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Biomedical subjects

T B Harris

Publications and source records attributed to T B Harris.

At least 19 recordsLinked to original sources
PubMed2006

Kidney function and markers of inflammation in elderly persons without chronic kidney disease: the health, aging, and body composition study.

Inflammatory markers are elevated in persons with estimated glomerular filtration rates less than 60 ml/min/1.73 m2. As cystatin C may detect small changes in kidney function not detected by estimated glomerular filtration rate, we evaluated the association between cystatin C and serum markers of inflammation in older adults with estimated glomerular filtration rate >or=60. This is an analysis using measures from the Health, Aging, and Body Composition Study, a cohort of well-functioning adults aged 70-79 years. Cystatin C correlated with all five inflammatory biomarkers: C-reactive protein (r=0.08), interleukin-6 (r=0.19), tumor necrosis factor alpha (TNF-alpha) (r=0.41), soluble TNF receptor 1 (STNF-R1) (r=0.61), and soluble TNF receptor 2 (STNF-R2) (r=0.54); P<0.0005 for all. In adjusted analyses, cystatin C concentrations appeared to have stronger associations with each biomarker compared with estimated glomerular filtration rate or serum creatinine. Participants with a cystatin C>or=1.0 mg/l had significantly higher levels of all five biomarkers compared to those with a cystatin C<1.0 (mean differences ranging 16-29%, all P<0.05). Cystatin C has a linear association with inflammatory biomarkers in an ambulatory elderly cohort with estimated glomerular filtration rates >or=60; associations are particularly strong with TNF-alpha and the STNF-R.

Adult↗
PubMed2006

The role of waist circumference in predicting disability in periretirement age adults.

OBJECTIVE: To measure the risk of periretirement age disability associated with five different anthropometric measures of body mass and shape, and to compare the measures in this group, the peak age group of obesity prevalence. DESIGN: Longitudinal study of Health Survey for England 1998 respondents followed-up in the English Longitudinal Study of Ageing in 2002. SUBJECTS: National population sample of 1030 women and 888 men aged 55-74 years. MEASUREMENTS: Five baseline exposure measures (weight (WT), body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-hip ratio (WHR)) at baseline, and disability outcomes (measured gait speed, self-reported mobility problems, instrumental and ordinary activities of daily living (I/ADLs)) after 5 years. RESULTS: Individually, the heaviest quartile of WC and WHR predicted disability using all outcomes in men. In women, the heaviest category of each of the five exposure measures predicted disability, for each of the outcomes. In competing measures models, WC was included in the best fit model of tested mobility disability in men (odds ratio (OR) 2.4; 95% confidence interval (CI) 1.4-4.1; P<0.05) and women (OR 3.0; 95% CI 1.9-4.8; P<0.001), adjusted for age, height, smoking, social class, and education. WC was also included in the best fit model of all self-reported disabilities in men, and for self-reported I/ADL disabilities in women. CONCLUSIONS: Across the periretirement age period, body mass and shape are major determinants of disability, with increases in WC, a marker for abdominal obesity, best predicting risk for most disability outcomes. This result adds to the case for WC to be used in estimates of obesity-related health risks for epidemiological monitoring and clinical care.

Activities of Daily Living↗
PubMed2005

Low subcutaneous thigh fat is a risk factor for unfavourable glucose and lipid levels, independently of high abdominal fat. The Health ABC Study.

