Search

It is known that in several chronic diseases, the level of physical activity on the part of the patient is inversely related to mortality; as the level of activity increases, the death rate decreases. There is no agreement, however, regarding the relationship of physical fitness, which is objectively measurable, to physical activity, which is more subjectively defined. In this study, which involved 13,344 men and women, each person was given a treadmill exercise test. Based upon treadmill performance, age, and sex, each person was assigned to one of five physical fitness categories. The people in the study were tracked for an average of more than eight years, and death rates were calculated for each fitness category. A relative risk of death factor (RR) was then computed, taking into consideration smoking, cholesterol level, blood pressure, blood sugar, and family history of heart disease. Low physical fitness was found to be an important risk factor in increasing death rates for both men and women. The results showed a strong, inverse relationship between physical fitness and death. Moderate levels of physical fitness seem to protect against early death. Two specific conditions, heart disease and cancer, showed lower death rates in the higher fitness categories. Factors which contribute to physical fitness are also discussed., We studied physical fitness and risk of all-cause and cause-specific mortality in 10 224 men and 3120 women who were given a preventive medical examination. Physical fitness was measured by a maximal treadmill exercise test. Average follow-up was slightly more than 8 years, for a total of 110 482 person-years of observation. There were 240 deaths in men and 43 deaths in women. Age-adjusted all-cause mortality rates declined across physical fitness quintiles from 64.0 per 10 000 person-years in the least-fit men to 18.6 per 10 000 person-years in the most-fit men (slope, - 4.5). Corresponding values for women were 39.5 per 10000 person-years to 8.5 per 10000 person-years (slope, -5. 5). These trends remained after statistical adjustment for age, smoking habit, cholesterol level, systolic blood pressure, fasting blood glucose level, parental history of coronary heart disease, and follow-up interval. Lower mortality rates in higher fitness categories also were seen for cardiovascular disease and cancer of combined sites. Attributable risk estimates for all-cause mortality indicated that low physical fitness was an important risk factor in both men and women. Higher levels of physical fitness appear to delay all-cause mortality primarily due to lowered rates of cardiovascular disease and cancer.

For physicians interested in studying the time course of the HIV (human immunodeficiency virus) infection from first transmission of the virus to development of AIDS, establishing a firm time-line is often difficult. Usually the actual time of infection and its source are unknown. However, for those patients infected by transfusion the time and the identity of the source is accurately established. These unfortunate victims provide the medical community with its best clinical source of information concerning the natural biology of the AIDS virus. The progress of 694 individuals who received blood from 143 donors who were later found to be infected with HIV was followed. Approximately half of the transfusion recipients were dead within one year; a similar percentage of patients in the study receiving transfusions not infected with HIV were also dead within one year. Of remaining recipients, not all could be followed; of those tested for AIDS, 85 showed no infection at the time of testing and 116 were identified as infected with HIV (19 of whom already had developed AIDS). Further studies of the patients' white blood cells and other clinical findings indicated the stage of their infection. Extrapolation of previous work and data from these patients allows an estimate that approximately one half of these infected recipients will develop AIDS within seven years of the time of their transfusion. Donors were grouped into two classes, those who developed AIDS within 29 months of the time of donation (early), and those who developed AIDS after that time (late). Recipients of blood from the early group of donors were more likely to have AIDS four years after transfusion.

This study examines the effect of age among patients hospitalized for severe heart attack, or acute myocardial infarction (MI) in the Worcester, Massachusetts area. The correspondence between age and the number of incidents of first MI was examined, as well as between age and survival, both in the hospital and long-term. Among discharged survivors, advanced age related to poorer long-term survival over a follow-up period lasting five years. Those patients older than 75 were more than twice as likely to die within five years of discharge as those patients aged less than 55 years. This study reinforces the need for the reduction of heart attack risk factors in both young and older individuals, and the importance of focused therapeutic efforts to repair the damaged hearts of elderly patients hospitalized with acute MI.

ABSTRACT: To evaluate the association between ectopic pregnancy and 22 potential risk factors, we conducted a population-based case-control study. The investigation included 274 cases diagnosed from 1935 through 1982 in residents of Rochester, Minn, and 548 matched controls selected from live-birth deliveries. Risk factor information documented prior to the last index menstrual period was obtained via medical record abstract. Univariate matched analyses revealed nine variables associated with a significantly elevated relative risk of ectopic pregnancy. Following conditional logistic regression, four variables remained as strong and independent risk factors for ectopic pregnancy: current intrauterine device use (relative risk, 13.7; 95% confidence interval, 1.6 to 120.6), a history of infertility (relative risk, 2.6; 95% confidence interval, 1.6 to 4.2), a history of pelvic inflammatory disease (relative risk, 3.3; 95% confidence interval, 1.6 to 6.6), and prior tubal surgery (relative risk, 4.5; 95% confidence interval, 1.5 to 13.9). Theoretically, any condition that prevents or retards migration of the fertilized ovum to the uterus could predispose a woman to ectopic gestation. Further research is needed to clarify the impact of other potential risk factors in the etiology of ectopic pregnancy.

