Prevalence changes in modifiable cardiovascular disease risk factors in three Missouri regions, 1990-1996

OBJECTIVES

To determine the prevalence and prevalence trend of modifiable cardiovascular disease (CVD) risk factors among African Americans and whites/others from 1990-1996. We also examined differential changes between African Americans and whites/others during the same time period.

METHODS

This study used data from two special Behavioral Risk Factor Surveillance System (BRFSS) based surveys in 1990 (N = 3,000+) and one in 1996 (N = 2,095) that targeted two metropolitan and one rural region in Missouri with substantial minority populations. Risk factors included physical inactivity, obesity, hypertension, unmonitored cholesterol and smoking. The percent change in prevalence estimates and corresponding confidence intervals between survey years were calculated for each of the above risk factors.

RESULTS

When compared with Missouri BRFSS data, overall prevalence of smoking, obesity, hypertension and unmonitored cholesterol was higher in the three-region study population than the state as a whole. African-American males did not experience any statistically significant reductions in CVD risk factor prevalence rates between 1990 and 1996, while the increase in obesity was driven mostly by the African-American female subgroup. The least amount of reduction in CVD risk factors was seen in individuals aged 55 or older, with a high school education or less and/or without health insurance.

CONCLUSIONS

Individuals of African-American ethnicity, aged 55 or older, with a high school education or less and/or without health insurance need to be the focus of future public health initiatives designed to reduce the prevalence of CVD risk factors.

Transthoracic Doppler echocardiography of normally originating coronary arteries in children

Transthoracic Doppler color flow and spectral velocity patterns of normal coronary arteries in children have not been well studied. We designed this study to evaluate coronary artery flow velocity characteristics in normal and hypertrophied hearts. Sixty-eight children with optimal two-dimensional echocardiographic images of the left coronary artery (LCA) and right coronary artery (RCA) were prospectively studied. The heart was normal in 45 children, and 23 had left and/or right ventricular hypertrophy assessed by echocardiography (mean age 5.8 versus 5.2 years, p = NS). Color flow signals were detected in the LCA in 63(92%) of the 68 children studied, and pulsed Doppler spectral waveforms were recorded in 47 (69%). The latter were recorded in 26 (58%) of 45 normal children and in 21 (91%) of 23 children with left ventricular hypertrophy. Diastolic RCA flow signals were detected mostly in those with right ventricular hypertrophy (10 of 10). Higher levels of LCA maximum diastolic velocity (42 +/- 23 versus 24 +/- 6 cm/sec, p = 0.0004), increased diastolic flow (16 +/- 15 versus 6 +/- 4 ml/min, p = 0.01), and delayed time to peak diastolic velocity expressed as a percentage of diastolic spectral duration (38% +/- 14% versus 20% +/- 8%, p = 0.0001) were observed in children with left ventricular hypertrophy than in those in normal children. A strong correlation was present between Doppler-derived LCA flow and left ventricular mass/m2 (r = 0.7, p = 0.001). In normal hearts, LCA spectral velocity pattern did not change with increasing age, but the time velocity integral became progressively larger, resulting in a strong correlation with weight (p < 0.001, r = 0.78). This study demonstrates (1) LCA flow signals can be detected and quantitated in the majority of children with and those without left ventricular hypertrophy. (2) Left ventricular hypertrophy is associated with increased LCA flow, higher diastolic velocity, and delayed peak diastolic velocity. (3) RCA flow signals are mostly detected when there is right ventricular hypertrophy. Studies on larger groups of patients are needed to further confirm our observations and to enhance understanding of coronary artery flow reserve.

Relation of biophysical response of coarcted aortic segment to balloon dilatation with development of recoarctation following balloon angioplasty of native coarctation

OBJECTIVE

To evaluate the role of biophysical response of the coarcted segment to balloon dilatation in the causation of aortic recoarctation.

SETTING

Tertiary care centre/university hospital.

DESIGN

Retrospective case series.

