Prevalence and correlates of functional disability in multiethnic elderly Singaporeans

OBJECTIVES: To make comparative estimates of prevalence of late-life functional disability, examine sociodemographic and health correlates, investigate sex and ethnic differences, and estimate population attributable risk of modifiable risk factors. DESIGN: Population-based survey. SETTING: Multiethnic population of Singapore (3 million residents). PARTICIPANTS: Noninstitutionalized Chinese, Malay, and Indian people aged 60 and older (N=1,079) MEASUREMENTS: Functional disability was defined as needing help in at least one basic activity of daily living (ADL) task in the 10 items of the Barthel Index. Five basic ADLs (eating, bathing, dressing, transferring, toileting) were used to compare prevalence with those reported from other national surveys and with reported past prevalence within the country. RESULTS: The prevalence of disability in at least one of five ADL items (6.6% in those aged > or = 65) appeared lower than elsewhere, including China, but higher than reported past prevalence within the country. Functional disability on at least one of the 10 ADL items was independently associated with female sex, Indian ethnicity, older age, poor self-rated health, specific chronic diseases, cognitive impairment, sensory impairment, and living with others. The population attributable risks for leading modifiable factors were arthritis (12%) and cognitive impairment (14%). CONCLUSION: Lower prevalence of functional disability accompanies rapid aging and health transition in Singapore than in other countries but higher prevalence than reported past prevalence within the country. Associations with sociodemographic and health-related factors were consistent with Western studies, including unexplained sex and ethnic differences.     

Folate, Vitamin B12, Homocysteine, and Depressive Symptoms in a Population Sample of Older Chinese Adults

OBJECTIVES: To investigate the independent associations between folate, B12, and homocysteine levels and depressive symptoms in older adults.
DESIGN: Cross-sectional study.
SETTING: Resident population in southeast Singapore.
PARTICIPANTS: Six hundred sixty-nine community-living noninstitutionalized Chinese adults aged 55 and older.
MEASUREMENTS: Laboratory values of folate, vitamin B12, and homocysteine were examined for their independent relationships with depressive symptoms (Geriatric Depression Scale (GDS) score ≥5).
RESULTS: Respondents with depression (n=178) had lower mean serum folate concentrations (21.5 nmol/L) than those without (n=491, 24.0 nmol/L, P =.04). There was a linear relationship between descending quartiles of folate concentrations and increasing odds of association with depressive symptoms, independent of other risk factors (demographic, psychosocial, alcohol and smoking, chronic morbidity, functional status, nutritional risk, albumin, anemia, depression-inducing medications, use of antidepressants and vitamin supplements), including B12 and homocysteine ( P for trend=.02). The odds ratio (OR) of association between low folate (lowest quartile: <14.6 nmol/L) and depressive symptoms independent of other risk factors, including homocysteine and B12, was 1.72 (95% confidence interval (CI)=1.11–2.66). Vitamin B12 across a range of values did not show a linear association, but B12 deficiency (<180 pmol/L) appeared to be significantly associated with depressive symptoms (OR=2.68, 95% CI=1.20–6.00), independent of folate and homocysteine.
CONCLUSION: Decreasing and low levels of serum folate and deficient levels of B12 were associated with greater risk of depressive symptoms in older Chinese adults.     

Anemia of the Belgrade rat: evidence for defective membrane transport of iron

The mechanisms underlying the impaired utilization of transferrin-bound iron by erythroid cells in the anemia of the Belgrade laboratory rat were investigated using reticulocytes from homozygous anemic animals and transferrin labeled with 59Fe and 125I. The results were compared with those obtained using reticulocytes from phenylhydrazine-treated rats and iron-deficient rats. Each step in the iron uptake mechanism was investigated, ie, transferrin-receptor interaction, transferrin endocytosis, iron release from transferrin, and transferrin exocytosis. Although there were quantitative differences, no fundamental difference was found in any of the abovementioned aspects of cellular function when the reticulocytes from Belgrade rats were compared with those from iron-deficient animals. The basic defect in the Belgrade reticulocytes must therefore reside in subsequent steps in iron uptake, after it is released from transferrin within endocytotic vesicles, ie, in the mechanism by which it is transferred across the lining membrane of the vesicles into the cell cytosol. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of reticulocyte ghosts extracts demonstrated a prominent protein band of mol wt 69,000 that was absent or present only in low concentration extracts from the other two types of reticulocytes. This may be a result of the genetic defect.     

Major Neurological Disease and Occupational Exposure to Organic Solvents

Five patients are described who presented with major organicbrain disease affecting one or more of pyramidal and extrapyramidaltracts, cerebellum, and higher cortical functions. All had ahistory of 10 years or more of regular occupational exposureto solvents in confined spaces, three in painting inside shipsand the others in weapons maintenance and printing. All hadbeen regularly exposed to high air vapour peaks as well as toskin contamination. Four showed some evidence of improvementafter the exposure ceased. None was initially suspected of havinga toxic encephalopathy by the consultant to whom he was referred.The spectrum of neurological disease presented by these menmirrors closely that described in solvent abusers. All wereforced by illness to retire from their work, a circumstancewhich might have in the past have led to such conditions beingmissed in cross-sectional studies, which in general have notshown evidence of major disease. We suggest that when such diseaseoccurs nowadays, its cause is usually not suspected. Furtherepidemiological study of the problem is necessary.     

Basilar venous plexus of the posterior fossa: a potential source of error in petrosal sinus sampling

Sampling of serum from the inferior petrosal sinus can provide important information about the source of elevated adrenocorticotropic hormone (ACTH) levels. This often leads to improved results of pituitary surgery for Cushing disease. The authors describe a successful catheterization technique and illustrate the venous anatomy of the inferior petrosal sinuses and basilar plexus.