Tracking of energy and nutrient intakes from adolescence to young adulthood: the experiences of the Young Hearts Project, Northern Ireland.

OBJECTIVE: To assess tracking of energy and nutrient intakes between adolescence and young adulthood. DESIGN: Longitudinal study of a random sample of adolescents (aged 15 years at baseline). The extent of tracking of dietary intakes (assessed by diet history) was investigated using weighted kappa statistics (kappa). SETTING: Northern Ireland population survey. SUBJECTS: Adolescents who participated in the Young Hearts Project, Northern Ireland at age 15 years, and subsequently at young adulthood aged between 20 and 25 years (n=245 males, n=231 females). RESULTS: Despite overall increases in height and weight (both P<0.001), increases in body mass index in males (P<0.001) and body fatness in females (P<0.001), median reported intakes of energy (kJ kg(-1) day(-1)), carbohydrate (g day(-1)) and fat (g day(-1)) decreased (all P<0.001) over time. Expressed as nutrient densities (per MJ), diets at young adulthood were overall richer in thiamin, vitamin B6, total folate (all P<0.001), vitamin C (P<0.01) and vitamin D (P<0.05). Whereas the nutrient density of the males' diets decreased over time for calcium (P<0.05) and vitamin A (P<0.001), iron and riboflavin densities increased in the females' diet (P<0.001). Tracking of energy (MJ day(-1)) and nutrient intakes (expressed per MJ day(-1)) at the individual level was only poor to fair (all kappa<0.25), indicating substantial drift of subjects between the low, medium and high classes of intake with increasing age. CONCLUSIONS: These data suggest that individual dietary patterns exhibited at 15 years of age are unlikely to be predictive of dietary intakes at young adulthood.

Associations between daily food intake and excess adiposity in Irish adults: towards the development of food-based dietary guidelines for reducing the prevalence of overweight and obesity.

BACKGROUND: The prevalence of obesity has nearly doubled in Ireland since 1990 and over half of the population has a large waist circumference (WC). No food-based, dietary guidelines exist in Ireland for a reduction in the prevalence of body fat or obesity. OBJECTIVE: To examine the association between daily food intake and categories of body mass index and WC for the development of dietary guidelines to combat obesity. DESIGN: Cross-sectional study of a random representative sample of 1379 adults aged 18-64 years from Northern Ireland and the Republic of Ireland. MEASUREMENTS: Weight, height and WC were measured according to standard procedures. Diet was assessed using a 7-day food diary from which 28 food groups were generated and entered into logistic regression analysis. RESULTS: Higher mean daily consumption of most of the 28 food groups was associated with an increased likelihood of being classified as obese or at waist action level 2, compared to normal weight and normal WC. The strongest associations were found for savoury snacks, butter and full fat spreads. Contrary to popular opinion, not one individual food group but rather a combination of many foods was associated with excess adiposity. CONCLUSIONS: Body mass index and WC in adults are strongly influenced by the amount of food consumed. Public health policies for a reduction in body fat and obesity may be more effective if the emphasis is placed on a reduction of food and beverages consumed as opposed to the traditional dietary recommendations for macronutrients.

Social deprivation and childhood injuries in North and West Belfast.

Injuries in childhood represent a major public health concern. North and West Belfast is an area in which a high rate of emergency department attendance due to injury has been observed, and in which social deprivation is widespread. We carried out a cross sectional survey of 479 injuries in children aged 0-12 years presenting to four emergency departments serving North and West Belfast. Injury rates were compared between the most deprived and least deprived areas, selected on the basis of Noble Economic Deprivation scores. A significant correlation between economic deprivation and injury rate was demonstrated (r = 2.14, p < or = 0.001). Children living within the most deprived areas were particularly likely to be involved in road traffic accidents (relative risk RR = 3.25, p = 0.002). We conclude that children living within the most deprived areas of North and West Belfast are at greater risk of injury than those in less deprived areas. Specific causes of injury, for example burns and scalds, high falls, and motor vehicle accidents are particularly associated with deprivation. Targeting should be taken into account when injury prevention strategies are being developed.

Factors affecting influenza vaccine uptake among health care workers.

