Embracing ligands. A synthetic strategy towards new nitrogen-thioether multidentate ligands and characterization of the cobalt(III) complexes

The synthesis of the hexadentate ligand 2,2,9,9-tetra(methyleneamine)-4,7-dithiadecane (EtN(4)S(2)amp) is reported. The ligand is of a type in which bifurcations of the chain occur at atoms other than donor atoms. The cobalt(III) complex [Co(EtN(4)S(2)amp)](3+) (1) was isolated and characterized. The synthetic methodology also results in a number of by-products, notably 2,9,9-tris(methyleneamine)-9-methylenehydroxy-4,7-dithiadecane (Et(HO)N(3)S(2)amp) and an eleven-membered pendant arm macrocyclic ligand 6,10-dimethyl-6,10-bis(methyleneamine)-1,4-dithia-8-azaacycloundec-7- ene (dmatue). The complexes [Co(Et(HO)N(3)S(2)amp)](3+) (2), in which the alcohol is coordinated to the metal ion, and [Co(dmatue)Cl](2+) (4) were isolated and characterized. Et(HO)N(3)S(2)amp also undergoes complexation with cobalt(III) to produce two isomers endo-[Co(Et(HO) N(3)S(2)amp)Cl](2+) (endo-3) and exo-[Co(Et(HO) N(3)S(2)amp)Cl](2+) (exo-3), both with an uncoordinated alcohol group. endo- 3 has the alcohol positioned cis, and exo-3 trans, to the sixth metal coordination site. Reaction of 1 with isobutyraldehyde, paraformaldehyde and base in dimethylformamide results in the encapsulated complex [Co(1,5,5,9,13,13-hexamethyl-18,21-dithia-3,7,11,15-tetraazabicyclo[7.7.6]docosa- 3,14-diene)](ClO4)(3) . 2H(2)O ([Co(Me(6)docosadieneN(4)S(2))](3+) ( 5). All complexes have been characterized by single crystal X-ray study. The low-temperature (11 K) absorption spectrum of 1 has been measured in Nafion films with spin-allowed (1)A(1g) --> T-1(1g) and (1)A(1g) --> T-1(2g) and spin forbidden (1)A(1g) --> T-3(1g) and (1)A(1g) --> T-3(2g) bands observed. The octahedral ligand-field parameters were determined (10Dq = 22570 cm(-1), B = 551 cm(-1); C = 3500 cm(-1)). For 5 10Dq and B were determined (20580 cm(-1); 516 cm(-1), respectively) and compared with those for similar expanded cavity complexes [Co(Me(8)tricosatrieneN(6))](3+) and [Co(Me(5)tricosatrieneN(6))](3+).

A new approach to the synthesis of conjugated polymer-nanocrystal composites for heterojunction optoelectronics

We report a simple one pot process for the preparation of lead sulfide (PbS) nanocrystals in the conjugated polymer poly (2-methoxy-5-(2'-ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV), and we demonstrate electronic coupling between the two components.

Er(3+) doped phosphoniobate glasses and planar waveguides: structural and optical properties

Phosphoniobate glasses with composition (mol%) (100-x) NaPO(3)-xNb(2)O(5) ( x varying from 11 to 33) were prepared and characterized by means of thermal analysis, Fourier transform infrared spectroscopy, Raman scattering and (31)P nuclear magnetic resonance. The addition of Nb(2)O(5) to the polyphosphate base glass leads to depolymerization of the metaphosphate structure. Different colors were observed and assigned as indicating the presence of Nb(4+) ions, as confirmed by electron paramagnetic resonance measurements. The color was observed to depend on the glass composition and melting temperature as well. Er(3+) containing samples were also prepared. Strong emission in the 1550 nm region was observed. The Er(3+4)I(15/2) emission quantum efficiency was observed to be 90% and the quenching concentration was observed to be 1.1 mol%( 1.45 x 10(20) ions cm(-3)). Planar waveguides were prepared by Na(+)-K(+)-Ag(+) ion exchange with Er(3+) containing samples. Optical parameters of the waveguides were measured at 632.8, 543.5 and 1550 nm by the prism coupling technique as a function of the ion exchange time and Ag(+) concentration. The optimized planar waveguides show a diffusion depth of 5.9 mu m and one propagating mode at 1550 nm.

