Association of estimated white matter hyperintensity age with cognition in elderly with controlled hypertension.

INTRODUCTION: Hypertension is associated with white matter hyperintensity (WMH) and cognitive impairment. Further, WMH is associated with cognitive impairment including executive, attention and visuospatial functions. The aim of this study was to investigate the effects of controlled hypertension (cHT) and previously developed concept, 'WMH age' on cognitive function and the mediating role of WMH in the effect of cHT on cognitive impairment. METHODS: We enrolled 855 Koreans without dementia aged 60 years or older, 326 of whom completed 2-year follow-up assessment. We measured their blood pressure thrice in a sitting position using an automated blood pressure monitoring device. We estimated 'WMH age' of every participant using previously developed WMH probability map of healthy older Koreans. We analyzed the mediating effect of WMH age in the association of cHT and cognitive function using the PROCESS Macro model. RESULTS: Old WMH age was associated with a faster decline in the Mini-Mental Status Examination (MMSE; p =.003), Consortium to Establish a Registry for Alzheimer's Disease total score (CERAD-TS; p =.003), and Frontal Assessment Battery (FAB; p =.007). Old WMH age showed an approximately-six times higher risk of incident mild cognitive impairment (OR = 6.47, 95 % CI = 1.37 - 9.50, p =.024) compared to young or normal WMH age over the 2-year follow-up period in the cHT group. WMH age mediated the effects of cHT on the MMSE, CERAD-TS, and FAB scores at baseline and two-year follow-up period. CONCLUSIONS: WMH mediates the adverse effect of hypertension on cognitive function. Elders with cHT who have older WMH age may be at a higher risk of cognitive decline.

Counterintuitive relationship between visceral fat and all-cause mortality in an elderly Asian population.

OBJECTIVE: Abdominal obesity is considered to be a risk factor for mortality. However, recent studies indicate that overweight may be negatively associated with mortality ("obesity paradox"). The relationships between mortality and various obesity markers in an elderly Asian cohort were evaluated. METHODS: Subjects of the Korean Longitudinal Study on Health and Aging (KLoSHA) (n = 1000, age ≥65 years) were included. The visceral fat area (VFA) and subcutaneous fat area (SFA) were measured using computed tomography. RESULTS: A total of 222 deaths occurred during the 6-year follow-up (median = 5.2 [range 0.1-6.3] years). Body mass index (BMI), VFA, SFA, and total fat mass were negatively associated with all-cause mortality in the univariable analyses (hazard ratio [HR] 0.67 per 1 SD [95% CI 0.57-0.77], 0.66 [0.55-0.79], 0.73 [0.61-0.86], and 0.74 [0.63-0.87], respectively). BMI and VFA were significantly associated with all-cause mortality in the multivariable analyses (HR 0.85 per 1 SD [95% CI 0.73-0.99] and 0.64 [0.47-0.87], respectively). When stratified by quartiles, the HR associated with VFA was the lowest in the third quartile. CONCLUSIONS: In this observational study with a short follow-up of elderly Asian people, higher amounts of visceral fat, a marker for central obesity, were associated with decreased all-cause mortality.

Prevalence of monoclonal gammopathy of undetermined significance in an elderly urban Korean population.

Research on the epidemiology of monoclonal gammopathy of undetermined significance (MGUS) is limited in Korea. The aim of this study was to determine the prevalence and characteristics of MGUS in an elderly urban Korean population. A random sample of 1118 Korean elders was selected from residents aged 65 years or older living in Seongnam, Korea 1 year from August 2005. We obtained plasma samples remaining after scheduled tests for the Korean Longitudinal Study on Health and Aging. The mean age of the study population was 72 years (range, 65-97 years). To screen for MGUS, immunofixation and free light-chain (FLC) assays were performed. Age-adjusted and gender-adjusted MGUS prevalence rates in 680 responders were estimated as 3.3% [95% confidence interval (CI) = 2.0-4.6%], and the estimated age-adjusted prevalence of MGUS was 4.3% in men (95% CI = 1.9-6.6%) and 2.6% in women (95% CI = 1.0-4.2%). Abnormal FLC ratios were detected in 10% of MGUS cases. Multivariate analysis of 945 participants revealed that significant risk factors for MGUS included advanced age, male sex, hyperproteinemia, increased erythrocyte sedimentation rate, and abnormal FLC ratio. MGUS is less prevalent among elderly Koreans (3.3%) than other races. This is the first study to estimate the prevalence of MGUS in the Korean elderly population. Our findings should be confirmed with additional studies analyzing follow-up samples from 2010.