The association between sleep patterns and obesity in older adults.

BACKGROUND: Reduced sleep duration has been increasingly reported to predict obesity. However, timing and regularity of sleep may also be important. In this study, the cross-sectional association between objectively measured sleep patterns and obesity was assessed in two large cohorts of older individuals. METHODS: Wrist actigraphy was performed in 3053 men (mean age: 76.4 years) participating in the Osteoporotic Fractures in Men Study and 2985 women (mean age: 83.5 years) participating in the Study of Osteoporotic Fractures. Timing and regularity of sleep patterns were assessed across nights, as well as daytime napping. RESULTS: Greater night-to-night variability in sleep duration and daytime napping were associated with obesity independent of mean nocturnal sleep duration in both men and women. Each 1 h increase in the standard deviation of nocturnal sleep duration increased the odds of obesity 1.63-fold (95% confidence interval: 1.31-2.02) among men and 1.22-fold (95% confidence interval: 1.01-1.47) among women. Each 1 h increase in napping increased the odds of obesity 1.23-fold (95% confidence interval: 1.12-1.37) in men and 1.29-fold (95% confidence interval: 1.17-1.41) in women. In contrast, associations between later sleep timing and night-to-night variability in sleep timing with obesity were less consistent. CONCLUSIONS: In both older men and women, variability in nightly sleep duration and daytime napping were associated with obesity, independent of mean sleep duration. These findings suggest that characteristics of sleep beyond mean sleep duration may have a role in weight homeostasis, highlighting the complex relationship between sleep and metabolism.

CD45-induced tumor necrosis factor alpha production in monocytes is phosphatidylinositol 3-kinase-dependent and nuclear factor-kappaB-independent.

The pro-inflammatory cytokine tumor necrosis factor (TNF)-alpha plays a pivotal role in the pathogenesis of rheumatoid arthritis. The mechanisms involved in regulating monocyte/macrophage TNFalpha production are not yet fully understood but are thought to involve both soluble factors and cell/cell contact with other cell types. Ligation of certain cell surface receptors, namely CD45, CD44, and CD58, can induce the production of TNFalpha in monocytes. In this paper, we investigate further the signaling pathways utilized by cell surface receptors (specifically CD45) to induce monocyte TNFalpha and compare the common/unique pathways involved with that of lipopolysaccharide. The results indicate that monocyte TNFalpha induced upon CD45 ligation or lipopolysaccharide stimulation is differentially modulated by phosphatidylinositol 3-kinase and nuclear factor-kappaB but similarly regulated by p38 mitogen-activated protein kinase. These results demonstrate that both common and unique signaling pathways are utilized by different stimuli for the induction of TNFalpha. These observations may have a major bearing on approaches to inhibiting TNFalpha production in disease where the cytokine has a pathogenic role.

The effectiveness of sponge-type intraoral applicators for applying topical fluorides in institutionalized older adults.

Many older adults who reside in nursing homes have disabilities which limit their capacity to benefit from the usual protocols for prevention of dental caries. This is a report of a study of the effectiveness of an alternative method of applying topical fluoride in the institutionalized elderly. Fluoride gel (1.1% NaF) was applied to the facial tooth surfaces of 10 elderly nursing home residents using a sponge-type intraoral applicator (IA). Subsequently, the same subjects rinsed with a commercial fluoride solution (0.05% NaF). Salivary fluoride levels were then assessed by the Taves (1968) method. The IA with fluoride produced significantly higher salivary fluoride levels over a period of three hours compared with rinsing.

Fluoride concentrations in plaque, whole saliva, and ductal saliva after application of home-use topical fluorides [published eerratum appears in J Dent Res 1993 Jan;72(1):87].