Prevalence of peripheral arterial disease: persistence of excess risk in former smokers

Objective: To determine the age-standardised prevalence of peripheral arterial disease (PAD) and associated risk factors, particularly smoking. Method: Design: Cross-sectional survey of a randomly selected population. Setting: Metropolitan area of Perth, Western Australia. Participants: Men aged between 65-83 years. Results: The adjusted response fraction was 77.2%. Of 4,470 men assessed, 744 were identified as having PAD by the Edinburgh Claudication Questionnaire and/or the ankle-brachial index of systolic blood pressure, yielding an age-standardised prevalence of PAD of 15.6% (95% confidence intervals (CI): 14.5%, 16.6%). The main risk factors identified in univariate analyses were increasing age, smoking current (OR=3.9, 95% CI 2.9-5.1) or former (OR=2.0, 95% CI 1.6-2.4), physical inactivity (OR=1.4, 95% CI 1.2-1.7), a history of angina (OR=2.2, 95% CI 1.8-2.7) and diabetes mellitus (OR=2.1, 95% CI 1.7-2.6). The multivariate analysis showed that the highest relative risk associated with PAD was current smoking of 25 or more cigarettes daily (OR=7.3, 95% CI 4.2-12.8). In this population, 32% of PAD was attributable to current smoking and a further 40% was attributable to past smoking by men who did not smoke currently. Conclusions: This large observational study shows that PAD is relatively common in older, urban Australian men. In contrast with its relationship to coronary disease and stroke, previous smoking appears to have a long legacy of increased risk of PAD. Implications: This research emphasises the importance of smoking as a preventable cause of PAD.

Effect of mesoporosity of vanadium oxide prepared by sol-gel process as cathodic material evaluated by cyclability during Li(+) insertion/deinsertion

The effect of pore structure on the behavior of lithium intercalation into an electrode containing porous V(2)O(5) film has been investigated and compared with the electrode containing a non-porous V(2)O(5) film. X-ray diffraction patterns indicate a lamellar structure for both materials. Nitrogen adsorption isotherms, t-plot method, and Scanning Electronic Microscopy show that the route employed for the preparation of mesoporous V(2)O(5) was successful. The electrochemical performance of these matrices as lithium intercalation cathode materials was evaluated. The porous material reaches stability after several cycles more easily compared with the V(2)O(5) xerogel. Lithium intercalation into the porous V(2)O(5) film electrode is crucially influenced by pore surface and film surface irregularity, in contrast with the non-porous surface of the V(2)O(5) xerogel.

Synthesis, characterization and electrochemical behavior of the vanadium pentoxide/cetyl pyridinium chloride hybrid material

In situ and ex situ studies concerning the new hybrid material vanadium pentoxide xerogel in the presence of the cationic surfactant cetyl pyridinium chloride (V(2)O(5)/CPC) are presented. The in situ characterization studies revealed the presence of a lamellar structure for the V(2)O(5)/CPC hybrid material. The intercalation reaction was evidenced on the basis of the increase in the d-spacing as well as the displacement of the infrared bands toward lower energy levels. Electrochemical studies comprising the cyclic voltammetry and the electrochemical impedance spectroscopy techniques showed that the behavior of the hybrid material is considerably influenced by the electrolyte composition. The ion insertion/de-insertion into the V(2)O(5) xerogel structure accompanying the charge transfer process is influenced by the solid-state diffusion process modeled by using the finite-space Warburg element.

Hemolymph ionic regulation and adjustments in gill (Na(+), K(+))-ATPase activity during salinity acclimation in the swimming crab Callinectes ornatus (Decapoda, Brachyura)

We evaluate hemolymph osmotic and ionic regulatory abilities and characterize a posterior gill microsomal (Na(+), K(+))-ATPase from the marine swimming crab, Callinectes ornatus, acclimated to 21 parts per thousand or 33 parts per thousand salinity. C ornatus is isosmotic after acclimation to 21 parts per thousand but is hyposmotic at 33 parts per thousand salinity; hemolymph ions do not recover initial levels on acclimation to 21 parts per thousand salinity but are anisoionic compared to ambient concentrations, revealing modest regulatory ability. NH(4)(+) modulates enzyme affinity for K(+), which increases 187-fold in crabs acclimated to 33%. salinity. The (Na(+), K(+))-ATPase redistributes into membrane fractions of different densities, suggesting that altered membrane composition results from salinity acclimation. ATP was hydrolyzed at maximum rates of 182.6 +/- 7.1 nmol Pi min(-1) mg(-1) (21 parts per thousand) and 76.2 +/- 3.5 nmol Pi min(-1) mg(-1) (33 parts per thousand), with little change in K(M) values (approximate to 50 mu mol L(-1)). K(+) together with NH(4)(+) synergistically stimulated activity to maximum rates of approximate to 240 nmol Pi min(-1) mg(-1). K, values for ouabain inhibition (approximate to 110 mu mol L(-1)) decreased to 44.9 +/- 1.0 mu mol L(-1) (21 parts per thousand) and 28.8 +/- 1.3 mu mol L(-1) (33 parts per thousand) in the presence of both K(+) and NH(4)(+). Assays employing various inhibitors suggest the presence of mitochondrial F(0)F(1)- and K(+)- and V-ATPase activities in the gill microsomes. (C) 2009 Elsevier Inc. All rights reserved.

