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Biomedical subjects

Arch G Mainous

Publications and source records attributed to Arch G Mainous.

At least 19 recordsLinked to original sources
PubMed2006

Association of a polychlorinated dibenzo-p-dioxin, a polychlorinated biphenyl, and DDT with diabetes in the 1999-2002 National Health and Nutrition Examination Survey.

The association of a polychlorinated dibenzo-p-dioxin, a polychlorinated biphenyl, and p,p'-DDT with diabetes was evaluated using the 1999-2002 National Health and Nutrition Examination Survey. Persons 20 years old and older were included. Relationships with diagnosed diabetes, undiagnosed diabetes (glycohemoglobin (HbA1c) >6.1%), and total diabetes (diagnosed plus undiagnosed) were tested. When all three chemicals were evaluated together for total diabetes, the unweighted number of participants was 1830. All three compounds were significantly associated with diagnosed diabetes. PCB 126 and p,p'-DDT were significantly associated with undiagnosed diabetes. 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (HxCDD) was not associated with undiagnosed diabetes. When the three chemicals were included in a combined model for total diabetes, PCB 126>83.8pg/g lipid adjusted had an odds ratio of 2.57 (95% CI 1.33-4.95) compared to PCB 126 < or = 31.2pg/g lipid adjusted. Also significant in a combined model for total diabetes was p,p'-DDT 20.8-26.6ng/g lipid adjusted with an odds ratio of 2.52 (95% CI 1.26-5.02) and p,p'-DDT >26.6ng/g lipid adjusted with an odds ratio of 2.74 (95% CI 1.44-5.23) both compared to p,p'-DDT < or = 20.7ng/g lipid adjusted. HxCDD was not associated with total diabetes in a combined model. When participants with poor liver function and poor kidney function were removed from the analysis, the combined model for total diabetes produced similar results with PCB 126 and p,p'-DDT having been significantly associated, and HxCDD not having been associated. These findings add to the list of chemicals found to be associated with diabetes in the 1999-2002 National Health and Nutrition Examination Survey.

Adult↗
PubMed2006

Competing impact of excess weight versus cardiorespiratory fitness on cardiovascular risk.

Obesity is a risk factor for cardiovascular disease, whereas high cardiorespiratory fitness (CRF) is cardioprotective. This study evaluated the competing effect of weight and fitness on biomarkers of cardiovascular risk in a nationally representative sample of 2,112 adults (20 to 49 years of age; body mass index [BMI] > or =18.5 kg/m(2)) without previously diagnosed cardiovascular disease from the National Health and Nutrition Examination Survey 1999 to 2002. CRF levels were assigned using age- and gender-specific reference points of estimated maximal oxygen consumption calculated from submaximal graded exercise treadmill testing. CRF was also categorized by sample-specific tertiles of maximal oxygen consumption. Weight was categorized using BMI. Fasting insulin level >12.2 mU/L, C-reactive protein level > or =3.0 mg/L, and total cholesterol/high-density lipoprotein ratio (TC/HDL) >5 characterized increased cardiovascular risk. CRF and BMI were independently associated with increased fasting insulin and C-reactive protein (p <0.05). When patients with low, moderate, and high CRF were further stratified as normal, overweight, or obese, weight remained significantly associated with increased fasting insulin, C-reactive protein, and TC/HDL (p <0.001), but CRF did not. Logistic regressions evaluating increased fasting insulin, C-reactive protein, and TC/HDL demonstrated no significant differences in overweight/obese patients by CRF level after adjustment for other factors. Significant differences were present between normal-weight and overweight or obese patients regardless of fitness level. Analyses using tertiles of CRF yielded similar results. In conclusion, patients who are "fat but fit" require weight-loss interventions to improve their cardiovascular risk profiles. Future interventions should emphasize weight control, even for those with high CRF.

Adult↗
PubMed2006

Long-term prognostic value of resting heart rate in subjects with prehypertension.