AIMS: We investigated whether low subcutaneous thigh fat is an independent risk factor for unfavourable glucose and lipid levels, and whether these associations differ between sexes, and between white and black adults. Our secondary aim was to investigate which body composition characteristics (lean tissue, fat tissue) are reflected by anthropometric measures (waist and thigh circumference). METHODS: Anthropometric measurements and computed tomography of the abdomen and of the thigh were performed for all participants of the Health, Aging and Body Composition Study, who were aged 70-79 years. Fasting glucose, triglycerides and HDL-cholesterol, and 2-h postload glucose were determined. RESULTS: After excluding those already diagnosed with diabetes or dyslipidaemia, we analysed data from 2,106 participants. After adjustment for abdominal subcutaneous and visceral fat, and intermuscular thigh fat, larger thigh subcutaneous fat area was statistically significantly associated with lower ln-transformed triglycerides [standardised beta (95% CI) -0.12 (-0.20 to -0.04) in men and -0.13 (-0.21 to -0.05) in women] and higher ln-HDL-cholesterol [0.10 (0.02 to 0.19) and 0.09 (0.01 to 0.18), respectively]. The associations with lower glucose levels were strong in men [-0.11 (-0.20 to -0.02) for fasting and -0.14 (-0.23 to -0.05) for postload glucose], but not statistically significant in women [-0.02 (-0.10 to 0.07) and -0.04 (-0.13 to 0.05), respectively]. There were no differences in the associations between white and black persons. Waist circumference was more strongly associated with abdominal subcutaneous fat, and this association became stronger with increasing BMI, whereas the association with visceral fat became weaker. Thigh circumference was equally dependent on thigh fat and thigh muscle in men, whereas in women the fat component was the main contributor. CONCLUSION: Larger subcutaneous thigh fat is independently associated with more favourable glucose (in men) and lipid levels (in both sexes) after accounting for abdominal fat depots, which are associated with unfavourable glucose and lipid levels. Anthropometric measures reflect different fat depots at different levels of BMI at the abdomen, and reflect both fat and lean tissue at the thigh. These results emphasise the importance of accurate measures of regional body composition when investigating potential health risks.

Abdomen↗
PubMed2005

Health consequences of obesity in the elderly: a review of four unresolved questions.

Obesity prevalence is growing progressively even among older age groups. Controversy exists about the potential harms of obesity in the elderly. Debate persists about the relation between obesity in old age and total or disease-specific mortality, the definition of obesity in the elderly, its clinical relevance, and about the need for its treatment. Knowledge of age-related body composition and fat distribution changes will help us to better understand the relationships between obesity, morbidity and mortality in the elderly. Review of the literature supports that central fat and relative loss of fat-free mass may become relatively more important than BMI in determining the health risk associated with obesity in older ages. Weight gain or fat redistribution in older age may still confer adverse health risks (for earlier mortality, comorbidities conferring independent adverse health risks, or for functional decline). Evaluation of comorbidity and weight history should be performed in the elderly in order to generate a comprehensive assessment of the potential adverse health effects of overweight or obesity. The risks of obesity in the elderly have been underestimated by a number of confounders such as survival effect, competing mortalities, relatively shortened life expectancy in older persons, smoking, weight change and unintentional weight loss. Identification of elderly subjects with sarcopenic obesity is probably clinically relevant, but the definition of sarcopenic obesity, the benefits of its clinical identification, as well as its relation to clinical consequences require further study. Studies on the effect of voluntary weight loss in the elderly are scarce, but they suggest that even small amounts of weight loss (between 5-10% of initial body weight) may be beneficial. In older as well as in younger adults, voluntary weight loss may help to prevent the adverse health consequences of obesity.

Adipose Tissue↗
PubMed2002

The prediction of visceral fat by dual-energy X-ray absorptiometry in the elderly: a comparison with computed tomography and anthropometry.

