Kazuo Sonoki

Oral Health and Mortality Risk from Pneumonia in the Elderly

Although poor oral health influences the occurrence of pulmonary infection in elderly people, it is unclear how the degree of oral health is linked to mortality from pulmonary infection. Therefore, we evaluated the relationship between oral health and four-year mortality from pneumonia in an elderly Japanese population. The study population consisted of 697 (277 males, 420 females) of the 1282 individuals who were 80 years old in 1997. Data on oral and systemic health were obtained by means of questionnaires, physical examinations, and laboratory blood tests. One hundred eight of the study persons died between 1998 and 2002. Of these, 22 deaths were due to pneumonia. The adjusted mortality due to pneumonia was 3.9 times higher in persons with 10 or more teeth with a probing depth exceeding 4 mm (periodontal pocket) than in those without periodontal pockets. Therefore, the increase in teeth with periodontal pockets in the elderly may be associated with increased mortality from pneumonia.

Peroxisome proliferator-activated receptor γ1 (PPARγ1) expresses in rat mesangial cells and PPARγ agonists modulate its differentiation

Thiazolidinediones, synthetic ligands of peroxisome proliferator-activated receptor gamma (PPARgamma), are reported to have direct beneficial effects on diabetic nephropathy without lowering blood glucose levels in human and rat. We hypothesized these effects of thiazolidinediones might be derived from PPARgamma activation of kidney cells, and we examined the expression of PPARgamma and the effect of PPARgamma agonists, troglitazone and 15-deoxy-delta-prostaglandin J2 (15d-PGJ2), on the proliferation and differentiation in rat mesangial cells. A single band of mRNA of PPARgamma with a predicted size was detected in reverse transcription-polymerase chain reaction products (RT-PCR) using established PCR probes of PPARgamma. PPARgamma protein in rat mesangial cells was identified as PPARgamma1 by a Western blot. In a gel mobility shift assay to determine a binding activity of PPARgamma, the nuclear protein from rat mesangial cells bound to a (32)P-labeled oligonucleotide probe, including PPAR response elements. A synthetic and a natural ligand of PPARgamma, troglitazone and 15d-PGJ2, decreased thymidine incorporation in a dose dependent manner. After 7 days incubation with troglitazone and 15d-PGJ2, alpha-smooth muscle actin expression, a marker of mesangial cell de-differentiation, was decreased significantly compared to that of control. These results indicate that PPARgamma1 is expressing in rat mesangial cells, and PPARgamma1 activation with its agonists modulates the proliferation and differentiation of cultured rat mesangial cells.

Association between body mass index and mortality in an 80-year-old population.

OBJECTIVES: To evaluate the association between body mass index (BMI) and all‐cause mortality and cardiovascular disease (CVD) in an 80‐year‐old population.

Relationship between Tooth Loss and Electrocardiographic Abnormalities in Octogenarians

Recent reports have suggested that periodontal disease is a risk factor for coronary heart disease (CHD). However, little is known about the relationship between periodontal disease and CHD in the very elderly. Therefore, we evaluated the association between tooth loss and abnormal ECG findings in octogenarians. Of the 1282 octogenarians in Fukuoka Prefecture, Japan, 697 participated. Oral examinations-including a tooth count and an assessment of the Community Periodontal Index-and a 12-lead ECG were performed. Logistic regression analysis revealed that individuals with < 20 teeth had increased prevalence of ST segment depression, and T-wave abnormalities, after we adjusted for gender, smoking, serum cholesterol and glucose, blood pressure, and body mass index. Compared with individuals with ≥ 20 teeth, edentulous individuals had an increased prevalence of T-wave abnormalities and arrhythmias after adjustment for coronary risk factors. We conclude that tooth loss may be an independent predictor of abnormal ECG findings in octogenarians.

