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Biomedical subjects

John M Flack

Publications and source records attributed to John M Flack.

At least 19 recordsLinked to original sources
PubMed2006

Large arterial elasticity varies as a function of gender and racism-related vigilance in black youth.

BACKGROUND: This exploratory study examined the relationship of gender and racism-related vigilance to baseline and task-induced changes in large arterial elasticity (LAE). METHODS: The convenience sample consisted of 153 black youth (M age = 11.5 years, SD = 1.4) who were normotensive. Large arterial elasticity was measured via pulse wave contour analysis, before, during, and after a sequentially administered digit forward and digit backward task. Racism-related vigilance was reported by participants. RESULTS: Although findings from general linear models indicated that the independent effects of gender and racism-related vigilance were not significantly related to LAE (baseline, reactivity, or recovery) (all p > .05), these analyses showed that gender and racism-related vigilance interacted to predict baseline LAE (p < .02) and task-induced changes (reactivity only) in LAE (p < .006). Follow-up regression analyses explicating the pattern of these interaction effects indicated that 1) racism-related vigilance was marginally and inversely related to baseline LAE among boys (p < .06) but not in girls (p > .21); and, 2) racism-related vigilance was positively and significantly associated with task-induced changes (reactivity) in LAE among boys (p < .008) but not in girls (p > .30). CONCLUSIONS: The relationship between racism-related vigilance and LAE varies as a function of gender, and may have longer-term implications for between and within-group disparities in cardiovascular health.

Adolescent↗
PubMed2006

The metabolic syndrome: recognition and management.

The National Cholesterol Education Program defines the metabolic syndrome as three or more of five abnormalities: waist circumference of >40 in (102 cm) for men or >35 in (88 cm) for women, triglyceride level of > or =150 mg/dL, high-density lipoprotein cholesterol of <40 mg/dL in men or <50 mg/dL in women, blood pressure of > or =130 or > or =85 mm Hg, and fasting glucose of > or =110 mg/dL. It is related to insulin resistance, but the two terms are not synonymous. Both are associated strongly with obesity. The metabolic syndrome is important as an indicator of increased risk of cardiovascular disease (CVD) in patients with and without clinical CVD. The CVD risk of the metabolic syndrome is greater than that conferred by any single CVD risk factor. Since risk factors tend to cluster, if one component of the metabolic syndrome is present, one should assess for other risk factors. The metabolic syndrome is also predictive of new-onset type 2 diabetes. Early diagnosis provides justification for measures that can improve components of the syndrome and reduce CVD risk. The management strategy for metabolic syndrome focuses on overall CVD risk rather than single risk factors; effective therapy includes priority for weight reduction and increased physical activity. Pharmacotherapy is typically needed for control of high blood pressure, hypercoagulability, and increased levels of blood glucose and triglycerides.

Adult↗
PubMed2006

Depression, stress, and blood pressure in urban African-American women.

African-American women have disturbingly high rates of hypertension, exceeding those of African-American men and other ethnic groups. Reasons for these disparities are not understood. Depression, more common in women than men, has been linked to endothelial dysfunction, inflammation, metabolic and hematologic abnormalities, and increased sympathetic nervous system activity--all factors associated with cardiovascular disease. A descriptive correlational design was used to test the following hypotheses: 1) African-American women with higher levels of depression will have higher blood pressure (BP) levels, more cardiovascular risk factors, greater stress, and lower social support; and 2) depression will mediate the relationship between stress and BP. A convenience sample of 245 hypertensive African-American women (mean age, 61+/-12.7 years) was recruited through free BP screenings offered in the community. All data were collected during a structured interview and brief physical examination. Pearson r correlation coefficients, analysis of variance, and multiple regression analyses were used to analyze the hypotheses. Women with higher levels of depression had higher diastolic BP and were more likely to smoke, eat fewer fruits and vegetables, and have more stress and less social support. Depression mediated the relationship between stress and diastolic BP. The findings emphasize the importance of assessing both behavioral and psychosocial factors in urban African-American women with hypertension.

Black or African American↗
PubMed2006

Efficacy and safety of coadministered amlodipine and atorvastatin in patients with hypertension and dyslipidemia: results of the AVALON trial.