INTRODUCTION: Effective methods for assessing visceral fat are important to investigate the role of visceral fat for the increased health risks in obesity. Techniques for direct measurement of soft tissue composition such as CT or MRI are expensive, time-consuming or require a relatively high radiation dose. Simple anthropometric methods, such as waist-to-hip ratio, waist circumference or sagittal diameter are widely used. However, these methods cannot differentiate between visceral and subcutaneous fat and are less accurate. The aim of the present study is to investigate whether the dual-energy X-ray absorptiometry (DXA) method, possibly combined with anthropometry, offers a good alternative to CT for the prediction of visceral fat in the elderly. METHODS: Subjects were participants in the Health ABC-study, a cohort study of black and white men and women aged 70-79, investigating the effect of weight-related health conditions on disablement. Total body fat and trunk fat were measured by DXA using a Hologic QDR 1500. A 10 mm CT scan at the L4-L5 level was acquired to measure visceral fat and total abdominal fat. Weight, height, sagittal diameter and waist circumference were measured using standard methods. Fat in a manually defined DXA subregion (4 cm slice at the top of iliac crest) at the abdomen was calculated in a sub-group of participants (n=150; 50% male; 45.3% Afro-American/54.7% Caucasian, age 70-79 y). This subregion, the standard trunk region and total fat were used as indicators of visceral fat. RESULTS: Total abdominal fat by DXA (subregion) was strongly correlated with total abdominal fat by CT (r ranging from 0.87 in white men to 0.98 in black women). The DXA subregion underestimated total abdominal fat by 10% compared to the CT slice. The underestimation by DXA was seen especially in people with less abdominal fat. The association of visceral fat by CT with the DXA subregion (r=0.66, 0.78, 0.79 and 0.65 for white and black men and women, respectively) was comparable with the association of the CT measure with the sagittal diameter (r=0.74, 0.70, 0.84 and 0.68). Combining DXA measurements with anthropometry gave only limited improvement for the prediction of visceral fat by CT compared to univariate models (maximal increase of r(2) 4%). CONCLUSION: DXA is a good alternative to CT for predicting total abdominal fat in an elderly population. For the prediction of visceral fat the sagittal diameter, which has a practical advantage compared to DXA, is just as effective.

Abdomen↗
PubMed2001

Cardiovascular disease, interleukin-6, and risk of mortality in older women: the women's health and aging study.

BACKGROUND: Systemic chronic inflammation has been found to be related to all-cause mortality risk in older persons. We investigated whether specific chronic conditions, particularly cardiovascular disease (CVD), affect the association between high interleukin (IL)-6 level and mortality in a sample of disabled older women. METHODS AND RESULTS: IL-6 serum level was measured at baseline in 620 women >/=65 years old. The presence and severity of medical conditions was ascertained by standard criteria that used multiple sources of information. The sample was surveyed over the 3-year follow-up. After adjustment for potential confounders, compared with those in the lowest tertile, women in the highest IL-6 tertile were at higher risk of all-cause mortality. The presence of CVD, however, strongly affected the risk of mortality associated with high IL-6. Among women with prevalent CVD, those with high IL-6 levels had >4-fold risk of death (RR 4.6; 95% CI 2.0 to 10.5) compared with women in the lowest tertile, whereas the relative risk associated with high IL-6 among those without CVD was much lower and not significant (RR 1.8; 95% CI 0.7 to 4.2). Adjustment for all chronic diseases and disease severity measures, including ankle-brachial index, forced expiratory volume, and exercise tolerance, did not change the results. CONCLUSIONS: IL-6 level is helpful in identifying a subgroup of older CVD patients with high risk of death over a period of 3 years. Systemic inflammation, as measured by IL-6, may be related to the clinical evolution of older patients with CVD.

Aged↗
PubMed2001

Prevalence and clinical implications of American Diabetes Association-defined diabetes and other categories of glucose dysregulation in older adults: the health, aging and body composition study.

Using data on history of diabetes, fasting glucose (FG) and the oral glucose tolerance test (OGTT), the authors contrasted cardiovascular disease (CVD) risk factors (body mass index, blood pressure, lipids and glycated hemoglobin) in 3052 African-American and White adults aged 70-79 in mutually exclusive categories of diagnosed diabetes, undiagnosed diabetes defined by the American Diabetes Association (ADA), isolated post-challenge hyperglycemia (IPH; FG < 126 mg/dL and 2 h post-OGTT > or = 200 mg/dL), impaired fasting glucose (IFG; FG > or = 110 but < 126 mg/dL), and individuals who were non-diabetic by both ADA and World Health Organization (WHO) criteria (FG < 126 mg/dL and 2 h post-challenge glucose < 200 mg/dL). The prevalence of diagnosed diabetes, undiagnosed ADA diabetes and IPH were 15.2, 3.8 and 4.7%, respectively, with more diagnosed and undiagnosed ADA diabetes in African-Americans than Whites. Compared to mean glycated hemoglobin (HbA(1c)) among ADA/WHO non-diabetic individuals (6.0%), HbA(1c) was substantially higher in the diagnosed diabetes and undiagnosed ADA diabetes groups (8.0% and 7.7%), but not in the IPH group (6.3%). The diagnosed and undiagnosed ADA diabetic groups had worse CVD risk factor profiles than the ADA/WHO non-diabetic group. IPH subjects had elevated levels of some CVD risk factors, but differences were more modest than those for the diabetic groups. Among people with IPH, those who also had IFG had worse CVD profiles than those with IPH alone. Although the OGTT may identify additional adults with more CVD risk factors than normals, these differences appear to be clustered among those who also have IFG.