BACKGROUND: In 2000, the UK Departments of Health recommended influenza immunization to employees directly involved in patient care. Uptake of this immunization had tended to be variable and usually low. AIMS: To assess personal and organizational factors associated with influenza immunization uptake among Health Care Workers (HCWs). METHODS: A cross-sectional survey of all HCWs within the Health and Social Care Trusts in Northern Ireland and a parallel-group study of nursing staff within Elderly Care using self-administered questionnaires. RESULTS: Of 203 nurses working in elderly care units 76(37%) were immunized and 127(63%) declined. Almost 70% of those not immunized perceived themselves to be 'healthy' and gave this reason for declining immunization. Nurses were more likely to be immunized by a factor of four if they believed there was benefit for healthy HCWs, three if they felt at-risk of contracting influenza and nine on a recommendation from the occupational health (OH) unit. Fifteen OH units participated in a survey of HCWs at the time of immunization. Five thousand two hundred and thirty (9.7%) HCWs were immunized. Increased uptake was correlated with immunization in area of work (r=0.74, P=0.02) and when provided out of hours (r=0.83; P<0.001) and by a factor of two with individual targeting of availability (P<0.001) and when individuals had been previously immunized (P<0.001). CONCLUSION: Uptake of influenza immunization is low. Attitudes to one's health and to the value of influenza immunization affect the uptake as does the delivery of the immunization programme.

Ten-year trends for fatness in Northern Irish adolescents: the Young Hearts Projects--repeat cross-sectional study.

OBJECTIVE: To examine secular trends in measures of fatness over a 10-y period (the 1990s) in Northern Irish schoolchildren. DESIGN: Repeat cross-sectional surveys. SUBJECTS: In total, 12- and 15-y-old children randomly selected from post-primary schools. A total of 1015 children studied between 1989 and 1990, and 2017 studied between 1999 and 2001. MEASUREMENTS: The same study methods were applied in both surveys. Body mass index (BMI) was calculated from height and weight, and percentage body fat (%BF) was derived from skinfold measurements at four sites. Dietary intake was assessed using a diet history method and habitual physical activity (PA) was estimated from a self-report questionnaire. RESULTS: Increases were seen in both height and weight in all age-sex groups. The overall prevalence of overweight/obesity increased from 15.0 to 19.6%, but 12-y-old girls contributed most to this increase (15.9-26.3%), with a modest increase observed also in 15-y-old boys. Increases in mean BMI (19.2-20.3 kg/m2) and mean %BF (25.8-27.1%) were seen in 12-y-old girls, with no significant changes in any of the other subgroups. Mean energy intake increased in girls but not in boys, while mean PA score decreased in 12-y-old girls, but was unchanged in the other three groups. All age-sex groups showed substantial increases in the sugar intake while fat intake increased in girls and decreased in boys. CONCLUSION: Increases in indices of fatness were seen among school-age children in Northern Ireland during the 1990s. Trends differed between age-sex groups with the largest changes seen in 12-y-old girls. It remains to be seen whether the large increase in overweight/obesity in this group tracks into adulthood, with consequences for chronic disease incidence in women.

Total homocysteine is not a determinant of arterial pulse wave velocity in young healthy adults.

AIMS: Hyperhomocysteinaemia has been associated with reduced pulse wave velocity (PWV) in patients with end-stage renal disease and in those with hypertension. The aim of this study was to examine the association between total homocysteine (tHcy) concentrations, the biochemical and genetic determinants of tHcy and PWV in healthy young adults. METHODS AND RESULTS: A total of 489 subjects aged 20-25 years participated. A fasting blood sample was taken and PWV measured using a non-invasive optical method. tHcy did not correlate with PWV, whether assessed at the aorto-iliac segment (P = 0.18), the aorto-radial segment (P = 0.39) or the aorto-dorsalis-pedis segment (P = 0.22). When tHcy was classified into normal (<15) and high (> or =15micromol/l), PWV did not differ between the two groups at any segment. PWV did not differ by MTHFR C677T or NOS3 G894T genotype, even when smoking and folate sub-groups were considered. Considering aortic PWV as a dependent variable, stepwise regression analysis showed that the only parameter entering the model for all segments was systolic blood pressure (aorto-iliac, P < 0.001; aorto-radial, P = 0.01; aorto-dorsalis-pedis, P = 0.001). Age, sex, COL1A1 genotype and triglycerides entered the model significantly for two of three segments. CONCLUSION: This study shows that arterial PWV is not associated with tHcy in a healthy young population.

