Effects of Alcohol Consumption and Smoking on the Onset of Hypertension in a Long-Term Longitudinal Study in a Male Workers' Cohort

Aim: To determine the effects of alcohol consumption and smoking on the onset of hypertension in a long-term longitudinal study. Methods: 7511 non-hypertensive male workers were enrolled. This cohort study was performed over an 8-year period using the results of the annual workers-health screening. The end-point was defined as systolic blood pressure ≥ 140 mmHg, diastolic blood pressure ≥ 90 mmHg, or use of antihypertensive drugs. For alcohol consumption, weekly alcohol intake (g ethanol/week) was estimated (1 “gou” = 22 g ethanol). Annual survey data were analyzed by pooled logistic regression that included alcohol consumption, smoking, age, body mass index, job schedule types, habitual exercise, and blood test measurements into the statistical model. Results: A significant positive dose–response relationship between alcohol consumption and onset of hypertension was observed, with synergistic health effects present. Compared with abstainers and nonsmokers, the adjusted odds ratios (95% confidence interval) for the onset of hypertension were: 1.51 (1.27–1.79) for 154 g ethanol/week and nonsmokers, and 1.81 (1.54–2.11) for 154 g ethanol/week and smokers. An interaction between alcohol and smoking was confirmed. Conclusions: This study provided information useful to the prevention of hypertension. By reducing alcohol consumption and smoking simultaneously, the risk of hypertension may be considerably lowered.

Truncated Epithelial Sodium Channel β Subunit Responsible for Liddle Syndrome in a Chinese Family

Background/Aims: Liddle syndrome (LS) is a rare autosomal dominant disease caused by mutations in genes coding for epithelial sodium channel (ENaC) subunits. The aim of this study was to identify the mutation responsible for the LS in an extended Chinese family. Methods: DNA samples from the proband with early-onset, treatment-resistant hypertension, and hypokalemia and 19 additional relatives were all sequenced for mutations in exon 13 of the β-ENaC and γ-ENaC genes, using amplification by polymerase chain reaction and direct DNA sequencing. Results: Genetic testing of exon 13 of SCNN1B revealed duplication of guanine into a string of 3 guanines located at codon 602. This frameshift mutation is predicted to generate a premature stop codon at position 607, resulting in truncated β-ENaC lacking the remaining 34 amino acids, including the crucial PY motif. Among a total of 9 participants with the identical mutation, different phenotypes were identified. Tailored treatment with amiloride was safe and effective in alleviating disease symptoms in LS. No mutation of SCNN1G was identified in any of the examined participants. Conclusions: We report here a family affected by LS harboring a frameshift mutation (c.1806dupG) with a premature stop codon deleting the PY motif of β-ENaC. Our study demonstrates that the earlier LS patients are diagnosed by genetic testing and treated with tailored medication, the greater the likelihood of preventing or minimizing complications in the vasculature and target organs.

Frequency of renal artery stenosis after renal denervation in patients with resistant arterial hypertension

Catheter-based ablation of nerves in the adventitia of renal arteries (renal artery denervation [RAD]) using radiofrequency energy can reduce blood pressure (BP) in patients with resistant arterial hypertension (RAH). Occurrence of renal artery stenosis after RAD is still an important concern. We systematically investigated the renal artery anatomy using magnetic resonance imaging (MRI) or computed tomography (CT) angiography in a consecutive series of patients 6 months after RAD. Patients with RAH were treated by RAD after exclusion of secondary causes of hypertension. RAH was defined by a mean systolic office BP >160 mm Hg. Renal artery imaging was performed 6 months after RAD by MRI angiography. In case of any contraindication for MRI, a CT angiography was performed. The primary end point was the incidence of significant renal artery stenosis (≥70% lumen diameter reduction). RAD was performed in 76 patients, and evaluation of renal artery anatomy by MRI (n = 66; 87%) or CT angiography (n = 10; 13%) was performed in all patients 6 months after RAD. We found no renal artery stenosis but 2 cases of new nonsignificant stenosis (50% TO 69% lumen diameter reduction). In responders, mean systolic office BP reduction was -30 mm Hg (p <0.001) and mean systolic 24-hour BP reduction was -18 mm Hg (p <0.001). In conclusion, the incidence of significant renal artery stenosis 6 months after RAD seems to be very low. However, late-onset development of nonsignificant renal artery narrowing cannot be excluded in some patients and should be anticipated in the case of RAH relapse or worsening of renal function after successful RAD.

