Prehypertension: is it relevant for nephrologists? Kidney Int. 2010;77:194-200. [PMID: 19924105 DOI: 10.1038/ki.2009.439]

Effect of regional medical disparities on complications in patients with hypertension: Cox's proportional hazard models

Objective

Complications associated with hypertension can be alleviated by providing necessary medical services. However, there may be disparities in their provision depending on regional differences. Thus, this study aimed to examine the effects of regional healthcare disparities on complications in patients with hypertension in South Korea.

Methods

Data from the National Health Insurance Service National Sample Cohort (2004-2019) were analyzed. The position value for the relative composite index was used to identify medically vulnerable regions. The diagnosis of hypertension within the region was also considered. The risk of complications associated with hypertension included cardiovascular, cerebrovascular, and kidney diseases. Cox proportional hazards models were used for statistical analysis.

Results

A total of 246,490 patients were included in this study. Patients who lived in medically vulnerable regions and were diagnosed outside their residential area had a higher risk of complications than those living in non-vulnerable regions and were diagnosed outside the residential area (hazard ratio: 1.156, 95% confidence interval: 1.119-1.195).

Conclusion

Patients living in medically vulnerable regions who were diagnosed outside their residential areas were more likely to have hypertension complications regardless of the type of complication. Necessary policies should be implemented to reduce regional healthcare disparities.

The effect of prehypertension and hypertension on the incidence of cardiovascular disease: A population-based cohort study in Kharameh, a city in the South of Iran

Background and Aim

Prehypertension and hypertension are important risk factors for cardiovascular diseases. This study was carried out to evaluate the effect of prehypertension and hypertension on the development of cardiovascular diseases.

Methods

This prospective cohort study was performed on 9442 people aged 40-70 in Kharameh, southern Iran. Individuals were divided into three groups: normal blood pressure (N = 5009), prehypertension (N = 2166), and hypertension (N = 2267). In this study, demographic data, disease histories, behavioral habits, and biological parameters were studied. At first, the incidence density was calculated. Then Firth's Cox regression models were used to investigate the association between prehypertension and hypertension with the incidence of cardiovascular diseases.

Results

The incidence density in the three groups of individuals with normal blood pressure, prehypertension, and hypertension was 1.33, 2.02, and 3.29 cases per 100,000 person-days, respectively. The results of multiple Firth's Cox regression by controlling all factors showed that the risk of occurrence of cardiovascular disease in people with prehypertension was 1.33 times (hazard ratio [HR] = 1.32, 95% confidence interval [CI]: 1.01-1.73, p = 0.03) and those with hypertension were 1.85 times higher (HR = 1.77, 95% CI: 1.38-2.29, p < 0.0001) than the individuals with normal blood.

Conclusion

Prehypertension and hypertension have played an independent role in the risk for developing cardiovascular diseases. Therefore, early detection of individuals with these factors and control of other risk factors in them can contribute to reducing the occurrence of cardiovascular diseases.

Identifying factors associated with of blood pressure using Structural Equation Modeling: evidence from a large Kurdish cohort study in Iran

BACKGROUND

Identifying the risk factors leading to hypertension can help explain why some populations are at a greater risk for developing hypertension than others. The present study seeks to identify the association between the risk factors of hypertension in 35- to 65-year-old participants in western Iran.

METHODS

This cross-sectional study was conducted on 9705 adults from baseline data of Ravansar Non-Communicable Disease (RaNCD) cohort study, in the west region of Iran. Each of the latent variables were confirmed by confirmatory factor analysis. Using Structural Equation Modeling (SEM), we assessed the direct and indirect effects of factors associated with blood pressure.

RESULTS

Socioeconomic status (SES), physical activity, mean of serum lipids, obesity, diabetes and family history of hypertension had a diverse impact on the blood pressure, directly and (or) indirectly. The standardized total effect of SES, physical activity, mean of serum lipids, and obesity were -0.09 vs. -0.14, -0.04 vs. -0.04, 0.13 vs. 0.13 and 0.24 vs. 0.15 in men and women, respectively. Diabetes had a direct relationship with the blood pressure in women (0.03).

