Pain in adults with sickle cell disease is the rule rather than the exception and is far more prevalent and severe than previous large-scale studies have portrayed. It is mostly managed at home; therefore, its prevalence is probably underestimated by health care providers, resulting in misclassification, distorted communication, and undertreatment.

Objective.\p=m-\To assess whether the dietary intake of long-chain n-3 polyunsaturated fatty acids from seafood, assessed both directly and indirectly through a biomarker, is associated with a reduced risk of primary cardiac arrest.Design.\p=m-\Population-based case-control study.Setting.\p=m-\Seattle and suburban King County, Washington. Participants\p=m-\A total of 334 case patients with primary cardiac arrest, aged 25 to 74 years, attended by paramedics during 1988 to 1994 and 493 population-based control cases and controls, matched for age and sex, randomly identified from the community. All cases and controls were free of prior clinical heart disease, major comorbidity, and use of fish oil supplements.Measures of Exposure.\p=m-\Spouses of case patients and control subjects were interviewed to quantify dietary n-3 polyunsaturated fatty acid intake from seafood during the prior month and other clinical characteristics. Blood specimens from 82 cases (collected in the field) and 108 controls were analyzed to determine red blood cell membrane fatty acid composition, a biomarker of dietary n-3 polyunsaturated fatty acid intake.Results.\p=m-\Compared with no dietary intake of eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3), an intake of 5.5 g of n-3 fatty acids per month (the mean of the third quartile and the equivalent of one fatty fish meal per week) was associated with a 50% reduction in the risk of primary cardiac arrest (odds ratio [OR], 0.5; 95% confidence interval [CI], 0.4 to 0.8), after adjustment for potential confounding factors. Compared with a red blood cell membrane n-3 polyunsaturated fatty acid level of 3.3% of total fatty acids (the mean of the lowest quartile), a red blood cell n-3 polyunsaturated fatty acid level of 5.0% of total fatty acids (the mean of the third quartile) was associated with a 70% reduction in the risk of primary cardiac arrest (OR, 0.3; 95% CI, 0.2 to 0.6).Conclusion.\p=m-\Dietary intake of n-3 polyunsaturated fatty acids from seafood is associated with a reduced risk of primary cardiac arrest.

Parkinson's disease seems to occur more commonly in men than women based primarily on studies of death rates and prevalence. In recent years, several population based incidence studies of Parkinson's disease that included sex data have been conducted in a variety of populations around the world. To investigate whether these incidence studies suggest an increased risk of Parkinson's disease in men, a meta-analysis was performed of the differences in incidence of Parkinson's disease between men and women reported in seven studies that met the inclusion criteria. A significantly higher incidence rate of Parkinson's disease was found among men with the relative risk being 1.5 times greater in men than women. Possible reasons for this increased risk of Parkinson's disease in men are toxicant exposure, head trauma, neuroprotection by oestrogen, mitochondrial dysfunction, or X linkage of genetic risk factors. Whether there is a sex difference in risk for Parkinson's disease (PD) is controversial.1 PD seems to occur more commonly in men than women based primarily on studies of death rates and prevalence. 1 2 Death rates, however, do not accurately reflect the incidence of PD 3 because of inaccurate diagnoses on death certificates. Likewise, prevalence data are problematic. Prevalence studies are subject to potential sex differences in survival, access to health care, access to the system whereby cases were ascertained for inclusion in the study, and sex differences in the underlying population. 1Because incidence of PD represents the number of new cases developed or diagnosed during a specific time interval within a predefined population at risk, incidence measurements are more direct and unambiguous epidemiological estimates of risk for developing PD than are death rates or prevalence. Incidence data from well defined populations obviate a number of concerns with prevalence data, such as differential mortality between men and women.In recent years, several population based incidence studies of PD that included sex data have been conducted in a variety of populations around the world. To determine whether these incidence studies suggest an increased risk of PD in men, we performed a meta-analysis of the differences in incidence of PD between men and women reported in these studies. METHODSThe Medline database was searched for population based ascertainment studies of PD average annual incidence rates adjusted for sex and age. The studies included in our metaanalysis met six criteria: (1) The study must have been published after 1980. Inclusion of studies published before 1980 would lead to the inclusion of neurodegenerative disorders that would be recognised now as not being PD (for example, progressive supranuclear palsy, multiple system atrophy, etc). Also, older studies are more likely to be contaminated with cases of post-encephalitic parkinsonism than studies published after 1980; (2) studies must have excluded secondary and/or drug induced parkinsonism; (3) studies must have ascertained at least 50 cases of PD; (4...

Increased mammographic breast density is a moderate independent risk factor for breast cancer, with findings of published studies in which quantitative methods of assessment were used showing a positive association. Breast density may be quantified by using visual assessment or planimetry. Although the category definitions vary, the odds ratio for developing breast cancer for the most dense compared with the least dense breast tissue categories ranges from 1.8 to 6.0, with most studies yielding an odds ratio of 4.0 or greater. Plausible explanations for the association of breast density with increased breast cancer risk may be the development of premalignant lesions such as atypical ductal hyperplasia, elevated growth factors, or increased estrogen production within the breast due to overactive aromatase. The amount of breast density may be due in part to genetic heredity. However, unlike other risk factors, breast density may be influenced. Specifically, breast density is very hormonally responsive and potentially may be influenced by lifestyle factors such as alcohol intake and diet. Assessment of breast density may become useful in risk assessment and prevention decisions.