuated the effects of HS on both ENaC activity and artery relaxation.

CONCLUSIONS AND IMPLICATIONS

These data suggest that HS diet blunts artery relaxation and causes hypertension via a pathway associated with aldosterone-dependent activation of ENaC in endothelial cells. This pathway provides one of the mechanisms by which HS causes hypertension in Dahl SS rats.

LINKED ARTICLES

This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc.

Extracellular renalase protects cells and organs by outside-in signalling

Renalase was discovered as a protein synthesized by the kidney and secreted in blood where it circulates at a concentration of approximately 3-5 μg/ml. Initial reports suggested that it functioned as an NAD(P)H oxidase and could oxidize catecholamines. Administration of renalase lowers blood pressure and heart rate and also protects cells and organs against ischaemic and toxic injury. Although renalase's protective effect was initially ascribed to its oxidase properties, a paradigm shift in our understanding of the cellular actions of renalase is underway. We now understand that, independent of its enzymatic properties, renalase functions as a cytokine that provides protection to cells, tissues and organs by interacting with its receptor to activate protein kinase B, JAK/STAT, and the mitogen-activated protein kinase pathways. In addition, recent studies suggest that dysregulated renalase signalling may promote survival of several tumour cells due to its capacity to augment expression of growth-related genes. In this review, we focus on the cytoprotective actions of renalase and its capacity to sustain cancer cell growth and also the translational opportunities these findings represent for the development of novel therapeutic strategies for organ injury and cancer.

The Role of Uric Acid in Hypertension of Adolescents, Prehypertension and Salt Sensitivity of Blood Pressure

Uric acid is the end product of purine metabolism. Metabolic disorders of uric acid are associated with many disease states. Substantial evidence suggests the possible role of uric acid as a mediator of high blood pressure. Elevated uric acid is closely associated with new onset essential hypertension in adolescents and prehypertension; and urate-lowering agents can significantly improve these early stages of hypertension. Uric acid also influences salt sensitivity of blood pressure through two phases. Local renin-angiotensin-aldosterone system activation initiates renal damage, arteriolopathy, and endothelium dysfunction, which is followed by the dysregulation of sodium homeostasis, thereby leading to increased salt sensitivity. In this review we summarize the available evidence to contribute to a better understanding of the casual relationship between uric acid and early or intermediate stages of hypertension. We hope our review can contribute to the prevention of hypertension or provide new insights into a treatment that would slow the progression of hypertension.

Effects of Salt Loading on Plasma Osteoprotegerin Levels and Protective Role of Potassium Supplement in Normotensive Subjects

BACKGROUND

Excess dietary salt is strongly correlated with cardiovascular disease, morbidity, and mortality. Conversely, potassium likely elicits favorable effects on cardiovascular disorders. In epidemiological studies, increased plasma osteoprotegerin (OPG) concentrations are associated with atherosclerosis and vascular deaths. Our study was designed to examine the effects of salt intake and potassium supplementation on plasma OPG levels in normotensive subjects.Methods and Results:The 18 normotensive subjects were selected from a rural community in China. They were sequentially maintained on low-salt diet for 7 days (3 g/day, NaCl), high-salt diet for 7 days (18 g/day), and high-salt diet with potassium supplementation for 7 days (18 g/day of NaCl+4.5 g/day of KCl). High-salt intake enhanced plasma OPG levels (252.7±13.9 vs. 293.4±16.1 pg/mL). This phenomenon was abolished through potassium supplementation (293.4±16.1 vs. 235.1±11.3 pg/mL). Further analyses revealed that the OPG concentration positively correlated with 24-h urinary sodium excretion (r=0.497, P<0.01). By contrast, OPG concentration negatively correlated with 24-h urinary potassium excretion (r=0.594, P<0.01).

CONCLUSIONS

Salt loading can enhance the production of circulating OPG. Potassium supplementation can reverse the effects of excessive OPG. Our study results may improve our understanding of the roles of salt and potassium in the risk of cardiovascular disorders.

Plasma Renalase is Not Associated with Blood Pressure and Brachial-Ankle Pulse Wave Velocity in Chinese Adults With Normal Renal Function

BACKGROUND/AIMS

This study aimed to investigate the association of renalase with blood pressure (BP) and brachial-ankle pulse wave velocity (baPWV) in order to better understand the role of renalase in the pathogenesis of hypertension and atherosclerosis.

METHODS

A total of 344 subjects with normal kidney function were recruited from our previously established cohort in Shaanxi Province, China. They were divided into the normotensive (NT) and hypertensive (HT) groups or high baPWV and normal baPWV on the basis of BP levels or baPWV measured with an automatic waveform analyzer. Plasma renalase was determined through an enzyme-linked immunosorbent assay.