CONCLUSION

With regard to control of high blood pressure, public health interventions must target obesity, lifestyle and other risk related to nutritional status such as hyperlipidemia and hyperglycemia in Iranian population and among those with higher SES.

The Association between Blood Pressure Trajectories and Risk of Cardiovascular Diseases among Non-Hypertensive Chinese Population: A Population-Based Cohort Study

Although previous studies have discussed the association between trajectories of blood pressure (BP) and risk of cardiovascular diseases (CVDs), the association among the non-hypertensive general population of youth and middle age has not been elucidated. We used the growth mixture model to explore the trajectories of BP among the non-hypertensive Chinese population and applied Cox regression to evaluate the association between trajectories of BP and the risk of stroke or myocardial infarction (MI). Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were categorized into three classes, respectively. Statistically significant associations were observed between SBP trajectories and stroke (range of adjusted hazard ratios (aHR): 1.369-3.837) or MI (rang of aHR = 6.047-13.017). Association between DBP trajectories and stroke (aHR: 3.685) or MI (range of aHR = 1.312-2.821) were also observed, although they did not reach statistical significance. Trajectories of SBP were more important risk factors than that of DBP in stroke and MI in our study population. BP management is important among pre-hypertensive adults to prevent stroke and MI when they age. Well-designed research with a larger sample size is required to confirm our findings and develop efficient methods to prevent CVDs.

Evaluation of affective temperaments and arterial stiffness in different hypertension phenotypes

Affective temperaments (depressive, anxious, irritable, hyperthymic, and cyclothymic) are stable parts of personality and describe emotional reactivity to external stimuli. Their relation to psychopathological conditions is obvious, but less data are available on their relationship with cardiovascular disorders. The aim of this study was to evaluate affective temperaments and hemodynamic and arterial stiffness parameters in healthy subjects (Cont), in white-coat hypertensive (WhHT) patients, and in non-resistant (non-ResHT) and resistant hypertensive (ResHT) patients. In this cross-sectional study, 363 patients were included: 82 Cont, 44 WhHT, 200 non-ResHT, and 37 ResHT. The patients completed the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A), and arterial stiffness was examined with tonometry (PulsePen). Significant differences were found between the Cont, WhHT, non-ResHT and ResHT groups in pulse wave velocity (7.76 ± 0.96, 8.13 ± 1.39, 8.98 ± 1.25, and 10.18 ± 1.18 m/s, respectively, p < 0.05 between Cont and non-ResHT/ResHT; p < 0.05 between non-ResHT and ResHT). Cyclothymic affective temperament points (4 (2.25-8)) were higher (p < 0.05) in the ResHT group than in the Cont (2 (0-5)) and non-ResHT (3 (1-5)) groups. The cyclothymic temperament points of the WhHT group (4 (2-7)) were also higher than those in the Cont group. ResHT was independently associated with a cyclothymic scale score above 6 (beta = 2.59 (95% CI: 1.16-5.77)), an irritable scale score above 7 (beta = 3.17 (95% CI: 1.3-7.69)) and an anxious scale score above 9 (beta = 2.57 (95% CI: 1.08-6.13)) points. WhHT was also independently associated with cyclothymic scale scores above 6 points (beta = 2.378, 95% CI: 1.178-4.802). In conclusion, white-coat and ResHT patients have specific affective temperament patterns, and the evaluation of these patterns can help to understand the psychopathological background of these conditions.

