December 2007

DECEMBER 14, 2007

Hypercholesteremia Linked to Ischemic Stroke
High cholesterol levels are associated with an increased risk for ischemic stroke in apparently healthy women, based on a study of 27,937 women aged 45 years or more who provided blood samples at baseline and were followed for 11 years. Comparing the highest with the lowest quintiles, the adjusted hazard ratios for ischemic stroke were: 2.27 for total cholesterol (244 or more vs less than179 mg/dL); 1.74 for low-density lipoprotein cholesterol (151 or more vs less than 96 mg/dL); 0.78 for high-density lipoprotein cholesterol (HDL-C; 65 or more vs less than 41 mg/dL); 2.45 for non?HDL-C and (190 or more vs less than 123 mg/dL); 1.65 for the total cholesterol-to-HDL-C ratio (5.2 or more vs less than 3.1).

Kurth T, et al. Lipid levels and the risk of ischemic stroke in women. Neurology. 2007;68:556-562.

Pulmonary Dysfunction Leads to Psychological Problems
Restrictive and obstructive pulmonary dysfunctions are associated with an increased likelihood of mental health problems. The finding emerged from an analysis of data from a representative sample of adults enrolled in the First National Health and Nutrition Examination Survey. All participants underwent spirometry; pulmonary dysfunction was determined on the basis of expected forced expiratory volume. Mental health problems were assessed using the General Well-Being scales. After adjusting for demographic variables, obstructive lung dysfunction was significantly associated with lower overall well-being. Restrictive lung dysfunction was significantly associated with lower overall well-being, general health, vitality, self-control, and with an increased risk for depression compared with normal lung function.

Goodwin RD, et al. Association between lung function and mental health problems among adults in the United States. Am J Epidemiol. 2007;165:383-388.

High Selenium Levels Reduce Risk for Prostate Cancer
Men with high selenium concentrations can lower their risk for prostate cancer if they also take vitamin E or multivitamin supplements, according to new data from an 8-year, nested, case-control study of more than 1600 men (aged 55-74 years). Overall, the average serum selenium concentration in the study population was 141.3 ng/mL. Although overall high selenium level was not associated with prostate cancer risk, high serum selenium level combined with high vitamin E intake (more than 28 IU/d) was associated with a lower risk for prostate cancer, as was seen in comparing men in the highest (158 to 253 ng/mL) and lowest (50.5 to less than 126.8 ng/mL) quartiles of selenium intake. A similar trend was found for men in the highest quartile of multivitamin intake.

Ulrike P, et al. Serum selenium and risk of prostate cancer. Am J Clin Nutr. 2007;85:209-217.

Selenium Supplementation May Slow HIV Progression
Daily intake of selenium supplementation was found to suppress the progression of HIV viral burden and provide indirect improvements in CD4+ counts in a 9-month study of 450 patients (aged 18-45 years) with HIV infection. As expected, mean serum selenium concentration increased in those receiving selenium supplementation (200 ?g/d) compared with those receiving placebo (P <.001). Higher serum levels predicted lower HIV viral loads, which, in turn, was associated with higher CD4+ counts.

Hurwitz BE, et al. Suppression of human immunodeficiency virus type 1 viral load with selenium supplementation. Arch Intern Med. 2007;167:148-154.

Regulator of Cholesterol Production Identified
A protein, whose human counterpart controls cholesterol production and potentially drug metabolism, has been discovered in a new study conducted to ascertain how 2 of 4 cytochrome (CY) P-450 enzymes found in yeast produce cholesterol. The protein, Dap1, was found to lock onto all 4 CYP-450 enzymes, including 1 involved in making bile and 1 required for steroid hormone production of natural in the adrenal glands. Because Dap1 affects the CYP-450 enzyme responsible for drug metabolism, variations in the genetic blueprint for Dap1 may provide clues about individual reactions to different drugs.

Hughes AL, et al. Dap1/PGRMC1 binds and regulates cytochrome P450 enzymes. Cell Metabo. 2007;5:143-149.

High-Carbohydrate Meals Help Patients Fall Asleep
Consuming a high glycemic-index, carbohydrate-based meal a few hours before bedtime results in significantly shortened sleep-onset latency. A dozen healthy men (aged 18-35 years) consumed low- or high-glycemic-index carbohydrate-based meals 4 hours before their usual bedtime and, on a separate occasion, a high-glycemic-index meal 1 hour before bedtime. The mean sleep-onset latency was 9 minutes after the high-glycemic-index meal and 17.5 minutes after the low-glycemic-index meal when either was consumed 4 hours before bedtime. But when the high-glycemic-index meal was consumed 1 hour before bedtime, the mean sleep-onset latency increased to 14.6 minutes.

Afaghi A, et al. High-glycemic-index carbohydrate meals may shorten sleep onset. Am J Clin Nutr. 2007;85:426-430.

