Left ventricular mass correlates with fat-free mass but not fat mass in adults.

BACKGROUND: Left ventricular mass is associated with body size, obesity and blood pressure. Echocardiography is routinely used to estimate this parameter, which is usually indexed to body surface area to allow comparisons to be made between individuals and groups of different body size. However, in obese subjects, using left ventricular mass indexed to body surface area may inappropriately normalize left ventricular mass. OBJECTIVES: The aim of this study was to investigate the relationships between left ventricular mass and body composition and to determine the best determinants of left ventricular mass. SUBJECTS AND METHODS: Echocardiography and dual-energy X-ray absorptiometry were performed in 106 subjects under primary care. Half were hypertensive subjects and the others were normotensive age- and sex-matched control subjects. Univariate correlations were studied between left ventricular mass and height, height1.5, height2.7, weight, body surface area, body mass index, waist: hip ratio, fat-free mass, bone mineral content and fat mass. Stepwise multiple linear regression was performed to determine the best determinants of left ventricular mass. RESULTS: Fat-free mass was correlated with left ventricular mass (r = 0.53, P = 0.0001) and was the only independent predictor of left ventricular mass (R2 = 0.30, P= 0.0001) by multivariate analysis. Fat mass did not correlate with left ventricular mass (r= -0.005, P= 0.96). Other measures of body size, including body surface area, waist: hip ratio, bone mineral content, weight, height, height 1.5, height2.7 and body mass index all were correlated with, but were not independent determinants of, left ventricular mass. CONCLUSIONS: Left ventricular mass is independently determined by fat-free mass but by no other measures of body size or composition. Specifically, left ventricular mass was neither correlated with nor determined by fat mass. None of the other measures of body size determined left ventricular mass. It may be more appropriate to index left ventricular mass to fat-free mass rather than to measures of body size which include fat mass.     

Physical fitness and occupational demands of the Belfast ambulance service

The objectives of this study were to evaluate the current fitness of an area ambulance service based in Belfast and to quantify the physiological demands of accident and emergency work. From a total staff of 230, 105 (46%) volunteered to undergo a series of fitness tests subject to health state. Results based on body mass indices showed that 52% of subjects could be classified as overweight and 10% of subjects as obese. Fitness levels were similar to other comparable samples and showed the expected but not inevitable decrease with age. A simple work related task (walking at 6 km/h) performed in the laboratory showed that 54% of men over 40 years of age and 24% under 40 found it taxing. This would favour selection for accident and emergency work on the basis of functional capacity rather than chronological age. Accident and emergency work consisted of long periods of inactivity interspersed with shorter periods of relatively intense activity, often above the anaerobic threshold. Lactate concentrations measured during a staged emergency incident also suggested that personnel may work at intensities exceeding their anaerobic threshold. The incorporation of physical fitness standards in the ambulance service may be appropriate and consideration should be given to a reduced age of retirement.     

Recent improvements in the UNO BP monitor/conditioner

A number of modifications and improvements have been made in the UNO system for monitoring and conditioning blood pressure, which have increased its accuracy and versatility. The purpose of this report, therefore, is to enumerate and describe the major changes in the present generation of the system.     

Specificity and sensitivity of random amplified polymorphic DNA analysis for the identification of single larvae of Trichinella after experimental infection of pigs

Single muscle larvae (ML) of Trichinella belonging to 5 species and 2 genotypes collected from 126 experimentally infected pigs and preserved in 75% ethyl alcohol at room temperature were identified by random amplified polymorphic DNA (RAPD) analysis to evaluate the specificity and sensitivity of this assay. A double-blind protocol was used to ensure that the interpretation of electrophoretic patterns after RAPD amplification was not influenced by an expected result. RAPD analysis of one larva from each sample showed a sensitivity of 100% when only samples with undamaged DNA were considered, and the specificity resulted in an 88% match with the species or genotype that had been used to infect pigs, whereas the identification reached 100% specificity when an additional one to four ML were examined. Received: 30 September 1998 / Accepted: 21 December 1998     

Chain saw injury of the mandibulofacial region.

Use of chain saws is hazardous. Public understanding of the hazards and of modern types of chain saws will eventually help in preventing these injuries. An injury of the mandibulofacial region resulting from a chain saw has been described with special emphasis on preoperative, intraoperative, and postoperative management.     

Arthropathy of the ankle in hemophilia

Seventy-five patients who had hemophilia were followed clinically and roentgenographically to assess the prevalence of hemarthrosis and the prevalence and severity of arthropathy of the ankle. The mean age of the patients at the time of follow-up was twenty-two years and seven months. The patients were divided into four age-groups: less than ten years (eleven patients), ten to nineteen years (twenty-one patients), twenty to thirty years (twenty-four patients), and more than thirty years (nineteen patients). Intra-articular bleeding occurred more frequently in the joints of the lower extremities than in the joints of the upper extremities. During the second decade of life, hemarthroses occurred more often in the ankle than in the knee. A history of recurrent bleeding into the ankle joint, chronic synovitis, and overgrowth of the medial portion of the distal tibial epiphysis was associated with an early onset of arthropathy. In older patients, compression arthrodesis of the ankle joint was helpful in eliminating pain, recurrent bleeding, and equinus deformity.