National trends in the management of cardiovascular disease risk factors in children: second NHLBI survey of primary care physicians.

BACKGROUND: The evidence that atherosclerosis begins during adolescence has led to the belief that primary prevention of cardiovascular disease (CHD) should commence in childhood. Although several national guidelines have been issued for the detection and treatment of CHD risk factors in children, concerns continue to be expressed regarding what constitutes appropriate measures and when to institute such measures in children. A 1988 national survey of primary care physicians revealed variation in the management of CHD risk factors in children by physician categories, which suggested the underlying quandary among physicians regarding CHD risk factors in children. OBJECTIVE: To assess current clinical management of pediatric CHD risk factors in the primary care setting and also to evaluate time trends between the current and 1988 surveys. METHODS: A 25-minute telephone survey was conducted with 1036 of eligible physicians (ie, >20 hours per week direct patient care including at least five pediatric patient contacts) selected from a national probability sample in three practice categories (family practitioners, pediatricians, and general practitioners). The questionnaire assessed the current practice of these physicians in the primary care setting regarding cholesterol and blood pressure (BP) screening and treatment, both nonpharmacologic and pharmacologic, and physician attitude and knowledge. RESULTS: Cholesterol screening in children was performed by 75.7% of all physicians. Nonscreening was highest among general practitioners (38%) and lowest among pediatricians (12%). BP was measured by almost all physicians. The majority of physicians (71%) prescribed diet as the first cholesterol-lowering step, but approximately 16% also used pharmacologic therapy. Cholesterol synthesis inhibitors and bile acid sequestrants were the drugs used most commonly. Approximately 25% of physicians have used drugs in children to treat high BP. Diuretics and beta-blockers were used most frequently. More than one fourth of the physicians had some concern about identifying and treating children for CHD risk factors. There was slightly less cholesterol measurement in 1995 compared with 1988, and no notable increase in the knowledge regarding major CHD risk factors. CONCLUSION: The results of the second National Heart, Lung, and Blood Institute survey of primary care physicians suggest that additional inroads need to be made in the dissemination of the national guidelines for the management of CHD risk factors in children, including appropriate use of pharmacologic agents.

Self-esteem and adiposity in black and white girls: the NHLBI Growth and Health Study.

PURPOSE: Obesity is assumed to have a negative impact on self-esteem because of the associated social stigmatization in Western society. Studies of the psychological effect of obesity in children are inconclusive and limited, particularly pertaining to minority populations. Most studies have assessed global rather than domain-specific measures of self-esteem and hence, may have lacked specificity to detect impairment of certain aspects of self-esteem most closely associated with obesity. The purpose of this study is to examine the effect of adiposity and other environmental factors on measures of perceived competence and self-adequacy in 2205 black and white girls aged 9-10 years. METHODS: Domain-specific measures of self-esteem were studied by race and degree of adiposity, using Harter's "Self-Perception Profile for Children". Three Harter scales deemed more relevant to obesity (social acceptance (SA), physical appearance (PA), and global self-worth (GSW)) were selected for univariate and multivariate linear regression models to examine relationships between self-esteem level and adiposity (measured by the sum of triceps, subscapular, and suprailiac skinfolds (SSF)), race, pubertal maturation, and parental education. The relationship between adiposity and Harter scores was further examined with LOESS curves and also by comparing the mean scores of each quintile of SSF by race, as well as inter-quintile differences within race. RESULTS: Adiposity in general impacted negatively on the scores of all three selected Harter scales. There was also racial variation in the relationship between the scores and adiposity, with the magnitude of the effect somewhat less in black girls. White girls exhibited a significant inverse relationship between SSF and SA scores while, in striking contrast, there was no variation in scores in black girls across all ranges of adiposity. Although there was a significant inverse relationship between adiposity and PA and GSW in both groups, the slope was steeper in white girls, particularly at higher ranges of SSF. Non-linearity in the relationship between SSF and the scores was seen in SA and PA scales. CONCLUSIONS: The present study demonstrated a significant negative association between adiposity and the level of self-esteem in girls as young as 9 to 10 years. There were also intriguing racial differences in the selected domains of esteem. These results may help better understand cultural differences regarding the psychological impact of obesity and could be used to formulate appropriate strategies for public health policy.

