Interaction between serum uric acid and triglycerides in relation to prehypertension in community-dwelling Japanese adults

Serum uric acid and risk of prehypertension: a dose-response meta-analysis of 17 observational studies of approximately 79 thousand participants

BACKGROUND

Studies examining the association between levels of serum uric acid (SUA) and risk of prehypertension still remained controversial conclusions. Also, a quantitative assessment of the dose-response association between them has not been reported. We aimed to quantitatively evaluate risk of prehypertension with levels of SUA based on observational study.

METHODS

We searched the PubMed, Embase, and Web of Science databases up to December 3, 2019 for relevant studies. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random-effects models. The possible linear or non-linear SUA-prehypertension association was modelled by restricted cubic splines.

RESULTS

We included 17 articles (17 studies) with a total of 79,358 participants and 34,591 cases of prehypertension. Compared with lowest levels of SUA, risk of prehypertension increased 46% (RR 1.46, 95% CI 1.28-1.66) for highest levels of SUA. For per 1 mg/dL increment in levels of SUA, risk of prehypertension increased by 12% (RR 1.12, 95% CI 1.08-1.17). Also, we found evidence of a linear SUA-prehypertension association (P_{non-linearity}=.368).

CONCLUSION

Elevated levels of SUA may be associated with increased risk of prehypertension. Present findings provide the evidence that lowering levels of SUA should be suggested in order to reduce the risk of prehypertension. More longitudinal and intervention studies are needed to clarify the optimal protective levels and whether reducing levels of SUA could prevent or control prehypertension and the progression of prehypertension to hypertension.

Low Serum Uric Acid Predicts Risk of a Composite Disease Endpoint

Background and objectives: Mortality may increase in hypouricemia as well as inhyperuricemia. We assessed the predictive value of low serum uric acid (SUA) levels on the risk of overall mortality or a composite endpoint of death and nonfatal events. Materials and Methods: In 1013 community-based middle-aged adults, free of uncontrolled diabetes and coronary heart disease at baseline, the association of sex-specific SUA tertiles with defined outcomes was evaluated prospectively by logistic regression, stratified to gender and presence of type-2 diabetes, using recent criteria. Results: Totally, 43 deaths and additional incident nonfatal events in 157 cases were recorded at a median 3.4 years' follow-up. Multivariable linear regression disclosed SUA to be significantly associated among non-diabetic individuals positively with creatinine, triglycerides, and body mass index in women further with fasted glucose. In multivariable-adjusted logistic regression analysis, sex-specifically dichotomized baseline uric acid (<5.1 and <4.1 mg/dL vs. higher values) significantly predicted the non-fatal events in the whole sample (relative risk (RR) 1.51 [95% confidence interval (CI) 1.02; 2.26]), as well as in men, while composite endpoint in the whole sample tended to rise (RR 1.38). Compared with the intermediate one, the top and bottom SUA tertiles combined tended to confer mortality risk (RR 2.40 [95% CI 0.89; 6.51]). Adverse outcomes in diabetic women were predicted by tertiles 2 and 3. Conclusions: Inverse association of SUA with adverse outcomes, especially in men, is consistent with the involvement of uric acid mass in autoimmune activation. The positive association of uric acid with adverse outcomes in diabetic women is likely mediated by concomitant high-density lipoprotein dysfunction.

Antihypertensive activity of oleanolic acid is mediated via downregulation of secretory phospholipase A2 and fatty acid synthase in spontaneously hypertensive rats

Oleanolic acid (OA) is reported to possess antihypertensive activity via the regulation of lipid metabolism; however, the mechanisms underlying lipid regulation by OA are yet to be fully elucidated. The aim of the present study was to evaluate the mechanisms via which OA regulates lipid metabolism in spontaneously hypertensive rats (SHRs) via ultra‑performance liquid chromatography‑quadrupole/Orbitrap‑mass spectrometry (MS)‑based lipidomics analysis. SHRs were treated with OA (1.08 mg/kg) for 4 weeks. The liver tissues were excised, homogenized in dichloromethane and centrifuged, and subsequently the supernatant layer was collected and concentrated under vacuum to dryness. The dichloromethane extract was subjected to MS analysis and database searching, and comparison of standards was performed to identify potential biomarkers. Partial least squares‑discriminant analysis performed on the liver lipidome revealed a total of 14 endogenous metabolites that were significantly changed in the SHR model group (SH group) compared with Wistar Kyoto rats [normal control (NC group)], including glycerophospholipids, sphingolipids and glycerides. Heatmaps revealed that the liver lipid profiles in the OA group were clustered more closely compared with those observed in the NC group, indicating that the antihypertensive effect of OA was mediated via regulation of liver lipid metabolites. It was observed that the protein levels of secretory phospholipase A2 (sPLA2) and fatty acid synthase (FAS) were increased in the SH group compared with the NC group. In addition, the levels of lysophosphatidylcholine and triglycerides in the liver were elevated, whereas the levels of low‑density lipoprotein cholesterol and high‑density lipoprotein cholesterol were reduced in the SH group. Upon treatment with OA, the mRNA and protein levels of PLA2 and FAS were observed to be downregulated. Collectively, the present study indicated that the antihypertensive activity of OA was mediated via downregulation of sPLA2 and FAS in SHRs, and that treatment with OA resulted in significant improvements in blood pressure and associated abnormalities in the lipid metabolites.