Corn Silk Tea for Hypertension: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Corn silk, a traditional Chinese medicine, has been found to exert an antihypertensive effect in clinical practice and trials. However, systematic review of current evidence on this topic was not available. Thus, this study aims to assess safety and efficacy of corn silk tea (CST) in improving clinical outcomes in patients with hypertension. A systematic literature search was conducted through popular electronic databases up to October 2018. Randomized controlled trials (RCTs) comparing CST plus conventional antihypertensive drugs with conventional antihypertensive drugs alone were included. The main outcome was total blood pressure lowering efficacy. The risk of bias assessment according to the Cochrane Handbook was used to evaluate the methodological quality of the included trials. Review Manager 5.3 software was used for data analyses. Five RCTs involving 567 participants were included. Due to the poor quality of methodologies of most trials, limited evidence showed that CST plus antihypertensive drugs might be more effective in lowering blood pressure compared with antihypertensive drugs alone (RR = 1.27; 95% CI: 1.17 to 1.38, P<0.00001; heterogeneity: P = 0.51, I² = 0%, fixed‐effect model). However, there is no evidence that CST plus conventional antihypertensive drugs has less adverse events than conventional antihypertensive drugs.

Association of blood pressure components with mortality and cardiovascular events in prehypertensive individuals: a nationwide population-based cohort study

BACKGROUND

The effects of each blood pressure index [systolic and diastolic blood pressure (SBP, DBP), pulse pressure (PP), mean arterial pressure (MAP)] on the occurrence of mortality and cardiovascular (CV) events have not yet been investigated in prehypertensive populations.

METHODS

A total of 30,258 prehypertensive Korean participants underwent periodic health examination between 2003 and 2004 were enrolled, and the associations of BP components with mortality and CV events were investigated. Moreover, based on the DBP [80 ≤ DBP <90 mmHg (N = 21,323) and DBP <80 mmHg (N = 8,935)], the effects of BP components were also evaluated.

RESULTS

Multivariate Cox analyses in prehypertensive group revealed that the hazard ratios (HRs) were 1.121 and 1.130 per 10 mmHg increase in SBP and PP for mortality, respectively. Additionally, 10 mmHg increase of SBP (HR:1.090) was still significantly, but increase of PP (HR:1.060) was marginally associated with higher incidence of CV events. However, there were no significant associations with increase in DBP or MAP on adverse clinical outcomes in prehypertensive group. In the prehypertensive subjects with DBP <80 mmHg, CV events more frequently occurred by 38.8% and 28.5% per 10 mmHg increase in SBP and PP, respectively.

CONCLUSIONS

Prehypertensive subjects might need to be cautioned when they have high SBP or PP with low DBP even in healthy populations. Key message Prehypertensive subjects should be cautioned when they have high-systolic blood pressure or pulse pressure with low-diastolic blood pressure, even without previous hypertension, diabetes mellitus or chronic kidney disease.

[Try to achieve quickly the blood pressure target in newly diagnosed hypertensive patients is safe and effective]

OBJECTIVES

To compare a so-called an "accelerated" antihypertensive strategy to a "standard" strategy, in terms of blood pressure control rates and adverse events.

METHODS

Prospective open-label randomized controlled trial, which included consecutive hypertensive patients, newly diagnosed, 40 to 70 years old, with no prior antihypertensive treatment. Hypertension was diagnosed if office blood pressure was≥140/90mmHg, confirmed by an increase of Home or a daytime ambulatory blood pressure. The patients were randomly assigned according to 1:1 ratio to an "accelerated" strategy or to a "standard" strategy. The primary end-point was the rate of blood pressure control at 12weeks. The secondary end-point was the rate of adverse events (a safety end-point).

RESULTS

We recruited 268 patients (132 in the "accelerated" strategy group), with a mean age of 55 years and 62% of men. The mean office blood pressure at baseline was 168/95mmHg. The clinical characteristics were on average similar between the 2 treatment groups. At 12 weeks, the rates of blood pressure control were 63.6% in the "accelerated" strategy and 38.2% in the "standard" strategy (P<0.001). There was no significantly difference between the rates of adverse events in the 2 strategies (6.06% versus 5.14%; P=0.8).

