Search PubMed⌕ Search

Biomedical subjects

R L Watson

Publications and source records attributed to R L Watson.

At least 19 recordsLinked to original sources
PubMed2000

Sensitivity and specificity of the indicators of sincere effort of the EPIC lift capacity test on a previously injured population.

STUDY DESIGN: Randomized control post-test only. OBJECTIVES: To investigate the reliability and validity of the EPIC Lift Capacity test's indicators of sincere effort. SUMMARY OF BACKGROUND DATA: The EPIC Lift Capacity test (ELC) (Employment Potential Improvement Corp., Santa Ana, CA) is a functional evaluation tool used to identify physical limitations involved in lifting and manual materials handling. Identification of insincere effort is an integral component of such functional testing because of the potential secondary gain issues surrounding the various populations typically involved in this form of testing. The purpose of this study was to determine the sensitivity and specificity of the "indicators of sincere effort" of the EPIC Lift Capacity test when used on a previously injured population typical of subjects for which the test is designed. METHODS: Subjects consisted of 41 volunteers (age 22 to 58 years) with a previously diagnosed musculoskeletal pathology of the spine or extremities. Volunteers were randomized into either the control group, instructed to give a sincere maximum effort, or the experimental group, instructed to give an insincere effort at 50% of their perceived maximum effort. All tests were administered by certified clinical evaluators according to the standardized EPIC Lift Capacity test protocol.- RESULTS: Overall accuracy in identifying participants' level of effort was 86.84%. The indicators of valid effort exhibited both high positive (94.44%) and negative (80.00%) predictive values. The indicators of valid effort accounted for 94.9% of the total variance in the determination of the subjects' overall effort level. Interrater reliability for agreement of subjects' overall effort was good (interclass correlation coefficient = 0.82). CONCLUSIONS: Through use of standardized indicators of sincere effort, certified EPIC Lift Capacity test evaluators were able to predict sincerity of effort with a high degree of reliability and validity. The rater's systematicobservational evaluation of effort was shown to be the single best indicator of sincere effort.

Adult↗
PubMed2000

Incident type 2 diabetes mellitus in African American and white adults: the Atherosclerosis Risk in Communities Study.

CONTEXT: Although the excess prevalence of type 2 diabetes mellitus in African Americans is well established, few studies have compared incident diabetes in African American and white persons. OBJECTIVES: To compare risk of incident diabetes in African American vs white adults and to identify explanatory factors for racial disparities. DESIGN: Prospective cohort study using baseline data collected from 1986 to 1989 from the ongoing Atherosclerosis Risk in Communities (ARIC) Study, with 9 years of follow-up. SETTING AND PARTICIPANTS: A total of 2646 African American and 9461 white adults aged 45 to 64 years without diabetes at baseline, sampled from 4 US communities. MAIN OUTCOME MEASURES: Incident type 2 diabetes, ascertained by self-report of physician diagnosis, use of diabetes medications, or fasting glucose level of at least 7.0 mmol/L (126 mg/dL), compared among white and African American subjects and by presence of potentially modifiable risk factors. RESULTS: Diabetes incidence per 1000 person-years was about 2.4-fold greater in African American women (25.1 [95% confidence interval [CI], 22.4-28.1] vs 10.4 [95% CI, 9.4-11.4]) and about 1.5-fold greater in men (23.4 [95% CI, 19.9-27.2] vs 15.9 [95% CI, 14.6-17.2]) than in their white counterparts (P<.001). Results from proportional hazards regression models indicated that racial differences in potentially modifiable risk factors, particularly adiposity, accounted for 47.8% of the excess risk in African American women but accounted for little excess risk in African American men. Compared with their white counterparts, African American men and women had higher blood pressures before diabetes onset (diastolic blood pressure difference=5.6 mm Hg in women and 8.4 mm Hg in men; P=.005). CONCLUSIONS: Our data indicate that compared with their white counterparts, middle-aged African Americans are at greater risk of developing type 2 diabetes and have higher blood pressure prior to development of diabetes. In women, almost 50% of this excess risk might be related to potentially modifiable factors.

