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Biomedical subjects

Sharon A Jackson

Publications and source records attributed to Sharon A Jackson.

11 recordsLinked to original sources

Metabolic syndrome and cardiovascular disease in older people: The cardiovascular health study.

OBJECTIVES: To assess the prospective association between metabolic syndrome (MetS) and cardiovascular disease (CVD) in older people and to evaluate the effect of lowering the threshold for impaired fasting glucose (IFG) on the prevalence of IFG and MetS and the risk of CVD. DESIGN: Prospective cohort study. SETTING: Four field centers in U.S. communities. PARTICIPANTS: Three thousand five hundred eighty-five subjects in the Cardiovascular Health Study free of diabetes mellitus and CVD at baseline (mean age 72, 62% female, 14% black). MEASUREMENTS: Baseline measures of MetS components and adjudicated incident CVD events. MetS (2001) was defined first using the original criteria from the Third Adult Treatment Panel Report of the National Cholesterol Education Program (> or =3 of the following: large waist circumference (women >88 cm, men >102 cm), elevated triglycerides (> or =1.70 mmol/L), low high-density lipoprotein cholesterol (men <1.04 mmol/L, women <1.30 mmol/L), elevated fasting glucose (6.1-6.9 mmol/L), and high blood pressure (> or =130/85 mmHg or self-reported use of medications for hypertension). Subjects were also classified according to the revised definition of the MetS (2005) that applies the lower threshold for fasting glucose (5.6-6.9 mmol/L). RESULTS: During follow-up (median 11 years), 818 coronary heart disease (CHD), 401 stroke, and 554 congestive heart failure (CHF) events occurred. Age- and race-adjusted hazard ratios (HRs) for CHD, stroke, and CHF were 1.30 (95% confidence interval (CI) = 1.07-1.57), 0.94 (95% CI = 0.73-1.21), and 1.40 (95% CI = 1.12-1.76) for women and 1.35 (95% CI = 1.10-1.66), 1.51 (95% CI = 1.08-2.12), and 1.47 (95% CI = 1.14-1.90) for men, respectively. Overall, women and men with MetS (2005) were 20% to 30% more likely to experience any CVD event than subjects without MetS (2005). Using the lower cut-point for IFG resulted in a near tripling in IFG prevalence (16% to 46%) and an additional 9% classified with MetS (2005) but HRs similar to those estimated from the original MetS (2001) criteria. High blood pressure was the component most strongly associated with incident CHD. CONCLUSION: Results from this study of an elderly, population-based cohort provide support for earlier investigations in primarily middle-aged populations that link the presence of MetS with the development of CVD and further underscore the importance of recognizing and treating its individual components, particularly high blood pressure.

Black or African American↗

Design, synthesis and characterization of a novel class of coumarin-based inhibitors of inducible nitric oxide synthase.

Inducible nitric oxide synthase (iNOS) has been implicated in various central and peripheral pathophysiological diseases. Our high throughput screening initially identified a weak inhibitor of iNOS, thiocoumarin 13. From this lead, a number of potent derivatives were prepared that demonstrate favorable potency, selectivity and kinetics. Compound 30 has an IC50 of 60 nM for mouse iNOS and 185-fold and 9-fold selectivity for bovine eNOS and rat nNOS, respectively. In cellular assays for iNOS, this compound has micromolar potency. Furthermore, two compounds (16 and 30) demonstrate a reasonable pharmacokinetic profile in rodents. The synthesis, SAR, and biological activity of this novel class of compounds is described.

Animals↗

Cadmium and prostate cancer: a critical epidemiologic analysis.