METHODS

Records of 67 consecutive infants and children undergoing balloon angioplasty of native aortic coarctations were examined for an 8.7 year period ending September 1993. At 12 months (median) follow up catheterisation, 15 (25%) of 59 children developed recoarctation, defined as a gradient > 20 mm Hg. Stretch (balloon circumference--preballoon coarcted segment circumference/preballoon coarcted segment circumference), gain (postballoon coarcted segment circumference--preballoon coarcted segment circumference), and recoil (balloon circumference--postballoon coarcted segment circumference) were calculated from measurements obtained from cineangiograms performed before and immediately after balloon dilatation.

RESULTS

The stretch in 44 children without recoarctation (2.18 (1.23)) was similar (p > 0.1) to that in 15 children with recoarctation (1.90 (0.65)), implying that similar balloon dilating stretch was applied in both groups. Greater gain (p < 0.05) was observed in the group without recoarctation (8.8 (8.0) mm) than in the recoarctation group (5.7 (2.7) mm) but this was not substantiated in the infant population. However, the recoil was greater (p < 0.001) in the group without recoarctation (5.1 (4.3) mm) than in the recoarctation group (2.1 (1.1) mm); this was also true in the infant group.

CONCLUSIONS

Greater recoil in the patients without recoarctation implies preservation of intact elastic tissue in the coarcted segment. In the recoarctation group, with less recoil, the elastic properties may not have been preserved, thereby causing recoarctation. There might be a more severe degree of cystic medial necrosis in the recoarctation group than in the no recoarctation group. This needs confirmation in future studies.

Genetic and environmental contributions to smoking

We estimate the magnitude of genetic and shared environmental contributions to risk of initiation and maintenance of smoking. Genetic models were fitted to data from 2,204 male-male monozygotic and 1,793 male-male dizygotic twin pairs from the Vietnam Era Twin Registry who responded to smoking questions on a 1987 mail and telephone survey. The best fitting model allowed for both genetic and shared environmental effects on smoking initiation, accounting for 50% and 30% of the variance in risk, but allowed for only genetic effects, (accounting for 70% of the variance in risk), on persistence in smoking among those who had become regular smokers. This finding of a major genetic influence on smoking persistence confirms similar results from studies in Scandinavia and Australia. The role of heritable traits such as nicotine sensitivity should be addressed in smoking prevention and cessation efforts.

Neurodevelopmental precursors to learning disabilities: a preliminary report from a parent survey

This study documented the number and type of neurodevelopmental problems reported by parents of children with and without learning disabilities (LD), and examined whether a pattern of problems could be identified. One hundred parents, 50 for each group, responded to a retrospective developmental survey. Their children were between 9 and 13 years of age and had a history of either typical academic achievement or classification of a learning disability. Results indicated that the children with learning disabilities were reported to have significantly more neurodevelopmental problems or delays across domains (e.g., language, motor, attention, social behavior) than normal achievers. The study showed that a sizeable portion, although not all, of the children with LD had a history of neurodevelopmental problems. Despite findings that suggest that some difficulties more commonly co-occurred than others, a pattern of neurodevelopmental difficulties was not observed in these children. However, some specific difficulties, such as with following multistep directions, printing letters of the alphabet, and understanding directions (e.g., up, down, right, left), seemed to most typify the students with learning disabilities.

Leukocytosis: a new look at an old marker for acute myocardial infarction

OBJECTIVE

To determine the test performance of leukocytosis for identifying acute myocardial infarction (AMI) in patients with nondiagnostic ECGs, admitted to rule out AMI.

METHODS

A retrospective, comparative test performance study was conducted using patients admitted to a university teaching hospital to rule out AMI. Clinical and laboratory information was reviewed and hospital laboratory ranges were used to define threshold elevations: total creatine kinase (CK), 275 U/L; CK-MB, 7.5 micrograms/L ; white blood cell (WBC) count, 11.5 x 10(9)/L; and absolute neutrophil count (ANC), 8.0 x 10(9). Sensitivity, specificity, and predictive values of the total CK, CK-MB, WBC count, and ANC were calculated, and receiver operating characteristic (ROC) curves constructed. Test performances of marker combinations also were determined.