High serum uric acid within the normal range is a useful predictor of hypertension among Japanese community-dwelling elderly women

Background

The risk associated with serum uric acid (SUA) levels when within the normal range is unknown. This study aims to examine whether SUA within the normal range is a predictor of hypertension.

Methods

The subjects comprised 704 men aged 71 ± 9 (mean ± standard deviation) years and 946 women aged 70 ± 8 years recruited for a survey at the community based annual medical check-up. The main outcome was the presence of hypertension (antihypertensive medication and/or having SBP ≥140 mmHg and/or DBP ≥90 mmHg).

Results

At baseline, 467 (66.3%) men and 608 (64.3%) women had hypertension. Comparing to lowest quartile in women (SUA-1, uric acid < 4.1 mg/dL), the unadjusted odds ratios (ORs) [95% confidence interval (CI)] for hypertension of SUA-2 (4.1 to 4.7 mg/dL), SUA-3 (4.8 to 5.4 mg/dL), and SUA-4 (≥5.5 mg/dL) were 1.11 (0.78–1.59), 1.75 (1.20–2.55), and 1.89 (1.30–2.77), respectively. These associations were apparent even after adjustments for age, but ORs were attenuated after adjusting for all confounding factors. During a follow-up of 3.0 years, there were 35 (24.0%) hypertension cases in men and 51 (20.8%) in women. In women only, a significant association between increased SUA categories and incidence of hypertension was observed, and the multivariate-ORs (95% (CI) for incident hypertension of SUA-3 (4.5–5.2 mg/dL) and SUA-4 (≥5.3 mg/dL) were 2.23 (0.81–6.11) and 3.84 (1.36–10.8), respectively.

Conclusions

These results suggest that baseline SUA within the normal range could be an important predictor for incidence of hypertension in Japanese community-dwelling elderly women.

Association between cardiovascular risk factors and stage 1 hypertension defined by the 2017 ACC/AHA guidelines

BACKGROUND

A blood pressure (BP) of 130-139/80-89 mmHg has been defined as stage 1 hypertension by the 2017 American College of Cardiology/American Heart Association High Blood Pressure Clinical Practice Guidelines. This study was conducted to assess the association of cardiovascular risk factors (CRFs) and newly defined stage 1 hypertension in China.

METHODS

We analyzed the data of 84,489 adults with a BP of <140/90 mmHg. The 10-year cardiovascular disease (CVD) risk score was calculated using the China-PAR equation. Logistic analysis was used to assess the association between CRFs and stage 1 hypertension.

RESULTS

The mean values of CRFs, the proportion of metabolic abnormalities, the prevalence of ≥2 CRFs, and the 10-year CVD risk of individuals with a BP of 130-139/80-89 mmHg were significantly higher than those of the population with a BP of <130/80 mmHg. The adjusted odds ratios (ORs) of waist circumference, fasting plasma glucose (FPG), and triglycerides were 1.362 (CI 95% = 1.081-1.715, p = .009), 1.264 (CI 95% = 1.093-1.462, p = .002), and 1.331 (CI 95% = 1.009-1.755, p = .043), respectively. Other CRFs were not significantly associated with stage 1 hypertension.

CONCLUSIONS

Multidisciplinary and targeted interventions are required to manage the CRFs (especially abdominal obesity, elevated FPG, and hypertriglyceridemia) of the population with a BP of 130-139/80-89 mmHg in China.