Black or African American↗
PubMed2001

The value of serum albumin and high-density lipoprotein cholesterol in defining mortality risk in older persons with low serum cholesterol.

OBJECTIVES: To investigate the relationship between low cholesterol and mortality in older persons to identify, using information collected at a single point in time, subgroups of persons with low and high mortality risk. DESIGN: Prospective cohort study with a median follow-up period of 4.9 years. SETTINGS: East Boston, Massachusetts; New Haven, Connecticut; and Iowa and Washington counties, Iowa. PARTICIPANTS: Four thousand one hundred twenty-eight participants (64% women) age 70 and older at baseline (mean 78.7 years, range 70-103); 393 (9.5%) had low cholesterol, defined as < or =160 mg/dl. MEASUREMENTS: All-cause mortality and mortality not related to coronary heart disease and ischemic stroke. RESULTS: During the follow-up period there were 1,117 deaths. After adjustment for age and gender, persons with low cholesterol had significantly higher mortality than those with normal and high cholesterol. Among subjects with low cholesterol, those with albumin> 38 g/L had a significant risk reduction compared with those with albumin < or =38 g/L (relative risk (RR) = 0.57; 95% confidence interval (CI) = 0.41-0.79). Within the higher albumin group, high-density lipoprotein cholesterol (HDL-C) level further identified two subgroups of subjects with different risks; participants with HDL-C <47 mg/dl had a 32% risk reduction (RR = 0.68; 95% CI = 0.47-0.99) and those with HDL-C > or =47 mg/dl had a 62% risk reduction (RR = 0.38; 95% CI = 0.20-0.68), compared with the reference category; those with albumin < or =38 g/L and HDL-C <47 mg/dl. CONCLUSIONS: Older persons with low cholesterol constitute a heterogeneous group with regard to health characteristics and mortality risk. Serum albumin and HDL-C can be routinely used in older patients with low cholesterol to distinguish three subgroups with different prognoses: (1) high risk (low albumin), (2) intermediate risk (high albumin and low HDL-C), and (3) low risk (high albumin and high HDL-C).

Aged↗
PubMed2001

The relationship of APOE genotype to cognitive functioning in older African-American and Caucasian community residents.

OBJECTIVES: To determine whether cognitive decline associated with the apolipoprotein E (APOE) epsilon4 allele is different in older African Americans than it is in Caucasians. DESIGN: Performance on a brief screen of cognitive functioning was examined at baseline (N = 1,891) and 4 years later (N = 1,389) to determine the extent to which the presence of APOE epsilon4 affected level of and change in performance, and whether this differed as a function of race, age, initial score, and change in score. SETTING: Five adjacent counties in the Piedmont area of North Carolina. PARTICIPANTS: In 1986, a stratified random household sample of community residents age 65 and older (n = 4,162; 54% African-American, 45% Caucasian, 1% other race) formed the Duke Established Populations for Epidemiologic Studies of the Elderly. Of those available at the sixth annual wave, 76% were genotyped, with 1,891 providing baseline data on this wave, and the available survivors (n = 1,389) providing longitudinal data 4 years later. MEASUREMENTS: The Short Portable Mental Status Questionnaire (SPMSQ), a brief screen of cognitive functioning, was administered to all subjects on both occasions. We examined score at baseline and cognitive decline (i.e., increase of 2+ errors) at follow-up. Control measures included demographic characteristics, health behaviors, health and functional status, and medication use. APOE status was coded as epsilon4 present versus absent. RESULTS: APOE epsilon4 was significantly and uniquely related to lower score at baseline and significantly increased the odds of cognitive decline by 59%. There was no statistically significant interaction between APOE epsilon4 and age, race, initial SPMSQ score, or SPMSQ score at follow-up. CONCLUSION: APOE epsilon4 is modestly, if significantly, related to poorer cognitive functioning and to decline in cognitive functioning. No differences were found by age or race in this community representative sample.

