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M J O'Grady

Publications and source records attributed to M J O'Grady.

10 recordsLinked to original sources

Edentulism and associated factors in people 60 years and over from urban, rural and remote Western Australia.

BACKGROUND: Edentulism is declining in the aged, in turn increasing demand on dental services. The aim of this study was to describe the pattern of edentulism and associated factors for people 60 years or over in urban, rural and remote Western Australia. METHODS: A cross-sectional telephone interview survey was conducted of 2100 people aged 60 years or over (urban n=800, rural n=800, remote n=500), identified through the State Electoral Roll, who were living in non-institutionalized accommodation in Western Australia and who were able to speak English sufficiently well to be interviewed in English. RESULTS: The main outcome measure was edentulism. The prevalence of edentulism was 25 per cent for people in urban areas, 34 per cent for people in rural areas and 32 per cent for people in remote areas. Respondents aged 60-69 years had less than half the edentulism than respondents aged 80 years or over. Multivariable logistic regression models showed geographic location, age, gender, education and occupation were significantly associated with edentulism. CONCLUSIONS: The percentage of edentulism was highest in rural areas with some clear demographic trends. These future aged cohorts are likely to follow the same patterns of social and geographic disadvantage as found for the current edentate cohort. The results were consistent with other studies while providing state level multivariate results to assist service planning.

Age Factors↗

Reference values for echocardiographic measurements in urban and rural populations of differing ethnicity: the Strong Heart Study.

Discrepancies in reported reference values for left ventricular (LV) dimensions and mass may be due to imaging errors with early echocardiographic methods or effects of subject characteristics and inclusion criteria. To determine whether contemporary echocardiographic methods provide stable normal limits for left ventricular measurements in different populations, M-mode/2-dimensional echocardiography was applied in 176 American Indian participants in the Strong Heart Study and 237 New York City residents who were clinically normal. No consistent difference in any measure of LV size or function existed between populations. Upper normal limits (98th percentile) for LV mass were 96 g/m(2) in women and 116 g/m(2) in men and 3.27 cm/m for LV chamber diameter normalized for height. Thus contemporary M-mode/2D echocardiography provides reference ranges for LV measurements that approximate necropsy measurements and have acceptable stability in apparently normal white, African-American/Caribbean, and American Indian populations.

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Impact of diabetes on cardiac structure and function: the strong heart study.

BACKGROUND: Whether diabetes mellitus (DM) adversely affects left ventricular (LV) structure and function independently of increases in body mass index (BMI) and blood pressure is controversial. METHODS AND RESULTS: Echocardiography was used in the Strong Heart Study, a study of cardiovascular disease in American Indians, to compare LV measurements between 1810 participants with DM and 944 with normal glucose tolerance. Participants with DM were older (mean age, 60 versus 59 years), had higher BMI (32.4 versus 28.9 kg/m(2)) and systolic blood pressure (133 versus 124 mm Hg), and were more likely to be female, to be on antihypertensive treatment, and to live in Arizona (all P<0.001). In analyses adjusted for covariates, women and men with DM had higher LV mass and wall thicknesses and lower LV fractional shortening, midwall shortening, and stress-corrected midwall shortening (all P<0.002). Pulse pressure/stroke volume, a measure of arterial stiffness, was higher in participants with DM (P<0.001 independent of confounders). CONCLUSIONS: Non-insulin-dependent DM has independent adverse cardiac effects, including increased LV mass and wall thicknesses, reduced LV systolic chamber and myocardial function, and increased arterial stiffness. These findings identify adverse cardiovascular effects of DM, independent of associated increases in BMI and arterial pressure, that may contribute to cardiovascular events in diabetic individuals.

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Differences in echocardiographic findings and systemic hemodynamics among non-diabetic American Indians in different regions: The Strong Heart Study.