RESULTS

Plasma renalase did not significantly differ between HT and NT groups (3.71 ± 0.69 µg/mL vs. 3.72 ± 0.73 μg/mL, P = 0.905) and between subjects with and without high baPWV (3.67 ± 0.66 µg/mL vs. 3.73 ± 0.74 µg/mL, P = 0.505). However, baPWV was significantly higher in the HT group than in the NT group (1460.4 ± 236.7 vs. 1240.7 ± 174.5 cm/s, P < 0.001). Plasma renalase was not correlated with BP levels and baPWV in the entire group. Linear and logistic regression analysis revealed that plasma renalase was not significantly associated with hypertension and high baPWV.

CONCLUSION

Plasma renalase may not be associated with BP and baPWV in Chinese subjects with normal renal function.

Oral CoQ10 attenuates high salt-induced hypertension by restoring neurotransmitters and cytokines in the hypothalamic paraventricular nucleus

High salt intake leads to an increase in some proinflammatory cytokines and neurotransmitters involved in the pathogenesis of hypertension. The purpose of this work was to know if oral administration of anti-oxidant and free-radical scavenger CoQ10 may attenuate high salt-induced hypertension via regulating neurotransmitters and cytokines in the hypothalamic paraventricular nucleus (PVN). Adult male Sprague-Dawley (SD) rats were fed with a normal salt diet (NS, 0.3% NaCl) or a high salt diet (HS, 8% NaCl) for 15 weeks to induce hypertension. These rats received CoQ10 (10 mg/kg/day) dissolved in olive oil was given by gavage (10 mg/kg/day) for 15 weeks. HS resulted in higher mean arterial pressure (MAP) and the sympathetic nerve activity (RSNA). These HS rats had higher PVN levels of norepinephrine (NE), tyrosine hydroxylase (TH), interleukin (IL)-1β, NOX2 and NOX4, lower PVN levels of gamma-aminobutyric acid (GABA), IL-10, copper/zinc superoxide dismutase (Cu/Zn-SOD) and the 67-kDa isoform of glutamate decarboxylase (GAD67), as compared with NS group. CoQ10 supplementation reduced NE, TH, IL-1β, NOX2 and NOX4 in the PVN, and induced IL-10, Cu/Zn-SOD and GAD67 in the PVN. These findings suggest that CoQ10 supplementation restores neurotransmitters and cytokines in the PVN, thereby attenuating high salt-induced hypertension.

Association of Renalase SNPs rs2296545 and rs2576178 with the Risk of Hypertension: A Meta-Analysis

Background/Aims

Two renalase single nucleotide polymorphisms (SNPs) rs2296545 and rs2576178 have been reported to be associated with the susceptibility to hypertension (HT). Given the inconsistent results, we conducted a meta-analysis to assess the association between these two SNPs and the risk of HT.

Methods

Electronic databases were systematically searched to find relevant studies. Subgroup analysis was conducted according to the different concomitant diseases and ethnicities in the study population. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated using fixed-effect or random-effect models.

Results

A total of six case–control studies on rs2296545 and six studies on rs2576178 were included. In the combined analysis, results showed a significant association between SNP rs2296545 and risk of HT in all genetic models (dominant model CG+CC/GG: OR = 1.43, 95% CI = 1.24–1.65; recessive model CC/CG+GG: OR = 1.36, 95% CI = 1.09–1.69; codominant model CC/GG: OR = 1.63, 95% CI = 1.20–2.20, CG/GG: OR = 1.30, 95% CI = 1.12–1.52; allelic model C/G: OR = 1.29, 95% CI = 1.10–1.51). In subgroup analysis, we observed a significant association between rs2296545 and risk of essential HT. Although we did not observe an association between rs2576178 polymorphism and HT in the combined analysis, an increased risk was observed in the essential HT patients versus healthy controls (subgroup 1) analysis under the dominant, recessive, and codominant genetic models.

Conclusions

Renalase gene rs2296545 polymorphism is significantly associated with increased risk of HT, whereas rs2576178 polymorphism may not be associated with the susceptibility to HT.

Elevation of Fasting Ghrelin in Healthy Human Subjects Consuming a High-Salt Diet: A Novel Mechanism of Obesity?