The authors examined the relation between serum cholesterol level and the risk of death from stroke during a six-year period in 350,977 men aged 35-57, who had no history of heart attack and were not being treated for diabetes. Using a statistical method which eliminated differences of age, cigarette smoking, (diastolic) blood pressure, race or ethnic group, the study finds that the risk of death from stroke was three times higher in men with low serum cholesterol levels. Findings indicate a positive association between cholesterol and death from other causes (nonhemorrhagic stroke). The investigation concludes that there is an inverse relation between blood cholesterol level and risk of death from stroke in middle-aged American men, but that its public health impact is overwhelmed by greater risk from other causes.

Selenium is an essential mineral. Deficiency of selenium in the body may lead to cardiomyopathy, a general term for disease of the heart muscle. The relationship between selenium levels in various parts of the body and the risk of heart attack (myocardial infarction) was studied. Selenium levels were measured in the blood and in the toenails of patients who had suffered a heart attack, as well as in a group of healthy subjects (controls). The selenium content in a toenail reflects the level of selenium content in the blood up to one year prior. The healthy group had lower average levels of selenium than the patients who had suffered a heart attack. Lower levels of selenium in the toenail indicated a greater risk of heart disease. Low selenium levels detected in toenail samples suggest that the patients had selenium deficiency in the blood before the heart attack., ABSTRACT: To study the association between selenium status and the risk of myocardial infarction, we compared plasma, erythrocyte, and toenail selenium levels and the activity of erythrocyte glutathione peroxidase among 84 patients with acute myocardial infarction and 84 population controls. Mean concentrations of all selenium measurements were lower in cases than controls. The differences were statistically significant, except for the plasma selenium level. A positive trend in the risk of acute myocardial infarction from high to low toenail selenium levels was observed, which persisted after adjustment for other risk factors for myocardial infarction. In contrast, erythrocyte glutathione peroxidase activity was significantly higher in cases than controls (31.3 +/- 8.4 U/g of hemoglobin and 28.0 +/- 8.1 U/g of hemoglobin, respectively), Because the toenail elenium level reflects blood levels up to one year before sampling, these findings suggest that a low selenium status was present before the infarction and, thus, may be of etiologic relevance. The higher glutathione peroxidase activity in the cases may be interpreted as a defense against increased oxidant stress either preceding or following the acute event.

EPA launches the Integrated Risk Information System (IRIS) Pilot Program to improve the quality of its human health risk assessment database. The pilot program consists of new health risk assessments for 11 chemicals that are most likely to have serious impacts to the environment. The new toxicity values will be included in the database and will be used for developing new policy guidelines such as standards for drinking water or cleanup levels for Superfund sites. The pilot program is expected to be completed by spring 1997.

Mutations in the tumor suppressor gene p53 are common in human cancer and, in fact, can be found in about half of all cases. The location and characteristics of these [...]

Is there anything quite like the smell of a chlorinated indoor pool? That smell, a quick olfactory clue that pool water has been sanitized for swimmers, also betokens the presence [...]

Bisphenol A (BPA), an industrial chemical used in a variety of consumer products, is ubiquitous in the modern environment, with residues found in the urine of an estimated 93% of [...]

The Division of Adolescent and School Health of the CDC (Centers for Disease Control) has issued a report as part of an effort to improve the health of children and adolescents. A Call to Action, as the report is titled, enlists the aid of schools toward this goal. The National Association of State Boards of Education and the American Medical Association joined with the Division to form the National Commission on the Role of the School and the Community in Improving Adolescent Health. It is felt that the rates of illness and death among children between 1 and 24 years of age due to certain behaviors is far too high. The 'behaviors' in question are motor vehicle accidents (33 percent of illnesses and mortality in this age group), unintended injuries such as falls or drowning (15 percent), homicide (10 percent), and suicide (10 percent). Sexually transmitted diseases and unintended pregnancy are serious health problems in young people. Drug, alcohol, and tobacco use are also prevalent problems. The goals of the Commission are to identify major risks in young populations, monitor these risks, attempt interventions, and assess their effects. A Youth Risk Behavior and Surveillance System will gather data on risk behaviors among high school students. Other efforts are aimed at college students and young people who are not in school, many of whom are at risk as prostitutes or homeless people. Many risky behaviors cannot be addressed at this time, and the major focus of the Commission's efforts is against the transmission of human immunodeficiency virus (HIV, the agent associated with AIDS). Funding to reach out-of-school youth has been taken from monies allocated elsewhere. (Consumer Summary produced by Reliance Medical Information, Inc.)

As primary author and co-principal investigator of the 16 Cities Study (Jenkins et al. 1996), I was disappointed to read the article by Barnes et al. (2006). Their methodology, relying [...]