Age-differential association between serum uric acid and incident hypertension

Increasing evidence suggests a positive association between the serum uric acid (SUA) level and incident hypertension. However, the association has been inconsistent based on age, sex, body mass index, and lipid profiles. Thus, we investigated whether there is an interaction between SUA and other risk factors on incident hypertension in the Korean general population. In this study, 808 participants aged 40-79 years were included. They were free of hypertension and major cardiovascular disease at baseline. Incident hypertension was defined as systolic blood pressure (SBP) ≥ 140 mmHg, diastolic blood pressure (DBP) ≥ 90 mmHg, or use of antihypertensive medication. To investigate whether the association between SUA and incident hypertension is modified by other risk factors for hypertension, a generalized linear model and Z test were used. During the mean follow-up of 3.3 years, 11.5% of men and 10.7% of women developed hypertension. The association between SUA and incident hypertension was inconsistent according to participant age (p for interaction = 0.009). The association between SUA level and incident hypertension was positively significant among people aged < 55 years (relative risk 1.74 per 1.0 mg/dL of SUA; p = 0.002), but there was no significant association among people aged ≥ 55 years (p = 0.894). In a secondary analysis, the SUA level was not associated with an increase in SBP, but positively associated with DBP. We observed an age-differential association between SUA level and incident hypertension among Koreans. An increased SUA level can be a trigger for hypertension through early vascular changes in the middle-aged population.

Triglycerides and blood pressure in relation to circulating CD34-positive cell levels among community-dwelling elderly Japanese men: a cross-sectional study

Background

Triglycerides are reported to be positively associated with blood pressure (both systolic and diastolic). However, in a previous study, we reported a significant positive association between triglycerides and circulating CD34-positive cells (endothelial repair) among non-hypertensive, but not hypertensive, participants. Since hypertension and endothelial dysfunction have a bi-directional association (vicious cycle), the status of circulating CD34-positive cells may influence the association between triglycerides and hypertension.

Methods

Since antihypertensive medication use may influence results of the present study, we conducted a cross-sectional study of 327 community dwelling elderly (aged 60–69 years) Japanese participants who were not taking anti-hypertensive medication and who had participated in a general health check-up in 2013–2015.

Results

Participants were classified into two groups based on median values of circulating CD34-positive cells (0.93 cells/μL). For participants with lower circulating CD34-positive cells (n = 165), a significant positive association was seen between triglycerides and blood pressure, but not for participants with higher circulating CD34-positive cells (n = 162). The multivariable standardized parameter estimates (β) and p values of systolic blood pressure and diastolic blood pressure were 0.23 (p = 0.007) and 0.18 (p = 0.036) for participants with lower circulating CD34-positive cells and 0.08 (p = 0.409) and 0.03 (p = 0.786) for those with higher circulating CD34-positive cells.

Conclusion

A significant positive association between triglycerides and blood pressure exists among those with lower, but not higher, circulating CD34-positive cells. The level of circulating CD34-positive cells acts as a determinant factor for the association between triglycerides and blood pressure.

Interactive association of serum uric acid and total bilirubin with renal dysfunction among community-dwelling subjects

PURPOSE

Chronic kidney disease is a major public health concern. Serum uric acid (SUA) at high levels was oxidative stress agents, and total bilirubin (T-BiL) at mildly increased levels was potent antioxidants, but whether SUA and T-BiL produce an additive interaction for the risk of renal dysfunction remains unclear.

METHODS

The subjects comprised 567 men aged 71 ± 8 (mean ± standard deviation) years and 853 women aged 70 ± 8 years from a rural village. We examined the relationship between SUA and T-BiL, and renal function was evaluated by estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease Study Group equation.

RESULTS

Stepwise multiple regression analysis using eGFR as an objective variable, adjusted for risk factors as explanatory variables, showed that SUA (β = -0.358, p < 0.001) as well as age (β = -0.534, p < 0.001), drinking status (β = 0.119, p < 0.001), and the presence of antihypertensive medication (β = -0.058, p = 0.005) were significantly and independently associated with eGFR, but T-BiL was not associated with eGFR. While in the group with the highest tertile of SUA, T-BiL (β = 0.081, p = 0.032) was significantly and independently associated with eGFR, and in the group with the lowest to middle tertile of SUA, T-BiL was not associated with eGFR. In addition, interaction between SUA and T-BiL (F = 8.512, p = 0.004) as well as age, drinking status, the presence of antihypertensive medication, SUA, and T-BiL was a significant and independent determinant for eGFR.