CONCLUSION

The "accelerated" antihypertensive strategy was more effective than a standard one, in terms of blood pressure control, without an increase in adverse events rate. This could translate into a future cardiovascular events reduction.

Joint Effect of Non-invasive Central Systolic Blood Pressure and Peripheral Systolic Blood Pressure on Incident Hypertension in a Chinese Community-based Population

Central blood pressure level is not always consistent with peripheral blood pressure level, and especially their joint effect on incident hypertension is not well established. A total of 1607 non-hypertensive subjects from an atherosclerosis cohort in Beijing, China were included. Central systolic blood pressure (cSBP) was obtained using Omron HEM-9000AI machine and peripheral systolic blood pressure (pSBP) was measured using Omron HEM-7117 electronic sphygmomanometer, separately. Hypertension was defined as BP ≥ 140/90 mmHg or self-reported hypertension or taking any antihypertension drugs at the follow-up survey. After a median follow-up of 2.3 years, incident hypertension was 13.1%. Every 1 standard deviation increase of cSBP and pSBP was associated with 1.98 (95%CI: 1.69-2.33) and 2.84 (95%CI: 2.30-3.52) times of incident hypertension after adjustment for confounders. Moreover, hypertension risk in single pSBP ≥ 120 mmHg group, single cSBP ≥ 120 mmHg group, and both pSBP and cSBP ≥ 120 mmHg group was 2.83 (95%CI: 0.98-8.16), 3.28 (95%CI: 1.24-8.70), and 11.47 (95%CI: 4.97-26.46) times higher than both pSBP and cSBP < 120 mmHg group, respectively. The joint effect of cSBP and pSBP is superior to either cSBP or pSBP to predict incident hypertension in a Chinese community-based population. Screening of central blood pressure should be considered in non-hypertensive population for the purpose of primary intervention, especially for subjects with pSBP ≥ 120 mmHg.

Hypertension and cardiovascular risk: General aspects

Hypertension is the strongest or one of the strongest risk factors for almost all different cardiovascular diseases acquired during life, including coronary disease, left ventricular hypertrophy and valvular heart diseases, cardiac arrhythmias including atrial fibrillation, cerebral stroke and renal failure. The continuous relationship between blood pressure and cardiovascular and renal events makes the distinction between high normal blood pressure and hypertension based on arbitrary cut-off values for blood pressures. Overall the prevalence of hypertension in different European countries appears to be around 30-45% of the general population, with a steep increase with ageing. The prevention of cardiovascular disease and treatment recommendations should be related to quantification of total cardiovascular risk which could be estimated from several different models. However the impact of age on risk is so strong that young adults (particularly women) are unlikely to reach high-risk levels even when they have more than one major risk factor and a clear increase in relative risk. Therefore age-adjusted models, models assessing relative risks compared to others of same age and models including thorough assessments of target organ damage and ambulatory 24h blood pressure are needed together with national models because of the large variations between countries.

Physical activity and blood pressure in 10,000 Mediterranean adults: The EPIC-Florence cohort

BACKGROUND AND AIMS

The relevant role of physical activity (PA) in cardiovascular risk prevention is widely agreed. We aimed to evaluate, in a large Mediterranean population, the influence of PA on systolic (SBP) and diastolic blood pressure (DBP), taking into account individual characteristics and lifestyle habits.

METHODS AND RESULTS

In the Florence section of the European Prospective Investigation into Cancer and Nutrition 10,163 individuals, 35-64 years, without a previous diagnosis of hypertension were recruited. Information on occupational and leisure-time PA and blood pressure were collected at recruitment, together with data on lifestyle, dietary habits and anthropometry. Multivariate regression models were applied to evaluate the effect of total, occupational and leisure-time PA on SBP and DBP. Mean values of SBP and DBP in the study subjects were 124.4 (SD 15.6) and 79.7 mmHg (SD 9.4), respectively. Overall, a total PA index and an index including cycling, fitness and occupational PA (Cambridge index) were inversely associated with DBP (beta -0.87, p-value 0.02 actives vs inactives, p for trend 0.02 and beta -0.84, p value 0.003 actives vs inactives, p for trend 0.002, respectively), while SBP was associated only with the latter index (beta -1.14, p-value 0.01 actives vs inactives, p for trend 0.006). An inverse association emerged between manual/heavy manual occupation and DBP (p 0.02, ref sedentary/standing occupation) and between increasing cycling activity and SBP (p for trend 0.04).