Differential classification of blood pressure by fourth and fifth Korotkoff phases in school-aged girls. The National Heart, Lung, and Blood Institute Growth and Health Study.

The use of the onset of the fourth (K4) or fifth (K5) Korotkoff phase to determine diastolic blood pressure in children has been controversial; most recently, the Second Task Force recommended the use of K4 for children up to age 13 years and K5 for children age 13 and above. We performed a cross-sectional analysis of 1,155 nine-year old (53% white and 47% black) and 1,224 ten-year old girls (45% white and 55% black) in the National Heart, Lung, and Blood Institute Growth and Health Study (NGHS). The mean blood pressures for the first, fourth, and fifth Korotkoff phases were 100.1 (+/- 8.9) mm Hg, 66.6 (+/- 9.8) mm Hg, and 56.8 (+/- 11.8) mm Hg for nine-year-olds and 102.8 (+/- 9.0) mm Hg, 68.1 (+/- 10.1) mm Hg, and 58.1 (+/- 11.9) mm Hg for ten-year-olds. The mean difference between K4 and K5 was 9.9 (+/- 6.4) mm Hg. The correlation between K1 and K4 was 0.45, between K1 and K5 was 0.34, and between K4 and K5 was 0.84. Elevation of blood pressure was defined at or above the 95th percentile based on the NGHS distribution for K1, K4, or K5; the relative risk of having an elevated K1 was 10.1 if K4 was elevated and 5.9 if K5 was elevated. Of the 159 subjects potentially classified with elevated diastolic pressure, 95 subjects (60%) would be classified differently depending on whether K4 or K5 was used to define elevated diastolic blood pressure. The choice of the onset of the fourth or fifth Korotkoff phase for determining diastolic blood pressure in children may have important implications for which individuals are classified as having hypertension.

Host cell-derived complement control proteins CD55 and CD59 are incorporated into the virions of two unrelated enveloped viruses. Human T cell leukemia/lymphoma virus type I (HTLV-I) and human cytomegalovirus (HCMV).

The current study was undertaken to determine whether the human T cell leukemia/lymphoma oncovirus type I (HTLV-I) and the herpesvirus human cytomegalovirus (HCM) incorporate host cell-derived C regulatory proteins. Our experiments showed that both CD59 and CD55 were associated with the external membrane of HTLV-I derived from MT2 cells, since virus could be captured by mAbs to these proteins, and antisera to CD55 and CD59 induced C-mediated lysis of HTLV-I virions. Additionally, both CD55 and CD59 were detected by immunoblot analysis of purified HTLV-I. Purified HCMV produced in human foreskin fibroblasts (HFF) also contained both CD55 and CD59, as detected by immunoblot analysis. However, treatment with anti-CD55, but not anti-CD59, reduced the HCMV infectious titer in the presence of C. Additional studies determined whether HTLV-I-associated CD55 and CD59 participated in the resistance of the virus to C-mediated lysis. Treatment of virus with phosphatidylinositol-specific phospholipase C (PI-PLC), which removes glycosylphosphatidylinositol-anchored CD55 and CD59, increased the sensitivity of HTLV-I to C-mediated destruction in the presence of anti-HTLV-I Abs. Reconstitution of PI-PLC-treated virus with purified CD55 and CD59 restored resistance to C. These experiments show that HTLV-I and HCMV acquire C control proteins from host cells. Together with our previous experiments showing that both CD55 and CD59 are present on HIV-1, these studies demonstrate a mechanism by which a variety of enveloped viruses may acquire resistance to C-mediated destruction.

Primary care physicians and children's blood cholesterol.

BACKGROUND. In a national survey sponsored by the National Heart, Lung, and Blood Institute, 62% of primary care physicians of children (under age 18 years) believed that high levels of low-density lipoprotein cholesterol in childhood had a great effect on subsequent heart disease risk. RESULTS. About 75% believed high blood pressure, smoking, and diabetes had similar effects. Although routine cholesterol screening in children under age 10 was infrequent, 72% of physicians screened high risk children. The age at which screening was done varied markedly; more pediatricians screened children younger than 5 years. The majority of physicians who saw children with high blood cholesterol instituted nondrug therapy, with pediatricians being most apt to do so. Low saturated fat diets were prescribed by 26% of these physicians and 9% of physicians prescribed increased polyunsaturated diets. Twelve percent of physicians treating hypercholesterolemic children used lipid-lowering drugs. Among those using drugs, 9% based drug use on total blood cholesterol measurements only. Factors that affected physician treatment of childhood hypercholesterolemia included physician specialty type, organization of practice (group or solo), and the age distribution of the pediatric patient population.

