Data from the 1970s first suggested that vitamin E may be effective in decreasing mortality from cardiovascular disease. As the understanding of the antioxidant effect of this vitamin evolved, researchers began to further study the biologic effects of vitamin E. In vitro studies have shown vitamin E to have several potentially cardioprotective effects, including antagonizing the oxidation of low-density lipoproteins, inhibiting platelet aggregation and adhesion, preventing smooth muscle proliferation, and preserving normal coronary dilation. Several prospective studies, including the US Nurses' Health Study and the US Health Professionals' Follow-up Study, found a 34% and 39% reduction, respectively, in the risk of having a cardiac event for those taking vitamin E supplements. The Iowa Women's Health Study found a 47% reduction in cardiac mortality. Results of randomized, controlled clinical trials have not found consistent benefit, however. The best known of these trials, the Cambridge Heart Antioxidant Study, found a 47% reduction in fatal and nonfatal myocardial infarction in patients with proven coronary atherosclerosis who were given 400 or 800 IU of vitamin E daily. There was, however, no effect on mortality. While emerging and promising data suggest the potential benefit of vitamin E for high-risk cardiac patients, physicians should be alert to the results of randomized, controlled clinical trials already in progress.

Gonorrhea has been declining since its 1975 peak. Risk factors include age 15 to 19 years, multiple or casual sexual contacts, sexual activity related to drug use, and low socioeconomic status. Infection is usually mild but may be asymptomatic. While no physical signs are specific to the gonococcus, pelvic inflammatory disease is a common complication and cause of infertility and should be treated if it is suspected. Diagnosis of gonorrhea is typically by culture. Newer, more accurate tests are available but are more expensive. For treatment, the CDC recommends only highly effective regimens. Patients need to refer recent sexual partners for treatment and abstain from sexual intercourse until completion of therapy and resolution of symptoms. The incidence of syphilis appears to be declining in the United States, but it should be considered if an ulcer is found in the genital region. If untreated, the disease progresses through primary, secondary, latent, and tertiary phases, and systemic symptoms can mimic other conditions. Positive standard screening tests should be confirmed by fluorescent treponemal antibody absorption testing. Darkfield microscopy is appropriate for diagnosis of an ulcer. The treatment of choice for all phases of syphilis is a single dose of intramuscular benzathine penicillin. Other components of therapy include partner notification and patient follow-up. The spread of HIV is closely linked to STD transmission. Therefore, testing for HIV is strongly encouraged when another STD has been diagnosed.

C trachomatis infection is the most commonly reported STD in the United States, and the majority of women infected are asymptomatic. Screening is recommended for those at high risk, including women who are between 15 and 21 years of age, live in urban areas, are single, or have new or multiple sexual partners. The "gold standard" for diagnosis is chlamydial culture; however, techniques that use DNA and RNA amplification are nearly 100% sensitive and specific and may prove cost-effective. Doxycycline is a recommended first-line therapy, but certain other antibiotics may also be effective. Herpes simplex virus affects more than one third of the world's population. It is diagnosed by observation of shallow, tender ulcerations around the genitalia and by viral isolation using tissue culture. Initial treatment is with antiviral drugs, which may also be necessary episodically or as a suppressive regimen for recurrences. Patient education about prevention of these and other STDs, as well as the impact of such disease on sexual partners, is critical. Physicians should therefore become comfortable questioning and counseling patients about sexual issues and risks for STDs.