CONCLUSIONS

Our data demonstrated that low T-BiL could be important as a potential risk factor for renal dysfunction in those with high SUA.

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.

Interaction between Marine-Derived n-3 Long Chain Polyunsaturated Fatty Acids and Uric Acid on Glucose Metabolism and Risk of Type 2 Diabetes Mellitus: A Case-Control Study

The present case-control study explored the interaction between marine-derived n-3 long chain polyunsaturated fatty acids (n-3 LC PUFAs) and uric acid (UA) on glucose metabolism and risk of type 2 diabetes mellitus (T2DM). Two hundred and eleven healthy subjects in control group and 268 T2DM subjects in case group were included. Plasma phospholipid (PL) fatty acids and biochemical parameters were detected by standard methods. Plasma PL C22:6n-3 was significantly lower in case group than in control group, and was negatively correlated with fasting glucose (r = −0.177, p < 0.001). Higher plasma PL C22:6n-3 was associated with lower risk of T2DM, and the OR was 0.32 (95% confidence interval (CI), 0.12 to 0.80; p = 0.016) for per unit increase of C22:6n-3. UA was significantly lower in case group than in control group. UA was positively correlated with fasting glucose in healthy subjects, but this correlation became negative in T2DM subjects. A significant interaction was observed between C22:6n-3 and UA on fasting glucose (p for interaction = 0.005): the lowering effect of C22:6n-3 was only significant in subjects with a lower level of UA. In conclusion, C22:6n-3 interacts with UA to modulate glucose metabolism.

Serum Uric Acid and Prehypertension Among Adults Free of Cardiovascular Diseases and Diabetes

The association between serum uric acid (SUA) and prehypertension was evaluated in a racially admixed sample of civil servants aged 35 to 74 years, enrolled (2008-2010) in the Brazilian Longitudinal Study of Health (ELSA-Brasil). Of the 15 105 patients who enrolled in the study, we analyzed 3412 after excluding those who reported previous cardiovascular diseases, diabetes, or hypertension; were heavy drinkers; or had a body mass index (BMI) ≥35 kg/m2. Among the men, logistic regression, adjusted for age, race, income, birth weight, salt intake, insulin resistance, BMI, and renal function revealed odds ratios (ORs) and 95% confidence intervals (CIs) of prehypertension from the bottom quartile (referent) to the top quartile of SUA levels as follows: 0.84 (95% CI, 0.61-1.38), 0.97 (0.71-1.34) and 1.44 (1.04-2.0; P for trend .01). Analyzing for 1-standard deviation of change in SUA, the ORs were 1.19 (1.06-1.32). This association persisted in the subgroup analysis consisting of patients who were white, overweight, with a high salt intake but with normal renal function, and without metabolic syndrome. No association was found among women. In conclusion, SUA levels were associated with prehypertension among men.

Serum uric acid and its relationship with cardiovascular risk profile in Chinese patients with early-onset coronary artery disease

The prevalence of coronary artery disease (CAD) is growing in the young population. We aimed to investigate the association between serum uric acid (SUA) levels and cardiovascular involvement in individuals under 45 years old diagnosed with early-onset CAD (EOCAD). Seven hundred eighty-six EOCAD patients were recruited and stratified into four groups by SUA levels. General information, serum indicators, and results of coronary angiography and echocardiography were recorded. The associations between SUA levels were explored by univariate and multivariate logistic regressions. With the increasing of SUA levels, the prevalence of hypertension and hyperlipidemia, triple branches involved, heart failure, and cardiac enlargement of left ventricle (LV), left atrium (LA), and right ventricle (RV) were significantly higher (all P < 0.05). The fourth group (SUA >8 mg/dl) had the highest proportions than other groups (all P < 0.05). After controlling potential confounders, multiple logistic regression analysis showed that odds ratios of SUA >8 mg/dl were 2.345 for triple branches involved (95 % confidence interval (CI) 1.335-4.119), 4.168 for heart failure (95 % CI 1.599-10.862), and 4.122 for LV enlargement (95 % CI 1.874-9.065) (P < 0.05). SUA >8 mg/dl was independently associated with triple branches involvement, heart failure and LV enlargement in Chinese EOCAD patients. Higher SUA level might play an important role in cardiac dysfunction and severity of EOCAD.

Prevalence and risk factors associated with prehypertension in Shunde District, southern China

OBJECTIVE

To explore the prevalence and combined cardiovascular risk factors of prehypertension in southern China.

DESIGN

A retrospective study; the logistic regression model was used to find the risk factors of prehypertension.

