Relationship between Oral Assessment Guide score and hypoalbuminemia in newly hospitalized patients.

This cross-sectional study investigated the relationship between Oral Assessment Guide (OAG) scores and malnutrition in newly hospitalized patients. A total of 880 hospitalized adults were enrolled. Hypoalbuminemia was defined as serum albumin less than 3.5 g/dL. Patients with hypoalbuminemia were older (P < 0.001), had a higher prevalence of respiratory diseases (P < 0.01), a higher prevalence of digestive diseases (P < 0.01), a lower prevalence of oral feeding (P < 0.001), a lower body mass index (P < 0.001), and higher OAG scores (P < 0.001) than those without hypoalbuminemia. Multivariate logistic regression analyses showed that the prevalence of hypoalbuminemia was significantly related to age (odds ratio [OR] = 1.05, P < 0.001), absence of oral feeding (OR = 2.72, P < 0.001), presence of respiratory diseases (OR = 2.53, P < 0.01), presence of digestive diseases (OR = 1.64, P < 0.01), and OAG scores (OR = 1.14, P < 0.01). Regarding OAG scores, the OR of hypoalbuminemia was greater in patients with disorders (scores 2 or 3) of swallowing (vs. score 1, OR = 1.83, P < 0.05) and saliva (vs. score 1, OR = 1.51, P < 0.05). There appears to be a positive association between OAG scores and hypoalbuminemia in hospitalized patients.

Effects of Active Mastication on Chronic Stress-Induced Bone Loss in Mice.

Chronic psychologic stress increases corticosterone levels, which decreases bone density. Active mastication or chewing attenuates stress-induced increases in corticosterone. We evaluated whether active mastication attenuates chronic stress-induced bone loss in mice. Male C57BL/6 (B6) mice were randomly divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube (60 min, 2x/day, 4 weeks). The stress/chewing group was given a wooden stick to chew during the experimental period. Quantitative micro-computed tomography, histologic analysis, and biochemical markers were used to evaluate the bone response. The stress/chewing group exhibited significantly attenuated stress-induced increases in serum corticosterone levels, suppressed bone formation, enhanced bone resorption, and decreased trabecular bone mass in the vertebrae and distal femurs, compared with mice in the stress group. Active mastication during exposure to chronic stress alleviated chronic stress-induced bone density loss in B6 mice. Active mastication during chronic psychologic stress may thus be an effective strategy to prevent and/or treat chronic stress-related osteopenia.

Chewing ameliorates chronic mild stress-induced bone loss in senescence-accelerated mouse (SAMP8), a murine model of senile osteoporosis.

Chronic mild stress is a risk factor for osteoporosis and chewing inhibits the stress response. We examined the effect of chewing on chronic stress-induced bone loss and bone microstructural deterioration in mice. The senescence-accelerated mouse strain P8 (SAMP8) was randomly divided into control, stress, and stress with chewing groups of fifteen animals each. Mice in the stress and stress with chewing groups were placed in a ventilated restraint tube for 60minutes, twice a day for 4weeks. The restrained mice were simultaneously subjected daily to one of the following stressors: water immersion, physical shaking and flashing lights. Mice in the stress with chewing group were allowed to chew a wooden stick during the experimental period. After the experiment, the bone response was evaluated using quantitative micro computed tomography, bone histomorphometry, and biochemical markers. Exposure of SAMP8 mice to chronic stress resulted in significant increase of the blood corticosterone and noradrenaline levels, and adrenal weight. The bone resorption was activated and the bone formation was suppressed. Trabecular bone volume and trabecular number were decreased in both the vertebra and distal femur of the stress group. Chewing under chronic stress prevented the increase in the blood corticosterone and noradrenaline levels, attenuated the reduced bone formation and increased bone resorption, improved the trabecular bone loss and bone microstructural deterioration induced by chronic mild stress. These findings indicate that chewing can ameliorate chronic stress-induced bone loss in SAMP8 mice. Thus, chewing may represent a useful method preventing and/or treating chronic stress-related osteoporosis.

Masticatory function and cognitive function.

Recent studies have suggest that masticatory (chewing) function is useful for maintaining neurocognitive function in the elderly. For example, a reduced ability to masticate, such as that resulting from toothlessness or soft-diet feeding, causes learning and memory deficits in aged animals and pathologic changes in the hippocampus. In addition, occlusal disharmony impairs hippocampal memory processes via chronic stress, and induces similar hippocampal pathology. Chewing, however, rescues stress-induced suppression of long-term potentiation in the hippocampus and the stress-induced impairment of hippocampal-dependent learning. These findings strongly suggest a link between mastication and neurocognitive function.