The August issue of the Journal of Hypertension includes a consensus document of the American Autonomic Society, the European Federation of Autonomic Societies, and the European Society of Hypertension on supine hypertension (Jordan et al., pp. 1541–1546), that is, a condition in which blood pressure (BP) is elevated (sometimes markedly) in the supine position with, however, an orthostatic fall that may not infrequently result into injury, especially when patients get up during the night. Although the primary pathogenetic factor is known to be a dysfunction of autonomic cardiovascular control, other mechanisms are responsible for the lying-standing BP imbalance, making this condition pathophysiologically complex. Epidemiological data on cardiovascular outcomes are limited and treatment presents with major difficulties because attempts to reduce the elevated BP when patients lie down are almost invariably associated with an enhancement of the BP fall when they stand up. The consensus document addresses all these problems, thereby representing useful reading for both researchers and clinicians involved with high BP.
The consensus document on supine hypertension is followed by four reviews and meta-analyses. Milan et al. (pp. 1547–1557) reviewed the studies validating the devices that measure carotid–femoral pulse wave velocity using different methods, that is, applanation tonometry, piezoelectric mechanotransducers, photodiode sensors, and so on. In several instances, the authors found a satisfactory adherence with the recommendations issued by the Artery Society Guidelines for validation studies. They also noted, however, that some studies depart from these recommendations, and that some important discrepancies may exist between the different methods, one of them being a different estimate of the carotid–femoral distance. This may lead to differences in the collected data on arterial stiffness that are of methodological rather than truly clinical nature. Roush et al. (pp. 1558–1566) meta-analyzed the randomized trials on the protective effects of BP reduction by treatment according to patients’ age. Compared with higher on-treatment BP targets, lowering SBP to within 120–140 mmHg was accompanied by greater cardiovascular benefits in the older (mean age 77, SD 72–81 years) than in the younger fraction of the study population, with no evidence of an associated increase in the risk of adverse effects. This adds to the current notion that antihypertensive treatment should include elderly and very elderly patients although, as the authors noted, the evidence cannot be extrapolated to most frail old patients because these patients have almost invariably been excluded from trials. Salam et al. (pp. 1567–1573) provides data from 14 randomized trials (11 457 patients) that adding a third antihypertensive drug lowers BP more effectively than increasing the doses of the previous dual treatment regimen (further SBP/DBP reduction 6.0/3.7 vs. 1.5/0.8 mmHg). This is in line with the recommendation of the recent European guidelines to increase treatment to three drugs after an initial two-drug administration when BP control is not achieved. Further considerations on the three-drug antihypertensive treatment strategy are made in an editorial commentary of Thomopoulos et al. (pp. 1587–1589). Burnier et al. (pp. 1574–1586) focus on the similarities and differences between the three diuretics equally weighted and mentioned as first-step agents by the recent European guidelines, that is, hydroclorothiazide, chlortalidone, and indapamide. They express the view that differentiating these diuretics on the basis of the side effect profile may overestimate the importance of their dysmetabolic effects, which are unfrequently clinically meaningful. This is the case also because the dysmetabolic effects of diuretics are closely dose-related and all diuretics are nowadays used at lower doses, that is, as components of the two or three drug combinations recommended by guidelines for most patients.
The following four articles address the epidemiological aspects of hypertension. Xing et al. (pp. 1596–1605) report that in rural northeast China the prevalence of hypertension has raised from 2013 to 2018, with an average BP increase of several mmHg and no increase in the percentage of patients with BP control (<140/90 mmHg), which in this part of the world remains extremely low, that is, about 4% of the hypertensive population. Breet et al. (pp. 1606–1614) show that, in South African blacks, BP values are lower than what has been consistently reported in studies on African Americans. This is the case in both men and women, although in women the current marked increase in body weight justifies the prediction that a BP increase will be seen in the future. Head et al. (pp. 1615–1623) describe the prevalence of white-coat and masked hypertension in a subset of individuals from the Australian Diabetes Obesity and Lifestyle study. White-coat hypertension was uncharacteristically infrequent (3%), whereas masked hypertension was detected in 21% of the study population. Because masked hypertension is a high cardiovascular risk condition, this adds to the evidence that office BP measurements alone may importantly underestimate the contribution of a BP elevation to the overall cardiovascular risk as well as to the number of cardiovascular outcomes worldwide. Kunutsor et al. (pp. 1624–1632) show that, in a white male population, the total volume and duration of leisure cross-country skiing were inversely associated with the incidence of future hypertension, the risk of developing this condition being 28% less in individuals practicing cross-country skiing compared with controls. The results are commented by Jennings (pp. 1594–1595) who provides information on the previous literature on this topic as well as on the methodological aspects of this type of studies.