Unexpected decline in survival from amyotrophic lateral sclerosis/motor neurone disease.

OBJECTIVES: To describe survival of 1226 Scottish adults with amyotrophic lateral sclerosis/motor neurone disease (ALS/MND). METHODS: Ten year, prospective, population based disease register. Cox time dependent proportional hazards modelling for multivariate survival analyses. RESULTS: Median survival from onset was 25 months (interquartile range 16-34 months). In multivariate models we found an increased hazard with more recently diagnosed cases-that is, there was an unexpected decline in survival over the 10 year period (hazard ratio (HR) 1.06 (95% CI 1.04 to 1.09). Positive effects on survival were demonstrated for longer time from onset to diagnosis (HR 0.38 (95% CI 0.33 to 0.42), assessment by a neurological specialist (HR 0.56 (95% CI 0.40 to 0.77), and treatment with riluzole (HR 0.24 (95% CI 0.14 to 0.42). Poor prognosis was associated with bulbar onset (HR 1.25 (95% CI 1.09 to 1.46) and a mixed lower and upper motor neurone syndrome (HR 1.23 (95% CI 1.01-1.49) and increasing age. CONCLUSIONS: We found an unexpected decline in survival over the 10 year period, despite controlling for potential confounding variables. We would be cautious about over-interpreting these observations and suggest that further research is required to confirm or refute these findings.

The effect of nutrient intake on bone mineral status in young adults: the Northern Ireland young hearts project.

Optimizing peak bone mass in early life may reduce osteoporosis risk in later life. Such optimization may be partly dependent upon diet. In the present study, nutrient intakes and selected lifestyle parameters were assessed in adolescent subjects (238 males, 205 females; aged 15 y) and again, in the same subjects, on one occasion in young adulthood (aged between 20 and 25 y). The extent of the relationships between these parameters and bone mineral density (BMD), dual energy X-ray absorptiometry (DXA), lumbar spine (L2-L4), and femoral neck measured concurrently with diet in young adulthood only, was assessed. Adjusted linear regression models were constructed. Variables included a measure of pubertal status (at age 15 y), age (at young adulthood), height, weight, physical activity, smoking, and mean daily intakes of energy, calcium, protein, vitamin D, phosphorus, total fat, and alcohol. In both sexes, body weight at adolescence and young adulthood was the only factor consistently positively associated with BMD at both measurement sites. Effects of nutrient intake on BMD were inconsistent. Vitamin D and calcium intakes reported by female adolescents showed significant positive relationships with BMD measured in young adulthood (vitamin D measured at the lumbar spine; calcium measured at the femoral neck). The positive relationship between vitamin D and BMD remained significant at young adulthood, but at the femoral neck rather than at the lumbar spine. Also in females, intakes of phosphorus and the calcium:phosphorus ratio (Ca:P) at adolescence were strongly negatively related to femoral neck BMD measured at young adulthood. In males, however, Ca:P reported at young adulthood had a significant positive relationship with lumbar spine BMD, whereas Ca:protein was negatively associated with BMD at the lumbar spine. Intakes of Ca reported by adolescent males also had a strong negative effect on lumbar spine BMD measured at young adulthood.

Repeat heart valve surgery: risk factors for operative mortality.

BACKGROUND: Patients undergoing repeat heart valve operations are a diverse population. We assessed risk factors for operative mortality in patients undergoing a first heart valve reoperation. METHODS: A retrospective review of hospital records was performed for 671 patients who underwent first repeat heart valve operations between 1969 and 1998. Univariable and multivariable analyses were performed. RESULTS: Operative mortality was 8.6%. Mortality fell each decade to 4.8% in the most recent period (adjusted chi(2) for linear trend P <.0005). Mortality increased from 3.0% for reoperation for a failed repair or reoperation at a new valve site to 10.6% for prosthetic valve dysfunction or periprosthetic leak and to 29.4% for endocarditis or valve thrombosis. Concomitant coronary artery bypass grafting was associated with a mortality of 15.4% compared with 8.2% when it was not required. Mortality for aortic valve replacement was 6.4%, mitral valve replacement 7.4%, aortic and mitral valve replacement 11.5%, tricuspid valve replacement 25.6%, periprosthetic leak repair 9.1%, and isolated valve repair 2.2%. Among 336 patients requiring replacement of prosthetic valves, mortality was 26.1% for replacement of a mechanical valve compared with 8.6% for replacement of a tissue valve (P <.0005). Multivariable analyses identified year of reoperation, age, coronary artery bypass grafting, indication, and replacement of a mechanical valve rather than a tissue valve as significant explanatory variables for operative mortality. CONCLUSIONS: Heart valve reoperations can be performed with an acceptable operative mortality. However, we have identified several categories of patients in whom reoperation carries an increased risk.