It is now well-accepted that the primary anti-caries activity of fluoride (F) is via topical action. The retention of F in the mouth after topical fluoride treatment is considered to be an important factor in the clinical efficacy of F. The purpose of this study was to evaluate F levels in ductal saliva, whole saliva, and pooled plaque after treatment with topical F agents intended for home use. Ten consenting adults, mean (SD) age 31.0 (8.2) years, participated in all aspects of the study. Two days before each test, subjects received a professional tooth cleaning and subsequently abstained from all oral hygiene procedures to permit plaque to accumulate, and from the use of F-containing dental products. Treatments consisted of a placebo dentifrice (PD), fluoride dentifrice (FD; 0.24% NaF), fluoride rinse (FR; 0.05% NaF), and fluoride gel (FG; 1.1% NaF). Unstimulated whole saliva and pooled plaque were sampled at multiple points over a 24-hour period. In a separate experimental series, stimulated parotid saliva was sampled over a two-hour period after treatment. Fluoride levels generally followed the same pattern in whole saliva and pooled plaque samples, with FG > FR > FD > PD. Night-time F application resulted in prolonged F retention in whole saliva but not in plaque. Fluoride levels in parotid saliva were only slightly higher after F treatment and returned to baseline levels within two h. The results of this study indicate that the method of F delivery, the F concentration of the agent, and the time of application (daytime vs. night-time) are important factors influencing F levels in the mouth.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies of fluoride retention by oral soft tissues after the application of home-use topical fluorides.

Previous studies have focused on enamel and plaque as the primary sites of fluoride (F) retention in the mouth. The present study was undertaken to evaluate the role of oral soft tissue as a site of F retention by comparing an edentulous subject panel (n = 9) with a fully dentate panel (n = 10). Unstimulated whole saliva samples were collected by having subjects pool saliva for two min. Samples were collected over a 24-hour period after application of a placebo dentifrice (PD; 0.4 ppm F), fluoride dentifrice (FD; 1100 ppm F), fluoride rinse (FR; 226 ppm F), or fluoride gel (FG; 5000 ppm F) delivered in custom trays. There was no statistically significant difference in salivary flow rate between the two panels for any of the treatments. The edentulous panel had higher salivary F levels than the dentate panel, which reached statistical significance (p less than 0.05) for the FD and FG treatments. In a separate study involving the same treatments, F levels at specific soft-tissue sites were measured over a one-hour period by use of absorbent discs placed in different soft-tissue areas of the mouth. The tongue and lower posterior vestibule retained the highest F levels, followed by the upper posterior buccal vestibule and upper anterior labial vestibule, with the lowest F levels retained in the lower anterior vestibule and the floor of the mouth. There was a strong-to-moderate correlation between whole saliva F concentration and F levels at specific soft-tissue sites. This study establishes the importance of oral soft tissue as the major site of F retention in the mouth.

Induction of rat hepatic microsomal drug metabolizing enzymes by pyrazole and 4-substituted pyrazoles.

Pyrazole and 4-methylpyrazole are potent inhibitors of liver alcohol dehydrogenase and as such have been proposed as potential antidotes to alcohol poisoning. These drugs are also inducers of hepatic cytochrome P-450. We tested pyrazole and four 4-substituted pyrazoles for their potential as inducers of cytochrome P-450 and drug metabolism in mature male rats. Total cytochrome P-450 was significantly increased (p less than 0.05) 1.3 fold by treatment with 4-methylpyrazole. P-nitrophenol hydroxylase (PNPH) activity (nmol/min/mg protein) was increased 1.9 fold following treatment with pyrazole and with 4-methylpyrazole. Treatment with 4-methylpyrazole also resulted in a 2.9 fold increase in ethoxyresorufin demethylase (EROD) activity. In addition, pyrazole treatment led to a significant decrease in the activity of benzphetamine demethylase. 4-Iodopyrazole increased the turnover (nmol/min/nmol P-450) of EROD and PNPH by 1.5 fold each. 4-Nitropyrazole had no significant effect on any of the activities or turnover rates tested. In contrast to results with cultured chick hepatocytes, where induction was directly related to the hydrophobicity of the 4-substituent, the present data indicate that the process of induction of in vivo is more complex.

Assessment of occupational exposure to organophosphates in pest control operators.

An occupational study was conducted for a firm employing 22 pest control operators (PCOs) exposed to three organophosphorus insecticides. Measurements of 8-hour exposure levels were less than: 131.0 microgram/m3 for Vaponite; 41.0 microgram/m3 for Diazinon; and 27.6 microgram/m3 for Dursban. Twenty-four-hour urines analyzed for alkyl phosphates showed the presence of metabolites for these three pesticides. The effect of this exposure is reflected by a statistically significant inhibition of plasma acetylcholinesterase (AChE) among the PCOs as AChE values of either group. Although physical examinations detected no apparent toxic effects in the study group, biological sampling results indicated a need for personal protective equipment during the handling and application of these pesticides.