Aged↗
PubMed2001

Epidemiologic data on the relationships of caloric intake, energy balance, and weight gain over the life span with longevity and morbidity.

Animal experiments have shown that calorically restricted (CR) animals weigh less and live longer than their ad libitum-fed peers. Are these observations applicable to human beings? This is an important question because the prevalence of obesity in America has increased markedly over recent years. We examine whether there are physiologic effects that occur with CR in humans that could plausibly explain the observed longevity of laboratory animals associated with CR. We also review epidemiologic data from observational and interventional studies on the relationships of caloric intake, energy balance, and weight gain with age-related diseases and longevity. Additionally, data on whether long-term, sustained maintenance of weight loss is feasible, as well as the degree of CR achieved in clinical trials, are summarized. Finally, we provide recommendations regarding further epidemiologic research that will help clarify unanswered questions in these areas.

Energy Intake↗
PubMed2001

Attenuation of skeletal muscle and strength in the elderly: The Health ABC Study.

Although loss of muscle mass is considered a cause of diminished muscle strength with aging, little is known regarding whether composition of aging muscle affects strength. The skeletal muscle attenuation coefficient, as determined by computed tomography, is a noninvasive measure of muscle density, and lower values reflect increased muscle lipid content. This investigation examined the hypothesis that lower values for muscle attenuation are associated with lower voluntary isokinetic knee extensor strength at 60 degrees/s in 2,627 men and women aged 70-79 yr participating in baseline studies of the Health ABC Study, a longitudinal study of health, aging, and body composition. Strength was higher in men than in women (132.3 +/- 34.5 vs. 81.4 +/- 22.0 N x m, P < 0.01). Men had greater muscle attenuation values (37.3 +/- 6.5 vs. 34.7 +/- 7.0 Hounsfield units) and muscle cross-sectional area (CSA) at the midthigh than women (132.7 +/- 22.4 vs. 93.3 +/- 17.5 cm(2), P < 0.01 for both). The strength per muscle CSA (specific force) was also higher in men (1.00 +/- 0.21 vs. 0.88 +/- 0.21 N x m x cm(-2)). The attenuation coefficient was significantly lower for hamstrings than for quadriceps (28.7 +/- 8.7 vs. 41.1 +/- 6.9 Hounsfield units, P < 0.01). Midthigh muscle attenuation values were lowest (P < 0.01) in the eldest men and women and were negatively associated with total body fat (r = -0.53, P < 0.01). Higher muscle attenuation values were also associated with greater specific force production (r = 0.26, P < 0.01). Multivariate regression analysis revealed that the attenuation coefficient of muscle was independently associated with muscle strength after adjustment for muscle CSA and midthigh adipose tissue in men and women. These results demonstrate that the attenuation values of muscle on computed tomography in older persons can account for differences in muscle strength not attributed to muscle quantity.

Adipose Tissue↗
PubMed2001

Race and sex effects on the association between muscle strength, soft tissue, and bone mineral density in healthy elders: the Health, Aging, and Body Composition Study.