Effects of renal denervation on ambulatory blood pressure measurements in patients with resistant arterial hypertension

BACKGROUND

The sympathetic nervous system is an important factor in hypertension. In patients suffering from resistant hypertension, transfemoral renal sympathetic denervation (RDN) reduces office blood pressure (BP) values.

HYPOTHESIS

Ambulatory BP measurement (ABPM) is a better predictor than office BP of cardiovascular morbidity and mortality. We thus believe that ABPM should be added to the systematic evaluation and follow-up protocol when treating patients with resistant hypertension with RDN. Therefore, we evaluated the effect of RDN on mean 24-hour BP by the use of ABPM.

METHODS

Patients with resistant hypertension (office systolic BP >160 mm Hg, or >150 mm Hg in patients with diabetes) have been treated with RDN. Ambulatory BP measurement was performed at baseline and at 3 and 6 months after RDN. Patients with a 24-hour systolic BP reduction of ≥5 mm Hg were classified as responders.

RESULTS

Of 86 patients initially enrolled in the study, 5 had to be excluded from the analysis because of <70% valid ABPM recordings. Out of the 81 studied patients, we found 49 responders (60.5%). In all patients, office BP decreased from 169.9/87.8 mm Hg to 153.5/86.3 mm Hg (P < 0.001/P = not significant [NS]) and 24-hour BP decreased from 144.3/86.0 mm Hg to 139.9/84.0 mm Hg (P = 0.025/P = NS) 6 months after RDN. In responders, office BP decreased from 169.6/90.3 mm Hg to 143.7/79.7 mm Hg (P < 0.001/P < 0.001). The ABPM levels started at 144.3/84.7 mm Hg and decreased to 138.3/81.5 mm Hg (P = 0.025/P = 0.045). In nonresponders, office BP was 150.2/84.0 mm Hg and 24-hour BP was 144.5/84.7 mm Hg at baseline; at 6 months, office BP was 168.7/96.4 mm Hg (P < 0.001/P = NS) and 24-hour BP was 142.2/81.5 mm Hg (P = NS/P = NS).

CONCLUSIONS

Office BP and AMBP levels can be significantly lowered by RDN in patients with resistant hypertension.

International expert consensus statement: Percutaneous transluminal renal denervation for the treatment of resistant hypertension

Catheter-based radiofrequency ablation technology to disrupt both efferent and afferent renal nerves has recently been introduced to clinical medicine after the demonstration of significant systolic and diastolic blood pressure reductions. Clinical trial data available thus far have been obtained primarily in patients with resistant hypertension, defined as standardized systolic clinic blood pressure ≥ 160 mm Hg (or ≥ 150 mm Hg in patients with type 2 diabetes) despite appropriate pharmacologic treatment with at least 3 antihypertensive drugs, including a diuretic agent. Accordingly, these criteria and blood pressure thresholds should be borne in mind when selecting patients for renal nerve ablation. Secondary forms of hypertension and pseudoresistance, such as nonadherence to medication, intolerance of medication, and white coat hypertension, should have been ruled out, and 24-h ambulatory blood pressure monitoring is mandatory in this context. Because there are theoretical concerns with regard to renal safety, selected patients should have preserved renal function, with an estimated glomerular filtration rate ≥ 45 ml/min/1.73 m(2). Optimal periprocedural management of volume status and medication regimens at specialized and experienced centers equipped with adequate infrastructure to cope with potential procedural complications will minimize potential patient risks. Long-term safety and efficacy data are limited to 3 years of follow-up in small patient cohorts, so efforts to monitor treated patients are crucial to define the long-term performance of the procedure. Although renal nerve ablation could have beneficial effects in other conditions characterized by elevated renal sympathetic nerve activity, its potential use for such indications should currently be limited to formal research studies of its safety and efficacy.