CONCLUSIONS

In this large cohort of Mediterranean adults without a diagnosis of hypertension we confirm the role of overall PA in modulating SBP and DBP values. Cycling and manual occupations were associated with lower DBP values.

Association of affective temperaments with blood pressure and arterial stiffness in hypertensive patients: a cross-sectional study

Background

Affective temperaments (anxious, depressive, cyclothymic, irritable and hyperthymic) measure subclinical manifestations of major mood disorders. Furthermore, cumulating evidence suggests their involvement in somatic disorders as well. We aimed to assess associations between affective temperament scores and blood pressure and arterial stiffness parameters in hypertensive patients.

Methods

In this cross-sectional study, 173 patients with well-controlled or grade 1 chronic hypertension, with no history of depression, completed the TEMPS-A, Beck Depression Inventory (BDI) and Hamilton Anxiety Scale (HAM-A) questionnaires in three GP practices. Arterial stiffness was measured with tonometry (PulsePen).

Results

According to multiple linear regression analysis, cyclothymic temperament score was positively associated with brachial systolic blood pressure independently of age, sex, total cholesterol, brachial diastolic blood pressure, BDI, HAM-A and the use of alprazolam (β = 0.529, p = 0.042), while hyperthymic temperament score was negatively related to augmentation index independent of age, sex, smoking, heart rate, BDI, HAM-A and the use of alprazolam (β = -0.612, p = 0.013). A significant interaction was found between cyclothymic temperament score and sex in predicting brachial systolic blood pressure (p = 0.025), between irritable and anxious temperament scores and sex in predicting pulse wave velocity (p = 0.021, p = 0.023, respectively) and an interaction with borderline significance between hyperthymic temperament score and sex in predicting augmentation index (p = 0.052).

Conclusions

The present findings highlight elevated blood pressure among subjects with high cyclothymic temperament as well as an increased level of arterial stiffening in subjects with low hyperthymic scores suggesting that affective temperaments may play a role in the development of hypertension and arterial stiffening and may thus represent markers of cardiovascular risk. Sex differences were also present in these associations.

Gender Differences in the relationship between carbonated sugar-sweetened beverage intake and the likelihood of hypertension according to obesity

OBJECTIVES

The aim of the present study was to investigate the association between hypertension and carbonated sugar-sweetened beverages (SSB) intake according to gender and obesity.

METHODS

The study used data from 2007, 2008 and 2009 Korea National Health and Nutrition Examination Surveys. A total of 9869 subjects (men = 3845 and women = 6024) were included. SSB intakes were calculated from food frequency questionnaires. Odds ratios (ORs) and 95 % confidence interval (CI) for hypertension were assessed using survey logistic regression and multivariable adjusted models.

RESULTS

A total of 14.5 % of individuals were classified as having hypertension. The likelihood of hypertension in the third, fourth and fifth quintiles for SSB intake increased to OR 1.00, 1.20 and 1.42 respectively, after adjusting for confounding factors. Compared to the participants in the lowest tertile for SSB intake, participants in the third tertile showed an increased likelihood of hypertension with ORs (CI) of 2.00 (1.21-3.31) and 1.75 (1.23-2.49) for obese women and non-obese men, respectively.

CONCLUSIONS

The present study showed gender differences in the relationship between carbonated SSB intake and the hypertension according to obesity.