Laboratory data implicate cadmium as a prostate carcinogen. However, epidemiological studies concerning the association between cadmium and prostate cancer are inconclusive. This article reviews the epidemiological literature on cadmium and prostate cancer with a special focus on highly exposed occupational cohorts. We searched the MEDLINE database from 1966 to 2002 for articles on cadmium and prostate cancer. All published analytical and descriptive studies that included relevant data were reviewed. In addition, we reviewed the experience of cohorts highly exposed to cadmium in nickel-cadmium battery plants. Of 4 descriptive studies, 3 reported a positive association between cadmium and prostate cancer. Of 10 case-control studies, 5 (50%) reported a positive association. Of 11 cohorts studies, 3 (33%) found a positive association. Finally, 4 studies on cohorts exposed in occupational nickel-cadmium batteries were identified and analyzed. The summary score of the standardized mortality ratios (SMRs) was weakly but not significantly positive 126 (95% confidence interval C.I.: 83-184). In contrast to laboratory studies, epidemiological studies do not convincingly implicate cadmium as a cause of prostate cancer. Future epidemiological studies that attempt to resolve the discrepancy between laboratory and epidemiological studies of cadmium carcinogenesis may benefit from incorporating biological measures of cadmium exposure.

Cadmium↗

The course of functional decline in older people with persistently elevated depressive symptoms: longitudinal findings from the Cardiovascular Health Study.

OBJECTIVES: To examine the relationship between persistently high depressive symptoms and long-term changes in functional disability in elderly persons. DESIGN: A community-based, prospective, observational study. SETTING: Participant data from the Cardiovascular Health Study. PARTICIPANTS: From the overall sample of 5,888 subjects, three types of participants were identified for this study: (1) persistently depressed individuals, who experienced an onset of depressive symptoms that persisted over 4 years (n=119); (2) temporarily depressed individuals, who experienced an onset of depressive symptoms that resolved over time (n=259); and (3) nondepressed individuals, with persistently low depressive symptoms throughout the follow-up period who were matched on baseline activity of daily living (ADL) scores, sex, and age to the previous two groups combined (n=378). MEASUREMENTS: Four consecutive years of data were assessed: validated measures of depression (10-item CES-D), functional disability (10-item ADL/instrumental ADL measure), physical performance, medical illness, and cognition. RESULTS: The persistently depressed group showed a greater linear increase in functional disability ratings than the temporarily depressed and nondepressed groups. This association between persistent depression and functional disability was robust even when controlling for baseline demographic and clinical/performance measures, including cognition. The persistently depressed group had an adjusted odds ratio (OR) of 5.27 (95% confidence interval (CI) 3.03-9.16) for increased functional disability compared with the nondepressed group over 3 years of follow-up, whereas the temporarily depressed group had an adjusted OR of 2.39 (95% CI=1.55-3.69) compared with the nondepressed group. CONCLUSION: Persistently elevated depressive symptoms in elderly persons are associated with a steep trajectory of worsening functional disability, generating the hypothesis that treatments for late-life depression need to be assessed on their efficacy in maintaining long-term functional status as well as remission of depressive symptoms. These results also demonstrate the need for studies to differentiate between persistent and temporary depressive symptoms when examining their relationship to disability.

Activities of Daily Living↗

The association of personal and neighborhood socioeconomic indicators with subclinical cardiovascular disease in an elderly cohort. The cardiovascular health study.

There has been recent interest in determining whether neighborhood characteristics are related to the cardiovascular health of residents. However, there are no data regarding the relationship between neighborhood socioeconomic status (SES) and prevalence of subclinical cardiovascular disease (CVD) in the elderly. We related personal SES (education, income, and occupation type) and neighborhood socioeconomic characteristics (a block-group score summing six variables reflecting neighborhood income and wealth, education, and occupation) to the prevalence of subclinical CVD (asymptomatic peripheral vascular disease or carotid atherosclerosis, electrocardiogram or echocardiogram abnormalities, and/or positive responses to Rose Questionnaire claudication or angina pectoris) among 3545 persons aged 65 and over, without prevalent CVD, in the Cardiovascular Health Study. Sixty percent of participants had at least one indicator of subclinical disease. Compared to those without, those with subclinical disease had significantly lower education, income, and neighborhood scores and were more likely to have blue-collar jobs. After adjustment for age, gender, and race, those in the lowest SES groups had increased prevalence of subclinical disease compared with those in the highest SES groups (OR = 1.50; 95% CI 1.21, 1.86 for income; OR = 1.41; 95% CI 1.18, 1.69 for education; OR = 1.39; 95% CI 1.16, 1.67 for block-group score). Those reporting a blue-collar lifetime occupation had greater prevalence of subclinical disease relative to those reporting a white-collar occupation (OR = 1.29; 95% CI 1.02-1.59). After adjustment for behavioral and biomedical risk factors, all of these associations were reduced. Neighborhood score tended to remain inversely associated with subclinical disease after adjustment for personal socioeconomic indicators but associations were not statistically significant. Personal income and blue-collar occupation remained significantly associated with subclinical disease after simultaneous adjustment for neighborhood score and education. Personal and neighborhood socioeconomic indicators were associated with subclinical disease prevalence in this elderly cohort. These relationships were reduced after controlling for traditional CVD risk factors.

