Validation of the Microlife BP W200-1 wrist device for blood pressure measurement.

OBJECTIVE: The objective of the study was to determine the accuracy of the BP W200-1 device for blood pressure measurement at the wrist developed by the Microlife Company. The BP W200-1 model features a 'Microlife Average Mode', which uses a 'weighted' average of a minimum of three consecutive blood pressure (BP) readings taken 15 s apart. METHOD: Device evaluation was carried out using the International Protocol of the European Society of Hypertension. Monitor performance was assessed in relation to patients' sex, age, wrist circumference, and systolic (SBP) and diastolic blood pressures (DBP). RESULTS: The BP W200-1 comfortably passed all three phases of the protocol for SBP and DBP. The device performed well in all ranges of SBP and DBP. Mean blood pressure differences for the BP W200-1 monitor were -1.2+/-4.5 mmHg for SBP and -0.2+/-3.1 mmHg for DBP. In multivariable analyses, the SBP and DBP discrepancies between device and observer were unrelated to age, sex, wrist circumference, and blood pressure level. CONCLUSION: These data show that the Microlife BP W200-1 wrist monitor satisfies the recommended European Society of Hypertension accuracy levels for SBP and DBP and therefore can be recommended for clinical use in the adult population. Its performance is uniform across subgroups of patients with different clinical characteristics.

Diagnosis of primary aldosteronism in the hypertension specialist centers in Italy: a national survey.

Primary aldosteronism (PA) is the most common endocrine cause of resistant hypertension. Individuals with PA are at increased cardiovascular risk, and an appropriate management and treatment would ideally reduce such risk. Screening and diagnosis of PA requires a specific diagnostic test which is considered time- and cost-consuming and, as a result, is underperformed in clinical practice. An online survey reviewing available diagnostic procedures, laboratory testing, and clinical protocols for screening and confirmation of PA diagnosis was conducted among clinical lead of Reference and Excellence centers of the Italian Hypertension Society. A total of 102 questionnaires were sent and 62 centers participated in the survey. Assessment of the plasma renin (plasma renin activity/direct renin concentration) and plasma aldosterone concentration (PAC) was available in all centers. Captopril challenge test (CCT) and saline infusion test (SIT) were available in 60% and 61% of the centers, respectively. Fludrocortisone suppression test was available in 32% of the units. Adrenal vein sampling was accessible in 32% of the centers. We found discrepancies in cutoff levels of aldosterone-to-renin ratio (ARR) and PAC after SIT. Other discrepancies involved the duration of the wash-out period before ARR testing and dosage of captopril administered during CCT. In conclusion, although all centers are sufficiently equipped to perform PA screening, often patients should be referred to other centers to confirm the diagnosis of PA. A greater uniformity across centers to define precise cutoffs for screening and confirmatory testing for the diagnosis of PA would be of utility.

Impaired arterial elasticity in young patients with white-coat hypertension.

BACKGROUND: Conflict still exists over whether patients with white-coat hypertension are at increased risk of developing target organ damage compared with normotensive individuals. METHODS: We studied vascular distensibility in 117 young-to-middle age patients with white-coat hypertension, 174 patients with sustained hypertension, and 51 normotensive controls. To obtain a measure of compliance, a model was used that divides the total systemic compliance into large artery (C1) and small artery (C2) compliance. With this aim, radial arterial pulse waves were recorded with a tonometer sensor array by means of an HDI CR2000 device (Eagan, Minnesota, USA). Moreover, pulse wave velocity and the augmentation index were measured using the Specaway DAT system (St Pauls, Sydney, Australia). RESULTS: Patients with sustained hypertension had a greater body mass index than patients with white-coat hypertension (P=0.04) or the normotensive individuals (P=0.01). C1 and C2 were decreased in the two hypertensive groups as compared with those in the normotensive group (P=0.0002 and 0.03, respectively, versus sustained hypertension; P=0.00007 and 0.0004, respectively, versus white-coat hypertension). Pulse wave velocity and aortic augmentation index were increased in the white-coat hypertension patients compared with the normotensive individuals (P=0.02 and 0.004, respectively). Aortic augmentation index (P=0.008) but not pulse wave velocity was increased in the sustained hypertensive patients compared with that in the normotensive individuals. All indexes of arterial distensibility were similar in the two hypertensive groups. CONCLUSIONS: Indexes of arterial distensibility are impaired in the white-coat hypertensive group and similar to those in the sustained hypertensive group, indicating that early changes in the arterial wall can occur in white-coat hypertension. This may account for the higher risk of stroke that has been described in this condition.

Hyperparathyroidism can be useful in the identification of primary aldosteronism due to aldosterone-producing adenoma.

