C-Reactive Protein Levels at the Extremes
Levels of high sensitivity C-reactive protein at both ends of the spectrum provide important prognostic information about cardiovascular risk, said researchers from Harvard Medical School in this week’s issue of the journal Circulation(Circulation. 2004;109;1955–1959).
Although high-sensitivity C-reactive protein is a known independent risk factor for cardiovascular events, patients with levels below 1 mg/L are considered to be at low risk, whereas those with levels between 1 and 3 mg/L are at considered to be at moderate risk and those with levels over 3 mg/L are considered to be high risk. These researchers, however, were concerned about what happened when the levels fell below 0.5 mg/L or went above 10 mg/L.
They obtained the baseline levels of high sensitivity C-reactive protein in 27 939 apparently healthy women and followed them for myocardial infarction, stroke, coronary revascularization, or death from cardiovascular causes. The relative risks of these events were calculated across the different risk levels. The researchers, led by Paul M Ridker, MD, MPH, of Harvard found that the risks increased as the levels of high sensitivity C-reactive protein went up. For example, when the C-reactive protein level was less than 0.5 mg/L, the relative risk was 1. If it was between 2 and 3 mg/L, the relative risk was 3.5, and at levels above 20 mg/L, the relative risk was 7.6.
When adjusted for Framingham Risk Score, the risks went down. For example, when the levels were over 20 mg/L, the relative risk was 3.1. The researchers noted that their findings provide important information about the need to use high sensitivity C-reactive protein measurements.
Diet Plus Exercise Can Reverse Obesity-Related Vascular Dysfunction in Children
Diet plus exercise, continued at least a year, reduced the waist-to-hip ratio and cholesterol levels in children, as well as improving arterial endothelial function, said researchers in a report in this week’s issue of the journal Circulation(Circulation. 2004;109;1981–1986).
Such studies are critical in the face of growing rates of obesity worldwide, said the scientists from Prince of Wales Hospital, The Chinese University of Hong Kong, and the Royal Prince Alfred Hospital, University of Sydney, Sydney, Australia. The researchers, led by Kam S. Woo, MD, of Prince of Wales Hospital, randomly assigned 82 overweight children to dietary modification only or diet plus a supervised structured exercise program for 6 weeks and then a year. After 6 weeks, the children in both groups experienced decreased waist-to-hip ratios and lowered cholesterol levels. However, those in the diet plus exercise group had a significantly greater improvement in endothelial function than those in the diet only group. After 1 year, the group that continued exercise experienced significantly less thickening of the carotid wall, as well as lower body fat content and healthier lipid profiles.
The researchers wrote, “. . .[I]mproving obesity-related arterial dysfunction in children by diet and exercise should be regarded as an important strategy for modifying vascular risk in this population.”
High-Dose Epinephrine of No Benefit in In-Hospital Pediatric Cardiac Arrest
High-dose epinephrine proved of no benefit as rescue therapy for children whose hearts had stopped in the hospital and who had already received a standard dose of epinephrine, said researchers in the April 22, 2004, issue of The New England Journal of Medicine (N Engl J Med. 2004;350:1722–1730OpenUrlCrossRefPubMed).
This international group of researchers led by Maria Beatriz M. Perondi, MD, of the University of São Paulo School of Medicine in Brazil, enrolled 68 children in a study in which the youngsters were randomly assigned to receive high-dose epinephrine from 0.1 mg per kilogram of body weight to a standard dose treatment of 0.01 mg/ kilogram of body weight. They found a lower rate of survival at 24 hours for the children who received the high dose of epinephrine when compared to those who received the standard dose. The survival rate was low in each group: 1 of 34 in the high dose group and 7 of 34 in the standard dose group. None of the children in the high dose group survived to hospital discharge, whereas 4 of those in the standard dose group did.
“The results of this study suggest that high-dose epinephrine rescue therapy in children with in-hospital cardiac arrest does not improve the rate of survival at 24 hours. Among children with asphyxia-precipitated cardiac arrest, high-dose epinephrine appears to be harmful,” the authors wrote.