Aged↗

Neighbourhood environments and mortality in an elderly cohort: results from the cardiovascular health study.

BACKGROUND: It has been postulated that neighbourhood conditions are related to the health of the elderly population but longitudinal studies are rare and confounding by individual level variables remains a possibility. METHODS: Data were obtained from the cardiovascular health study, a population based study of adults aged 65 years and older. Census block groups were used as proxies for neighbourhoods. A summary score was used to characterise the neighbourhood socioeconomic environment. Information on personal socioeconomic indicators, cardiovascular disease prevalence, and cardiovascular risk factors was obtained from the baseline examination. Proportional hazards regression and propensity score matching were used to control for individual level variables. RESULTS: Over the eight year follow up there were 1346 deaths among the 5074 participants, of which 43% were attributable to cardiovascular disease. Among white participants, living in the most disadvantaged neighbourhood group was associated with higher rates of cardiovascular death, after adjustment for income, education, and occupation (hazard ratio (HR) 1.5, 95% confidence intervals (CI) 1.2 to 1.9). No neighbourhood differences were observed for non-cardiovascular deaths. Estimates for black participants were 1.3 (95% CI 0.7 to 2.3) for cardiovascular deaths and 1.4 (95% CI 0.8 to 2.4) for non-cardiovascular deaths, but sample size was small. In white participants, associations of neighbourhood characteristics with cardiovascular mortality persisted after adjustment for prevalent baseline disease and cardiovascular risk factors. The use of propensity score matching led to similar results (HR for the lowest compared with the highest neighbourhood score group: 1.6 95% CI 1.1 to 2.5, controlling for personal socioeconomic indicators). CONCLUSION: Neighbourhood disadvantage is related to rates of cardiovascular death in elderly white adults.

Black or African American↗

Weight-modification trials in older adults: what should the outcome measure be?

BACKGROUND: Overweight older adults are often counseled to lose weight, even though there is little evidence of excess mortality in that age group. Overweight and underweight may be more associated with health status than with mortality, but few clinical trials of any kind have been based on maximizing years of healthy life (YHL), as opposed to years of life (YOL). OBJECTIVE: This paper examines the relationship of body mass index (BMI) to both YHL and YOL. Results were used to determine whether clinical trials of weight-modification based on improving YHL would be more powerful than studies based on survival. DESIGN: We used data from a cohort of 4,878 non-smoking men and women aged 65-100 at baseline (mean age 73) and followed 7 years. We estimated mean YHL and YOL in four categories of BMI: underweight, normal, overweight, and obese. RESULTS: Subjects averaged 6.3 YOL and 4.6 YHL of a possible 7 years. Both measures were higher for women and whites. For men, none of the BMI groups was significantly different from the normal group on either YOL or YHL. For women, the obese had significantly lower YHL (but not YOL) than the normals, and the underweight had significantly lower YOL and YHL. The overweight group was not significantly different from the normal group on either measure. CONCLUSIONS: Clinical trials of weight loss interventions for obese older women would require fewer participants if YHL rather than YOL was the outcome measure. Interventions for obese men or for the merely overweight are not likely to achieve differences in either YOL or YHL. Evaluations of interventions for the underweight (which would presumably address the causes of their low weight) may be conducted efficiently using either outcome measure.

Journal Article↗

Prevalence of renovascular disease in the elderly: a population-based study.