PURPOSE: This study was undertaken to determine whether differences in left ventricular (LV) and systemic hemodynamic findings exist between American Indians in different regions that might contribute to known differences in cardiovascular morbidity rates among American Indians. METHODS: We compared echocardiography results in 290 non-diabetic Strong Heart Study (SHS) participants in Arizona, 595 in Oklahoma and 572 in North/South Dakota (ND/SD). RESULTS: Participants in the 3 regions were similar in age and gender but those in Arizona had the highest body mass indices and lowest heart rates while those in ND/SD had the lowest diastolic blood pressures (BP). In analyses that adjusted for significant covariates, ND/SD participants had larger aortic (Ao) anular, Ao root, and LV chamber size as well as higher cardiac output and lower peripheral resistance, whereas Arizona participants had increased LV wall thickness and mass and reduced LV myocardial contractility. These findings may contribute to the known high rates of cardiovascular events in ND/SD Indians and to the proportionately higher rate of cardiovascular death than of non-fatal cardiovascular events that has been recently documented in Arizona Indians. CONCLUSIONS: Application of echocardiography to non-diabetic SHS participants reveals that LV chamber and arterial size are larger in ND/SD Indians and that LV wall thicknesses and mass are higher and LV myocardial contractility lower in Arizona Indians, possibly contributing to the higher than expected rates of cardiovascular morbidity and mortality among Indians in Arizona.

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Relations of left ventricular mass to fat-free and adipose body mass: the strong heart study. The Strong Heart Study Investigators.

BACKGROUND: It is unclear whether increased left ventricular (LV) mass in overweight individuals is related to their adiposity or to greater fat-free mass (FFM). METHODS AND RESULTS: We compared echocardiographic LV mass to FFM and adipose body mass by bioelectric impedance and to anthropometric measurements in 3107 American Indian participants in the Strong Heart Study. In men and women, the relations of LV mass and FFM (r=0.37 and 0.38, P<0.001) were closer (P<0.05 to <0.001) than they were with adipose mass, waist/hip ratio, body mass index, systolic blood pressure, height, or height2.7. Regression analyses showed that in men LV mass had the strongest independent relation with FFM, followed by systolic blood pressure and age (all P<0.001); in women, LV mass was related to FFM more strongly than it was to systolic blood pressure, age (all P<0. 001), and diabetes (P=0.012). Adipose mass had no independent relation to LV mass. When waist/hip ratio or body mass index were substituted for adipose mass, LV mass was independently related to FFM (P<0.001) and body mass index (P=0.02) but not to waist/hip ratio in men and was independently related to FFM and waist/hip ratio (both P<0.001) but not to body mass index in women. Using 97.5 percentile gender-specific partitions for LV mass/FFM in reference individuals, we found that LV hypertrophy occurred in 20.8% of Strong Heart Study participants with hypertension, overweight, or diabetes compared with 10.5% and 16.7% by LV mass indexed for body surface area or height2.7. CONCLUSIONS: LV mass is more strongly related to FFM than to adipose mass, waist/hip ratio, body mass index, or height-based surrogates for lean body weight; LV mass/FFM criteria may increase sensitivity to detect LV hypertrophy.

Adipose Tissue↗

Relations of left ventricular mass to demographic and hemodynamic variables in American Indians: the Strong Heart Study.

BACKGROUND: Previous studies have identified associations of left ventricular (LV) mass with demographic (body habitus and sex) and hemodynamic variables (blood pressure, stroke volume [SV], and myocardial contractility), but the relative strength and independence of these associations remain unknown. METHODS AND RESULTS: We examined the relations of echocardiographically determined LV mass to demographic variables, blood pressure, Doppler SV, and measures of contractility (end-systolic stress [ESS]/end-systolic volume index and midwall fractional shortening [MFS] as a percentage of predicted for circumferential end-systolic stress [stress-independent shortening]) in 1935 American Indian participants in the Strong Heart Study phase 2 examination without mitral regurgitation or segmental wall motion abnormalities. Weak positive relations of LV mass with systolic and diastolic pressures (r=.22 and r=.20) were exceeded by positive relations with height (r=.30), weight (r=.47), body mass index (r=.31), body surface area (r=.49), and Doppler SV (r=.50) and negative relations with ESS/volume index ratios (r= -.33 and -.29) and stress-independent MFS (r= -.26, all P<.0001). In multivariate analyses that included blood pressure, SV, and a different contractility measure in each model, systolic pressure, stroke volume, and the contractility measure were independent correlates of LV mass (multiple R=.60 to .66, all P<.0001). When demographic variables were added, LV mass was more strongly predicted by higher SV and lower afterload-independent MFS than by greater systolic pressure, height, and body mass index (each P<.00001, multiple R=.71). CONCLUSIONS: Additional characterization of volume load and contractile efficiency improves hemodynamic prediction of LV mass (R(2)=.30 to .44) over the use of systolic blood pressure alone (R(2)=.05), with a further increase in R(2) to .51 when demographic variables are also considered. However, nearly half of the ventricular mass variability remains unexplained.

