- © 2004 Canadian Medical Association or its licensors
Cognitive decline and dementia: research and review

Figure. Photo by: Wolfgang Krolow
Dementia has a profound impact on patients, their families and society in general. Hsiung and colleagues examined data from the Canadian Study of Health and Aging and found that the presence of the apolipoprotein E ε4 allele (ApoE ε4), a well-established risk factor for Alzheimer's disease (AD), was also a risk factor for conversion from “cognitive impairment no dementia” (CIND) to AD and for incident vascular dementia. However, they found no association between ApoE ε4 and conversion from normal to CIND. In a related commentary, Gauthier points out that ApoE ε4 testing will have a clinical and diagnostic value for AD only after effective prevention and treatment strategies for the disease are developed. In the meantime, as Hsiung and colleagues also conclude, information on ApoE ε4 may be useful in research to optimize patient inclusion in trials of interventions designed to delay progression to AD. Also in this issue, Garcia and Zanibbi review the evidence of an association between increased homocysteine levels and cognitive decline. They also review the potential mechanisms through which homocysteine acts on the brain to cause cognitive impairment.
Informed consent and uninsured childhood vaccines
Childhood vaccination programs have been key in reducing morbidity and mortality from common infectious diseases among children. Public funding for new varicella and meningococcal vaccines is limited, but a small study by Paterson and colleagues shows that most of the family physicians they surveyed routinely recommend the vaccines and provide verbal and written information about the vaccines and the possible consequences of refusing them. When the vaccines were not recommended, cost was cited as a factor: family physicians often know their patients' financial circumstances. Until a national immunization strategy is in place, the authors ask whether “informed refusal” forms for parents are appropriate.
See page 877
Increased fracture risk among First Nations people
Canadian First Nations people are known to have a heavy medical and social burden that may affect fracture rates. Leslie and colleagues found that First Nations people in Manitoba were at substantially increased risk for any type of fracture; the risk was almost double that of non-First Nations people for hip and spine fractures and even greater for wrist and craniofacial fractures.
See page 869
In Synopsis

Figure.
From tennis toe to black heel, Freiman and colleagues provide descriptions and management suggestions for 8 of the most common dermatoses that can result from physical exercise (see page 851). The rate of genital Chlamydia trachomatis infection has increased by more than 60% since 1997, and Weir reviews management and prevention strategies (see page 855). In Clinical Vistas, Schattner and colleagues share their surprise in discovering the actual cause of high fever in an elderly patient who had received a prosthetic aortic valve 3 weeks earlier (see page 859). Hackam reviews a study that investigated whether statin therapy should be routinely prescribed to diabetic patients for primary prevention of cardiovascular disease (see page 857).