Black People↗
PubMed1999

Serum and dietary magnesium and the risk for type 2 diabetes mellitus: the Atherosclerosis Risk in Communities Study.

BACKGROUND: Experimental studies in animals and cross-sectional studies in humans have suggested that low serum magnesium levels might lead to type 2 diabetes; however, this association has not been examined prospectively. METHODS: We assessed the risk for type 2 diabetes associated with low serum magnesium level and low dietary magnesium intake in a cohort of nondiabetic middle-aged adults (N = 12,128) from the Atherosclerosis Risk in Communities Study during 6 years of follow-up. Fasting serum magnesium level, categorized into 6 levels, and dietary magnesium intake, categorized into quartiles, were measured at the baseline examination. Incident type 2 diabetes was defined by self-report of physician diagnosis, use of diabetic medication, fasting glucose level of at least 7.0 mmol/L (126 mg/dL), or nonfasting glucose level of at least 11.1 mmol/L (200 mg/dL). RESULTS: Among white participants, a graded inverse relationship between serum magnesium levels and incident type 2 diabetes was observed. From the highest to the lowest serum magnesium levels, there was an approximate 2-fold increase in incidence rate (11.1, 12.2, 13.6, 12.8, 15.8, and 22.8 per 1000 person-years; P = .001). This graded association remained significant after simultaneous adjustment for potential confounders, including diuretic use. Compared with individuals with serum magnesium levels of 0.95 mmol/L (1.90 mEq/L) or greater, the adjusted relative odds of incident type 2 diabetes rose progressively across the following lower magnesium categories: 1.13 (95% CI, 0.79-1.61), 1.20 (95% CI, 0.86-1.68), 1.11 (95% CI, 0.80-1.56), 1.24 (95% CI, 0.86-1.78), and 1.76 (95% CI, 1.18-2.61) (for trend, P = .01). In contrast, little or no association was observed in black participants. No association was detected between dietary magnesium intake and the risk for incident type 2 diabetes in black or white participants. CONCLUSIONS: Among white participants, low serum magnesium level is a strong, independent predictor of incident type 2 diabetes. That low dietary magnesium intake does not confer risk for type 2 diabetes implies that compartmentalization and renal handling of magnesium may be important in the relationship between low serum magnesium levels and the risk for type 2 diabetes.

Adult↗
PubMed1999

Neighbourhood differences in diet: the Atherosclerosis Risk in Communities (ARIC) Study.

STUDY OBJECTIVE: To investigate whether neighbourhood characteristics are related to dietary patterns independently of individual level variables. DESIGN: A cross sectional analysis of the relation between neighbourhood median household income and food and nutrient intakes, before and after adjustment for individual level variables. SETTING: Four United States communities (Washington Co, MD; Suburban Minneapolis, MN; Forsyth Co, NC, and Jackson, MS). PARTICIPANTS: 13,095 adults aged 45 to 64 years participating in the baseline examination of the Atherosclerosis Risk in Communities (ARIC) Study, a prospective study of atherosclerosis. MEASUREMENTS AND MAIN RESULTS: Information on diet and individual level income was obtained from the baseline examination of the ARIC Study. Diet was assessed using a semi-quantitative food frequency questionnaire. Information on neighbourhood (census defined block groups) median household income was obtained from the 1990 US Census. Multilevel models were used to account for the multilevel structure of the data. Living in lower income neighbourhoods was generally associated with decreased energy adjusted intake of fruits, vegetables, fish, and increased intake of meat. Patterns generally persisted after adjustment for individual level income, but were often not statistically significant. Inconsistent associations were recorded for the intake of saturated fat, polyunsaturated fat, and cholesterol. Overall, individual level income was a more consistent predictor of diet than neighbourhood income. CONCLUSION: Despite limitations in the definition and characterisation of neighbourhoods, this study found consistent (albeit small) differences across neighbourhoods in food intake, suggesting that more in depth research into potential neighbourhood level determinants of diet is warranted.