Renal denervation in the era of HTN-3. Comprehensive review and glimpse into the future

The pathophysiological role of sympathetic overactivity in conditions such as hypertension has been well documented. Catheter-based renal denervation (RDN) is a minimally invasive percutaneous procedure which aims to disrupt sympathetic nerve afferent and efferent activity through the application of radiofrequency energy directly within the renal artery wall. This technique has emerged as a very promising treatment with dramatic effects on refractory hypertension but also in other conditions in which a sympathetic influence is present. Several studies have evaluated the safety and efficacy of this procedure, presently surrounded by controversy since the recent outcome of Symplicity HTN-3, the first randomized, sham-control trial, which failed to confirm RDN previous reported benefits on BP and cardiovascular risk lowering. Consequently, although some centers halted their RDN programs, research continues and both the concept of denervation and treatment strategies are being redefined to identify patients who can drive the most benefit from this technology. In the United States, the Food and Drug Administration (FDA) has appropriately mandated that RDN remains an investigative procedure and a new generation of sham-controlled trials are ongoing and aimed to assess not only its efficacy against pharmacotherapy but also trials in drug free patients with the objective of demonstrating once and for all whether the procedure actually does lower BP in comparison to a placebo arm. In this article, we present an overview of the sympathetic nervous system and its role in hypertension, examine the current data on RDN, and share some insights and future expectations.

Hypertension criterion for stroke prevention--to strengthen the principle of individualization in guidelines

The diagnosis of hypertension, as recommended by most guidelines, is determined by systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg. A threshold-based definition of hypertension, however, ignores sex and age, pathophysiology, and disparities in patient-specific conditions. Moreover, the harmful effects of hypertension-induced target organ damage cannot be ignored. Although the principle of individualization for hypertension management is recommended, especially for stroke prevention, how to practice it in a clinical setting has not been clearly elaborated. Therefore, we put forward a proposal for individualized hypertension management incorporating target organ damage, the main harmful effect of hypertension. We propose that hypertension should be diagnosed when an individual's blood pressure exceeds some difference from their own baseline in young adulthood, accompanied by any hypertension-induced target organ damage, confirmed by various detection methods. Application of this proposal to stroke prevention will hopefully strengthen the principle of individualized hypertension management.

Gender differences in the relationship between risk of hypertension and fruit intake

OBJECTIVE

To investigate the relationship between hypertension and fruit intake in an Asian population.

METHOD

This study was based on the data from 2007, 2008 and 2009 Korea National Health and Nutrition Examination Survey. In the final analysis, a total of 9791 subjects (men=3819, women=5972) were included. Daily energy and nutrient intakes were assessed using 24-h recall. The odds ratios (ORs) for hypertension were assessed by using logistic regression and multivariable models.

RESULTS

A total of 10.6% of individuals were classified as having hypertension. Compared with the lowest quintile of fruit intake, the fifth quintile showed the lowest likelihood of hypertension (OR 0.73; 95% confidence interval [CI], 0.61-0.88) after adjusting for age and gender. For women, the likelihood of hypertension in the 2nd, 3rd, 4th and 5th quintiles of fruit intake decreased to 0.67 (95% CI, 0.34-1.30), 0.76 (0.56-1.05), 0.90 (0.67-1.22) and 0.54 (0.38-0.77), respectively, after adjusting for confounding factors (P value for trend=0.0011). An inverse association of fruit intake and hypertension was shown only in non-obese women. For men and obese women, there was no relationship between fruit intake and hypertension.

CONCLUSION

Dietary fruit recommendation for hypertension should be taken into account together with ethnic background, gender as well as the presence of obesity in individuals.