Quality of life and physical fitness in an 85-year-old population

Since little is known about the very elderly population aged 80 years and older, we evaluated the association of quality of life (QoL) in an 85-year-old population with physical fitness measurements assessed at age 80 and 85 years. Two hundred seven individuals (90 males, 117 females) aged 85 years underwent the Short Form-36 (SF-36) questionnaires for QoL assessment and physical fitness measurements (handgrip strength, leg-extensor strength, one-leg standing time, stepping rate of legs, walking speed). In 85-year-olds, significant associations were found, by multiple regression analysis or logistic regression analysis, with adjustment for various influencing factors in QoL assessed by SF-36 with physical fitness measurements examined at the age of 85 and 80 years. Physical scales and scores in SF-36, such as physical functioning (PF), limitation in role functioning for physical reasons (role physical; RP), bodily pain (BP), and the physical component score (PCS) tended to be more tightly associated with fitness measurements than mental scales and scores such as limitation in role functioning for emotional reasons (role emotional; RE), and emotional well-being (mental health; MH), and mental component score (MCS). Three scales the general health perceptions (GH), the vitality (VT), and the social functioning (SF) consisting of both physical and mental components were associated with fitness, the extent being intermediate between physical scales and mental scales. Of the several physical fitness measurements, leg-extensor strength and the walking speed of 85-year-olds, and the stepping rate of 80-year-olds were most closely associated with QoL. In a very elderly population of 85- and 80-year-olds, significant associations were found between QoL by SF-36 and physical fitness measurements, suggesting that increases in the levels of physical fitness, even in the very elderly, can contribute to improvements in QoL.

Physical Fitness and Cognitive Function in an 85-Year-Old Community-Dwelling Population

Background: Little is known about the association between physical fitness and cognitive function in very elderly people (over 80 years of age). Objectives: To evaluate that relationship in 85-year-old community-dwelling individuals. Methods: Out of 207 participants (90 males, 117 females) who were 85 years old and community-dwelling, 205 completed the Mini-Mental State Examination (MMSE) for evaluating cognitive function. The numbers of subjects who completed physical fitness measurements such as hand-grip strength, isometric leg extensor strength, one-leg standing time, stepping rate, and walking speed were 198, 159, 169, 168, and 151, respectively. Results: There were significant associations in MMSE with hand-grip strength (right or left hand), isometric leg extensor strength, stepping rate, and walking speed by simple regression analysis. MMSE was still significantly associated with hand-grip strength (β = 0.305, p = 0.005 for right side; β = 0.309, p = 0.004 for left side), stepping rate (β = 0.183, p = 0.046), and walking speed (β = –0.222, p = 0.014) by multiple regression analysis after adjustments for the amount of education, gender, smoking, drinking, complication of stroke, body weight, body height, regular medical care, serum albumin, blood HbA1c, and marital status. By logistic regression analysis, the prevalence of a normal MMSE score (MMSE ≧24) was increased by 9% with each 1-kg increase in hand-grip strength of the left hand (OR 1.087, 95% CI 1.003–1.179, p = 0.042), and was increased by 6% with each step per 10 s in stepping rate (OR 1.060, 95% CI 1.000–1.122, p = 0.048). Conclusion: In a very elderly population of 85-year-olds, cognitive function was associated with some physical fitness measurements, independent of confounding factors.

Relationship between tooth loss and mortality in 80-year-old Japanese community-dwelling subjects

BackgroundFindings from several studies suggest associations between tooth loss and health outcomes, including malnutrition, poor quality of life, and mortality, in older individuals. However, limited information is available regarding whether those associations remain true in very elderly subjects after adequately considering confounding factors such as sex and smoking status. Herein, we determined whether the number of teeth in 80-year-old subjects is an independent predictor of mortality.MethodsWe initially contacted 1282 80-year-old community-dwelling individuals born in 1917, of whom 697 responded and participated in a baseline study, with follow-up examinations conducted 4 and 5.5 years later. Data from interviews and medical and oral examinations were obtained, and oral health was determined according to the number of teeth remaining in the oral cavity.ResultsA total of 108 and 157 subjects died in 4 years and 5.5 years, respectively, after the baseline study. Tooth loss was significantly associated with mortality at age 85.5, but not at age 84, after adjusting for potential confounders. When the analysis was stratified by sex, we found a stronger association in females in follow-up examinations conducted at both 4- and 5.5 years. On the other hand, the effect of tooth loss on mortality was not significantly different between smokers and non-smokers.ConclusionTooth loss is a significant predictor of mortality independent of health factors, socio-economic status, and lifestyle in octogenarians, with a stronger association in females.