Arteriosclerosis↗
PubMed1999

Antimicrobial use for pediatric upper respiratory infections: reported practice, actual practice, and parent beliefs.

BACKGROUND: In response to the dramatic emergence of resistant pneumococci, more judicious use of antibiotics has been advocated. Physician beliefs, their prescribing practices, and the attitudes of patients have been evaluated previously in separate studies. METHODS: This 3-part study included a statewide mailed survey, office chart reviews, and parent telephone interviews. We compared survey responses of 366 licensed pediatricians and family physicians in Georgia to recently published recommendations on diagnosis and treatment of upper respiratory infections (URIs). We further evaluated 25 randomly selected pediatricians from 119 surveyed in the Atlanta metropolitan area. For each, charts from the first 30 patients between the ages of 12 and 72 months seen on a randomly selected date were reviewed for encounters during the preceding year. A sample of parents from each practice were interviewed by telephone. RESULTS: In the survey, physicians agreed that overuse of antibiotics is a major factor contributing to the development of antibiotic resistance (97%), and that they should consider selective pressure for resistance in their decisions on providing antibiotic treatment for URIs in children in their practices (83%). However, many reported practices do not conform to the recently published principles for judicious antibiotic use. For example, 69% of physicians considered purulent rhinitis a diagnostic finding for sinusitis; 86% prescribed antibiotics for bronchitis regardless of the duration of cough; and 42% prescribed antibiotics for the common cold. Reported practices by family physicians were more often at odds with the published principles: they were significantly more likely than pediatricians to omit pneumatic otoscopy (46% vs 25%); to omit the requirement for prolonged symptoms to diagnose sinusitis (median 4 vs 10 days); and to omit laboratory testing for pharyngitis (27% vs 14%). Of the 7531 encounters analyzed in the chart review, 43% resulted in an antibiotic prescription, including 11% of checkups, 18% of telephone calls, and 72% of visits for URIs. There was wide variability in the overall antibiotic use rates among the 25 physicians (1-10 courses per child per year). There was an even wider variability in some diagnosis-specific rates; bronchitis and sinusitis in particular. Those with the highest antibiotic prescribing rates had up to 30% more return office visits. Physicians who prescribed antibiotics for purulent rhinitis were more likely to see parents who believed that their children should be evaluated for cold symptoms. CONCLUSIONS: Physicians recognize the problem of antibiotic resistance but their reported practices are not in line with recently published recommendations for most pediatric URIs. The actual prescribing practices of pediatricians are often considerably different from their close colleagues. Patient beliefs are correlated with their own physician's practices.

Anti-Bacterial Agents↗
PubMed1998

Is fasting insulin concentration inversely associated with rate of weight gain? Contrasting findings from the CARDIA and ARIC study cohorts.

OBJECTIVE: To test whether a higher fasting insulin concentration is associated with a lower rate of weight gain over six to seven years. DESIGN: Two longitudinal epidemiologic cohorts including blacks and whites. SUBJECTS: The Coronary Artery Risk Development in Young Adults (CARDIA) Study examined subjects aged 18-30 y in 1985-86 and 1992-93 (n = 3636), and the Atherosclerosis Risk in Communities (ARIC) Study examined subjects aged 45-64 y in 1987-89 and 1993-95 (n = 11179). MEASUREMENTS: In each study, fasting insulin at baseline and weight change during follow-up were measured in participants without diabetes. RESULTS: In whites and black men in CARDIA, there was a positive age-adjusted association between baseline insulin and weight change, although weight change was not entirely monotonic across the insulin quartiles. In these race-gender groups, the linear regression coefficients indicated that each 50 pmol/L increment of baseline insulin was associated (P < 0.05) with approximately 0.10 kg/y greater rate of weight gain (95% confidence intervals (CI) for this estimate in kg/y were 0.023-0.187 for white women, 0.015-0.150 for black men, and 0.011-0.158 for white men). The association was eliminated entirely with adjustment for baseline weight. In contrast, among whites and black women in ARIC, the association was negative, with the linear regression coefficients suggesting that each 50 pmol/L higher fasting insulin concentration was associated (P < 0.05) with a 0.03-0.10 kg/y lower rate of weight gain (95% CI for this estimate in kg/y were -0.133 to -0.061 for black women, -0.106 to -0.054 for white women, and -0.055 to -0.009 for white men). This finding was generally strengthened by adjustment for baseline body mass index (BMI). CONCLUSIONS: A higher fasting insulin concentration is associated modestly with a lower rate of weight gain in ARIC, but not in CARDIA.