Absence of the palmaris longus muscle: a population study.

We examined 300 Caucasian subjects (150 males, 150 females) aged 18-40 years to assess the incidence of palmaris longus absence. The presence or absence of palmaris longus was assessed by clinical inspection. Forty-nine subjects had unilateral absence of palmaris longus (16%). The tendon was absent bilaterally in 26 subjects (9%). Unilateral and bilateral absence was more common in males, however this was not statistically significant (p = 0.25 and 0.56 respectively). In those subjects with unilateral absence, the right side was found to be more commonly affected however no statistical significance was evident (p = 0.25).

Tracking of nutrient intakes in adolescence: the experiences of the Young Hearts Project, Northern Ireland.

This study evaluated the tracking of energy and nutrient intakes, assessed by diet history, in a random sample of adolescents (boys n 225, girls n 230) at baseline (age 12 years), and subsequently at age 15 years. Median energy (MJ/d) and macronutrient (g/d) intakes increased significantly (all P < 0.001) with increasing age in the boys. The girls' reported energy intake (MJ/d) remained stable over time, despite significant increases in BMI, weight and % body fat. Age-related changes in the girls' macronutrient intakes were inconsistent. When expressed in terms of nutrient density, the diets of both sexes became significantly richer, over time, in total folate (both sexes, P < 0.01), but poorer in Ca (boys P < 0.01, girls P < 0.001) and riboflavin (both sexes P < 0.001). Vitamin B6 (P < 0.001) and Fe (P < 0.05) densities increased in the boys, while the thiamin density of the girls' diets decreased (P < 0.001). Tracking, defined as maintenance of rank over time, was summarised using weighted kappa statistics (kappa). There were some significant changes in intakes at the group level; however, tracking of energy and nutrients in both sexes was only poor to fair (kappa < 0.40), indicating substantial drift of individuals between classes of intake over time. Particularly poor tracking was evident for % energy from sugars (kappa 0.09) and total fat (kappa 0.09) in the girls' diets. In conclusion, the poor to fair tracking observed in this cohort suggests that individual dietary patterns exhibited at 12 years of age are unlikely to be predictive of energy and nutrient intake at age 15 years.

Parental recall of birthweight: a good proxy for recorded birthweight?

Recent evidence suggests potential associations between birthweight and disease in later life. For resource or other reasons recorded birthweight may be unavailable to researchers who have access to uniquely relevant outcome data. The present study examined the validity of parental recall of birthweight. Parents of 1015 males and females aged 12 and 15 years participating in the Young Hearts Study (a cluster random sample of 1015 males and females aged 12 and 15 years from post-primary schools in Northern Ireland) completed a questionnaire which included a question about their child's birthweight. The answer provided was compared with recorded birthweight obtained from archived computerised child health records with a cut-off point for inaccurate reporting set at +/- 227 g (1/2 lb). The influence of social class and weight at birth on accuracy of recall was also determined. A total of 84.8% of parents accurately recalled their child's birthweight to within 227 g. Parents from non-manual occupation social classes recalled birthweight more accurately than those from manual occupation social classes (88.0 vs. 82.6% accurate: chi2 = 4.81, p = 0.03). Parents of low birthweight infants tended to recall their birthweight less accurately than parents of normal weight infants: 76.1% accurate compared to 86.1% accurate: chi2 = 3.54, p = 0.06. Parents of high birthweight infants recalled their birthweight less accurately than parents of normal weight infants: 78.5% accurate: chi2 = 3.94, p = 0.05. In conclusion, parentally recalled birthweight may be a suitable proxy for recorded birthweight for population based research into disease in childhood and adolescence.