PURPOSE: The purpose of this investigation was to estimate the population-based prevalence of renovascular disease (RVD), defined as > or = 60% diameter-reducing renal artery stenosis or occlusion, and to define its associations with age, gender, race, and other potential risk factors among participants in the Cardiovascular Health Study (CHS). METHODS: The CHS is a multicenter, longitudinal cohort study of cardiovascular disease risk factors, morbidity, and mortality among free-living adults of more than 65 years of age. As part of an ancillary investigation, participants in the Forsyth County cohort of the CHS were invited to undergo renal duplex sonography (RDS) to define the presence or absence of RVD. RVD was defined as stenosis with a focal renal artery peak systolic velocity exceeding 1.8 m/s in the main renal artery and defined as occlusion when an imaged renal artery lacked a Doppler signal. Demographic and atherosclerotic risk factor data were gathered as part of the baseline CHS examination. Univariable tests of association were performed with chi(2) and Student t tests and logistic regression analysis. Multivariate associations were examined with logistic regression analysis. RESULTS: Eight hundred seventy CHS participants underwent RDS. Of these examinations, 834 (96%) were technically adequate to define the presence or absence of RVD. The RDS study cohort had a mean age of 77.2 +/- 4.9 years and consisted of 63% women and 37% men. Participant race was 76% white and 23% African American. The overall prevalence rate of RVD was 6.8%. Among the 57 patients with RVD, 50 (88%) had unilateral disease and seven (12%) had bilateral disease. Seven cases were seen of renal artery occlusion, including one case with contralateral renal artery stenosis. The mean ages of patients with and without RVD were 78.7 +/- 5.7 years and 77.1 +/- 4.9 years (P =.018). RVD was present in 5.5% of women and 9.1% of men (P =.053). RVD was present in 6.9% of white participants and 6.7% of African American participants (P =.933). Multivariate analysis revealed increasing participant age (P =.028; odds ratio, 1.34; 95% CI, 1.03, 1.73), high-density lipoprotein cholesterol levels of less than 40 mg/dL (P =.003; odds ratio, 2.63; 95% CI, 1.40, 4.93), and increasing systolic blood pressure (P =.007; odds ratio, 1.44; 95% CI, 1.10, 1.87) to be significantly and independently associated with the presence of RVD. CONCLUSION: This investigation provides the first population-based estimate of the prevalence of RVD among free-living, elderly black and white Americans. RVD was present in 6.8% of the study cohort. RVD showed no association with ethnicity. However, its presence was significantly and independently associated with increasing age, low high-density lipoprotein cholesterol levels, and increasing systolic blood pressure.

Age Factors↗

Racial differences in service utilization: the Forsyth County Aging Study.

Racial differences in correlates and use of formal home and community services and in the predictive ability of the Andersen-Newman model were examined in older African American and white, community-dwelling adults. Results show greater service use by older African Americans and suggest racial differences in the correlates of service use. Racial differences in the predictive ability of the Andersen-Newman model were also evident. While approximately 78 percent of participants (82 percent of whites and 66 percent of African Americans) were correctly identified, findings regarding sensitivity and specificity suggest that much remains to be learned about factors associated with the use of formal home and community services among older adults.

Activities of Daily Living↗

Preventive foot-care practices among adults with diabetes in North Carolina, 1997 to 2001.

Preventive foot-care practices, such as annual foot examinations by a health-care provider, can substantially reduce the risk of lower-extremity amputations. We examined the level of preventive foot-care practices (reported rates of having at least one foot examination by a physician) among patients with diabetes mellitus in North Carolina and determined the factors associated with these practices. Of 1,245 adult respondents to the 1997 to 2001 North Carolina Behavioral Risk Factor Surveillance System, 71.6% reported that they had had their feet examined within the past year, a rate that is much higher than that previously reported by Bell and colleagues in the same population for 1994 to 1995 (61.7%). Foot care was more common among insulin users than nonusers, those having diabetes for 20 years or longer than those having diabetes for less than 10 years, blacks than whites, and those who self-monitored their blood glucose level daily than those who did not. The results of this study indicate that diabetes educational services can be directed at populations at high risk of ignoring the recommended foot-care practices indicated in these analyses, thereby reducing diabetes-related lower-extremity complications.

Adolescent↗