Two factors generally reported to influence bone density are body composition and muscle strength. However, it is unclear if these relationships are consistent across race and sex, especially in older persons. If differences do exist by race and/or sex, then strategies to maintain bone mass or minimize bone loss in older adults may need to be modified accordingly. Therefore, we examined the independent effects of bone mineral-free lean mass (LM), fat mass (FM), and muscle strength on regional and whole body bone mineral density (BMD) in a cohort of 2,619 well-functioning older adults participating in the Health, Aging, and Body Composition (Health ABC) Study with complete measures. Participants included 738 white women, 599 black women, 827 white men, and 455 black men aged 70-79 years. BMD (g/cm2) of the femoral neck, whole body, upper and lower limb, and whole body and upper limb bone mineral-free LM and FM was assessed by dual-energy X-ray absorptiometry (DXA). Handgrip strength and knee extensor torque were determined by dynamometry. In analyses stratified by race and sex and adjusted for a number of confounders, LM was a significant (p < 0.001) determinant of BMD, except in white women for the lower limb and whole body. In women, FM also was an independent contributor to BMD at the femoral neck, and both FM and muscle strength contributed to limb BMD. The following were the respective beta-weights (regression coefficients for standardized data, Std beta) and percent difference in BMD per unit (7.5 kg) LM: femoral neck, 0.202-0.386 and 4.7-5.9%; lower limb, 0.209-0.357 and 2.9-3.5%; whole body, 0.239-0.484 and 3.0-4.7%; and upper limb (unit = 0.5 kg), 0.231-0.407 and 3.1-3.4%. Adjusting for bone size (bone mineral apparent density [BMAD]) or body size BMD/height) diminished the importance of LM, and the contributory effect of FM became more pronounced. These results indicate that LM and FM were associated with bone mineral depending on the bone site and bone index used. Where differences did occur, they were primarily by sex not race. To preserve BMD, maintaining or increasing LM in the elderly would appear to be an appropriate strategy, regardless of race or sex.

Absorptiometry, Photon↗
PubMed2001

Low-grade systemic inflammation in overweight children.

OBJECTIVE: Human adipose tissue expresses and releases the proinflammatory cytokine interleukin-6, potentially inducing low-grade systemic inflammation in persons with excess body fat. To limit potential confounding by inflammation-related diseases and subclinical cardiovascular disease, we tested the hypothesis that overweight is associated with low-grade systemic inflammation in children. DESIGN AND SETTING: The third National Health and Nutrition Examination Survey, 1988-1994, a representative sample of the US population. PARTICIPANTS: A total of 3512 children 8 to 16 years of age. OUTCOME MEASURES: Elevated serum C-reactive protein concentration (CRP; >/=.22 mg/dL) and white blood cell count (10(9) cells/L). RESULTS: Elevated CRP was present in 7.1% of the boys and 6.1% of the girls. Overweight children (defined as having a body mass index or a sum of 3 skinfolds (triceps, subscapula, and supra-iliac) above the gender-specific 85th percentile) were more likely to have elevated CRP than were their normal-weight counterparts. After adjustment for potential confounders, including smoking and health status, the odds ratio (OR) was 3.74 (95% confidence interval [CI]: 1.66-8.43) for overweight boys and the OR was 3.17 (95% CI: 1.60-6.28) for overweight girls, based on the body mass index. Based on the sum of 3 skinfolds, these ORs were 5.11 (95% CI: 2.36-11.06) and 2.89 (95% CI: 1.49-5.59) for boys and girls, respectively. Overweight was also associated with statistically significant higher white blood cell counts. The results were similar when restricted to healthy, nonsmoking, nonestrogen-using children. CONCLUSIONS: In children 8 to 16 years of age, overweight is associated with higher CRP concentrations and higher white blood cell counts. These findings suggest a state of low-grade systemic inflammation in overweight children. inflammation, obesity, children.

Adipose Tissue↗
PubMed2001

Is serum uric acid level associated with all-cause mortality in high-functioning older persons: MacArthur studies of successful aging?