Physical activity, sports participation, and risk factors in adolescents.

The purpose of this study was to analyze the relationships between physical activity (ACT), including sports participation (SP) and antecedent risk factors for coronary heart disease (CHD), in a representative sample of adolescents from Northern Ireland, a region of high coronary mortality. Biological and behavioral risk factors were measured in a random sample of 1015 school children aged 12 and 15 yr. ACT and SP were assessed by self-report questionnaire, and relationships with biological risk factors were analyzed with stepwise multiple linear regression after controlling for potential confounders. Results showed that in 15-yr-old males ACT was beneficially associated with systolic blood pressure (P < 0.05), lipid profile, and cardiorespiratory fitness (both P < 0.01). In 15-yr-old females, SP was associated beneficially with fatness and cardiorespiratory fitness. Odds ratios calculated from logistic regression revealed that for the older children, a relatively small drop (-20%) in ACT (boys) or SP (girls) was significantly related to the probability of exposure to multiple risk factors. Overall, relationships were stronger for males rather than females and for older rather than younger children. This study provides further evidence for beneficial associations between ACT, SP, and CHD risk status in adolescents.

Estimates of food and macronutrient intake in a random sample of Northern Ireland adolescents.

Estimates of food consumption and macronutrient intake were obtained from a randomly selected population sample (2%) of 1015 adolescents aged 12 and 15 years in Northern Ireland during the 1990/1991 school year. Dietary intake was assessed by diet history with photographic album to estimate portion size. Reported median energy intakes were 11.0 and 13.1 MJ/d for boys aged 12 and 15 years respectively and 9.2 and 9.1 MJ/d for girls of these ages. Protein, carbohydrate and total sugars intakes as a percentage of total energy varied little between the age and sex groups and were approximately 11, 49 and 20% respectively of daily total energy intakes. Median dietary fibre intakes were approximately 20 and 24 g/d for boys aged 12 and 15 years respectively and 18 and 19 g/d for girls of these ages. Major food sources of energy (as a percentage of total energy intakes) were bread and cereals (15-18%), cakes and biscuits (12-14%), chips and crisps (13-14%), dairy products (9-11%), meat and meat products (9-11%) and confectionery (9%). Fruit and vegetable intakes were low at about 2.5% and 1.5% respectively of total energy intakes. Median fat intakes were high at 39% of total daily energy intakes. Major food sources of fat as a percentage of total fat intakes were from the food groupings: chips and crisps (16-19%), meat and meat products (14-17%), fats and oils (14-16%), cakes and biscuits (13-16%) and dairy products (12-15%). Median intakes of saturated fatty acids were also high at approximately 15% of daily total energy intake while intakes of monounsaturated fatty acids averaged 12% of daily total energy intake. Median polyunsaturated fatty acid (PUFA) intakes were low, comprising 5.2 and 5.5% of daily total energy intake for boys aged 12 and 15 years respectively and were lower than the PUFA intakes (5.9 and 6.3% of daily total energy intake) for girls of these ages. About 1.3% for boys and 1.4% for girls of daily total energy intake was in the form of n-3 PUFA. Ca and Mg intakes were adequate for both sexes. Based on these results, some concern about the dietary habits and related health consequences in Northern Ireland adolescents appears justified.

Cholesterol screening and family history of vascular disease.

Hypercholesterolaemia is a major risk factor for the development of coronary heart disease (CHD). Early detection and management of hypercholesterolaemia could retard the atherosclerotic process. Given that CHD and hypercholesterolaemia cluster within families, a screening strategy based on a family history of vascular disease has been advocated. Serum total cholesterol concentrations were measured in a random stratified sample of 1012 children aged from 12-15 years old participating in a coronary risk factor surveillance study in Northern Ireland. Information about vascular disease in close family members was obtained by means of a questionnaire. The study population was divided into two groups according to total cholesterol values: (i) normal, < 5.2 mmol/l (n = 822) and (ii) raised, > or = 5.2 mmol/l (n = 190). A family history identified 63 out of 190 individuals with hypercholesterolaemia yielding a sensitivity of 33.2% and specificity of 71.5%. Our data indicated that a strategy whereby only children from high risk families are screened for hypercholesterolaemia is ineffective. While primary prevention emphasising a healthy diet for all is essential, the role of universal screening deserves further appraisal.

