In observational studies, individuals with elevated levels of plasma homocysteine tend to have moderately increased risk of coronary heart disease (CHD). The MTHFR 677C-->T polymorphism is a genetic alteration in an enzyme involved in folate metabolism that causes elevated homocysteine concentrations, but its relevance to risk of CHD is uncertain.

Osteoporosis causes substantial morbidity and costs $13.8 billion annually in the United States. Measurement of bone mass by densitometry is a primary part of diagnosing osteoporosis and deciding a preventive treatment course. Bone mineral densitometry has become more widely available and commonly used in practice.

The coexistence of type 2 diabetes and hypertension is especially damaging to cardiovascular health. Most trials of exercise training for these conditions have focused on glycemic control and blood pressure reduction. Less is known about the effects of exercise on the cardiovascular consequences of diabetes and hypertension. This article reviews the available evidence and plausible mechanisms by which exercise training may improve the cardiovascular health of persons with type 2 diabetes and hypertension and provides practical guidelines for exercise prescription. A MEDLINE search was performed for January 1985 to June 2002. Bibliographies from relevant articles, professional society clinical practice guidelines, and books were also reviewed. Because few large, randomized trials exist on these topics, meta-analyses, smaller trials, nonrandomized trials, and animal studies were also considered. Data quality was determined by publication in peer-reviewed journals or professional society literature. Type 2 diabetes and hypertension result in abnormalities in central and peripheral parameters of cardiovascular structure and function. Evidence for an exercise training benefit is strongest for improvements in endothelial vasodilator function and left ventricular diastolic function. The data for exercise training's improvement of arterial stiffness and system inflammation and reduction of left ventricular mass are less robust. However, this assertion is based more on a lack of randomized controlled trials rather than data to the contrary. Exercise training also reduces total and abdominal fat. These changes in body composition mediate improvements in insulin sensitivity and blood pressure and may improve endothelial vasodilator function. The current evidence, albeit not fully confirmed in randomized trials, suggests that the benefits of exercise training go beyond the recognized benefits of glycemic control and blood pressure reduction.

Hysteroscopy (direct endoscopic visualization of the endometrial cavity) is used extensively in the evaluation of common gynecologic problems, such as menorrhagia and postmenopausal bleeding. However, there is a continuing debate about the value of this technology in the diagnosis of serious endometrial disease.

Stroke is a major cause of morbidity and mortality, and the application of evidence for stroke prevention varies considerably.

Reduced sleep time is commonplace for many interns and residents. Recent studies, however, suggest that sleep loss and fatigue result in significant neurobehavioral impairments in healthy young adults. We reviewed studies addressing the effects of sleep loss on cognition, performance, and health in surgical and nonsurgical residents. We describe the effectiveness of countermeasures for sleepiness, including recent work-hour restrictions. A more complete understanding of the issues of sleep loss during residency training can inform innovative strategies to minimize the effects of sleepiness and fatigue on patient care and resident safety.

The use of antibiotics for treatment of Escherichia coli O157:H7 infection has become controversial since a recent small study found that it may increase the risk of hemolytic uremic syndrome (HUS). However, other larger studies have reported a protective effect or no association.

Although postmenopausal hormone replacement therapy (HRT) is widely used in the United States, new evidence about its benefits and harms requires reconsideration of its use for the primary prevention of chronic conditions.

Physician gender has been viewed as a possible source of variation in the interpersonal aspects of medical practice, with speculation that female physicians facilitate more open and equal exchange and a different therapeutic milieu from that of male physicians. However, studies in this area are generally based on small samples, with conflicting results.

The cognitive and behavioral outcomes of school-aged children who were born preterm have been reported extensively. Many of these studies have methodological flaws that preclude an accurate estimate of the long-term outcomes of prematurity.

Refugees experience multiple traumatic events and have significant associated health problems, but data about refugee trauma and health status are often conflicting and difficult to interpret.

beta-Blocker therapy remains substantially underused in cardiac patients despite its proven mortality benefits. Reluctance to prescribe these agents may derive from concerns about their association with symptoms of depression, fatigue, and sexual dysfunction.

New information warrants updated recommendations for the 4 central issues in antiretroviral therapy: when to start, what drugs to start with, when to change, and what to change to. These updated recommendations are intended to guide practicing physicians actively involved in human immunodeficiency virus (HIV)- and acquired immunodeficiency syndrome (AIDS)-related care.

Although vitamin deficiency is encountered infrequently in developed countries, inadequate intake of several vitamins is associated with chronic disease.

There is concern about the potential harm associated with the use of poor quality health information on the Internet. To date, there have been no systematic attempts to examine reported cases of such harm.