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Relation of hemodynamic volume load to arterial and cardiac size.

OBJECTIVES: This study sought to assess the relation of Doppler stroke volume (SV) to cardiac and carotid artery size and to determine whether volume load accounts for the parallelism between the two. BACKGROUND: It has been suggested that altered hemodynamic volume load can modify the degree and pattern of left ventricular (LV) hypertrophy from that predicted from blood pressure (BP) alone. METHODS: We related Doppler echocardiographic SV in 342 normotensive or unmedicated asymptomatic hypertensive adults to echocardiographic LV mass, LV internal dimension (LVID), wall thickness, carotid ultrasound arterial lumen diameter, intimal-medial thickness (IMT) and cross-sectional area (CSA). RESULTS: SV was positively related to LV mass (r = 0.42), LVID (r = 0.45), ventricular wall thickness (r = 0.20 to 0.29) and carotid diameter (r = 0.23, all p < 0.0001); CSA (r = 0.17, p < 0.002); and IMT (r = 0.12, p = 0.03). In multivariate analyses controlling for awake ambulatory BP and the circumferential end-systolic stress/end-systolic volume index ratio, SV remained an independent predictor of LV mass and chamber size (both p < 0.0001) but not LV wall thickness. SV also predicted carotid diameter (p < 0.0002), CSA (p = 0.001) and, to a lesser degree, IMT (p = 0.02) after controlling for mean awake BP and age. In additional analyses, LV and carotid dimensions were significantly interrelated independent of SV. CONCLUSIONS: SV measured by invasively validated Doppler echocardiography is associated with LV and carotid artery enlargement and eccentric hypertrophy, independent of arterial pressure, LV contractility, age and body size; however, SV and other variables do not account for the previously documented parallelism between cardiac and arterial structure.

Age Factors↗

Relations of Doppler stroke volume and its components to left ventricular stroke volume in normotensive and hypertensive American Indians: the Strong Heart Study.

Doppler echocardiographic measurement of time-velocity integral of blood flow across the aortic annulus ("stroke distance") or of stroke volume (SV) have been proposed as noninvasive measures of cardiac pump performance that could elucidate the hemodynamics of hypertension. To evaluate the performance of these measures of hemodynamic volume load in a population with a wide range of body build and other characteristics, we obtained technically adequate imaging and Doppler echocardiograms in 1,935 of 2,212 (87%) American Indian Strong Heart Study participants, without mitral regurgitation or segmental left ventricular (LV) dysfunction, in Arizona, Oklahoma, and South/North Dakota. The subjects ranged widely in age (48 to 81 years) and body mass index (17.0 to 62.6 kg/m2); 65% were women; 1,161 were normotensive and 774 were hypertensive. As a reference standard, LV and stroke volumes were calculated from LV internal dimensions by the Teichholz method. Doppler SVs were moderately related to LV SVs (r = 0.63), but Doppler SV was slightly lower in both normotensive (mean = 69.8 and 72.9 mL, respectively) and hypertensive subjects (71.1 v 73.6 mL). Aortic stroke distance was less closely related than was aortic annular area to LV SV (r = 0.34 v 0.40, P < .001). Aortic annular area (r = 0.44) but not stroke distance (r = 0.04) was moderately correlated with body surface area. Stroke distance was inversely related to annular area (r = -0.29) and in subjects stratified by aortic annular diameter 1.6 to 1.9, 2.0 to 2.1, and 2.3 to 2.9 cm, mean LV SV increased from 67 to 74 to 80 mL, but average stroke distance fell from 22.8 to 21.6 to 20.1 cm. Stroke distance also failed to identify gender differences in LV SV but did identify that due to obesity. Thus Doppler SV closely parallels independently measured LV SV but slightly underestimates SV in both normotensive and hypertensive adults, whereas aortic stroke distance yields misleading comparisons between genders or individuals of different body sizes.

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