BACKGROUND: Increased resting heart rate increases cardiovascular risk in individuals with hypertension. The extent to which such risk extends to people with prehypertension is not known. The purpose of this study was to determine whether elevated resting heart rate contributes to increased coronary heart disease (CHD) risk in people with prehypertension. METHODS: The cohort for the current study consisted of 3275 persons from the Atherosclerosis Risk in Communities (ARIC) study, 45 to 64 years old in 1986 to 1989, with a mean follow-up of 10.1 years. The primary outcomes were CHD and all-cause mortality. RESULTS: Individuals with prehypertension and elevated resting heart rate had 50% higher all-cause mortality than people with prehypertension and lower resting heart rate (hazard ratio [HR] 1.50, 95% confidence interval [CI] 1.0-2.15), which was essentially unchanged after controlling for age, ethnicity, gender, diabetes, smoking status, LDL-cholesterol, exercise, and use of antilipemic agents (P < .01). Similarly, in unadjusted analyses, CHD risk was 49% higher for people with increased heart rate (HR 1.49, 95% CI 1.03-2.14). In adjusted analyses, elevated resting heart rate remained a factor in increased risk of CHD in women (adjusted HR 2.18, 95% CI 1.08-4.42), but not in men. CONCLUSIONS: Resting heart rate is an easily accessible tool that may be helpful for stratifying CHD and mortality risk in people with prehypertension.

Coronary Disease↗
PubMed2006

Combining serum biomarkers: the association of C-reactive protein, insulin sensitivity, and homocysteine with cardiovascular disease history in the general US population.

BACKGROUND: Elevated levels of serum biomarkers such as C-reactive protein (CRP) and homocysteine have been independently associated with cardiovascular risk. However, the prevalence of concurrent elevations of these biomarkers in the general population is unknown, as is their association with cardiovascular disease (CVD). METHODS: Data from adults (n = 4900) in the National Health and Nutrition Examination Survey were used to investigate the relationship between combinations of serum biomarkers of inflammation (CRP), atherosclerosis (homocysteine), and insulin sensitivity [homeostatic model assessment (HOMA) fasting insulin] and CVD. Using SUDAAN, logistic regression models were constructed to examine the relationships between elevated serum biomarkers (CRP, homocysteine, HOMA, or insulin), singly or in combination, and having a history of heart failure, myocardial infarction (MI), stroke, or any CVD, while controlling for age, race, sex, obesity, smoking, cholesterol level, diabetes history, hypertension history, exercise level, and dietary fiber intake. RESULTS: After adjustment for covariates, there was a significant relationship between concomitant elevations of CRP plus homocysteine and a history of MI [odds ratio (OR) 2.21], heart failure (OR 2.14), and any CVD (OR 1.87) that was stronger than the relationship between individual biomarkers alone and a history of CVD. In addition, combinations of elevated CRP plus HOMA and CRP plus insulin, remained significantly related to having a history of any CVD. CONCLUSION: Recent scientific evidence and the present findings demonstrate the possibility for improving cardiovascular risk stratification through the concurrent evaluation of multiple biomarkers. In particular, these findings demonstrate the need to evaluate the combination of CRP and homocysteine prospectively as predictors of CVD.

Adolescent↗
PubMed2006

The effect of extended-release metoprolol succinate on C-reactive protein levels in persons with hypertension.

The objective of this study was to determine whether 3 months of treatment with extended-release metoprolol succinate would reduce C-reactive protein (CRP) levels. Seventy-five patients aged 30-65 years with uncontrolled hypertension were treated with extended-release metoprolol at 25-50 mg, titrated up to 100-200 mg daily. CRP was evaluated at baseline and at 1 and 3 months. In the 61 hypertensive patients who completed the study, CRP decreased from 6.2+/-7.5 mg/L at baseline to 5.4+/-7.0 mg/L (p=0.03) at 1 month and showed no further change at 3 months (5.6+/-6.5 mg/L; p=0.13). The 13 patients who received 200 mg of extended-release metoprolol had a 32% decline in CRP from 7.0+/-9.0 mg/L to 4.8+/-6.6 mg/L (-2.2 mg/L) (p=0.005) over the 3-month period, whereas lower doses did not reduce CRP (p>0.05). Age, race, sex, and change in blood pressure were not related to the reduction in CRP in multivariate analysis. If CRP evolves into a confirmed modifiable risk factor, a beta blocker such as metoprolol may be a useful addition to pharmacotherapy options.

Adrenergic beta-Antagonists↗
PubMed2006

Antihypertensive prescribing practices: impact of the antihypertensive and lipid-lowering treatment to prevent heart attack trial.

