Comparable effects of nicotine in smokers and nonsmokers on a prospective memory task

In a double-blind placebo-controlled study, we examined the effect of nicotine, a cholinergic agonist, on performance of a prospective memory (ProM) task in young adult volunteers.

Volunteers were required to complete an ongoing lexical decision task while maintaining the ProM task (responding with a different button press to items containing particular target letters). Half of the volunteers were smokers, half were nonsmokers. Half of each group received a single dose (1 mg) of nicotine nasal spray before completing the task; the remaining volunteers received a matched inactive placebo spray.

Nicotine improved performance on the ProM task when volunteers were able to devote resources to that task. Under a variant procedure, where volunteers completed a concurrent auditory monitoring task, ProM performance was impaired under nicotine. Results are discussed in terms of the resource model of ProM, and the arousal model of drug effects.

Association between sexual behavior and cervical cancer screening

Background: Not much is known about whether women who follow Pap testing recommendations report the same pattern of sexual behavior as women who do not.
Methods: Data come from part of a larger population-based computer-assisted telephone survey of 8656 Australians aged 16–64 years resident in Australian households with a fixed telephone line (Australian Longitudinal Study of Health and Relationships [ALSHR]). The main outcome measure in the current study was having had a Pap test in the past 2 years.
Results: Data on a weighted sample of 4052 women who reported sexual experience (ever had vaginal intercourse) were analyzed. Overall, 73% of women in the sample reported having a Pap test in the past 2 years. Variables individually associated with Pap testing behavior included age, education, occupation, cohabitation status, residential location, tobacco and alcohol use, body mass index (BMI), lifetime and recent number of opposite sex partners, sexually transmitted infection (STI) history, and condom reliance for contraception. In adjusted analyses, women in their 30s, those who lived with their partner, and nonsmokers were more likely to have had a recent Pap test. Those who drank alcohol at least weekly were more likely to have had a recent test than irregular drinkers or nondrinkers. Women with no sexual partners in the last year were less likely to have had a Pap test, and women who reported a previous STI diagnosis were more likely to have had a Pap test in the past 2 years.
Conclusions: There are differences in Pap testing behavior among Australian women related to factors that may affect their risk of developing cervical abnormalities. Younger women and regular smokers were less likely to report a recent test. Screening programs should consider the need to focus recruitment strategies for these women.

Adverse effects of cigarette smoke on NO bioavailability : role of arginine metabolism and oxidative stress

Endothelial dysfunction is a hallmark of cardiovascular disease, and the l-arginine:NO pathway plays a critical role in determining endothelial function. Recent studies suggest that smoking, a well-recognized risk factor for vascular disease, may interfere with l-arginine and NO metabolism; however, this remains poorly characterized. Accordingly, we performed a series of complementary in vivo and in vitro studies to elucidate the mechanism by which cigarette smoke adversely affects endothelial function. In current smokers, plasma levels of asymmetrical dimethyl-arginine (ADMA) were 80% higher (P=0.01) than nonsmokers, whereas citrulline (17%; P<0.05) and N-hydroxy-l-arginine (34%; P<0.05) were significantly lower. Exposure to 10% cigarette smoke extract (CSE) significantly affected endothelial arginine metabolism with reductions in the intracellular content of citrulline (81%), N-hydroxy-l-arginine (57%), and arginine (23%), while increasing ADMA (129%). CSE significantly inhibited (38%) arginine uptake in conjunction with a 34% reduction in expression of the arginine transporter, CAT1. In conjunction with these studies, CSE significantly reduced the activity of eNOS and NO production by endothelial cells, while stimulating the production of reactive oxygen species. In conclusion, cigarette smoke adversely affects the endothelial l-arginine NO synthase pathway, resulting in reducing NO production and elevated oxidative stress. In conjunction, exposure to cigarette smoke increases ADMA concentration, the latter being a risk factor for cardiovascular disease.

Postprandial plasma phospholipids in men are influenced by the source of dietary fat

BACKGROUND: Postprandial lipemia represents a risk factor for chronic diseases, including type 2 diabetes. Little is known about the effect of dietary fat on the plasma lipidome in the postprandial period. OBJECTIVE: The objective of this study was to assess the effect of dairy fat and soy oil on circulating postprandial lipids in men. METHODS: Men (40-60 y old, nonsmokers; n = 16) were randomly assigned in a crossover design to consume 2 breakfast meals of dairy-based or soy oil-based foods. The changes in the plasma lipidome during the 4-h postprandial period were analyzed with electrospray ionization tandem mass spectrometry and included 316 lipid species in 23 classes and subclasses, representing sphingolipids, phospholipids, glycerolipids, and sterols. RESULTS: Nonparametric Friedman tests showed significant changes in multiple plasma lipid classes, subclasses, and species in the postprandial period after both dairy and soy meals. No difference was found in triglyceridemia after each meal. However, 6 endogenous lipid classes increased after dairy but decreased after soy (P < 0.05), including ether-linked phospholipids and plasmalogens and sphingomyelin (not present in soy), dihexosylceramide, and GM3 ganglioside. Phosphatidylcholine and phosphatidylinositol were not affected by the soy meal but were significantly elevated after the dairy meal (8.3% and 16%, respectively; P < 0.05). CONCLUSIONS: The changes in postprandial plasma phospholipids in men relate to the diet composition and the relative size of the endogenous phospholipid pools. Despite similar lipemic responses as measured by changes in triglyceride concentrations, the differential responses to dairy and soy meals derived through lipidomic analysis of phospholipids suggest differences in the metabolism of soybean oil and dairy fat. The increased concentrations of plasmalogens, with potential antioxidant capacity, in the postprandial period after dairy but not soy meals may represent a further important difference in the response to these sources of fat. The trial was registered at www.anzctr.org.au as ACTRN12610000562077.

Obesity in adulthood and its consequences for life expectancy: a life-table analysis

BACKGROUND: Overweight and obesity in adulthood are linked to an increased risk for death and disease. Their potential effect on life expectancy and premature death has not yet been described. OBJECTIVE: To analyze reductions in life expectancy and increases in premature death associated with overweight and obesity at 40 years of age. DESIGN: Prospective cohort study. SETTING: The Framingham Heart Study with follow-up from 1948 to 1990. PARTICIPANTS: 3457 Framingham Heart Study participants who were 30 to 49 years of age at baseline. MEASUREMENTS: Mortality rates specific for age and body mass index group (normal weight, overweight, or obese at baseline) were derived within sex and smoking status strata. Life expectancy and the probability of death before 70 years of age were analyzed by using life tables. RESULTS: Large decreases in life expectancy were associated with overweight and obesity. Forty-year-old female nonsmokers lost 3.3 years and 40-year-old male nonsmokers lost 3.1 years of life expectancy because of overweight. Forty-year-old female nonsmokers lost 7.1 years and 40-year-old male nonsmokers lost 5.8 years because of obesity. Obese female smokers lost 7.2 years and obese male smokers lost 6.7 years of life expectancy compared with normal-weight smokers. Obese female smokers lost 13.3 years and obese male smokers lost 13.7 years compared with normal-weight nonsmokers. Body mass index at ages 30 to 49 years predicted mortality after ages 50 to 69 years, even after adjustment for body mass index at age 50 to 69 years. CONCLUSIONS: Obesity and overweight in adulthood are associated with large decreases in life expectancy and increases in early mortality. These decreases are similar to those seen with smoking. Obesity in adulthood is a powerful predictor of death at older ages. Because of the increasing prevalence of obesity, more efficient prevention and treatment should become high priorities in public health.