Obstructive Sleep Apnea Is Common and Independently Associated With Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is associated with arrhythmias and cardiovascular death. Left atrial enlargement and atrial fibrillation (AF) are considered markers for death due to heart failure in patients with HCM. Obstructive sleep apnea (OSA) is independently associated with heart remodeling and arrhythmias in other populations. We hypothesized that OSA is common and is associated with heart remodeling and AF in patients with HCM. Methods: We evaluated 80 consecutive stable patients with a confirmed diagnosis of HCM by sleep questionnaire, blood tests, echocardiography, and sleep study (overnight respiratory monitoring). Results: OSA (apnea-hypopnea index [AHI] > 15 events/h) was present in 32 patients (40%). Patients with OSA were significantly older (56 [41-64] vs 38.5 [30-53] years, P < .001) and presented higher BMI (28.2 +/- 3.5 vs 25.2 +/- 5.2 kg/m(2), P < .01) and increased left atrial diameter (45 [42-52.8] vs 41 [39-47] mm, P = .01) and aorta diameter (34 [30-37] vs 29 [28-32] mm, P < .001), compared with patients without OSA. Stepwise multiple linear regression showed that the AHI (P = .05) and BMI (P = .06) were associated with left atrial diameter. The AHI was the only variable associated with aorta diameter (P = .01). AF was present in 31% vs 6% of patients with and without OSA, respectively (P < .01). OSA (P = .03) and left atrial diameter (P = .03) were the only factors independently associated with AF. Conclusions: OSA is highly prevalent in patients with HCM and it is associated with left atrial and aortic enlargement. OSA is independently associated with AF, a risk factor for cardiovascular death in this population. CHEST 2010; 137(5):1078-1084

Long-Term Pharmacotherapy for Obesity in Elderly Patients A Retrospective Evaluation of Medical Records from a Specialized Obesity Outpatient Clinic

Background: Obesity is a serious chronic disease and the prevalence of this condition is increasing among the elderly. Although the benefits of weight loss to improve control of associated diseases are well known in young adults, they are not in older patients. The use of anti-obesity drugs to promote weight loss is widespread in Brazil and other countries, and obesity specialists frequently prescribe medicines in doses and for durations previously unreported in the literature. Sibutramine, orlistat and amfepramone (diethylpropion) have been evaluated in clinical trials of more than 2 years` duration in adults, demonstrating safety and efficacy, but long-term studies in obesity treatment are absent for other drugs. The efficacy and safety of obesity pharmacotherapy among the elderly is unknown. Objective: To describe the experience of obesity pharmacotherapy in the elderly in a specialized obesity care setting in Brazil, with a focus on efficacy and safety. Methods: A retrospective evaluation was conducted on medical charts from an outpatient clinic of a specialized tertiary centre for the treatment of obesity. We included patients who had had at least one consultation between January and December 2007, were aged >= 60 years at the beginning of the treatment, had had at least 6 months of follow-up and had received a prescription of at least one potential weight-loss drug. Diagnoses reported on medical records were documented. Age, weight, height and body mass index (BMI) were recorded at admission, after 6, 12, 18 and 24 months, and at the last available visit. The medicines prescribed, together with the dose, duration of use, adverse effects and reasons for discontinuation, were documented. Results: The group consisted of 44 women (86%) and 7 men (14%), with a mean +/- SD age of 65.2 +/- 4.5 years, weight of 95.3 +/- 12.5 kg and BMI of 38.5 +/- 4.3 kg/m(2). The mean +/- SD time of follow-up was 39.3 +/- 26.4 months, and the mean weight loss was 6.65 kg (p < 0.01). After the first 6 months, the mean +/- SD weight loss was 5.7 +/- 3.8 kg (p < 0.0001). A smaller weight loss was seen between the 6th and 12th months, with no statistically significant change in weight thereafter. A weight loss of >= 5% was achieved by 64.71%, 63.64%, 62.16% and 69.70% in the 6th, 12th, 18th and 24th months, respectively, and a weight loss of >= 10% was achieved by 17.65%, 34.09%, 32.43% and 39.39% in the 6th, 12th, 18th and 24th months, respectively. The medicines prescribed were sibutramine, orlistat, fluoxetine, sertraline, topiramate, fenproporex, mazindol and amfepramone, alone or in combinations, concomitantly or sequentially. The reasons for discontinuation were lack of response (n = 13), loss of response (development of tolerance) [n= 11], lack of adherence (n = 14) and adverse effects (n= 14). One episode of atrial flutter occurred in a patient taking fenproporex. The weight-loss medications were generally well tolerated, and only transient adverse events were reported. Conclusions: Long-term pharmacotherapy for obesity was effective and well tolerated by this group of elderly patients.