Caffeine Reduces CV Mortality After Age 65
Older adults who regularly drink caffeinated beverages may be lowering their risk of death from cardiovascular (CV) causes, according to a prospective study of 6594 persons aged 32 to 86 years who had no history of cardiovascular (CV) disease at baseline. A total of 426 deaths attributed to CV disease occurred during 8.8 years of follow-up. Among persons aged 65 years or older, those who consumed high levels of caffeinated drinks had a lower risk of CV mortality than those with low intake levels. Compared with those who drank less than 0.5 servings of caffeinated beverages daily, the relative risk of CV disease mortality was 0.77, 0.68, and 0.47 in those who drank 0.5 to 2.0, 2 to 4, and 4 or more such beverages daily, respectively. The protective effects of caffeine were evident only in those aged 65 years or older who did not have severe hypertension.

Greenburg JA, et al. Caffeinated beverage intake and the risk of heart disease mortality in the elderly: a prospective study. Am J Clin Nutr. 2007;85:392-396.

Hot Flashes Linked to Elevated Systolic BP
Hot flashes are significantly associated with elevated systolic blood pressure (BP), independent of menopausal status. Ambulatory diurnal BP patterns were measured in 154 women (mean age, 46 years) who were normotensive or mildly hypertensive. Overall, one third of the participants reported having hot flashes during the previous 2 weeks. Compared with women who did not have hot flashes, mean systolic BP when awake and asleep was significantly higher in those with a history of hot flashes. The association between hot flashes and systolic BP was independent of age, race/ethnicity, body mass index, and menopausal status. Hot flashes were not associated with diastolic BP or nocturnal dipping in BP.

Gerber LM, et al. Hot flashes are associated with increased ambulatory systolic blood pressure. Menopause. 2007;14:308-315.

TV Viewing Linked to Glycemic Indices
Sedentary behavior, indicated by TV viewing time, is positively associated with glycemic measures in women without diabetes. The finding is based on a study of 8357 nondiabetic men and women older than 35 years who underwent an oral glucose tolerance test and who self-reported their TV viewing time. Glycemic measures included a homeostasis model assessment (HOMA) of insulin sensitivity (HOMA-%S) and beta-cell function (HOMA-%B). In women, time spent watching TV was independently associated with 2-hour postchallenge plasma glucose level, log fasting insulin, and log HOMA-%B, and inversely associated with log HOMA-%S but not with fasting plasma glucose. TV viewing time was more strongly associated with 2-hour postchallenge plasma glucose level than with the other glycemic measures. No associations between TV watching and glycemic measures were observed in men.

Dunstan DW, et al. Association of television viewing with fasting and 2-h postchallenge plasma glucose levels in adults without diagnosed diabetes. Diabetes Care. 2007;30:516-522.

Smoking a Risk Factor for TB
Smoking increases the risk for tuberculosis (TB) infection, as well as for active TB disease, according to a meta-analysis of 24 epidemiologic studies. All the studies analyzed included a relative risk estimate for the association between TB (ie, infection, pulmonary disease, or mortality) and active tobacco smoking, stratified by (or adjusted for) confounding variables, such as age or sex. The estimated relative risk was 1.73 for TB infection and 2.33 to 2.66 for active disease, indicating a relative risk of 1.4 to 1.6 for active TB disease in an infected population. The analysis showed there was no additional risk of mortality associated with smoking in smokers who already have active TB.

Bates MN, et al. Risk of tuberculosis from exposure to tobacco smoke. Arch Intern Med. 2007;167:335-342.

Long-Term Aspirin Use Prevents Cancer
Long-term daily use of adult-strength aspirin decreases overall cancer incidence in populations at an increased risk for colorectal, prostate, or breast cancers. The association between long-term daily use of adult-strength aspirin (dose, 325 mg/d or greater) and overall and select cancer incidences was examined in 69,810 older men and 76,303 older women. During about 10 years of follow-up, 10,931 men and 7196 women were diagnosed with cancer. Daily use of adult-strength aspirin for 5 years or more was associated with a significant 16% decrease in overall cancer incidence in men and a nonsignificant 14% decrease in women. Long-term daily aspirin use decreased the combined incidence of colorectal cancer in men and women by 32%, the incidence of prostate cancer in men by 19%, and of breast cancer in women by a nonsignificant 17%.

Jacobs EJ, et al. A large cohort study of long-term daily use of adult-strength aspirin and cancer incidence. J Natl Cancer Inst. 2007;99:608-615.

Moderate Alcohol Use Slows Progression to Dementia
Moderate daily consumption of alcohol or wine slows the rate of progression to dementia in patients with mild cognitive impairment. The finding emerged from a study of 121 patients (aged 65-84 years) with mild cognitive impairment who were followed for a mean of 3.5 years. Compared with abstainers, moderate drinkers (defined as consuming less than 1 drink of alcohol/wine daily, amounting to about 15 g of alcohol) had an 85% decreased risk for progression to dementia. Higher levels of alcohol (1 drink/d or more) had no significant effect on the rate of progression to dementia. In a separate group of 1445 persons without cognitive impairment, no significant association was found between any level of drinking and the incidence of mild cognitive impairment.

Solfrizzi V, et al. Alcohol consumption, mild cognitive impairment, and progression to dementia. Neurology. 2007;68:1790-1799.

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