The April issue of the Journal of Hypertension opens with two review articles on topics of considerable diagnostic and therapeutic interest. In the former article, Sheppard et al. (pp. 660–670) systematically review the studies that have compared arm and leg blood pressure (BP) values. Forty-four articles (out of 887) were considered for a total of almost 10 000 individuals. Predictably, ankle SBP was markedly lower than arm SBP (−33 mmHg) in patients with vascular disease, whereas in healthy supine individuals ankle SBP exceeded, by an average of 17 mmHg, arm SBP, positioning the ankle-based diagnostic threshold for a hypertensive state at approximately 155 mmHg rather than the 140 mmHg arm value. Given the expanding use of the ankle–brachial index (ABI) for the search of asymptomatic vascular damage, this represents valuable information for investigators and physicians involved with hypertension. Driscoll et al. (pp. 671–679) review the studies that have examined the BP-lowering effect of herbs and spices. Only nine articles were found to have a randomized controlled design and were thus regarded as providing sound data. In only three studies a BP reduction was reported, the evidence being limited to prehypertensive or hypertensive individuals with no BP effect in those with a normal BP. The conclusion would appear to be that, although unable to affect BP when its values are normal, herbs and spices may have some BP-lowering effect, but the limited number of reliable data also indicate that this area needs more studies to allow a final conclusion to be reached.
The three subsequent articles provide original epidemiological data. Tymejczyk et al. (pp. 685–695) show that, in an adult population living in the slums of Port-au-Prince (Haiti), hypertension has a high prevalence and shows an association with overweight and obesity, as well as with an array of other factors, two of which are a greater hypertension prevalence in surrounding areas and a recent (<3 years) immigration to the country. Huang et al. (pp. 696–701) show, in more than 22 000 Chinese individuals, a significant association of new onset hypertension with hemodynamic (heart rate) and metabolic factors. This is per se not new, but two additional interesting aspects of the study are that the risk accumulates with the risk factor combination as well as that the hypertension development can be quite rapid because the 2035 observed cases developed over an average follow-up of only 3.6 years. Peled et al. (pp. 702–709) report the results obtained by comparing, cross-sectionally, the prevalence of hypertension in adolescents migrating to Israel at various ages from many other countries, taking Israeli-born adolescents as controls. Recent immigrants, that is individuals arriving in Israel at an age between 12 and 19 years, exhibited a much lower risk of hypertension compared with those arriving when aged less than 11 years, whose risk was comparable with that of Israeli-born individuals. These very interesting observations are discussed in the Editorial Commentary of Lurbe and Redon (pp. 680–682), who examine in detail the multiple factors that are probably involved, calling attention to the need to devote to the BP effects of immigration more in-depth studies. This is because immigration may involve so many factors that its result may hardly be univocal and predictable. Just to cite the two articles referring to immigration published in this issue of the Journal in one (the Haiti slums) recent immigration was accompanied by an increased prevalence of hypertension, whereas the opposite was the case for the recent immigration to Israel.
Other contributions to the Journal focus on the diagnosis of masked hypertension and the association of BP elevations with metabolic abnormalities. Koletsos et al. (pp. 710–719) show that, compared with normotensive individuals, in individuals with masked hypertension isometric exercise was associated with a greater BP increase, similarly to what was seen in patients with sustained hypertension. This supports the recommendation of recent European hypertension guidelines to perform out-of-office BP measurements when an exercise test reveals an excessive BP rise, because this rise may reflect a tendency of daily life BP to hyperreact to environmental conditions or stimuli, and thus to be above normal levels. This is by no means of marginal clinical importance because, although evidence from outcome trials is still unavailable, masked hypertension represents a condition of high risk in which antihypertensive treatment may have to be considered. Sapiña-Beltrán et al. (pp. 720–727) show that in normotensive individuals with obstructive sleep apnea treatment with continuous positive airway pressure (CPAP) is accompanied by a very modest reduction of 24-h mean BP values (DBP < 1.4 mmHg), but also that the reduction is greater (−4.8 mmHg) in individuals with masked hypertension. The message is that when clinic BP is normal, ambulatory BP may help identifying individuals in whom CPAP may have more than its usually disappointing BP-lowering effect. Lo Cicero et al. (pp. 728–731) confirm in the Brisighella population that both serum lipid and uric abnormalities are independent risk factors for the development of hypertension adding, however, that the risk of new hypertension is more clearly elevated when uric acid is increased as well as when the two abnormalities are both present. Di Bonito et al. (pp. 732–738) show that in 6137 overweight or obese young people, the subgroup classified as being at high risk of developing hypertension was 13% larger according to the American than to the European pediatric guidelines. Importantly, individuals diagnosed as being at high risk of new onset hypertension according to the European pediatric guidelines also showed a greater risk of an abnormal left ventricular (LV) geometry at echocardiography, providing the epidemiological observation with support from cardiac structural alterations.