Cholesterol and heart disease in older persons and women. Review of an NHLBI workshop.

The value of serum total cholesterol measurement in predicting coronary heart disease (CHD) is well established in middle-aged men, but has been questioned in middle-aged women and older people of both sexes. To address this, the most recent follow-up data from 25 populations in 22 US and international cohort studies were presented and analyzed at a recent National Heart, Lung, and Blood Institute (NHLBI) workshop. Crude relative and absolute excess risks of fatal CHD were determined for individual studies and pooled across studies to determine pooled risk estimates. Serum total cholesterol and low-density-lipoprotein (LDL) cholesterol levels predicted fatal CHD in middle-aged (< 65 years) and older (> or = 65 years) men and women, though the strength and consistency of these relationships in older women were diminished. High-density-lipoprotein (HDL) cholesterol levels inversely predicted CHD in middle-aged men and women and in older women, but not in older men. Data for minority groups and for overseas populations were similar to those for white people in the United States. Relative risk estimates were generally lower for older than for middle-aged subjects, but absolute excess risk was greater. Older people and middle-aged women with elevated cholesterol levels are clearly at increased risk of coronary disease; whether this risk can be modified by dietary or drug therapy, and at what level intervention is appropriate, must not be determined.

Management of cardiovascular disease risk factors in children. A national survey of primary care physicians.

A national survey of family physicians, general practitioners, and pediatricians revealed substantial physician differences in managing cardiovascular disease risk factors in children aged 2 to 18 years. Pediatricians tended to screen younger children but were more conservative in treatment. General practitioners tended to screen less and to initiate intervention in older children, but were more aggressive in therapy. While only 9% of surveyed physicians measured blood cholesterol levels routinely, 72% screened children with family histories of cardiovascular disease. The majority routinely measured blood pressure, but the ages of first measurements differed among physicians. Surprisingly, of those who had treated children with elevated blood pressure or blood cholesterol, 54% said that they had ever used antihypertensive and 12% used lipid-lowering drugs in children, including angiotensin converting enzyme inhibitors and clofibrate. Half the surveyed physicians felt prepared to provide dietary counseling, but only 14% felt successful with it. When asked what they considered were the major cardiovascular risk factors, less than one third of the physicians cited all three major factors: hypertension, hypercholesterolemia, and smoking.

Termination of clinical trials: the beta-blocker heart attack trial and the hypertension detection and follow-up program experience.

The close-out of clinical trials that end ahead of schedule often involves problems that differ from those of trials that end as planned. The Beta-Blocker Heart Attack Trial (BHAT), a double-blind study of 3837 post-myocardial infarction patients, was a multicenter clinical trial that ended early because therapeutic benefit had been demonstrated. The Hypertension Detection and Follow-up Program (HDFP), a randomized unblinded study of 10,940 hypertensive individuals, was a multicenter trial that ended as planned. Using these trials as illustrations, the issues arising in multicenter trials that end ahead of schedule are contrasted to those that arise in trials that end as scheduled. Close-out activities that are discussed include documentation of close-out procedures, release of trial information, preparation of trial participants and staff, ascertaining vital status, continuing patient care, data collection and coding, and publication of trial results. Because of the possibility a study might end early, advance planning for close-out is essential.

Serum cholesterol and cancer in the Hypertension Detection and Follow-up Program.

The relation between serum cholesterol and cancer incidence was investigated in the population of the Hypertension Detection and Follow-up Program. During the 5 years of follow-up, 286 new cancer cases were documented among the 10,940 participants. Overall, age-adjusted cancer incidence rates, computed by baseline serum cholesterol quartiles, showed a small, but statistically significant, inverse relation between serum cholesterol and cancer incidence. No evidence suggested that the observed relationship was primarily due to confounding by other cancer risk factors, association of low serum cholesterol with incipient but undiagnosed cancer, or problems of competing risks. However, the relationship is weak and a causal interpretation of these immediate results cannot be argued persuasively. Examinations of specific cancer sites and factors related to serum cholesterol are suggested as important lines of research toward clarification of the complex relationships observed.