The health status of an ambulance service.

The purpose of the study was to evaluate the current health status of male ambulance personnel based in Belfast, taking the opportunity to compare results with those from a comparable local survey of the general population. Risk factors for coronary heart disease were assessed. Ninety-three men were studied. Blood pressure values were significantly higher (P < 0.05) in the present study than in a comparable local survey of the general population, with 23 per cent of systolic values being over 140 mmHg and 27 per cent of diastolic readings being over 90 mmHg. The incidence of self-reported smoking was also higher in the ambulance service (36 per cent) compared with the local population (31 per cent). Computation of body mass indices for ambulancemen showed that 52 per cent of personnel fell outside the acceptable range of 20-25 kg/m2 with 10 per cent being greater than 30 kg/m2, recognized as the threshold of clinical obesity. With regard to serum cholesterol, 52 per cent of personnel exceeded the desirable threshold of 5.2 mmol/l, while 18 per cent were above 6.4 mmol/l. In addition, the high density lipoprotein fraction was significantly lower (P < 0.05) in the ambulancemen compared with the general population (mean +/- SEM: 1.10 +/- 0.3 vs 1.18 +/- 0.01, respectively). Although 54 per cent of the sample claimed to be physically active, only 35 per cent reportedly took sufficient exercise to be of benefit to their health. Cardiorespiratory fitness was significantly higher in this group. The ambulance service nationally remains the only emergency service without a strategy for health and fitness.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary risk factors in Belfast schoolchildren.

Although Northern Ireland leads the world in terms of coronary heart disease mortality, the prevalence of coronary risk factors in the childhood population is largely unknown. The aims of the present study were to assess the feasibility of collecting this data and to undertake a preliminary investigation of risk factor status. One hundred and three out of 154 first year pupils (67%), mean age 12.3 years from a Belfast secondary school had their height, weight, pubertal status and blood pressure estimated. Blood samples were analysed for serum cholesterol and thiocyanate in 99 children. 31% had elevated cholesterol, 13% had raised blood pressure, 13% were overweight and 5% were identified as smokers. There appeared to be relatively high risk factor levels with at least one risk factor present in 45% of children. No difficulties arose in compliance with the test protocol suggesting that coronary profiling in children on a large-scale is feasible. On the basis of these results, we feel that coronary risk factor status in Northern Irish children needs further evaluation.

Long term health implications of fitness and physical activity patterns.

Northern Ireland has the highest incidence of coronary heart disease (CHD) in the world. The physical fitness, activity patterns, health knowledge, attitudes, and dietary habits of a random, stratified sample of 3211 Northern Irish children, comprising 1540 boys and 1671 girls, age range 11-18 years were examined. At all ages boys were significantly more active than girls. The most important finding was an appreciable decline in physical activity levels after the age of 14 years reaching extremely low levels in older girls. While 75% of exercise taken was not related to school, physical education classes constituted the only exercise taken by one third of pupils. Girls had healthier nutritional habits and were more inclined to employ weight control measures than boys. There was a preponderance of children with a higher body mass index indicating a tendency to obesity in the child population. Over 20% of school leavers of both sexes regularly smoked cigarettes and 20% regularly drank alcohol. The postulated relationship between childhood inactivity, adult sedentary lifestyle, and increased risk of CHD raises serious cause for concern regarding the future cardiovascular health of many children.

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.

Diagnosis of myocardial infarction from serum creatine kinase MB isoenzyme (CKMB) measurement.

The cardiospecific isoenzyme MB of creatine kinase (CKMB) has previously been shown to be of value in the diagnosis of myocardial infarction (MI). We studied 418 admissions to a coronary care unit (CCU) with suspected MI and calculated the sensitivity, specificity and positive and negative predictive values for several CKMB test functions. Several functions performed better than any combination of the other enzymes in common use. 97% of patients achieving a CKMB activity of at least 15 U/l did so between 6 and 30 h following the onset of symptoms. The present study confirms that the use of the CKMB isoenzyme leads to an earlier and more accurate diagnosis or exclusion of MI compared to the "cardiac enzyme series". The timing of blood sampling for CKMB estimation is also discussed.