Biomedical subjects

Siu L Hui

Publications and source records attributed to Siu L Hui.

26 records · Page 2Linked to original sources

PubMed2003

Apolipoprotein E and mortality in African-Americans and Yoruba.

The literature on the association between apolipoprotein E (ApoE) and mortality across ethnic and age groups has been inconsistent. No studies have looked at this association in developing countries. We used data from the Indianapolis-Ibadan Dementia study to examine this association between APOE and mortality in 354 African-Americans from Indianapolis and 968 Yoruba from Ibadan, Nigeria. Participants were followed up to 9.5 years for Indianapolis and 8.7 years for Ibadan. Subjects from both sites were divided into 2 groups based upon age at baseline. A Cox proportional hazards regression model adjusting for age at baseline, education, hypertension, smoking history and gender in addition to time-dependent covariates of cancer, diabetes, heart disease, stroke, and dementia was fit for each cohort and age group. Having ApoE epsilon4 alleles significantly increased mortality risk in Indianapolis subjects under age 75 (hazard ratio: 2.00; 95% CI: 1.19-3.35; p = 0.0089). No association was found in Indianapolis subjects 75 and older (hazard ratio: 0.71; 95% CI: 0.45-1.10; p = 0.1238), Ibadan subjects under 75 (hazard ratio: 1.04; 95% CI: 0.78 to 1.40; p = 0.7782), or Ibadan subjects over 75 (hazard ratio: 1.21; 95% CI: 0.83 to 1.75; p = 0.3274).

Aged↗

PubMed2002

Risk of mortality for dementia in a developing country: the Yoruba in Nigeria.

BACKGROUND: Limited data exist on the impact of dementia in developing nations, including its association with mortality. OBJECTIVE: The purpose of this paper is to assess the relationship between dementia and five-year mortality on a community dwelling elderly Yoruba population in the developing country of Nigeria and to compare those results with those from an elderly African-American community in Indianapolis. METHODS: A two-phase design was used to ascertain dementia status in two sites. In the first phase, the Community Screening Instrument for Dementia (CSI-D) was administered. In the second phase, subjects were sampled for the clinical assessment according to their CSI-D performance category. Proportional hazards regression was used to assess the relationship between mortality and cognitive status at both sites after adjusting for demographics and chronic disease conditions. RESULTS: For the entire screened population, poor and intermediate performance on the CSI-D is associated with increased mortality at both sites; however the effect of CSI-D performance did not significantly differ between the two sites. For the clinically assessed sample, dementia was significantly associated with increased mortality at both sites (Ibadan RR = 2.83, Indianapolis RR = 2.05), but the effect was not significantly different across the two sites. CONCLUSION: Dementia resulted in an increased risk of mortality for Yoruba of a magnitude similar to African-Americans suggesting that the impact of dementia on mortality risk may be similar for developing and developed countries.

Aged↗

PubMed2002

Six-item screener to identify cognitive impairment among potential subjects for clinical research.

OBJECTIVE: To design a brief cognitive screener with acceptable sensitivity and specificity for identifying subjects with cognitive impairment. DESIGN: Cohort one is assembled from a community-based survey coupled with a second-stage diagnostic evaluation using formal diagnostic criteria for dementia. Cohort two is assembled from referrals to a specialty clinic for dementing disorders that completed the same diagnostic evaluation. SETTING: Urban neighborhoods in Indianapolis, Indiana and the Indiana Alzheimer Disease Center. PATIENTS: Cohort one consists of 344 community-dwelling black persons identified from a random sample of 2212 black persons aged 65 and older residing in Indianapolis; cohort two consists of 651 subject referrals to the Alzheimer Disease Center. MEASUREMENTS: Formal diagnostic clinical assessments for dementia including scores on the Mini-mental state examination (MMSE), a six-item screener derived from the MMSE, the Blessed Dementia Rating Scale (BDRS), and the Word List Recall. Based on clinical evaluations, subjects were categorized as no cognitive impairment, cognitive impairment-not demented, or demented. RESULTS: The mean age of the community-based sample was 74.4 years, 59.4% of the sample were women, and the mean years of education was 10.1. The prevalence of dementia in this sample was 4.3% and the prevalence of cognitive impairment was 24.6%. Using a cut-off of three or more errors, the sensitivity and specificity of the six-item screener for a diagnosis of dementia was 88.7 and 88.0, respectively. In the same sample, the corresponding sensitivity and specificity for the MMSE using a cut-off score of 23 was 95.2 and 86.7. The performance of the two scales was comparable across the two populations studied and using either cognitive impairment or dementia as the gold standard. An increasing number of errors on the six-item screener is highly correlated with poorer scores on longer measures of cognitive impairment. CONCLUSIONS: The six-item screener is a brief and reliable instrument for identifying subjects with cognitive impairment and its diagnostic properties are comparable to the full MMSE. It can be administered by telephone or face-to-face interview and is easily scored by a simple summation of errors.

Black or African American↗

PubMed2002

Bone loss at the femoral neck in premenopausal white women: effects of weight change and sex-hormone levels.

To investigate whether bone loss occurs in the premenopause, we measured the bone mineral content (BMC), bone mineral density (BMD), and bone area in the spine (L2-L4), femoral neck, and total hip, as well as the sex hormone levels of 130 healthy premenopausal white women (age, 31-50 yr) at least three times over 1-9 yr. We found an increase in all three bone measurements at the spine but no change in volumetric density. Neither could we detect any age-related changes in any of the three measurements in the total hip. In contrast, we detected a significant decrease in femoral neck BMD over time, due to a decrease in BMC and increase in bone area. Greater loss in femoral neck BMD was associated independently with weight loss and lower levels of estrone sulfate or E2. Separating the women into those with FSH spikes (>20 IU/liter) and women with consistently low FSH, we found the latter group had smaller decrease in BMD and that the decrease was due less to a decline in BMC and more to an increase in bone area. In summary, femoral neck BMD decreases in premenopausal women, particularly those with lower levels of estrogens resulting from slowing ovarian function despite regular menses. This decrease can be offset by more rapid weight gain.

