Postprandial hypotension as a predictor of respiratory failure in patients with foodborne botulinum intoxication - a case-control study in outbreak investigation.

OBJECTIVES: Botulism is a rare syndrome characterized by acute, flaccid paralysis with possible involvement of respiratory muscle-producing pump failure requiring mechanical ventilation. A predominance of autonomic involvement can occur. METHODS: We enrolled patients affected by foodborne botulism during an outbreak. All patients underwent the detection of the toxin in stool specimens, and 24-hour ambulatory blood pressure monitoring (ABPM). A blinded expert operator analyzed ABPM data for the diagnosis of hypertension and postprandial hypotension (PPH). RESULTS: Twenty male patients met the inclusion and exclusion criteria. Thirty-four healthy subjects matched for sex and age were enrolled as a control group. PPH was significantly more frequent in the botulin group than in healthy subjects (40% vs 2.9%, P <0.0001). At the logistic regression, the probability that patients affected by botulinum could require ventilation was increased by 733% (adjusted odds ratio: 8.33) when PPH is encountered. CONCLUSIONS: The likelihood of resorting to ventilation in subjects with botulinum intoxication was seven times greater in patients presenting PPH. These results could allow the prompt identification of patients at high risk for requiring ventilation.

Neutralizing and binding antibodies to interferon beta in patients with multiple sclerosis: a comparison of assay results from three italian centres.

Interferon (IFN) beta therapy for multiple sclerosis (MS) is associated with the development of binding antibodies (BAbs) and neutralizing antibodies (NAbs) in a percentage of patients. This study investigated the reproducibility of results of two different antibody detection techniques using serum from 100 patients with MS who were receiving IFN beta therapy. Fifty samples were analysed using a commercially available kit-based BAb assay and a further 50 different samples were analysed using a widely used NAb cytopathic effect assay, at three different laboratories. All three centres agreed on the BAb status of all serum samples. However, only 84% agreement was reached on serum NAb status, and there was significant inter-laboratory variation in NAb titre values. Further analysis of these data revealed a correlation between the mean NAb titre and the coefficient of variation of serum samples, indicating greater discordance with higher NAb titres. A significant interlaboratory variation in NAb titres does exist; thus, caution is required when comparing titres from different centres. It is clear that validated detection assays are needed to accurately quantify NAb titres.

Influence of the metabolic syndrome on aortic stiffness in never treated hypertensive patients.

BACKGROUND AND AIM: Metabolic syndrome (MS) carries an increased risk for cardiovascular events and there is a growing awareness that large artery stiffening is a powerful predictor of cardiovascular morbidity and mortality. Little is known about the relationship of MS with aortic stiffness. The aim of our study was to analyze, in patients with essential hypertension, the influence of MS, defined according to the criteria proposed by the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (NCEP-ATP III), on carotid-femoral pulse wave velocity (PWV), a measure of aortic stiffness. METHODS: Ninety-three untreated essential hypertensives, aged between 23 and 61 years, without diabetes mellitus, were studied. All subjects underwent routine blood chemistry, oral glucose tolerance test with glucose and insulin determinations, albumin excretion rate (AER) measurement, 24-h ambulatory blood pressure monitoring, and measurement of carotid-femoral PWV, by means of a computerized method. RESULTS: Patients with MS (n = 28) showed higher age-adjusted carotid-femoral PWV (10.1 +/- 1.4 vs 9.3 +/- 1.4 m/s; p = 0.01) when compared to subjects without MS. This difference held after controlling for gender and for 24-h mean blood pressure (MBP) (p = 0.02) and lost its statistical significance after further adjustment for AER. In a multiple regression model, excluding the individual components of MS, in which metabolic syndrome was added along with age, gender, smoking habit, LDL cholesterol, HOMA index, 24-h MBP and 24-h heart rate, MS remained independently associated with carotid-femoral PWV (beta = 0.29; p = 0.002). The statistical significance of this association disappeared after the inclusion into this model of AER. CONCLUSIONS: Metabolic syndrome is associated with an increased aortic stiffness. Main explanatory factors of this association are age, systolic blood pressure and albumin excretion rate.

Relationships between ambulatory white coat effect and left ventricular mass in arterial hypertension.

The aim of our study was to analyze, in a group of 296 essential hypertensives, the relationship between left ventricular mass (LVM) and ambulatory white coat effect (WCE); that is the difference between the elevation of the first measurements of ambulatory blood pressure monitoring and the mean daytime pressure. The study population was separated into two groups according to the median of the WCE. The LVM was greater in the groups with higher systolic and diastolic ambulatory WCE. The significant association between ambulatory WCE and LVM was confirmed by the results of multiple regression analysis, suggesting that ambulatory WCE may not be an innocent phenomenon.

Value of home blood pressures as predictor of target organ damage in mild arterial hypertension.

BACKGROUND: Home blood pressure measurement has gained increasing importance for the management of hypertensive patients. The aim of our study was to compare levels of clinic (CBP), ambulatory (ABP), and home blood pressure (HBP) measurements, and their relationships with various indexes of target organ damage in I-II grade essential hypertension. DESIGN AND METHODS: Thirty-eight essential hypertensives underwent evaluation of clinic, ambulatory and home blood pressures. Each patient recorded HBP for 2 days with a digital BP monitor three times daily, the first time on the same day during which ABP monitoring was simultaneously performed. Moreover, in all subjects electrocardiogram recording, echocardiographic study, microalbuminuria assay and fundus oculi examination were obtained. RESULTS: The average HBPs obtained on the first day, in particular systolic values, were quite similar to mean daytime ambulatory BP recorded on the same day. Clinic BP, both systolic and diastolic, showed no significant correlation with left ventricular mass index (LVMI) and with albumin excretion rate (AER), whereas a correlation barely significant was observed with an index of global target organ damage (GTODi), including cardiac, renal and retinal parameters. On the contrary, home blood pressures, especially those recorded on the second day, correlated significantly, and more tightly than clinic BP, with LVMI, AER and GTODi. CONCLUSIONS: Our study seems to justify the adoption of home BP monitoring in the management of hypertensive patients, as a useful complement to clinical readings, and may provide additional prognostic information.