Three articles of the August issue of the Journal deal with experimental hypertension in rats and five with organ damage. The studies on experimental hypertension provide evidence that in hypertensive rats, (1) hydrogen sulfide improves endothelial dysfunction by inhibiting the deleterious effects of oxidative stress and inflammation (Li et al., pp. 1633–1643), (2) previously undescribed genes may cause or worsen hypertension in spontaneously hypertensive and stroke-prone rats (Ikawa et al., pp. 1644–1656), and (3) placental ischemia increases salt sensitivity of BP via an increased production of vasopressin (Matsuura et al., pp. 1657–1667). As to the studies on organ damage Sonaglioni et al. (pp. 1668–1675) show that in pregnant hypertensive women left atrial strain may predict persistent hypertension after pregnancy. This adds to the evidence that detecting left atrial abnormalities is clinically important independently on and additionally to the detection of left ventricular (LV) abnormalities. Thus, an accurate examination of the left atrium should be always part of an echocardiographic examination, which is unfortunately not always the case. Further considerations are made in the editorial commentary of Cuspidi and Tadic (pp. 1590–1593) whose articles have significantly contributed to the growth of evidence on the prognostic relevance of atrial abnormalities in hypertension. Satoh et al. (pp. 1676–1681) show that in a sample of Japanese men randomly selected from the general population home BP exhibited an association with coronary artery calcification, as assessed by computer tomography. Significantly, a similar association was seen between coronary calcification and office BP, an observation which is not line with the closer relationship between home BP and organ damage reported in several cross-sectional and longitudinal studies. Vallée et al. (pp. 1682–1688) describe a diagnostic method based on clinical and hemodynamic factors that appear to improve the estimate of coronary risk. An interesting aspect of the study is that the model includes the aortic pulse wave velocity index, which scores in favor of the routine addition of this measure to the diagnostic examinations to be performed in hypertensive patients. The readers may remember that this is a debated aspect of guidelines recommendations because measuring pulse wave velocity is often regarded as unfeasible in clinical practice. Dempsey et al. (pp. 1689–1698) report that, in children with repaired coarctation of the aorta, carotid intima–media thickness is greater than in controls. As discussed by the authors, this may be due to the persistence of some BP elevation. Other factors, however, such as an unfavorable cardiovascular risk profile, or the inability of even a successful correction of the aortic coarctation to completely reverse the structural arterial changes induced by the previously elevated BP, may also be involved. Lind et al. (pp. 1699–1704) report the findings of the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) on the association of LV mass with body weight. Visceral and subcutaneous abdominal fat were associated with LV mass but one third of the association was explained by BP and blood glucose values, indicating its overall multifactorial nature.
The final three articles focus on the treatment of hypertension. Koutsaki et al. (pp. 1705–1713) report the results obtained in patients undergoing orthopedic surgery in whom office and ambulatory BP measurements allowed a detailed description of the BP profile during the perioperative period. The most interesting finding was that, in the two days of hospitalization before surgery, office BP values were substantially higher than the ambulatory values, both falling to a similar lower level intraoperatively. This implies that in the presurgical period office BP measurements are characterized by a pronounced white-coat effect, limiting their reliability for the decision on whether, based on the patient's prevailing BP, physicians should proceed with or delay the surgical intervention. Zamunér et al. (pp. 1714–1721) report that somatosensory stimulation of the forefeet in patients with Parkinson's disease reduced BP and sympathetic cardiovascular modulation, possibly through an increase of baroreflex sensitivity. Azizi et al. (pp. 1722–1728) show that, in 34 hypertensive patients, a 4-week administration of firibastat (an aminopeptidase A inhibitor prodrug) reduced ambulatory BP compared with placebo with no effect on heart rate and no modifications of variables related to the renin–angiotensin system. This justifies the design and conduction of larger and longer studies on the BP-lowering efficacy and tolerability of this new drug.
Conflicts of interest
There are no conflicts of interest.