This national study examines the impact of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) on the prescribing of thiazide-type diuretics and other antihypertensive medications for patients with newly diagnosed hypertension. A cross-sectional analysis was conducted using data from a national network of electronic health records for 2 groups with newly diagnosed hypertension and started on antihypertensive medications: one a year before and the other a year after the publication of ALLHAT. The percentage of new hypertensives started on thiazides increased from 29% pre-ALLHAT to 39% post-ALLHAT. An increase was also seen for angiotensin receptor blockers, while prescribing for angiotensin-converting enzyme inhibitors, calcium channel blockers, and beta-blockers declined. There was no significant change in prescriptions for alpha-blockers. Prescriptions for thiazides for patients with newly diagnosed hypertension increased after the publication of ALLHAT. Data from large national trials can have a considerable impact on prescribing practices.

Adrenergic alpha-Antagonists↗
PubMed2006

Rural residence and Hispanic ethnicity: doubly disadvantaged for diabetes?

CONTEXT: Hispanics are at increased risk for diabetes, while rural residents have historically had decreased access to care. PURPOSE: To determine whether living in a rural area and being Hispanic confers special risks for diagnosis and control of diabetes. METHODS: We analyzed the Third National Health and Nutrition Examination Survey (1988-1994). Hispanics and non-Hispanic white adults were classified according to rural/urban residence to create 4 ethnicity-residence groups. Investigated outcomes were previously diagnosed and undiagnosed diabetes. Among those with diagnosed diabetes, we investigated control of glucose, hypertension, and lipids. FINDINGS: The prevalence of diagnosed diabetes was greatest for rural residents, especially for rural Hispanics (8.2%) versus that for urban whites (4.6%), rural whites (6.5%), or urban Hispanics (4.5%), (P < .01). However, urban Hispanics were most likely to have undiagnosed diabetes at 3.7%, versus 2.3% of rural whites, 2.8% of urban whites, and 2.7% of rural Hispanics (P = .04). Among people with diagnosed diabetes, there was no difference in glycemic control between the 4 groups. Rural Hispanics with diagnosed diabetes had the greatest prevalence of elevated systolic blood pressure at 45%, compared to 37% of urban whites, 29% of rural whites, 28% of urban Hispanics (P = .01). In regression models controlling for potential confounders, there were no differences among urban and rural whites and Hispanics in the likelihood of undiagnosed diabetes or in glycemic control for those with diagnosed diabetes. CONCLUSIONS: Initiatives that target Hispanic health, and especially diabetes, should acknowledge rural/urban Hispanic health differences.

Adult↗
PubMed2006

Ambulatory antibiotic prescribing for acute bronchitis and cough and hospital admissions for respiratory infections: time trends analysis.

OBJECTIVES: To examine the relationship between ambulatory antibiotic prescribing for acute bronchitis and cough with hospital admissions for respiratory infections in the USA between 1996 and 2003. DESIGN: Analysis of data on antibiotic prescribing for episodes of acute bronchitis/cough illness in ambulatory care and hospitalization for respiratory infections for adults between 1996 and 2003 in the USA. SETTING: USA: ambulatory prescribing behaviour was derived from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey while hospitalizations in acute care hospitals were assessed in the National Hospital Discharge Survey. PARTICIPANTS: Adults 18-64 years old. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Proportion of visits for acute bronchitis/cough receiving a prescription for antibiotics and hospitalization for respiratory infections. RESULTS: Ambulatory antibiotic prescribing practices for acute bronchitis/cough and hospitalizations for respiratory infections exhibited non-linear patterns over the 8 year period. However, antibiotic prescribing practices for acute bronchitis/cough and hospitalizations for respiratory infections had a weak/moderate negative association. For three of the seven yearly changes in prescribing and hospitalizations as one increased the other decreased (P<0.01). CONCLUSIONS: Ambulatory antibiotic prescribing for respiratory tract infections was inversely associated with hospital admissions for respiratory tract infections.

Acute Disease↗
PubMed2006

Diabetes management in the USA and England: comparative analysis of national surveys.