OBJECTIVES: To explore the effect of serum uric acid level on subsequent all-cause mortality in high-functioning community-dwelling older persons. It is controversial whether high serum uric acid level is a true independent risk factor for cardiovascular and total mortality or the association is due to other confounding variables. Furthermore, it remains unclear whether the predictive value of uric acid level on mortality observed in younger cohorts can be extended to older people. DESIGN: Prospective cohort study. SETTING: A sample of community-dwelling older people. PARTICIPANTS: A cohort of 870 participants from the MacArthur Studies of Successful Aging. MEASUREMENTS: Baseline information was obtained for serum uric acid level, C-reactive protein (CRP), interleukin-6 (IL-6), prevalent medical conditions, and health behaviors. Crude and multivariate logistic regression analyses were used to examine the association between serum uric acid levels and 7-year all-cause mortality, while adjusting for potential confounders. RESULTS: In men, the multiply adjusted risk ratios for 7-year total mortality were 1.07 (95% CI=0.61-1.88) for the mid tertile of uric acid level and 1.24 (95% CI=0.70-2.20) for the top tertile. In women, the multiply adjusted risk ratios were 0.58 (95% CI=0.29-1.18) and 0.47 (95% CI=0.22-0.99), for the mid and top tertiles respectively. CRP and IL-6 were important confounders in the relationship between serum uric acid and overall mortality. CONCLUSIONS: High serum uric acid level is not independently associated with increased total mortality in high-functioning older men and women. When evaluating the association between serum uric acid and mortality, the potential confounding effect of underlying inflammation and other risk factors must be considered.

Aged↗
PubMed2000

Apo E genotype, diabetes, and peripheral arterial disease in older men: the Honolulu Asia-aging study.

The epsilon4 allele of the gene coding for apolipoprotein (apo) E is associated with an atherogenic lipid profile that has been linked to increased risk of coronary artery disease (CAD). Apo E genotype may also be associated with peripheral arterial disease (PAD). If present, this association may be modified by diabetes, which is also associated with dyslipidemia that predisposes to macrovascular disease. Observable associations between both ApoE genotype and diabetes with PAD may be confounded by smoking, a potent PAD risk factor that is unrelated to lipids. From 1991 to 1993, apo E genotypes (2/3, 3/3, 3/4), PAD (defined as ankle-brachial index [ABI] <0.9), diabetes (prevalent and newly-diagnosed), and smoking history (ever/never) were determined for 3,161 Japanese-American men aged 71-93. Data on hypertension and other potential confounders were also collected. Logistic regression was used to determine odds ratios (OR) between groups cross-categorized by apo E genotype and diabetes with prevalence of PAD, within strata of smoking. In each smoking stratum, non-diabetic apo epsilon3/3 carriers were considered the reference. Among ever-smokers, there was no association between apo E and PAD, regardless of diabetes status. Among never-smokers there appeared to be both apo E- and diabetes effects on PAD prevalence. Compared to the non-diabetic epsilon3/3 group, the ORS of PAD were 2.3 (1.2-4.4) and 2.0 (1.1-3.4) for epsilon3/3 newly-diagnosed and epsilon3/3 prevalent diabetic subjects, respectively. Associations were stronger among diabetic individuals in the epsilon3/4 group: the ORS were 3.0 (1.1-8.8) and 4.1 (1.9-8.7) for epsilon3/4 newly-diagnosed and epsilon3/4prevalent diabetic subjects, respectively. Despite associations whose pattern and magnitude suggested interaction between apo E genotype and diabetes on PAD prevalence among never-smokers, formal testing of this interaction did not reach statistical significance. Our finding of an apo E-PAD association among never-smokers may result from the effects of an apo epsilon4-related atherogenic lipid profile on peripheral arteries. Further studies are needed to clarify the potential mediating role of diabetes on the apo E-PAD association.

Aged↗
PubMed2000

Waist circumference and abdominal sagittal diameter as surrogates of body fat distribution in the elderly: their relation with cardiovascular risk factors.