RESULTS

The initial WBC count was significantly higher for the subjects who had AMI (11.1 vs 8.8 x 10(9)/L, p < 0.001). For the 688 subjects who had nondiagnostic ECGs, sensitivities for the initial total CK, CK-MB, WBC, and ANC were 39%, 73%, 35%, and 36%, respectively, while the corresponding specificities were 94%, 93%, 85%, and 86%. Logistic regression analysis confirmed leukocytosis as an independent predictor of AMI (adjusted odds ratio 4.08, 95% CI 1.73-9.63). While CK-MB alone was 73% sensitive for AMI, the decision rule of either an elevated CK-MB or an elevated WBC count increased this sensitivity to 88% (corresponding specificity 79%). Similarly, while CK-MB alone was 93% specific for AMI, the combination of an elevated CK-MB and an elevated WBC count increased this specificity to 99% (corresponding sensitivity 20%).

CONCLUSIONS

Leukocytosis is significantly associated with AMI, and is a weak but independent laboratory predictor of this condition. In this preliminary study of admitted patients suspected of AMI, the combination of the WBC and the CK-MB may have additional diagnostic value over an isolated CK-MB result. Neither parameter in isolation was satisfactorily sensitive for AMI. Prognostic assessment of the role of the WBC count in clinical decision making should address its complementary role to that of other clinical and ancillary test parameters.

Phonologic and semantic processing in reading-disabled and nondisabled males at two age levels

The purpose of the following study was to replicate the confusability paradigm of Byrne and Shea (1979) by examining phonologic and semantic performances of good and poor readers. This study added an older age group and a phonological awareness task to examine other aspects of phonological processing across age. The confusability tasks included a pseudoword recognition task with only phonological information available for coding and a word recognition task with both phonetic and semantic information available for coding. Forty poor readers and 40 good readers were divided into two separate age groups (8-10 years, 14-16 years). Rhyming, semantic, control, and general errors were recorded. On the pseudoword task poor readers' rhyming versus control errors increased whereas good readers' rhyming versus control errors decreased with age. On the word task poor readers made more errors on semantic than rhyming trials while good readers made more rhyming than semantic errors. Poor readers made significantly more errors on the phonological awareness task than good readers. The combined results suggest, as did Byrne and Shea, that poor readers have a weak-functioning phonological system which they rely upon less when semantic information is available for coding.

Social theory and medicine

Three sociolgists-Talcott Parson, Eliot Freidson, and Mechanic-have explained medical phneomena within a broader theoretical framework. Although all three have made significant contributions, their conclusions remain incomplete on the theoretical level and seldom have been helpful for workers concerned with ongoing problems of health care. Our purpose here is to summarize some of the strengths and weakness of each theoretical position. Parsons has elucidated the sick role as a deviant role in society, the function of physicians as agents of social control, and the normative patterns governing the doctor-patient relationship. The principal problems in Parsons' analysis center on an uncritical acceptance of physicians' social control functions, his inattention tot the ways in which physicians' behavior may inhibit change in society, and overoptimism about the medical profession's ability to regulate itself and to prevent the exploitation of patients. Viewing medical phenomena within a broader theory of the professions in general, Freidson has formulated w wide ranging critique of the medical profession and professional dominance. On the other hand, Freidson's work neglects the full political implications of bringing professional autonomy under control. Mechanic's coceptual approach emphasizes the social psychologic factors, rather than the institutional conditions, which are involved in the genesis of illness behavior. Mechanic also overlooks the ways in which illness behavior, by permitting a controllable from of deviance, fosters institutional stability. In conclusion, we present a breif overview of a theoretical framework whose general orientation is that of Marixian analysis. Several themes recur in this framework: illness as a source of exploitation, the sick role as a conservative mechanism fostering social stability, stratification in medicine, and the imperialsm of large medical institutions and health-related industries.