Histological features of acute tubular necrosis in native kidneys and long-term renal function

There are few studies on the relationship between the morphology of acute tubular necrosis (ATN) in native kidneys and late functional recovery. Eighteen patients with acute renal failure (ARF) who had undergone renal biopsy were studied. All had the histological diagnosis of ATN and were followed for at least six months. Clinical characteristics of ARF were analyzed, and histological features were semi-quantitatively evaluated (tubular atrophy, interstitial inflammatory infiltrate, interstitial fibrosis, and ATN). According to the maximal GFR achieved during the follow-up, patients were divided into two groups: complete recovery (GFR >= 90 mL/min/1.73 m(2)) and partial recovery (GFR < 90 mL/min/1.73 m(2)). Only 39% of the patients achieved complete recovery. Patients with partial recovery achieved their maximal GFR (63 +/- 9 mL/min/1.73 m(2)) 37 +/- 14 months after ARF, a period of time similar to those patients with complete recovery (i.e., 54 +/- 22 months). Patients with partial recovery had more severe ARF: oliguria was more frequent (90 versus 17%, p < 0.01), and they had higher peak creatinine (13.85 +/- 1.12 versus 8.95 +/- 1.30 mg/dL, p = 0.01), and longer hospitalization (45 +/- 7 versus 20 +/- 4 days, p = 0.03). No single histological parameter was associated with partial recovery, but the sum of all was when expressed as an injury index [4.00 (2.73-5.45) versus 2.00 (1.25-3.31), p < 0.05]. In conclusion, among patients with atypical ATN course, those with more severe ARF and tubule-interstitial lesions are more prone to partial recovery.

In vivo biological performance of a novel highly bioactive glass-ceramic (Biosilicate (R)): A biomechanical and histomorphometric study in rat tibial defects

This study aimed to investigate bone responses to a novel bioactive fully crystallized glass-ceramic of the quaternary system P(2)O(5)-Na(2)O-CaO-SiO(2) (Biosilicates (R)). Although a previous study demonstrated positive effects of Biosilicate (R) on in vitro bone-like matrix formation, its in vivo effect was not studied yet. Male Wistar rats (n = 40) with tibial defects were used. Four experimental groups were designed to compare this novel biomaterial with a gold standard bioactive material (Bioglass (R) 45S5), unfilled defects and intact controls. A three-point bending test was performed 20 days after the surgical procedure, as well as the histomorphometric analysis in two regions of interest: cortical bone and medullary canal where the particulate biomaterial was implanted. The biomechanical test revealed a significant increase in the maximum load at failure and stiffness in the Biosilicate group (R) (vs. control defects), whose values were similar to uninjured bones. There were no differences in the cortical bone parameters in groups with bone defects, but a great deal of woven bone was present surrounding Biosilicate (R) and Bioglass (R) 45S5 particulate. Although both bioactive materials supported significant higher bone formation; Biosilicate (R) was superior to Bioglass (R) 45S5 in some histomorphometric parameters (bone volume and number of osteoblasts). Regarding bone resorption, Biosilicate (R) group showed significant higher number of osteoclasts per unit of tissue area than defect and intact controls, despite of the non-significant difference in the osteoclastic surface as percentage of bone surface. This study reveals that the fully crystallized Biosilicate (R) has good bone-forming and bone-bonding properties. (C) 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 978: 139-147, 2011.