OBJECTIVES: To compare diabetes management in adults between England and the United States, particularly focusing on the impact of a universal access health insurance system. DESIGN: Analysis of the nationally-representative surveys Health Survey of England, 2003 (unweighted n =14 057) and the National Health and Nutrition Examination Survey, 2001-2002 (unweighted n =5411). SETTING AND PARTICIPANTS: Adults 20-64 years of age; individuals >65. MAIN OUTCOME MEASURES: Glycaemic, lipid and blood pressure control and medication use among individuals with previously diagnosed diabetes. RESULTS: Among those aged 20-64 the prevalence of diagnosed diabetes was lower in England (2.7%) than in the USA (5.0%). The proportion with diabetes receiving treatment was similar for the two countries. However, the mean HbA1c in England was 7.6%: in the USA it was 7.5% for those with insurance and 8.6% for those without insurance. The proportion of individuals on ACE inhibitors in England was 39%: in USA it was 39% for those with insurance, and 14% for those without. CONCLUSIONS: Individuals in a healthcare system providing universal access have better managed diabetes than those in a market based system once one accounts for insurance.

Adult↗
PubMed2006

Hyperinsulinemia and cognitive decline in a middle-aged cohort.

OBJECTIVE: Determining modifiable risks factors for cognitive decline and dementia are a public health priority as we seek to prevent dementia. Type 2 diabetes and related disorders such as hyperinsulinemia increase with aging and are increasing in the U.S. population. Our objective was to determine whether hyperinsulinemia is associated with cognitive decline among middle-aged adults without type 2 diabetes, dementia, or stroke in the Atherosclerosis Risk in Communities (ARIC) cohort. RESEARCH DESIGN AND METHODS: Middle-aged adults (aged 45-64 years at baseline) in the ARIC cohort had fasting insulin and glucose assessed between 1987 and 1989. Subjects with dementia, type 2 diabetes, or stroke at baseline were excluded from analysis. Three tests of cognitive function available at baseline and 6 years later were delayed word recall (DWR), digit symbol subtest (DSS), and first letter word fluency (WF). Cross-sectional comparisons and linear regression models were computed for cognitive tests at baseline and change in cognitive test scores to determine whether cognitive function was associated with two measures of insulin resistance, fasting insulin and homeostasis model assessment (HOMA). Linear regression models controlled for age, sex, race, marital status, education level, smoking status, alcohol use, depression, hypertension, and hyperlipidemia. RESULTS: In unadjusted and adjusted analyses, hyperinsulinemia based on fasting insulin and HOMA at baseline was associated with significantly lower baseline DWR, DSS, and WF scores and a greater decline over 6 years in DWR and WF. CONCLUSIONS: Insulin resistance is a potentially modifiable midlife risk factor for cognitive decline and dementia.

Cognition Disorders↗
PubMed2006

Practice patterns in sildenafil prescribing.

BACKGROUND: This study explores the incorporation of sildenafil into treatment of the common conditions of psychosexual and erectile dysfunction (ED). METHODS: The 2002 National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey were analyzed for visits in which sildenafil was prescribed. Patient, visit, and provider characteristics for visits in which sildenafil was prescribed were compared between visits that documented a presenting complaint or diagnosis consistent with ED and those without documentation consistent with ED. RESULTS: Of visits by men 30 years or older receiving sildenafil, 50% had no documented presenting complaint or diagnosis consistent with ED. No significant differences were found between those prescribed sildenafil with or without a reason for visit or diagnosis of ED based on age, race, or payment type. Individuals with more visits in the last 12 months were significantly less likely to have a recorded diagnosis consistent with ED. Urologists documented ED significantly more often than family medicine, internal medicine, and other physicians. CONCLUSIONS: Sildenafil is being prescribed at a significant number of visits without documentation of a reason for visit or diagnosis consistent with psychosexual or erectile dysfunction.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2006

Protecting participants in family medicine research: a consensus statement on improving research integrity and participants' safety in educational research, community-based participatory research, and practice network research.

Recent events that include the deaths of research subjects and the falsification of data have drawn greater scrutiny on assuring research data integrity and protecting participants. Several organizations have created guidelines to help guide researchers working in the area of clinical trials and ensure that their research is safe and valid. However, family medicine researchers often engage in research that differs from a typical clinical trial. Investigators working in the areas of educational research, community-based participatory research, and practice-based network research would benefit from similar recommendations to guide their own research. With funding from the US Office of Research Integrity and the Association of American Medical Colleges, we convened a panel to review issues of data integrity and participant protection in educational research, community-based participatory research, and research conducted by practice-based networks. The panel generated 11 recommendations for researchers working in these areas. Three key recommendations include the need for (1) all educational research to undergo review and approval by an institutional review board (IRB), (2) community-based participatory research to be approved not just by an IRB but also by appropriate community representatives, and (3) practice-based researchers to undertake only valid and meaningful studies that can be reviewed by a central IRB, rather than separate IRBs for each participating practice.