Adult↗
PubMed1997

Neighborhood environments and coronary heart disease: a multilevel analysis.

The authors investigated whether neighborhood socioeconomic characteristics are associated with coronary heart disease prevalence and risk factors, whether these associations persist after adjustment for individual-level social class indicators, and whether the effects of individual-level indicators vary across neighborhoods. The study sample consisted of 12,601 persons in four US communities (Washington County, Maryland; Forsyth County, North Carolina; Minneapolis, Minnesota; and Jackson, Mississippi) participating in the baseline examination of the Atherosclerosis Risk in Communities Study (1987-1989). Neighborhood characteristics were obtained from 1990 US Census block-group measures. Multilevel models were used to estimate associations with neighborhood variables after adjustment for individual-level indicators of social class. Living in deprived neighborhoods was associated with increased prevalence of coronary heart disease and increased levels of risk factors, with associations generally persisting after adjustment for individual-level variables. Inconsistent associations were documented for serum cholesterol and disease prevalence in African-American men. For Jackson African-American men living in poor neighborhoods, coronary heart disease prevalence decreased as neighborhood characteristics worsened. Additionally, in African-American men from Jackson, low social class was associated with increased serum cholesterol in "richer" neighborhoods but decreased serum cholesterol in "poorer" neighborhoods. Neighborhood environments may be one of the pathways through which social structure shapes coronary heart disease risk.

Black or African American↗
PubMed1997

Racial differences in risk factors for atherosclerosis. The ARIC Study. Atherosclerosis Risk in Communities.

This paper describes black/white differences in risk factors for atherosclerosis in the large multicenter Atherosclerosis Risk in Communities (ARIC) Project sponsored by the National Heart, Lung, and Blood Institute. It is based on data collected at baseline in ARIC's four geographically distinct clinical centers. Participants were randomly selected (4264 black and 11,479 white men and women, ages forty-five to sixty-four years at entry). There were striking differences in obesity between black and white women, higher fasting glucose and greater prevalence of diabetes in blacks, and lower high-density lipoprotein values in white men. Not unexpectedly, blood pressure in black participants exceeded that in whites. Clustering of multiple risk factors was more common in the black population. Conversely, prevalence of no risk factors was greatest among whites. In conclusion, while African-Americans and Caucasians share much the same group of risk factors for atherosclerosis, there are clinically important racial differences in emphasis.

Arteriosclerosis↗
PubMed1996

Clustering of dyslipidemia, hyperuricemia, diabetes, and hypertension and its association with fasting insulin and central and overall obesity in a general population. Atherosclerosis Risk in Communities Study Investigators.

Clustering of elevated triglycerides, decreased high-density lipoprotein cholesterol (HDL-C), hyperuricemia, diabetes, and hypertension has been related to insulin resistance/high insulin levels and central and/or overall obesity. The extent to which these abnormalities cluster and whether hyperinsulinemia, central adiposity, and overall obesity each independently associate with this clustering were evaluated in 14,481 US whites and African-Americans 45 to 64 years of age. With the exception of hypertension, abnormalities rarely existed in isolated form. Clustering greatly exceeded chance association (P < .001). Although this clustering was greater in relative terms (ratio of observed to expected cluster frequency) in the lean and less centrally obese, it was greater in absolute terms (observed minus expected cluster frequency as a percent of total population) in the more centrally and more generally obese. The greatest excesses were found for clusters that included both hypertriglyceridemia and low HDL-C. Multiple logistic regression models showed strong and independent graded relationships of clusters with quintiles of fasting insulin (fifth quintile odds ratio, 10 to 54, P < .001) and to a lesser degree with quintiles of the waist to hip ratio (2.2 to 5.4, P < .001 for most) and of body mass index (1.6 to 4.5, P < .05 for most). In conclusion, all abnormalities cluster in excess of that predicted by chance, with clusters showing remarkable and graded independent associations with fasting hyperinsulinemia and to a lesser extent with central and overall obesity. Thus, a metabolic syndrome occurs in both lean and obese middle-aged US adults.