Hemodynamic Changes during Myocardial Revascularization without Extracorporeal Circulation

Background and objectives: Cardiac positioning and stabilization during myocardial revascularization without extracorporeal circulation (ECC) may cause hemodynamic changes dependent to the surgical site. The objective of this study was to evaluate these changes during distal coronary anastomosis. Methods: Twenty adult patients undergoing myocardial revascularization without ECC were monitored by pulmonary artery catheter and transesophageal Echo Doppler. Hemodynamic data were collected at the following times before removing the stabilizer wall: (1) after volume adjustments, (2) at the beginning of distal anastomosis, and (3) after 5 minutes. Treated coronary arteries were grouped according to their location in the lateral, anterior, or posterior wall. Two-way ANOVA with repetition and Newman-Keuls post-test were used in the analysis. A p value < 0.05 was considered statically significant. Results: During myocardial revascularization without ECC, pulmonary artery wedge pressure showed elevation from 17.7 +/- 6.1 to 19.2 +/- 6.5 (p < 0.001) and 19.4 +/- 5.9 mmHg (p < 0.001), while the central venous pressure went from 13.9 +/- 5.4 to 14.9 +/- 5.9 mmHg (p = 0.007) and 15.1 +/- 6.0 mmHg (p = 0.006). Intermittent cardiac output was reduced from 4.70 +/- 1.43 to 4.23 +/- 1.22 (p < 0.001) and 4.26 +/- 1.25 L.min(-1) (p < 0.001). According to transesophageal Doppler, a significant group-time interaction was observed in cardiac output, which was reduced in the lateral group from 4.08 +/- 1.99 to 2.84 +/- 1.82 (p = 0.02) and 2.86 +/- 1.73 L.min(-1) (p = 0.02), and aortic blood flow, which went from 2.85 +/- 1.39 to 1.99 +/- 1.26 (p = 0.02) and 2.00 +/- 1.21 L.min(-1) (p = 0.02). Other hemodynamic changes were not observed during anastomoses. Conclusions: A significant hemodynamic deterioration was observed during myocardial revascularization without ECC. Transesophageal Doppler detected a decrease in cardiac output only in the lateral group.

The Parkes half-jansky flat-spectrum sample

We present a new sample of Parkes half-jansky flat-spectrum radio sources, having made a particular effort to find any previously unidentified sources. The sample contains 323 sources selected according to a flux limit of 0.5 Jy at 2.7 GHz, a spectral index measured between 2.7 and 5.0 GHz of alpha(2.7/5.0) > -0.5, where S(nu) proportional to nu(alpha), Galactic latitude \b\ > 20 degrees and -45 degrees < declination (B1950) < +10 degrees. The sample was selected from a region 3.90 steradians in area. We have obtained accurate radio positions for all the unresolved sources in this sample, and combined these with accurate optical positions from digitized photographic sky survey data to check all the optical identifications. We report new identifications based on R- and Kn-band imaging and new spectroscopic measurements of many of the sources. We present a catalogue of the 323 sources, of which 321 now have identified optical counterparts and 277 have measured spectral redshifts.

Effects of (-)-RO363 at human atrial beta-adrenoceptor subtypes, the human cloned beta(3)-adrenoceptor and rodent intestinal beta(3)-adrenoceptors