SETTING

The study was conducted in Shunde District, southern China, using the community-based health check-up information.

PARTICIPANTS

Participants aged ≥35 years with complete health check-up information data between January 2011 and December 2013 were enrolled and divided into hypertension, prehypertension and optimal blood pressure (BP) groups. Prehypertension was further divided into low-range (BP 120-129/80-84 mm Hg) and high-range (BP 130-139/85-89 mm Hg) subgroups.

OUTCOME MEASURES

The prevalence of prehypertension and the combined cardiovascular risk factors within the prehypertensive subgroups.

RESULTS

Of the 5362 initially reviewed cases (aged ≥35 years), 651 were excluded because of missing data. The proportions of optimal BP, prehypertension and hypertension were 39.1%, 38.6% and 22.3%, respectively. The average age, proportion of male sex, overweight, impaired fasting glucose (IFG), dyslipidaemia and hyperuricaemia were significantly higher in the prehypertension group than in the optimal BP group (all p <0.05). Compared with low-range prehypertension, the proportions of overweight, dyslipidaemia and IFG were higher in the high-range prehypertension group (all p<0.05). Multivariate logistic regression analysis showed that overweight (OR=2.84, 95% CI 1.55 to 5.20), male sex (OR=2.19, 95% CI 1.39 to 3.45), age (per 10 years, OR=1.21, 95% CI 1.02 to 1.44, p=0.03) and hyperuricaemia (OR=1.70, 95% CI 1.14 to 2.54) were independent risk factors of prehypertension.

CONCLUSIONS

Prehypertension is highly prevalent in southern China. Prehypertensive individuals presented with many other cardiovascular risk factors. There was heterogeneity of combined risk factors within the prehypertensive subgroups.

Prehypertension in rural northeastern China: results from the northeast China rural cardiovascular health study

This study aimed to determine the present status of prehypertension in rural China. It was conducted between January and August 2013, using a multistage clustering method to select a representative sample of individuals (≥35 years old), resulting in a study population of 11,576 adults. Prehypertension was defined as a systolic blood pressure (BP) in the range of 120 mm Hg to 139 mm Hg and/or a diastolic BP between 80 mm Hg and 89 mm Hg according to the Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). The results showed that the mean±standard deviation systolic and diastolic BP values for the entire population were 141.8±23.5 mm Hg and 82.1±11.8 mm Hg, respectively. Among the whole population, 35.1% of men and 32.5% of women were prehypertensive. Multiple logistic regression analysis showed that high body mass index, advanced age, alcohol consumption, diabetes, high triglyceride and low-density lipoprotein cholesterol levels, and elevated diet score were risk factors for prehypertension. This study indicates that there is a high prevalence of prehypertension in rural China and confirms the importance of healthy lifestyles--including the control of obesity, diabetes, and dyslipidemia--to decrease the incidence of prehypertension.

Association and interaction analysis of PPARGC1A and serum uric acid on type 2 diabetes mellitus in Chinese Han population

BACKGROUND

Peroxisome proliferator-activated receptor gamma coactivator-1α (PPARGC1A/ PGC-1α) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily. The activity of PGC-1α or genetic variations in the gene encoding the enzyme may contribute to individual variations in mitochondrial function and insulin resistance or diabetes. The objective of this study was to assess the extent to which PPARGC1A (rs8192678) and serum uric acid (UA) and its interaction impact on T2DM susceptibility in Chinese Han population.

METHOD

We conducted a study in a cohort that included 1166 T2DM patients and 1135 controls, and was genotyped for the presence of the PPARGC1A rs8192678 polymorphisms. Genotyping was performed by iPLEX technology. The association between rs8192678 or UA and T2DM was assessed by univariate and multivariate logistic regression (MLR) analysis controlling for confounders. The interaction between rs8192678 and UA for T2DM susceptibility was also assessed by MLR analysis.

RESULTS

The generalized linear regression analysis failed to show an association between the PPARGC1A rs8192678 polymorphisms and T2DM. Interestingly, the present study provided data suggesting that the minor A-allele of PPARGC1A (rs8192678) had a protective effect against T2DM in subjects with higher level of UA (ORint =1.50 95% CI: 1.06-2.12 for allele and P = 0.02, ORint =1.63 95% CI: 1.17-2.26 for genotype and P = 0.004).

CONCLUSION

The combination of higher level of UA and PPARGC1A (rs8192678) was an independent predictor for T2DM.