Hyperparathyroidism represents as a novel feature of primary aldosteronism (PA). Its occurrence in patients with the surgically correctable aldosterone-producing adenoma (APA) and not in those with bilateral adrenal hyperplasia suggested that the measurement of parathyroid hormone could help in differentiating between these subtypes of PA. To test this hypothesis we measured the plasma levels of intact parathyroid hormone, Ca(2+), and several markers of calcium/phosphorus metabolism in 132 hypertensive patients, including 74 with primary (essential) hypertension and 58 consecutive PA patients. Of the latter, 46 were conclusively diagnosed as APA (by finding of lateralized aldosterone excess, pathology, correction of the hyperaldosteronism, and evidence of a fall of blood pressure after adrenalectomy) and 12 as bilateral adrenal hyperplasia. Based on these diagnoses we used the area under the receiver operator characteristic curve analysis to assess the accuracy of serum parathyroid hormone for identifying the PA cases in the whole group and for distinguishing between APA and bilateral adrenal hyperplasia. In this selected population of hypertensive patients for identifying PA cases, the accuracy of serum parathyroid hormone tended to be lower than that of the aldosterone:renin ratio. However, for discriminating between APA and bilateral adrenal hyperplasia patients it was better than that under the identity line and also that for the aldosterone:renin ratio for pinpointing APA cases among patients with PA. Hence, these findings indicate that raised serum parathyroid hormone levels are a feature of APA that can be useful for selecting the PA patients to be submitted to adrenal vein sampling.

Interplay between miR-155, AT1R A1166C polymorphism, and AT1R expression in young untreated hypertensives.

BACKGROUND: A silent polymorphism (+1166 A/C single-nucleotide polymorphism) localized in the 3'-UTR (untranslated region) of the human angiotensin II type-1 receptor (AT1R) has been associated with hypertension and cardiovascular complications. The +1166 A/C is recognized by a specific microRNA-155 (miR-155), which is base-pairing complementary with the +1166 A-allele but not with the mutant +1166 C allele. Aim of our study was to investigate the interplay between miR-155 and AT1R protein expression. METHODS: Sixty-four subjects were selected for the +1166 A/C from the cohort of hypertensives (n = 573) of the Hypertension and Ambulatory Recording Venetia Study (HARVEST): 25 were homozygous for the 1166 A allele, 20 heterozygous, and 19 homozygous for the 1166 C allele. RESULTS: miR-155 expression was significantly decreased in subjects with CC genotype in comparison to AA and AC genotype. AT1R protein expression was significantly increased in the CC group in comparison to AA and AC (P < 0.01) although AT1R mRNA expression was not significantly different in the three groups. AT1R protein expression was positively correlated with systolic and diastolic blood pressure and negatively correlated with miR-155 expression level. Plasma transforming growth factor-ß1 (TGF-ß1) may have a modulator role in the interplay between miR-155 and AT1R protein expression as it was correlated negatively with miR-155 expression and positively with AT1R protein expression in subjects with CC genotype. CONCLUSION: The interplay between miR-155 expression, +1166C polymorphism, and AT1R protein expression may have a role in the regulation of blood pressure.

Validation of the Microlife WatchBP O3 device for clinic, home, and ambulatory blood pressure measurement, according to the International Protocol.

To determine the accuracy of the Microlife WatchBP O3 blood pressure measuring device tested according to the requirements of the International Protocol of the European Society of Hypertension. The WatchBP O3 is designed to provide clinic, ambulatory, and self blood pressure (BP) measurements. Device evaluation was performed in 33 participants with a mean +/- standard deviation age of 56.1+/-20.7 years (range 30-95 years). Their systolic BP (SBP) was 144.7+/-24.1 mmHg (range 90-180 mmHg), diastolic BP (DBP) was 86.8+/-18.3 mmHg (range 50-120 mmHg), and arm circumference was 28.1+/-2.9 cm (range 22.0-34.0 cm). Blood pressure measurements were performed in the sitting position. The WatchBP O3 passed all three phases of the European Society of Hypertension protocol for SBP and DBP. Mean blood pressure differences for the WatchBP O3 (device observer) were -1.7+/-6.9 mmHg for SBP and -1.1+/-4.3 mmHg for DBP. In conclusion, these results indicate that the Microlife WatchBP O3 monitor can be recommended for clinical use in the adult population.

Validation of Microlife BP W100 wrist device assessed according to the European Society of Hypertension and the British Hypertension Society protocols.

The objective of this study was to determine the accuracy of the Microlife BP W100 device for blood pressure measurement. The device evaluations were performed in 85 participants, by using both the protocol of the European Society of Hypertension (ESH) and the protocol of the British Hypertension Society (BHS). Initially, the data from 33 participants were examined according to the ESH protocol. Furthermore, 52 participants were then enrolled to fulfill the BHS protocol requirements. In all participants, sequential same arm measurements were made by two trained observers. The device passed all three phases of the ESH protocol for systolic blood pressure (SBP) and diastolic blood pressure (DBP) and was graded A according to the criteria of the BHS protocol for both SBP and DBP. The A/A grade was achieved in low (<130/80 mmHg), medium (130-160/80-100 mmHg) and high (>160/100 mmHg) blood pressure categories. Mean blood pressure difference between BP W100 and observers in the 85 participants was 0.1+/-5.3 mmHg for SBP and 1.1+/-3.4 mmHg for DBP, and thus, the device also met the requirements of the Association for the Advancement of Medical Instrumentation. In conclusion, these data show that the Microlife BP W100 wrist monitor satisfied the recommended ESH accuracy levels and achieved A/A grade of the BHS protocol across a wide range of blood pressure.

