Elevated depressive symptoms in metabolic syndrome in a general population of Japanese men: a cross-sectional study

BACKGROUND

Uncertainty still surrounds the association between metabolic syndrome (MetS) and depression. We aimed to evaluate the association between MetS and elevated depressive symptoms in a general Japanese population.

METHODS

This is a cross-sectional survey of 3,113 community-dwelling individuals aged 40 years or over. MetS was defined according to the joint interim statement. MetS was diagnosed when a subject had three or more of the following components: 1) central obesity (waist circumference ≥ 90 cm for men, ≥ 80 cm in for women); 2) elevated blood pressure (≥ 130/85 mmHg or current use of antihypertensive medication); 3) hypertriglyceridemia (≥ 1.7 mmol/L); 4) low HDL cholesterol (< 1.0 mmol/L for men, < 1.3 mmol/L for women); and 5) elevated fasting plasma glucose (≥ 5.55 mmol/L or current use of antidiabetic medication). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). The age- and multivariable-adjusted odds ratio (OR) and 95% confidence interval (CI) were estimated using a logistic regression model.

RESULTS

Elevated depressive symptoms were observed in 4.3% of male and 6.3% of female participants. In men, the age-adjusted prevalence of elevated depressive symptoms was significantly higher in subjects with MetS than in those without (7.1% versus 3.6%, p = 0.04). The prevalence of elevated depressive symptoms rose progressively as the number of MetS components increased (3.5%, 3.6%, 5.8%, and 9.2% in male subjects with 0-1, 2, 3, and ≥ 4 components, respectively; p = 0.02 for trend). This association remained significant even after adjustment for age, marital status, history of cardiovascular disease, smoking habit, alcohol intake, and regular exercise. In women, on the other hand, there was no clear association between MetS and depressive symptoms.

CONCLUSIONS

MetS was associated with elevated depressive symptoms in a general population of Japanese men.

Trends in prevalence of Alzheimer's disease and vascular dementia in a Japanese community: the Hisayama Study

OBJECTIVE

To examine secular trends in the prevalence of Alzheimer's disease (AD) and vascular dementia (VD) in a general Japanese population.

METHOD

Four cross-sectional examinations were conducted among residents of a Japanese community aged >or=65 in 1985, 1992, 1998 and 2005.

RESULTS

The age- and sex-adjusted prevalence of all-cause dementia significantly increased with time (6.0% in 1985, 4.4% in 1992, 5.3% in 1998 and 8.3% in 2005; P for trend = 0.002). A similar trend was observed for AD (1.1%, 1.3%, 2.3% and 3.8% respectively; P for trend < 0.001), while the age- and sex-adjusted prevalence of VD and other/unclassified dementia showed J-shaped patterns (for VD: 2.3%, 1.5%, 1.5% and 2.5%, respectively, P for trend = 0.82; for other/unclassified dementia: 2.6%, 1.7%, 1.5% and 2.0%, P for trend = 0.26). The prevalence of AD was likely to increase with time from 1985 to 2005 among subjects aged 75 or older. The ratio of the prevalence of VD to that of AD decreased with time (2.1 in 1985, 1.2 in 1992, 0.7 in 1998 and 0.7 in 2005).

CONCLUSION

Our findings suggest that the prevalence of all-cause dementia and AD significantly increased over the past two decades in the general Japanese population.

Insulin resistance is associated with the pathology of Alzheimer disease: the Hisayama study

OBJECTIVE

We examined the association between diabetes-related factors and pathology of Alzheimer disease (AD) to evaluate how diabetes affects the pathogenic process of AD.

METHODS

This study included specimens from a series of 135 autopsies of residents of the town of Hisayama in Fukuoka prefecture (74 men and 61 women) performed between 1998 and 2003, who underwent a 75-g oral glucose tolerance test in clinical examinations in 1988. We measured diabetes-related factors including fasting glucose, 2-hour post-load plasma glucose, fasting insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) in 1988. Neuritic plaques (NPs) were assessed according to the Consortium to Establish a Registry for Alzheimer's Disease guidelines and neurofibrillary tangles (NFTs) were assessed according to Braak stage. The associations between each factor and AD pathology were examined by analysis of covariance and logistic regression analyses.