OBJECTIVE: To evaluate the relationship between supine sagittal abdominal diameter (SAD) and other indicators of body fat distribution with cardiovascular (CVD) risk factors in the elderly. SUBJECTS: One-hundred and forty-six women aged from 67 to 78 y with a body mass index (BMI) ranging from 18.7 to 50.6 kg/m2 and 83 men aged between 67 and 78 y with BMI ranging from 19.8 to 37.1 kg/m2. MEASUREMENT: Body fat distribution was assessed using anthropometric indicators: waist circumference, SAD, waist-to-hip ratio (WHR), waist-to-height ratio and SAD-to-thigh ratio. RESULTS: In women, there was a negative correlation between HDL-cholesterol and body weight, BMI, waist, SAD, WHR, waist-to-height ratio and SAD-to-thigh ratio. A significant association was found between triglycerides, basal glucose, 2 h glucose during oral glucose tolerance test (OGTT), systolic blood pressure (SBP), diastolic blood pressure (DBP) and anthropometric variables. In men a negative correlation was found between HDL-cholesterol and all the anthropometric variables. A significant association was found between triglycerides, DBP and body weight, BMI, waist, SAD and waist-to-height ratio. In women, after adjusting for age and BMI, a significant correlation was observed between waist and HDL-cholesterol, triglycerides and basal glucose. This was also seen with SAD and SAD-to-thigh ratio and triglycerides, basal and 2 h glucose. In men, after adjusting for age and BMI a significant correlation was found between SAD and HDL-cholesterol and triglycerides. When adjustments were made for age and waist, the correlations between BMI and metabolic variables as well between BMI and SBP and DBP were no longer significant. CONCLUSIONS: Our study shows that indicators of body fat distribution are associated with CVD risk factors in the elderly independently of BMI. Our data also show that waist and SAD are the anthropometric indicators of fat distribution which are most closely related to CVD risk factors in old age.

Abdomen↗
PubMed2000

Age, functional status, and racial differences in plasma D-dimer levels in community-dwelling elderly persons.

BACKGROUND: Dysregulation of immunologic and coagulation systems is common in elderly persons and is associated with many diseases of aging. Thrombotic events are a major cause of morbidity and mortality in the elderly population. This study assesses whether D-dimer, a marker of fibrinolytic activity, varies systematically by demographic, health, and functional measures, and derives a prediction model for factors related to D-dimer in a sample of community-dwelling elderly persons. METHODS: D-dimer levels were assessed in a random sample of 1,727 community-dwelling elderly persons from five rural and urban counties in North Carolina in 1992, as part of the Established Populations for the Epidemiologic Studies of the Elderly (Duke University). All subjects were 72 years or older at the time of the blood draw. In addition, all subjects were surveyed yearly by telephone or in person each year from 1986 to 1992 for a variety of health, functional, and social factors. Levels of D-dimer in 1992 were related cross-sectionally to demographics (age, race, education, income, gender, smoking), function (Nagi, Rosow-Breslau, Katz, Older Americans Resources and Services procedures instrumental activities of daily living), life satisfaction and self-rated health, self-reported diseases (heart attack, cancer, stroke, diabetes, and hypertension), and weight change from 1986 to 1992. RESULTS: D-dimer levels increased with increasing age and functional disability. Among the health variables, only high blood pressure was predictive of D-dimer level. D-dimer levels were dramatically higher in blacks. Blacks were nearly four times more likely to have an extreme value of D-dimer (>600 microg/l) than whites when high D-dimer (yes/no) was analyzed, and blacks had an average level that was nearly 40% higher than whites in analyses of the continuous version of the outcome. This racial effect was not substantively affected in multivariable analyses with demographic and socioeconomic variables controlled. Race, age, functional status, current smoking, high blood pressure, and weight loss were related to level of D-dimer, and race, age, and functional status were related to the presence of a high D-dimer level (in the top 10% of the sample). CONCLUSIONS: Black, older, and functionally impaired persons had significantly higher levels of D-dimer in this sample of community-dwelling elderly persons. The findings for race were particularly striking and persisted even after controlling for smoking and other factors known to be related to thrombosis and were not mediated by social factors. This result may contribute to our understanding of the increased levels of thrombotic events found in these groups.

Aged↗