Relationship between chewing ability and high‐level functional capacity in an 80‐year‐old population in Japan

OBJECTIVES To evaluate the association between high-level functional capacity and chewing in a middle-old community-based population. BACKGROUND Although basic and instrumental activities of daily living are known to be associated with chewing ability in the elderly, an association between higher levels of competence and chewing ability has not been evaluated in the elderly. MATERIALS AND METHODS The association between chewing ability using a number of different foods and high-level functional capacity by the Tokyo Metropolitan Institute of Gerontology was evaluated in 694, 80-year-old people residing in Fukuoka Prefecture, Japan. RESULTS A significant correlation was found, using multiple regression or logistic regression analyses adjusted for various confounding factors, between the number of total chewable foods, hard foods or moderately hard foods, and total functional capacity, instrumental activity, intellectual activity or social role ability. In contrast, the number of slightly hard foods, easily chewable foods and remaining teeth were only partly related to total functional capacity and intellectual activity. CONCLUSION High-level functional capacity including intellectual activity and social role in middle-old elderly was associated with the ability to chew hard foods than to chew easily chewable foods. Maintenance of chewing ability in elderly might result in better intellectual activity and social role.

Association of cortisol and dehydroepiandrosterone sulphate levels in serum with periodontal status in older Japanese adults.

BACKGROUND AND AIM The associations between periodontitis and stress-related steroid hormone levels released by the hypothalamic-pituitary-adrenal axis are poorly understood. In this study, we examined the association between levels of the stress-related steroid hormones cortisol and dehydroepiandrosterone-sulphate (DHEAS) and periodontitis in elderly subjects. METHODS A total of 467 subjects participated in this study. Serum cortisol and DHEAS levels were determined, and a medical questionnaire regarding medical conditions and lifestyle was administered. In addition, clinical examinations including probing depth (PD), bleeding on probing (BOP), and clinical attachment loss (CAL) were conducted. RESULTS The subjects were divided into tertiles on the basis of periodontitis severity. When the analysis was stratified by smoking status, we found that cortisol levels were significantly higher in those with severe CAL among subjects who had never smoked. Furthermore, multiple regression analysis showed that a higher level of cortisol was significantly associated with greater numbers of sites with severe CAL only in those who had never smoked, while a somewhat weaker association was also observed regarding cortisol/DHEAS ratio. In contrast, the level of DHEAS in serum was not associated with periodontitis. CONCLUSION There were significant associations between serum cortisol level, including cortisol/DHEAS ratio, and periodontitis severity in elderly subjects who had never smoked.

Impaired Insulin Secretion by Diphenyleneiodium Associated with Perturbation of Cytosolic Ca2+ Dynamics in Pancreatic β-Cells

Pancreatic islets express the superoxide-producing nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system, but its role remains unknown. To address this, we studied the mechanisms of impaired insulin secretion induced by diphenyleneiodium (DPI), an NADPH oxidase inhibitor. We investigated the effects of DPI on glucose- and nonfuel-stimulated insulin secretion, islet glucose metabolism, and intracellular Ca2+ concentration ([Ca2+]i) dynamics in rat islets and beta-cell line RINm5F cells. DPI did not affect insulin secretion at 3.3 mm glucose but totally suppressed insulin secretion stimulated by 16.7 mm glucose (percentage of control, 9.2 +/- 1.2%; P <0.001). DPI also inhibited insulin release by high K+-induced membrane depolarization (percentage of control, 36.0 +/- 5.3%; P <0.01) and protein kinase C activation (percentage of control, 30.2 +/- 10.6% in the presence of extracellular Ca2+, P <0.01; percentage of control, 42.0 +/- 4.7% in the absence of extracellular Ca2+, P <0.01). However, DPI had no effect on mastoparan-induced insulin secretion at 3.3 and 16.7 mm glucose under Ca2+-free conditions. DPI significantly suppressed islet glucose oxidation and ATP content through its known inhibitory action on complex I in the mitochondrial respiratory chain. On the other hand, DPI altered [Ca2+]i dynamics in response to high glucose and membrane depolarization, and DPI per se dose-dependently increased [Ca2+]i. The DPI-induced [Ca2+]i rise was associated with a transient increase in insulin secretion and was attenuated by removal of extracellular Ca2+, by L-type voltage-dependent Ca2+ channel blockers, by mitochondrial inhibitors, or by addition of 0.1 or 1.0 microm H2O2 exogenously. Our results showed that DPI impairment of insulin secretion involved altered Ca2+ signaling, suggesting that NADPH oxidase may modulate Ca2+ signaling in beta-cells.