Cluster Analysis↗
PubMed1996

A metabolic syndrome in whites and African-Americans. The Atherosclerosis Risk in Communities baseline study.

OBJECTIVE: To describe clustering of hypertriglyceridemia, low HDL cholesterol, hypertension, diabetes, and hyperuricemia and its association with fasting insulin, waist-to-hip ratio (WHR), and BMI for African-American and white men and women. RESEARCH DESIGN AND METHODS: Observed frequencies of clusters were compared with those expected in 14,481 participants, 45-64 years of age, of the Atherosclerosis Risk in Communities (ARIC) baseline survey, 1987-1989. Associations of clusters with insulin, central adiposity, and overall obesity, as well as with abnormalities, were analyzed through multiple logistic regression. RESULTS: Clustering beyond chance was observed in all four sex/ethnic groups (P < 0.001), with 7% of the sample presenting 30% of the abnormalities in large clusters (> or = 3 abnormalities per individual). The odds ratio (OR) for the association of each abnormality with clustering of the remaining four ranged from 1.6 to 8.8 (P < 0.01). These odds of clustering were notably large in white women. Of the abnormalities, hypertriglyceridemia demonstrated the highest OR (5.0-8.8) and diabetes had the lower OR in African-American subjects than in white subjects (P < 0.001). Insulin, WHR, and BMI were statistically associated with clustering in all groups (P < 0.001, except for BMI in African-Americans.

Arteriosclerosis↗
PubMed1995

Fasting hyperinsulinemia and cardiovascular disease risk factors in nondiabetic adults: stronger associations in lean versus obese subjects. Atherosclerosis Risk in Communities Study Investigators.

The association between hyperinsulinemia and atherogenic risk factors has not been well studied in blacks and may be different for obese versus lean individuals. To investigate this possibility and to confirm the associations of hyperinsulinemia with cardiovascular disease risk factors in blacks and whites, we analyzed the joint associations of fasting serum insulin and obesity with risk factors in the Atherosclerosis Risk in Communities (ARIC) Study (1,293 black men, 4,797 white men, 2,033 black women, and 5,445 white women). Insulin values > or = 90th percentile (> or = 21 microU/mL) constituted hyperinsulinemia; body mass index (BMI) values > or = 27.3 kg/m2 for women and > or = 27.8 for men constituted obesity. Participants with hyperinsulinemia in all four race-sex groups had more atherogenic levels of most risk factors studied than those with normoinsulinemia. Among black men and women, mean levels of triglycerides, low-density lipoprotein cholesterol (LDL-C), apolipoprotein (apo) B, glucose, and fibrinogen (men only) were higher in hyperinsulinemic lean participants as compared with the normoinsulinemic obese group. Furthermore, most associations between insulin level and risk factors were stronger among lean versus obese subjects. For example, among lean black men, the difference in mean triglyceride concentration between those with hyperinsulinemia and those with normoinsulinemia was 147 - 99 = 48 mg/dL; among obese black men, the difference was 155 - 121 = 34 mg/dL (P < .05 for the interaction). Generally, similar negative interactions between BMI and insulin concentration were also observed among whites.(ABSTRACT TRUNCATED AT 250 WORDS)

Black People↗
PubMed1994

Lipoprotein(a) as a correlate of stroke and transient ischemic attack prevalence in a biracial cohort: the ARIC Study. Atherosclerosis Risk in Communities.

