Resting heart rate and arterial stiffness: a longitudinal prospective study in a population of hypertensive patients

Background

The role of resting Heart Rate on the progression of arterial stiffness has not yet been extensively evaluated. The aim of this study is to investigate the relationship between resting HR and baseline arterial stiffness (evaluated by cfPWV) as well as its progression in a population of hypertensive patients over a 3.7 years follow-up period.

Methods

We enrolled 572 hypertensive outpatients 18–80 aged, followed by one hospital in Northern Italy. Anamnestic, clinical and laboratory data, BP and cfPWV were assessed at baseline and after a median follow-up time of 3.7±0.5 years

Results

At baseline the mean age was 53.9±12.7 years, SBP and DBP were 141.2±17.8 and 86.5±10.5 mmHg, HR was 65.6±10.9 bpm and PWV was 8.6±2.0 m/s. Despite an improvement in BP values (from 141.2/86.5 to 132.6/79.2 mmHg, p<0.001), during follow-up, PWV increased (ΔPWV 0.5±2.2 m/s). In patients with a ΔHR above as compared to those under the median value (9 bpm), ΔPWV was significantly higher (0.82±2.22 vs. 0.27±2.25 m/s, p=0.003). At multivariate analysis, HR was among the significant determinants of both baseline PWV and its progression (β = 0.031, p<0.001). Furthermore, ΔHR was a significant determinant of ΔPWV (β = 0.019; p=0.017).

Conclusions

in hypertensive patients there is a significant relationship between basal resting HR and basal PWV as well as between the increase of HR and the increase of PWV during the follow-up period. Beyond age and BP, resting HR must be considered as an independent determinant of arterial stiffness. This represents a possible mechanism through which HR contributes to the increase in CV risk.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Niguarda Hospital, Milan, Italy

C68 RESTING HEART RATE AND ARTERIAL STIFFNESS: A LONGITUDINAL PROSPECTIVE STUDY IN A POPULATION OF HYPERTENSIVE PATIENTS

Objective

The role of resting Heart Rate on the progression of arterial stiffness has not yet been extensively evaluated. The aim of this study is to investigate the relationship between resting HR and baseline arterial stiffness (evaluated by cfPWV) as well as its progression in a population of hypertensive patients over a 3.7 years follow–up period.

Methods

We enrolled 572 hypertensive outpatients 18–80 aged, followed by the Hypertension Unit of St. Gerardo Hospital (Monza, Italy). Anamnestic, clinical and laboratory data, BP and cfPWV (complior) were assessed at baseline and after a median follow–up time of 3.7 ± 0.5 years.

Results

At baseline the mean age was 53.9 ± 12.7 years, SBP and DBP were 141.2 ± 17.8 and 86.5 ± 10.5 mmHg, HR was 65.6 ± 10.9 bpm and PWV was 8.6 ± 2.0 m/s. Despite an improvement in BP values (from 141.2/86.5 to 132.6/79.2 mmHg, p < 0.001), during follow–up, PWV increased (ΔPWV 0.5 ± 2.2 m/s). In patients with a ΔHR above as compared to those under the median value (9 bpm), ΔPWV was significantly higher (0.82 ± 2.22 vs. 0.27 ± 2.25 m/s, p = 0.003). At multivariate analysis, HR was among the significant determinants of both baseline PWV and its progression (β = 0.031, p < 0.001). Furthermore, ΔHR was a significant determinant of ΔPWV (β = 0.019; p = 0.017).

Conclusions

In hypertensive patients there is a significant relationship between basal resting HR and basal PWV as well as between the increase of HR and the increase of PWV during the follow–up period. Beyond age and BP, resting HR must be considered as an independent determinant of arterial stiffness. This represents a possible mechanism through which HR contributes to the increase in CV risk.

Antimicrobial resistance pattern of methicillin-resistant Staphylococcus aureus in the food industry

There is increasing concern about the impact on public health of methicillin-resistant Staphylococcus aureus (MRSA) associated with animal food products. MRSA remains a serious problem because of the high incidence and multidrug resistance of the strains, even for strains isolated from foods, food environments and food handlers. The objectives of this study are: (i) to evaluate the susceptibility of S. aureus strains isolated from food, food handlers and food-processing environments to 14 antibiotics currently used in veterinary and human therapy; (ii) to assess the presence of the mecA gene. A total of 1007 samples were collected from food, food handlers, and environments and were analyzed for the presence of S. aureus. S. aureus was present in 165 of the 1007 samples. A total of 157 isolates were methicillin-susceptible S. aureus (MSSA) and 8 isolates were MRSA. In particular, out of 8 MRSA strains detected, 4 strains harboured the mecA gene. All MRSA strains were resistant to at least one of the tested antibiotics and 6 strains demonstrated multi-resistance. Considering the high level of resistances in S. aureus and the isolation of MRSA strains, the surveillance of antimicrobial resistance and the spreading of this pathogen is of crucial importance in the food production chain. These data are useful in improving background data on antimicrobial resistance of S. aureus isolated from food, processing environments and food handlers, supporting the prudent use of antibiotics and the development of international control programs.

Comparison of contaminant and residue levels in organic and conventional milk and meat products from Northern Italy

Due to the growing interest in organic products, a comparison between the chemical safety of organic and conventional products was undertaken. Milk and meat were the products chosen for study. The parameters evaluated to assess chemical safety were organochlorine pesticides, polychlorinated biphenyls (PCBs), lead, cadmium and mycotoxin contamination. Pesticides and PCBs residues in both organic and conventional milk and meat were lower than legal limits. Lead and cadmium residues were very low and did not differ between organic and conventional products. However, aflatoxin M1 contamination in some but not all samples of organic milk was significantly higher than those of conventional milk, although factors other than organic production might be implicated.

Residues of beta-lactam antibiotics in bovine milk: confirmatory analysis by liquid chromatography tandem mass spectrometry after microbial assay screening

A procedure for the simultaneous determination of the residues of seven beta-lactam antibiotics (penicillin G, ampicillin, oxacillin, amoxicillin, dicloxacillin, cephalexin, cephapirin) in bovine raw milk using tandem liquid chromatography mass spectrometry (LC-MS/MS) is described. The antibiotics were extracted by an acetic acid solution after centrifugation and filtration. The beta-lactams were separated using reversed-phase liquid chromatography. A triple quadrupole mass spectrometer was used in positive-ion mode as a detector via a Turbo Ionspray interface for electrospray ionization (ESI). The limits of detection and quantitation of the method were below the legal tolerances, except for ampicillin. The method was used to confirm 53 samples found positive by a microbial method (Delvotest SP) at the Istituto Zooprofilattico Sperimentale per la Lombardia e l'Emilia Romagna of Brescia during 2001. Penicillin G was found in 26 samples at concentrations ranging from less than 4 to 6240+/-550 microg x l(-1). Amoxicillin was found in three samples at concentrations ranging from 8.5+/-0.1 to 53.7+/-2.3 microg x l(-1). Cephapirin was found in two samples at 5.7+/-0.1 and 6.4+/-0.3 microg x l(-1).