RESULTS

Higher levels of 2-hour post-load plasma glucose, fasting insulin, and HOMA-IR were associated with increased risk for NPs after adjustment for age, sex, systolic blood pressure, total cholesterol, body mass index, habitual smoking, regular exercise, and cerebrovascular disease. However, there were no relationships between diabetes-related factors and NFTs. Regarding the effects of APOE genotype on the risk of AD pathology, the coexistence of hyperglycemia and APOE epsilon4 increased the risk for NP formation. A similar enhancement was observed for hyperinsulinemia and high HOMA-IR.

CONCLUSION

The results of this study suggest that hyperinsulinemia and hyperglycemia caused by insulin resistance accelerate NP formation in combination with the effects of APOE epsilon4.

[Lifestyle-related diseases as risk factors for dementia]

In this article, we have reviewed the findings of prospective cohort studies throughout the world to examine influences of lifestyle-related diseases on the risks of total dementia, Alzheimer disease (AD), and vascular dementia (VD). In some cohort studies on elderly populations, diabetes was found to be consistently associated with the risk of VD, but was inconsistently associated with the risk of AD. A cohort study on the elderly residents of the town of Hisayama, Japan, revealed the significant associations between glucose intolerance and the risks of both VD and AD. Clinical and experimental evidence has indicated that glucose intolerance and diabetes induce dementia through various mechanisms such as atherosclerosis,microvascular disease, glucose toxicity, and impaired insulin metabolism. No cohort studies have indicated significant associations between late-life hypertension and the risk of AD, and only 1 study has revealed the significant influence of hypertension on the risk of VD in an elderly population. The Hisayama study revealed that late-life hypertension was a significant risk factor for the development of VD but not for AD. A few cohort studies have suggested the presence of significant associations between midlife hypertension and the risks of late-life AD and VD. Metabolic syndrome has been shown to be a risk factor for the development of cognitive impairment, but no prospective cohort studies have investigated the significant influence of this syndrome on the risk of AD or VD. Some cohort studies have examined the associations of hypercholesterolemia with the risk of AD, but the results were inconsistent. Further studies are required to resolve these issues.

Clinicopathological outline of dementia with Lewy bodies applying the revised criteria: the Hisayama study

To explore the validity of the criteria for dementia with Lewy bodies (DLB) revised in 2005, we examined community based consecutive autopsy cases. 10.3% of the non-demented subjects and 31.2% of the demented subjects showed the Lewy body pathology. Applying the revised pathological criteria to the 205 demented subjects, the types of LB pathology of 11 cases (5.4%) were brainstem-predominant, 24 cases (11.7%) were limbic type and 24 cases (11.7%) were diffuse neocortical type, although there were many subjects not to fit the criteria exactly. The prevalence of Lewy bodies (LBs) was almost same regardless of gender; however, the extent of the LB pathology among females was more severe than that in males. The likelihood of DLB being modified by concomitant Alzheimer's pathology was as follows: 27 cases (13.2%) showed low likelihood, 16 cases (7.8%) showed intermediate likelihood and 16 cases (7.8%) showed high likelihood. Since the numbers of clinical features of DLB were significantly higher in the pathological intermediate and high likelihood DLB groups than in the low likelihood DLB group or no LB group, both the intermediate and high likelihood groups of DLB should be considered as pathological DLB.

Lithium concentration correlates with QTc in patients with psychosis

QT prolongation induced by antipsychotics has been reported to be a determinant for the development of torsade de pointes and sudden death. However, the effect of lithium on QT interval has not been fully clarified. The aim of the present study was to elucidate the relationship between serum lithium concentration and QT interval in patients treated with lithium. We examined serum lithium concentrations and electrocardiographic features in 39 inpatients with bipolar affective disorder or schizophrenia. The longest QT interval in the 12 electrocardiographic leads was measured using GE Marquette QT guard System Software, and Bazett formula was used for heart rate correction. The longest QTc was positively correlated with lithium concentration ( r = 0.46, P = .003). Multiple regression analysis revealed that sex (female, P = .037), lower serum K + concentration ( P = .029), and especially, higher serum lithium concentration ( P = .009) were determinants for the prolongation of the QTc.