Overweight/obesity is a chronic disease that carries an increased risk of hypertension, diabetes mellitus, and premature death. Several epidemiological studies have demonstrated a clear relationship between salt intake and obesity, but the pathophysiologic mechanisms remain unknown. We hypothesized that ghrelin, which regulates appetite, food intake, and fat deposition, becomes elevated when one consumes a high-salt diet, contributing to the progression of obesity. We, therefore, investigated fasting ghrelin concentrations during a high-salt diet. Thirty-eight non-obese and normotensive subjects (aged 25 to 50 years) were selected from a rural community in Northern China. They were sequentially maintained on a normal diet for three days at baseline, a low-salt diet for seven days (3 g/day, NaCl), then a high-salt diet for seven days (18 g/day). The concentration of plasma ghrelin was measured using an immunoenzyme method (ELISA). High-salt intake significantly increased fasting ghrelin levels, which were higher during the high-salt diet (320.7 ± 30.6 pg/mL) than during the low-salt diet (172.9 ± 8.9 pg/mL). The comparison of ghrelin levels between the different salt diets was statistically-significantly different (p < 0.01). A positive correlation between 24-h urinary sodium excretion and fasting ghrelin levels was demonstrated. Our data indicate that a high-salt diet elevates fasting ghrelin in healthy human subjects, which may be a novel underlying mechanism of obesity.

High Salt Diet Affects Renal Sodium Excretion and ERRα Expression

Kidneys regulate the balance of water and sodium and therefore are related to blood pressure. It is unclear whether estrogen-related receptor α (ERRα), an orphan nuclear receptor and transcription factor highly expressed in kidneys, affects the reabsorption of water and sodium. The aim of this study was to determine whether changes in the expressions of ERRα, Na⁺/K⁺-ATPase and epithelial sodium channel (ENaC) proteins affected the reabsorption of water and sodium in kidneys of Dahl salt-sensitive (DS) rats. SS.13BN rats, 98% homologous to the DS rats, were used as a normotensive control group. The 24 h urinary sodium excretion of the DS and SS.13BN rats increased after the 6-week high salt diet intervention, while sodium excretion was increased in DS rats with daidzein (agonist of ERRα) treatment. ERRα expression was decreased, while β- and γ-ENaC mRNA expressions were increased upon high sodium diet treatment in the DS rats. In the chromatin immunoprecipitation (CHIP) assay, positive PCR signals were obtained in samples treated with anti-ERRα antibody. The transcriptional activity of ERRα was decreased upon high salt diet intervention. ERRα reduced the expressions of β- and γ-ENaC by binding to the ENaC promoter, thereby increased Na+ reabsorption. Therefore, ERRα might be one of the factors causing salt-sensitive hypertension.

Effects of salt intake and potassium supplementation on renalase expression in the kidneys of Dahl salt-sensitive rats

Renalase is currently the only known amine oxidase in the blood that can metabolize catecholamines and regulate sympathetic activity. High salt intake is associated with high blood pressure (BP), possibly through the modulation of renalase expression and secretion, whereas potassium can reverse the high salt-mediated increase in blood pressure. However, whether potassium could also modulate BP through renalase is unclear. In this study, we aim to investigate how salt intake and potassium supplementation affect the level of renalase in rats. Eighteen salt-sensitive (SS) and 18 SS-13BN rats were divided into six groups, receiving normal salt (0.3% NaCl), high salt (8% NaCl) and high salt/potassium (8% NaCl and 8% KCl) dietary intervention for four weeks. At the end of experiments, blood and kidneys were collected for analysis. mRNA level of renalase was measured by quantitative real-time PCR and protein level was determined by Western blot. We found that mRNA and protein levels of renalase in the kidneys of SS and SS-13BN rats were significantly decreased (P < 0.05) after high salt intervention, whereas dopamine in plasma was increased (P < 0.05) compared with rats received normal salt, suggesting that salt may induce salt-sensitive hypertension through inhibition of renalase expression. We also found increased mRNA level and protein level of renalase, decreased catecholamine levels in plasma, and decreased BP in SS rats treated with high salt/potassium, compared with that of the high salt SS group. Taken together, the salt-induced increase and potassium-induced decrease in BP could be mediated through renalase. More studies are needed to confirm our findings and understand the underlying mechanisms.

Endogenous hydrogen peroxide in the hypothalamic paraventricular nucleus regulates neurohormonal excitation in high salt-induced hypertension

Reactive oxygen species (ROS) in the brain plays an important role in the progression of hypertension and hydrogen peroxide (H2O2) is a major component of ROS. The aim of this study is to explore whether endogenous H2O2 changed by polyethylene glycol-catalase (PEG-CAT) and aminotriazole (ATZ) in the hypothalamic paraventricular nucleus (PVN) regulates neurotransmitters, renin-angiotensin system (RAS), and cytokines, and whether subsequently affects the renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) in high salt-induced hypertension. Male Sprague-Dawley rats received a high-salt diet (HS, 8% NaCl) or a normal-salt diet (NS, 0.3% NaCl) for 10 weeks. Then rats were treated with bilateral PVN microinjection of PEG-CAT (0.2 i.u./50nl), an analog of endogenous catalase, the catalase inhibitor ATZ (10nmol/50nl) or vehicle. High salt-fed rats had significantly increased MAP, RSNA, plasma norepinephrine (NE) and pro-inflammatory cytokines (PICs). In addition, rats with high-salt diet had higher levels of NOX-2, NOX-4 (subunits of NAD(P)H oxidase), angiotensin-converting enzyme (ACE), interleukin-1beta (IL-1β), glutamate and NE, and lower levels of gamma-aminobutyric acid (GABA) and interleukin-10 (IL-10) in the PVN than normal diet rats. Bilateral PVN microinjection of PEG-CAT attenuated the levels of RAS and restored the balance of neurotransmitters and cytokines, while microinjection of ATZ into the PVN augmented those changes occurring in hypertensive rats. Our findings demonstrate that ROS component H2O2 in the PVN regulating MAP and RSNA are partly due to modulate neurotransmitters, renin-angiotensin system, and cytokines within the PVN in salt-induced hypertension.