1 Chronic treatment of patients with beta-blockers causes atrial inotropic hyperresponsiveness through beta(2)-adrenoceptors, 5-HT4 receptors and H-2-receptors but apparently not through beta(1)-adrenoceptors despite data claiming an increased beta(1)-adrenoceptor density from homogenate binding studies. We have addressed the question of beta(1)-adrenoceptor sensitivity by determining the inotropic potency and intrinsic activity of the beta(1)-adrenoceptor selective partial agonist (-)-RO363 and by carrying out both homogenate binding and quantitative beta-adrenoceptor autoradiography in atria obtained from patients treated or not treated with beta-blockers. In the course of the experiments it became apparent that (-)-RO363 also may cause agonistic effects through the third atrial beta-adrenoceptor. To assess whether (-)-RO363 also caused agonistic effects through beta(3)-adrenoceptors we studied its relaxant effects in rat colon and guinea-pig ileum, as well as receptor binding and adenylyl cyclase stimulation of chinese hamster ovary (CHO) cells expressing human beta(3)-adrenoceptors. 2 beta-Adrenoceptors were labelled with (-)-[I-125]-cyanopindolol. The density of both beta(1)- and beta(2)-adrenoceptors was unchanged in the 2 groups, as assessed with both quantitative receptor autoradiography and homogenate binding. The affinities of (-)-RO363 for beta(1)-adrenoceptors (pK(i) = 8.0-7.7) and beta(2)-adrenoceptors (pK(i) = 6.1-5.8) were not significantly different in the two groups. 3 (-)-RO363 increased atrial force with a pEC(50) of 8.2 (beta-blocker treated) and 8.0 (non-beta-blocker treated) and intrinsic activity with respect to (-)-isoprenaline of 0.80 (beta-blocker treated) and 0.54 (non-beta-blocker treated) (P<0.001) and with respect to Ca2+ (7 mM) of 0.65 (beta-blocker treated) and 0.45 (non-beta-blocker treated) (P<0.01). The effects of (-)-RO363 were resistant to antagonism by the beta(2)-adrenoceptor antagonist, ICI 118,551 (50 nM). The effects of 0.3-10 nM (-)-RO363 were antagonized by 3-10 nM of the beta(1)-adrenoceptor selective antagonist CGP 20712A. The effects of 20-1000 nM (-)-RO363 were partially resistant to antagonism by 30-300 nM CGP 20712A. 4 (-)-RO363 relaxed the rat colon, partially precontracted by 30 mM KCl, with an intrinsic activity of 0.97 compared to (-)-isoprenaline. The concentration-effect curve to (-)-RO363 revealed 2 components, one antagonized by (-)-propranolol (200 nM) with pEC(50)=8.5 and fraction 0.66, the other resistant to (-)-propranolol (200 nM) with pEC(50)=5.6 and fraction 0.34 of maximal relaxation. 5 (-)-RO363 relaxed the longitudinal muscle of guinea-pig ileum, precontracted by 0.5 mu M histamine, with intrinsic activity of 1.0 compared to (-)-isoprenaline and through 2 components, one antagonized by (-)-propranolol (200 nM) with pEC(50)=8.7 and fraction 0.67, the other resistant to (-)-propranolol with pEC(50)=4.9 and fraction 0.33 of maximal relaxation. 6 (-)-RO363 stimulated the adenylyl cyclase of CHO cells expressing human beta(3)-adrenoceptors with pEC(50)=5.5 and intrinsic activity 0.74 with respect to (-)-isoprenaline (pEC(50)=5.9). (-)-RO363 competed for binding with [I-125]cyanopindolol at human beta(3)-adrenoceptors transfected into CHO cells with pK(i)=4.5. (-)-Isoprenaline (pk(i)=5.2) and (-)-CGP 12177A (pK(i)=6.1) also competed for binding at human beta(2)-adrenoceptors. 7 We conclude that under conditions used in this study, (-)-RO363 is a potent partial agonist for human beta(1)- and beta(3)-adrenoceptors and appears also to activate the third human atrial beta-adrenoceptor. (-)-RO363 relaxes mammalian gut through both beta(1)- and beta(3)-adrenoceptors. (-)-RO363, used as a beta(1)-adrenoceptor selective tool, confirms previous findings with (-)-noradrenaline that beta(1)-adrenoceptor mediated atrial effects are only slightly enhanced by chronic treatment of patients with beta-blockers. Chronic treatment with beta(1)-adrenoceptor-selective blockers does not significantly increase the density of human atrial beta(1)- and beta(2)-adrenoceptors.

Measurements of adipocity and high blood pressure among children and adolescents living in Belo Horizonte

Objective: To verify an association, if it exists, between obesity and blood pressure raised beyond the 90th percentile in children and adolescents, and to determine the measure of adiposity that best correlates with blood pressure in these subjects. Design: Cross-sectional study. Setting: A school-based study in Belo Horizonte, Brazil. Participants: We selected randomly 1,403 students, aged from 6 to 18 years, from 545,046 students attending 521 public and private schools. Those selected completed the study. Main measures of outcome: We recorded the weight, height, skin fold in the triceps, subscapular, and suprailiac areas, waist and hip circumference, body-mass index, and resting systolic and diastolic blood pressures using a mercury sphygmomanometer. Results: In univariate analyses, body mass index greater or lesser than 85th percentile, measurements of skin thickness in the subscapular and suprailiac areas, and the sum of all measurements of skinfold thickness, were associated with both systolic and diastolic measurements of blood pressure. After multivariate analyses that adjusted for all measurements of adiposity except itself, and age, race, and socioeconomic state, we found that the increased body mass index was associated with a 3.6-fold increased frequency of elevated systolic measurements of blood pressure, with 9596 confidence intervals from 2.2 to 5.8, and a 2.7-fold increased frequency of elevated measurements of diastolic blood pressure, with 95% confidence intervals from 1.9 to 4.0. Conclusions: Body-mass index serves as a better predictor of elevated blood pressure among children than do local measurements of adiposity.