Prehypertension: Underlying pathology and therapeutic options

Prehypertension (PHTN) is a global major health risk that subjects individuals to double the risk of cardiovascular disease (CVD) independent of progression to overt hypertension. Its prevalence rate varies considerably from country to country ranging between 21.9% and 52%. Many hypotheses are proposed to explain the underlying pathophysiology of PHTN. The most notable of these implicate the renin-angiotensin system (RAS) and vascular endothelium. However, other processes that involve reactive oxygen species, the inflammatory cytokines, prostglandins and C-reactive protein as well as the autonomic and central nervous systems are also suggested. Drugs affecting RAS have been shown to produce beneficial effects in prehypertensives though such was not unequivocal. On the other hand, drugs such as β-adrenoceptor blocking agents were not shown to be useful. Leading clinical guidelines suggest using dietary and lifestyle modifications as a first line interventional strategy to curb the progress of PHTN; however, other clinically respected views call for using drugs. This review provides an overview of the potential pathophysiological processes associated with PHTN, abridges current intervention strategies and suggests investigating the value of using the "Polypill" in prehypertensive subjects to ascertain its potential in delaying (or preventing) CVD associated with raised blood pressure in the presence of other risk factors.

Prehypertension is not associated with all-cause mortality: a systematic review and meta-analysis of prospective studies

OBJECTIVES

Quantitative associations between prehypertension or its two separate blood pressure (BP) ranges and cardiovascular disease (CVD) or all-cause mortality have not been reliably documented. In this study, we performed a comprehensive systematic review and meta-analysis to assess these relationships from prospective cohort studies.

METHODS

We conducted a comprehensive search of PubMed (1966-June 2012) and the Cochrane Library (1988-June 2012) without language restrictions. This was supplemented by review of the references in the included studies and relevant reviews identified in the search. Prospective studies were included if they reported multivariate-adjusted relative risks (RRs) and corresponding 95% confidence intervals (CIs) of CVD or all-cause mortality with respect to prehypertension or its two BP ranges (low range: 120-129/80-84 mmHg; high range: 130-139/85-89 mmHg) at baseline. Pooled RRs were estimated using a random-effects model or a fixed-effects model depending on the between-study heterogeneity.

RESULTS

Thirteen studies met our inclusion criteria, with 870,678 participants. Prehypertension was not associated with an increased risk of all-cause mortality either in the whole prehypertension group (RR: 1.03; 95% CI: 0.91 to 1.15, P = 0.667) or in its two separate BP ranges (low-range: RR: 0.91; 95% CI: 0.81 to 1.02, P = 0.107; high range: RR: 1.00; 95% CI: 0.95 to 1.06, P = 0.951). Prehypertension was significantly associated with a greater risk of CVD mortality (RR: 1.32; 95% CI: 1.16 to 1.50, P<0.001). When analyzed separately by two BP ranges, only high range prehypertension was related to an increased risk of CVD mortality (low-range: RR: 1.10; 95% CI: 0.92 to 1.30, P = 0.287; high range: RR: 1.26; 95% CI: 1.13 to 1.41, P<0.001).

CONCLUSIONS

From the best available prospective data, prehypertension was not associated with all-cause mortality. More high quality cohort studies stratified by BP range are needed.

Association of high blood pressure with renal insufficiency: role of albuminuria, from NHANES, 1999-2006

BACKGROUND

The relationship between hypertension and kidney disease is complicated. Clinical trials found intense blood pressure control was not associated with alterations in glomerular filtration rate (GFR) in all patients but did slow the rate of GFR decline among those with a higher baseline proteinuria. However, the underlying mechanism has been unclear.

METHODS

We tested the hypothesis that the association between high blood pressure and renal function is modified by albuminuria status by conducting analyses in a cross-sectional study with 12,440 adult participants without known kidney diseases, diabetes or cardiovascular diseases, participating in the National Health and Nutrition Examination Survey (NHANES) 1999-2006.

RESULTS

1226 out of 12440 were found to have unknown high blood pressure and 4494 were found to have reduced renal function. Overall, a moderate association was found between high blood pressure and renal function insufficiency in all participants analyzed. However, among participants with albuminuria, the prevalence of moderate-severe renal insufficiency substantially and progressively increased from normal subjects to prehypertensive and undiagnosed hypertensive subjects (1.43%, 3.44%, 10.96%, respectively, P for trend<0.0001); on the other hand, the prevalence of undiagnosed hypertension was also significantly higher among subjects with moderate-severe renal insufficiency than those with mild renal insufficiency (35.54% Vs 19.09%, P value <0.05), supporting an association between hypertension and renal function damage. In contrast, no association between hypertension and renal insufficiency was observed among those without albuminuria in this population. Similar findings were observed when the CKD-EPI equation was used.