Effect of Salt Intake and Potassium Supplementation on Urinary Renalase and Serum Dopamine Levels in Chinese Adults

Objective: The aim of our study was to assess the effects of altered salt and potassium intake on urinary renalase and serum dopamine levels in humans. Methods: Forty-two subjects (28-65 years of age) were selected from a rural community of northern China. All subjects were sequentially maintained on a low-salt diet for 7 days (3.0 g/day of NaCl), a high-salt diet for an additional 7 days (18.0 g/day of NaCl), and a high-salt diet with potassium supplementation for a final 7 days (18.0 g/day of NaCl + 4.5 g/day of KCl). Results: Urinary renalase excretions were significantly higher during the high-salt diet intervention than during the low-salt diet. During high-potassium intake, urinary renalase excretions were not significantly different from the high-salt diet, whereas they were significantly higher than the low-salt levels. Serum dopamine levels exhibited similar trends across the interventions. Additionally, a significant positive relationship was observed between the urine renalase and serum dopamine among the different dietary interventions. Also, 24-hour urinary sodium excretion positively correlated with urine renalase and serum dopamine in the whole population. Conclusions: The present study indicates that dietary salt intake and potassium supplementation increase urinary renalase and serum dopamine levels in Chinese subjects.

Effect of salt intake and potassium supplementation on brachial-ankle pulse wave velocity in Chinese subjects: an interventional study

Accumulating evidence has suggested that high salt and potassium might be associated with vascular function. The aim of this study was to investigate the effect of salt intake and potassium supplementation on brachial-ankle pulse wave velocity (PWV) in Chinese subjects. Forty-nine subjects (28-65 years of age) were selected from a rural community of northern China. All subjects were sequentially maintained on a low-salt diet for 7 days (3.0 g/day NaCl), a high-salt diet for an additional 7 days (18.0 g/day NaCl), and a high-salt diet with potassium supplementation for a final 7 days (18.0 g/day NaCl+4.5 g/day KCl). Brachial-ankle PWV was measured at baseline and on the last day of each intervention. Blood pressure levels were significantly increased from the low-salt to high-salt diet, and decreased from the high-salt diet to high-salt plus potassium supplementation. Baseline brachial-ankle PWV in salt-sensitive subjects was significantly higher than in salt-resistant subjects. There was no significant change in brachial-ankle PWV among the 3 intervention periods in salt-sensitive, salt-resistant, or total subjects. No significant correlations were found between brachial-ankle PWV and 24-h sodium and potassium excretions. Our study indicates that dietary salt intake and potassium supplementation, at least in the short term, had no significant effect on brachial-ankle PWV in Chinese subjects.

Effect of salt intake and potassium supplementation on serum renalase levels in Chinese adults: a randomized trial

Renalase, a recently discovered enzyme released by the kidneys, breaks down blood-borne catecholamines and may thus regulate blood pressure (BP). Animal studies have suggested that high levels of dietary salt might reduce blood and kidney renalase levels. We conducted a randomized trial to assess the effects of altered salt and potassium intake on serum renalase levels and the relationship between serum renalase levels and BP in humans.Forty-two subjects (28-65 years of age) were selected from a rural community of northern China. All subjects were sequentially maintained on a low-salt diet for 7 days (3.0 g/day of NaCl), a high-salt diet for additional 7 days (18.0 g/day of NaCl), and a high-salt diet with potassium supplementation for final 7 days (18.0 g/day of NaCl + 4.5 g/day of KCl).Serum renalase levels were significantly higher than baseline levels during the low-salt diet intervention period. Renalase levels decreased with the change from the low-salt to high-salt diet, whereas dietary potassium prevented the decrease in serum renalase induced by the high-salt diet. There was a significant inverse correlation between the serum renalase level and 24-h urinary sodium excretion. No significant correlation was found between the renalase level and BP among the different dietary interventions.The present study indicates that variations in dietary salt intake and potassium supplementation affect the serum renalase concentration in Chinese subjects.