Adult↗

PubMed2002

Measurement of tartrate-resistant acid phosphatase and the brain isoenzyme of creatine kinase accurately diagnoses type II autosomal dominant osteopetrosis but does not identify gene carriers.

Autosomal dominant osteopetrosis type II (ADO2) is typically diagnosed from radiographs, which demonstrate the pathognomonic findings of osteosclerosis and endobone formation. Individuals with ADO2 also have elevated serum levels of tartrate-resistant acid phosphatase (TRAP) and the BB isoenzyme of creatine kinase (CK-BB). In the current study, we tested the utility of these enzymes in making or refuting a diagnosis of ADO2. Furthermore, because ADO2 has incomplete penetrance, we examined whether TRAP and CK-BB were helpful in identifying gene carriers. We studied eight families, measured serum levels of TRAP and CK-BB in 52 affected individuals and 12 obligate gene carriers, and compared their values with age-matched controls. Our results demonstrate that affected patients have significantly elevated levels of both TRAP and CK-BB. In contrast, gene carriers have values that are not different from controls. Furthermore, in our study population, TRAP and CK-BB have a high diagnostic sensitivity and specificity, particularly in children. From this large study of ADO2 patients and carriers, we conclude that: 1) TRAP and CK-BB are significantly elevated in patients with ADO2, 2) obligate carriers cannot be adequately identified by measurement of these analytes, and 3) TRAP and CK-BB are highly sensitive and specific diagnostic tests that can efficiently and effectively screen high-risk individuals who have not had previous radiographic assessment.

Acid Phosphatase↗

PubMed2002

Sibling pair linkage and association studies between peak bone mineral density and the gene locus for the osteoclast-specific subunit (OC116) of the vacuolar proton pump on chromosome 11p12-13.

A major determinant of the risk of osteoporosis is peak bone mineral density (BMD), which has been shown to have substantial heritability. The genes for 3 BMD-related phenotypes (autosomal dominant high bone mass, autosomal recessive osteoporosis-pseudoglioma, and autosomal recessives osteopetrosis) are all in the chromosome 11q12-13 region. We reported linkage of peak BMD in a large sample of healthy premenopausal sister pairs to this same chromosomal region, suggesting that the genes underlying these 3 disorders may also play a role in determining peak BMD within the normal population. To test this hypothesis, we examined the gene responsible for 1 form of autosomal recessive osteopetrosis, TCIRG1, which encodes an osteoclast-specific subunit (OC116) of the vacuolar proton pump. We identified 3 variants in the sequence of TCIRG1, but only one, single nuclear polymorphism 906713, had sufficient heterozygosity for use in genetic analyses. Our findings were consistent with linkage to femoral neck BMD, but not to spine BMD, in a sample of 995 healthy premenopausal sister pairs. However, further analysis, using both population and family-based disequilibrium approaches, did not demonstrate any evidence of association between TCIRG1 and the spine or femoral neck BMD. Therefore, our linkage data suggest that the chromosomal region that contains OC116 harbors a gene that affects peak BMD, but our association results indicate that polymorphisms in the OC116 gene do not affect peak BMD.

Adult↗

PubMedDate not supplied

Low yield of thyroid-stimulating hormone testing in elderly patients with depression.

Although hypothyroidism is purportedly an important cause of depression, prior studies have involved small samples of young people and produced conflicting results. We examined the yield of thyroid-stimulating hormone (TSH) testing in a large group of elderly patients with major depression or dysthymic disorder. The study sample comprised 883 outpatients aged 60 years or older from 18 primary care sites enrolled in the intervention arm of a clinical trial of depression management. Thyroid function was assessed by a single TSH value. Depressive diagnoses were confirmed with the Structured Clinical Interview for DSM-IV (SCID) and depression severity was assessed with the HSCL-20, a modified depression scale of the Hopkins Symptom Checklist. TSH results were available for 725 (82.1%) participants. Although 32 (4.4%) of those tested had TSH>5 mIU/L, the vast majority (27/32) had marginally elevated results (5.1-9.4 mIU/L). Only five patients (0.7%) had TSH levels >10 mIU/L. Patients with elevated TSH did not differ from those with TSH < or = 5 mIU/L in the severity or symptom pattern of depression as measured by the baseline HSCL-20 score (P=.37) or SCID score (P=.44). These findings should caution physicians against acceptance of borderline TSH values as the primary cause of a patient's clinical depression.

Aged↗

PubMedDate not supplied

Informant reports of changes in personality predict dementia in a population-based study of elderly african americans and yoruba.

OBJECTIVE: The authors conducted a longitudinal, population-based survey of African Americans in Indianapolis, Indiana, and Yoruba in Ibadan, Nigeria, using the Community Screening Interview for Dementia to assess the predictive value of informant reports of changes in personality on incident dementia and Alzheimer disease. METHODS: In all, 3,021 subjects had informants' reports of changes in personality and dementia status (2,084 subjects residing in Ibadan and 937 subjects residing in Indianapolis). RESULTS: After adjusting for demographic, cognitive, and functional characteristics in two markedly different populations, socioeconomically and culturally, subjects with changes in personality had approximately twice the odds of having dementia as subjects with no change in personality. CONCLUSION: The finding that in two markedly different populations, personality change is a significant predictor of future dementia, independent of cognition and functional status, should make clinicians particularly sensitive to these reports when they occur in their elderly patients.

Black or African American↗