The article by Di Bonito et al. is followed by articles on cardiac, vascular and renal damage in hypertension. Kühl et al. (pp. 739–746) report on the use of cardiac computer tomography in a large number of individuals (n = 4942) and show this diagnostic approach to help detection of LV hypertrophy over and above ECG diagnostic criteria. Tadic et al. (pp. 747–753) show that in patients with moderate aortic stenosis hypertension does not additionally affect the global longitudinal strain of the left ventricle but it additionally reduces circumferential strain. Tabata et al. (pp. 754–764) show that atherosclerosis, as reflected by the ankle-brachial index (ABI) and arterial stiffening, is accelerated and more advanced in the presence of malignancy in whom it promotes a higher risk of cardiovascular events. Gavish and Bursztyn (pp. 765–774) describe a pulse pressure (PP)-based model that can improve the predictive ability of ambulatory BP for cardiovascular events, arguing in favor of the possibility that this originates from the relationship, imperfect as it may be, of PP with arterial stiffness. Zhang et al. (pp. 775–789) describe the association of genetic variants of EPHA4, a receptor tyrosine kinase, with an increased risk of hypertension in diabetic women, using the database of ADVANCE and HCHS/SOL studies and hypothetically linking the effect with an influence on vascular smooth muscle contractility, which they document in the same article. Finally, four articles provide interesting data on the association of hypertension with renal damage. Kim et al. (pp. 790–794) show, by a retrospective analysis of about 9000 Korean adults, that an increased inter-arm SBP difference is an independent predictor of incident chronic kidney disease, which expands on the evidence that links inter-arm BP differences with vascular events. Kolkenbeck-Ruh et al. (pp. 795–804) show that in South African blacks an increased carotid intima–media thickness exhibited a close independent association with the risk of lower limb ischemia and stroke, thereby strengthening the evidence in favor of the prognostic value of this measure for vascular events. However, the relationship did not extend to variables such as serum creatinine or estimated glomerular filtration rate, scoring against a predictive value of structural carotid wall alterations (hypertrophy or plaques) for renal events. Other studies have shown a relationship between carotid intima–media thickness and measures of renal damage such as an increased urinary protein excretion, which makes future studies on this topic desirable. Viazzi et al. (pp. 805–813) report that in a retrospective analysis of the clinical records from more than 30 000 patients with type 2 diabetes mellitus visit-to-visit SBP variability correlated with the incidence of chronic kidney disease. This confirms the results obtained in ADVANCE on the relationship between visit-to-visit BP variations and renal damage in type 2 diabetes as well as in hypertension and the general population. There are, however, few dissenting voices as well as criticism that make also this topic worthy of further investigations. In this context, a major issue is that visit-to-visit BP variability is usually expressed as a value (SD) which is not independent on the mean BP value, raising the question whether mean BP values may be, at least in part, responsible for the results. Wen et al. (pp. 814–819) show a satisfactory agreement between 24-h sodium intake as quantified by repeated dietary recalls and 24-h urine collections in estimating sodium intake at the Chinese population level. How to measure urinary sodium excretion in large-scale long-term epidemiological or intervention studies has always been a debated issue, and additional fuel has recently been provided by a large epidemiological study which has shown that sodium intake may have a J curve type of relationship with cardiovascular events. That is, that a greater cardiovascular risk can accompany not only high but also low sodium intakes. This study has quantified sodium in spot urine samples, an approach vigorously defended by the authors against the criticism that spot urine samples cannot accurately reflect 24-h urine sodium values, that is the gold standard measure. Criticism underestimates, however, that large-scale long-term prospective studies (the only ones that can answer the outstanding issues that characterize this area) can only be performed by using simple sodium measuring methods, which makes the data by Wen et al. that other perhaps simpler methods can be considered quite relevant.
The last five articles deal with various aspects of antihypertensive treatment. Momma et al. (pp. 820–826) show that, in a Japanese male population, fitness level was related to the risk of new onset hypertension. Taylor et al. (pp. 827–836) show that isometric exercise reduces both mean and variability of 24-h BP values, a result that upgrades this type of exercise vis-à-vis the much more commonly recommended isotonic exercise type. Gitsels et al. (pp. 837–843) show that, in contrast to the results of the SPRINT trial, in the THIN database (a UK heart service database) SBP reduction to less than 120 mmHg was accompanied by an increased risk of cardiovascular events, thereby supporting the recommendation of the European guidelines to consider a SBP less than 120 mmHg a cutoff below which not to go with treatment. Bombelli et al. (pp. 844–850) showed that, although uric acid levels predict incident hypertension, they do not seem to predict the response to antihypertensive drug treatment as well the achievement of BP control. This was found in the patients with moderate hypertension of the ELSA study in whom BP control was frequently achieved also with monotherapy, leaving the question of the predictive value of uric acid for the response to treatment in more resistant hypertensive patients still unanswered. Finally, Krousel-Wood et al. (pp. 851–859) show that in older hypertensive adults with no prior cardiovascular disease a self-reported adherence scale was capable of predicting incident cardiovascular disease. This somewhat challenges the widely held view that in clinical practice adherence cannot be reliably assessed, that is that in most instances the information provided by the patient cannot fill the practicing physician's need to know whether his/her prescribed treatment regimen will be followed and thus have the expected protective effect. Measurements of adherence are all imperfect and most cannot, for a variety of reasons, be applied to clinical practice. As discussed in the Editorial Commentary of Mehta and Pothineni (pp. 683–684) the article of Krousel-Wood et al. shows that even at the clinical practice level progress is being made.
Conflicts of interest
There are no conflicts of interest.