CONCLUSIONS

The association between high blood pressure and reduced renal function could be dependent upon the albuminuria status. This finding may provide a possible explanation for results observed in clinical trials of intensive blood pressure control. Further studies are warranted to confirm our findings.

Glomerular hyperfiltration in prediabetes and prehypertension

BACKGROUND

This study aimed to investigate the associations of hyperfiltration and hypofiltration with prediabetes and prehypertension.

METHODS

The study subjects included 99 140 people aged 20-89 years who underwent health checkups in Aichi Prefecture, Japan. The prevalence of hyperfiltration [estimated glomerular filtration rate (eGFR) above the age-/sex-specific 95th percentile] and hypofiltration (eGFR below the age-/sex-specific 5th percentile) was compared among stages of prediabetes (fasting plasma glucose <100, 100-109, 110-125 and ≥126 mg/dL for no prediabetes, Stage 1 prediabetes, Stage 2 prediabetes and diabetes, respectively) and prehypertension [blood pressure (BP) <120/80, 120-129/80-84, 130-139/85-89 and ≥140/90 mmHg for no prehypertension, Stage 1 prehypertension, Stage 2 prehypertension and hypertension, respectively).

RESULTS

The prevalence of hyperfiltration increased with increasing stage of prediabetes [odds ratios (ORs): 1.29, 1.58 and 2.47 for Stage 1 prediabetes, Stage 2 prediabetes and diabetes, respectively] and prehypertension (ORs: 1.10, 1.33 and 1.52 for Stage 1 prehypertension, Stage 2 prehypertension and hypertension, respectively). Hypofiltration was not associated with prediabetes or prehypertension.

CONCLUSIONS

The prevalence of glomerular hyperfiltration increased with increasing stages of prediabetes and prehypertension. Therefore, kidney function should be monitored in subjects with prediabetes or prehypertension. In subjects with hyperfiltration, earlier treatment of hyperglycemia and high BP may be necessary to prevent the development of kidney damage.

A simple model for predicting incidence of chronic kidney disease in HIV-infected patients

BACKGROUND

Human immunodeficiency virus (HIV)-infected individuals have concurrent risk factors for chronic kidney disease (CKD), but there are no prediction models to quantify the effect of multiple factors on the development of incident CKD.

METHODS

A 1-year prognostic model was developed using prospective data between January 2008 and March 2009, from a derivation cohort of 623 patients with an estimated glomerular filtration rate (eGFR) exceeding 60 ml/min/1.73 m(2) at baseline. Incident CKD was defined as both an eGFR falling below 60 ml/min/1.73 m(2) and a decrease in eGFR of at least 25% during the period. Continuous variables were divided into categories using the mean value of the whole cohort. Multivariate logistic regression was used to determine baseline categories associated with incident CKD. The model was tested with prospective data between April 2009 and March 2010, from a validation cohort of 534 patients exceeding 60 ml/min/1.73 m(2) at baseline, consisting of part of the derivation cohort and newly enrolled patients. The discriminative ability was evaluated using the area under the receiver operating characteristic (AROC) curve.

RESULTS

Eighteen subjects developed incident CKD (2.9%). In a multivariate logistic regression analysis of the derivation cohort, 5 variables (age, CD4 cell count, diabetes, proteinuria, and eGFR at baseline) were independently associated with the incidence of CKD. The AROC curve was 0.841 (95% CI 0.799-0.894) in the validation cohort.

CONCLUSION

This prediction model may be a useful tool for identifying HIV-infected individuals with a high likelihood of new-onset CKD.