Although both mean lipoprotein(a) [Lp(a)] concentration and national stroke prevalence estimates are consistently higher in American blacks than in whites, no information exists on the relationship of Lp(a) and stroke prevalence in African-Americans. Associations of Lp(a) with stroke or transient ischemic attack (TIA) are addressed in this report for 15,160 participants--4160 blacks and 11,000 whites--in the Atherosclerosis Risk in Communities (ARIC) Study. Lp(a) was measured in ARIC as its total protein component by double-antibody enzyme-linked immunosorbent assay (ELISA) for apo(a) detection. Self-reported stroke/TIA history was assessed as part of a standardized questionnaire, and resulted in age-adjusted stroke/TIA prevalences of 3.0% in blacks (n = 120) and 2.0% in whites (n = 222). Overall, mean Lp(a) protein levels were markedly higher for blacks than for whites (160.5 versus 81.6 micrograms/mL, respectively), and were statistically significantly higher among individuals reporting stroke/TIA history for both races (191.3 versus 159.6 micrograms/mL in blacks; 100.6 versus 81.2 micrograms/mL in whites). Multivariable logistic regression analysis for the association of Lp(a) protein with stroke/TIA status yielded a prevalence odds ratio (OR) (95% confidence intervals) of 1.17 (1.05, 1.30) overall (based on one standard deviation difference, 108.2 micrograms/mL, in Lp[a] protein). Race-specific ORs, after adjustment for the same covariates, were equivalent for blacks [OR = 1.17 (0.99, 1.39)] and whites [OR = 1.19 (1.04, 1.36)]. These data suggest that Lp(a) is an independent risk factor for stroke/TIA in both blacks and whites, and that the relative risk of stroke/TIA associated with Lp(a) protein does not vary by race.(ABSTRACT TRUNCATED AT 250 WORDS)

Black or African American↗
PubMed1992

The effects of exercise on serum potassium levels.

In view of the significant influence of potassium on the heart, a decision was made to study the effect of exercise on this important ion in two exercise groups of different intensity. The first group consisted of 44 individuals with known coronary artery disease participating in a supervised cardiac rehabilitation program while the other consisted of 30 healthy joggers. Postexercise mean potassium levels were higher in both groups than resting baseline values. In addition, 5 of 44 participants in the coronary artery disease group experienced major potassium increases of 0.9 mmol/L or more while 7 of 30 healthy joggers experienced this magnitude of increase. Remaining unanswered is the question of whether such abrupt rises in potassium levels in this subset of patients alter their vulnerability to cardiac rhythm and conduction disturbances. A question is also raised as to whether rapid return of potassium levels to baseline postexercise contributes to any risks.

Aged↗
PubMed1990

Potassium and calcium intake, excretion, and homeostasis in blacks, and their relation to blood pressure.

Blacks in the United States have higher blood pressures than whites. They ingest and excrete less calcium and potassium. There is some evidence that blacks have a difference in vitamin D metabolism that might increase any problem caused by low calcium intake. Some studies can be interpreted to suggest that calcium or potassium therapy has greater hypotensive effects in blacks than in whites. Decreased intake of calcium and potassium may be major causes of the greater prevalence of hypertension in blacks than in whites.

Black People↗
PubMed1989

Medical and financial implications of discontinuing a statewide free insulin program involving 3,720 people.

In 1981 a statewide program supplying free insulin to 3,720 patients of state health clinics was discontinued. We attempted to assess whether this action had an adverse effect medically and financially on those concerned. A computer randomized sample of 351 patients (9%) was studied by personal interview and questionnaire. Information obtained focused on certain events that occurred 18 months before and after the program ceased. Measurements used to determine medical impact were number of hospitalizations, emergency room and physician visits, changes in weight and glucose levels, and episodes of ketoacidosis. Financial impact was measured by cost of hospitalization and physician visits. Our results revealed no significant changes in any of the medical parameters studied except for fasting serum glucose levels above 300 mg/dl, which occurred less frequently after the free insulin program was discontinued. There were fewer hospitalizations, more visits to physicians, and no change in number of emergency room visits after discontinuance of the free program. The overall cost saving was estimated to be +883,558 for the 18-month study period, in addition to the +550,000 the plan had been costing the state.

Blood Glucose↗