CYP1A2 genotype modifies the association between coffee intake and the risk of hypertension.

OBJECTIVES: The longitudinal relationship between coffee use and hypertension is still controversial. Cytochrome P450 1A2 (CYP1A2) is the main responsible enzyme for the metabolism of caffeine. The aim of the present study was to investigate the effect of coffee intake on the risk of developing hypertension needing antihypertensive treatment in individuals stratified by CYP1A2 genotype. DESIGN: We assessed prospectively 553 young White individuals screened for stage 1 hypertension. Coffee intake was ascertained from regularly administered questionnaires. Incident physician-diagnosed hypertension was the outcome measure. Genotyping of CYP1A2 SNP was performed by real time PCR. RESULTS: During a median follow-up of 8.2 years, 323 individuals developed hypertension. For carriers of the slow *1F allele (59%), hazard ratios of hypertension from multivariable Cox analysis were 1.00 in abstainers (reference), 1.72 (95%CI, 1.21-2.44) in moderate coffee drinkers (P = 0.03), and 3.00 (1.53-5.90) in heavy drinkers (P = 0.001). In contrast, hazard ratios for coffee drinkers with the rapid *1A/*1A genotype were 0.80 (0.52-1.23, P = 0.29) for moderate drinkers and 0.36 (0.14-0.89, P = 0.026) for heavy drinkers. In a two-way ANCOVA, a gene x coffee interactive effect was found on follow-up changes in systolic (P = 0.000) and diastolic (P = 0.007) blood pressure. Urinary epinephrine was higher in coffee drinkers than abstainers but only among individuals with slow *1F allele (P = 0.001). CONCLUSION: These data show that the risk of hypertension associated with coffee intake varies according to CYP1A2 genotype. Carriers of slow *1F allele are at increased risk and should thus abstain from coffee, whereas individuals with *1A/*1A genotype can safely drink coffee.

Natural history of hypertension subtypes in young and middle-age adults.

BACKGROUND: The evolution of hypertension (HT) subtypes in young-to-middle-age subjects is unclear. METHODS: We did a prospective study in 1,141 participants aged 18-45 years from the HARVEST study screened for stage 1 HT, and 101 nonhypertensive subjects of control during a median follow-up of 72.9 months. RESULTS: At baseline, 13.8% of the subjects were classified as having isolated systolic HT (ISH), 24.8% as having isolated diastolic HT (IDH), and 61.4% as having systolic-diastolic HT (SDH). All hypertensive groups developed sustained HT (clinic blood pressure > or =140/90 mm Hg from two consecutive visits occurring at least after > or =6 months of observation) more frequently than nonhypertensive subjects (P < 0.001 for all) with adjusted odds ratio of 5.2 (95%CI 2.9-9.2) among the SDH subjects, 2.6 (95%CI 1.5-4.5) among the IDH subjects, and 2.2 (95%CI 1.2-4.5) among the ISH subjects. When the definition of HT was based on ambulatory blood pressure (mean daytime blood pressure > or =135/85 mm Hg, n = 798), odds ratios were 5.1 (95%CI 3.1-8.2), 5.6 (95%CI 3.2-9.8), and 3.3 (95%CI 1.7-6.3), respectively. In the fully adjusted logistic model, the risk of ambulatory HT was smaller for the ISH than the IDH (P = 0.049) or SDH (P = 0.053) individuals. CONCLUSIONS: The present results indicate that young-to-middle-age subjects with ISH have a smaller risk of developing ambulatory HT than either subjects with SDH or IDH. Whether antihypertensive treatment can be postponed for long periods of time in young subjects with mild elevations of clinic systolic BP and low global cardiovascular risk should be examined in further studies.

Validation of A&D UA-85X device for blood pressure measurement.

To determine the accuracy of the UA-85X (UA-851, 852, 853, 854, and 855) device developed by the A&D company. Device evaluations were performed using the protocol of the European Society of Hypertension (ESH). Monitor performance was assessed in relation to patients' age, arm circumference, and systolic and diastolic blood pressures (BPs). The device was assessed in two different samples according to ESH requirements, which are based on four zones of accuracy differing from the mercury standard by 5, 10, 15 mmHg, or more. The UA-85X passed all three phases of the protocol for systolic BP and diastolic BP. Mean BP difference between device and observers was -0.3+/-4.4 mmHg for systolic BP and -2.7+/-4.8 mmHg for diastolic BP. These passed the Association for the Advancement of Medical Instrumentation standard requirements. In multivariable analyses, systolic BP discrepancies between device and observers were related to age (P=0.03) and diastolic BP discrepancies were related to diastolic BP level (P<0.001). These data show that the UA-85X satisfies the recommended ESH and Advancement of Medical Instrumentation accuracy levels for both systolic BP and diastolic BP.