Alongitudinal study in healthy volunteers from a health maintenance organization in central Massachusetts confirms the presence of seasonal variation in blood lipid levels. The results suggest greater amplitude in seasonal variability in women and in individuals with hypercholesterolemia. Seasonal changes in plasma volume appear to explain a significant proportion of the variation in lipid levels. A relative plasma hypervolemia during the summer appears to be linked to increases in temperature and/or physical activity. These findings may have implications for lipid screening guidelines. The authors indicate that further research is needed to better understand the effects of a relative winter hemoconcentration.
Intravascular catheters and urinary catheters are the 2 most commonly inserted medical devices each year in the United States. Formation of a biofilm consisting of attached bacteria, their secreted polysaccharide matrix, and deposits from host bodily fluids on the surfaces of indwelling catheters are central to the pathogenesis of infection of both types of catheters. Strict attention to infection control practices is the most important factor in prevention of intravascular catheter infections, but antimicrobial-impregnated intravascular catheters are a useful adjunct. Prevention of urinary catheter-associated infections is hindered by the numbers and types of organisms present in the periurethral area as well as by the typically longer duration of catheter placement. Antimicrobial agents in general have not been effective in preventing catheter-associated urinary tract infections in persons with long-term, indwelling urethral catheters. Preventive strategies that avoid the use of antimicrobial agents may be necessary in this population.
In a long-term randomized controlled trial, Reid et al directly compare the effects of raloxifene hydrochloride and hormone therapy on bone and lipid metabolism and on adverse events. Whereas raloxifene and estrogen differ in their effects on bone metabolism only in degree (those on bone are greater), they produce quite distinct patterns of effects on circulating lipids. A potentially very important difference was found in their adverse event profiles, the development of urinary incontinence being more common in those receiving hormone therapy than in either placebo or raloxifene groups. This throws into doubt the widespread practice of using hormone therapy to manage this problem.
Dietary factors influence the risk of kidney stone formations; however, no prospective information is available in younger women. Curhan et al prospectively examined, during an 8-year period, the association between dietary factors and the risk of incident symptomatic kidney stones among 96 245 female participants in the Nurses' Health Study II who were aged 27 to 44 years and who had no history of kidney stones. The authors documented 1223 incident symptomatic kidney stones during 685 973 person-years of follow-up. After relevant risk factors were adjusted for, dietary factors that were independently associated with a reduced risk of kidney stones were dietary calcium, phytate, and fluid intake. Sucrose intake was associated with an increased risk. Sodium, potassium, and magnesium intake were not independently associated with risk. These findings indicate that a higher intake of dietary calcium decreases the risk of kidney stone formation in younger women and should not be routinely restricted. The authors also suggest that dietary phytate may be a new, important, and safe addition to options for stone prevention.
Surveys show that many Americans believe in the healing power of prayer, yet little is known about the patterns of use of prayer for health concerns. Using data from a nationally representative survey, McCaffrey et al describe respondent characteristics associated with prayer for health concerns. The authors found that prayer is used by over one third of US adults for health concerns and that users reported that prayer is helpful. While people most often used prayer in conjunction with conventional medical care, they rarely discussed prayer with their physicians. Asking patients about their use of prayer may help to identify and understand patients' beliefs and practices beyond the biomedical model.
In This Issue of Archives of Internal Medicine. Arch Intern Med. 2004;164(8):823. doi:10.1001/archinte.164.8.823