Biomedical Research↗
PubMed2006

How well are practice management curricula preparing family medicine residents?

BACKGROUND: While emphasis has been placed on practice management curricula in residency, studies indicate that residents are not adequately prepared. To assess the effectiveness of current practice management skills training in residency, we examined the confidence levels of family medicine residents and recent graduates in practice management skills. METHODS: A survey was sent to family medicine residency programs within South Carolina. Participants ranked their confidence level in 13 practice management skills on a 5-point Likert scale. Analysis of covariance compared confidence levels in their skills while controlling for program, gender, and age. Residency directors of these programs were also surveyed about the content of their practice management programs. RESULTS: Residents and graduates rated their confidence in all areas moderately high. Graduates rated themselves significantly more confident than residents did in seven practice management skills. CONCLUSIONS: Family medicine practice management curricula appear to be effective in establishing confidence regarding practice management skills in residents and recent graduates.

Adult↗
PubMed2006

Multiple lipid scoring system for prediction of coronary heart disease risk: application to African Americans.

BACKGROUND: Clinicians often obtain a panel of lipids but then only use low-density-lipoprotein (LDL) cholesterol to make clinical decisions. We previously described the multiple lipid measure, a strategy that integrates information about seven lipid measures. Our current inquiry uses the multiple lipid measure to create a scoring system and validates that system in a second cohort. METHODS AND RESULTS: A scoring system that uses total cholesterol, high-density lipoprotein (HDL) cholesterol, LDL cholesterol and triglycerides was developed and tested. African-American participants of the Atherosclerosis Risk in Communities (ARIC) Study were used to validate the multiple lipid measure score. For nonsmokers, scores > or = 2 had a hazard ratio of 4.25 (95% CI 1.92-9.40) compared to reference scores of < or = -3 in adjusted survival analysis predicting incident coronary heart disease risk in the ARIC. The best conventional single lipid measure for nonsmokers was LDL cholesterol. Compared to LDL cholesterol <100 mg/dl, those with LDL cholesterol > or = 160 mg/dl had a hazard ratio of 2.31 (95% CI 1.13-4.75). For current smokers, the best conventional lipid measure was the total cholesterol/HDL cholesterol ratio, which was similar in predictive ability to the multiple lipid measure score. However, the multiple lipid measure score predicted an additional 10% of the cohort at risk compared to the total cholesterol/HDL cholesterol ratio. CONCLUSIONS: The use of the multiple lipid scoring system improves the assessment of incident coronary heart disease risk and may have utility for clinicians in integrating lipid values.

Black or African American↗
PubMed2005

Iron, lipids, and risk of cancer in the Framingham Offspring cohort.

Iron and lipids combine to create oxidative stress, and oxidative stress has a role in the development of cancer. The objective was to determine the risk of cancer among persons who had both elevated iron and lipids. The authors conducted an analysis of the cohort available in the Framingham Offspring Study. Adults aged 30 or more years at baseline had serum iron and high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol, and very low density lipoprotein cholesterol (VLDL-C) assessed in 1979-1982 and were followed for development of cancer until 1996-1997 (n = 3,278). Cox regression models were computed while controlling for age, gender, smoking status, and body mass index. In adjusted models, both elevated iron (hazard ratio (HR) = 1.66, 95% confidence interval (CI): 1.11, 2.46; 29 cases) and VLDL-C (HR = 1.54, 95% CI: 1.04, 2.28; 93 cases) had significant independent risks for development of cancer. When elevated iron was combined with elevated VLDL-C, the adjusted relative risk of cancer increased (HR = 2.68, 95% CI: 1.49, 4.83; 18 cases). Elevated iron and low HDL-C also had a significant adjusted relative risk of cancer (HR = 2.82, 95% CI: 1.50, 5.28; 14 cases). The results suggest that elevated serum iron levels coupled with either high VLDL-C or low HDL-C appear to interact to increase cancer risk in this cohort.

Adult↗
PubMed2005

Predicting coronary heart disease risk using multiple lipid measures.

Principal component analysis was used to summarize variations among 7 lipid measures included in the Framingham Offspring Study (n = 2,694). An overall measure combining information from the 7 lipids was compared with conventional lipid measures in adjusted survival analyses and was found to be a superior predictor of coronary heart disease risk.

Adult↗