The AVALON study was a randomized, multicenter trial to assess the efficacy and safety of coadministered amlodipine and atorvastatin in patients with hypertension and dyslipidemia. Phase one was an 8-week, double-blind, double-dummy, placebo-controlled period whereby patients received amlodipine 5 mg, atorvastatin 10 mg, amlodipine 5 mg and atorvastatin 10 mg, or placebo. Thereafter, all patients received single-blind amlodipine 5 mg and atorvastatin 10 mg for 8-weeks, followed by 12 weeks of open-label treatment where doses could be titrated to improve low-density lipoprotein cholesterol and blood pressure control. A total of 847 patients entered the double-blind phase. At Week 8, 45% of the patients receiving amlodipine 5 mg and atorvastatin 10 mg reached both their blood pressure and low-density lipoprotein cholesterol goals, compared with 8.3% with amlodipine (p < 0.001), 28.6% with atorvastatin (p < 0.001), and 3.5% with placebo. At 28 weeks, 67.1% of patients coadministered amlodipine and atorvastatin (mean doses, 7.6 mg and 28.4 mg, respectively) achieved both targets. Framingham estimated 10-year risk of coronary heart disease declined from baseline levels of 15.1% to 6.9% at Week 28. Following coadministered treatment, the adverse events reported were similar to either agent alone. Concomitant administration of amlodipine and atorvastatin is an effective and well tolerated treatment for coexisting hypertension and dyslipidemia.

Adolescent↗
PubMed2006

African American culture and hypertension prevention.

A qualitative study was done to explore attitudes and beliefs of African Americans regarding hypertension-preventive self-care behaviors. Five focus groups, with 34 participants, were held using interview questions loosely based on the Theory of Planned Behavior (TPB). Analysis revealed themes broadly consistent with the TPB and also identified an overarching theme labeled "circle of culture." The circle is a metaphor for ties that bind individuals within the larger African American community and provides boundaries for culturally acceptable behaviors. Three subthemes were identified: One describes how health behaviors are "passed from generation to generation," another reflects a sense of being "accountable" to others within the culture, and the third reflects negative views toward people who are "acting different," moving outside the circle of culture. Findings provide an expanded perspective of the TPB by demonstrating the influence of culture and collective identity on attitude formation and health-related behaviors among African Americans.

Black People↗
PubMed2005

A noninferiority comparison of valsartan/hydrochlorothiazide combination versus amlodipine in black hypertensives.

The objective of the study was to demonstrate that reduction in mean 24-hour diastolic blood pressure with 160 mg valsartan and 12.5 mg hydrochlorothiazide was not inferior to 10 mg amlodipine in hypertensive blacks. A total of 482 blacks with stage 1 and stage 2 hypertension (mean seated blood pressure 140 to 180/90 to 110 mm Hg) were enrolled in a double-blind, randomized, prospective study. After a placebo run-in period, patients were randomized to 160 mg valsartan or 5 mg amlodipine for 2 weeks, then force-titrated to 160 mg valsartan and 12.5 mg hydrochlorothiazide or 10 mg amlodipine for an additional 10 weeks. Blood pressure was assessed by 24-hour ambulatory blood pressure monitoring. Other assessments included quality of life, peripheral edema, and safety. Noninferiority of valsartan/hydrochlorothiazide to amlodipine was demonstrated by comparable reductions in mean 24-hour diastolic blood pressure with both treatments (-10.2+/-8.6 mm Hg versus -9.1+/-8.3 mm Hg, respectively; P<0.001 for noninferiority), as well as in mean 24-hour systolic blood pressure (-15.9+/-12.1 mm Hg versus -14.5+/-12.2 mm Hg; P<0.001 for noninferiority). The proportion of patients reporting adverse events and the incidence of most events were similar in both treatment groups, although more patients treated with amlodipine reported peripheral edema (5.8% versus 1.7%; P=0.03) and joint swelling (2.9% versus 0%; P=0.008) compared with valsartan/hydrochlorothiazide. We conclude that a starting dose of valsartan/hydrochlorothiazide (160/12.5 mg) is as effective as high-dose amlodipine (10 mg) in reducing blood pressure in blacks with stage 1 and stage 2 hypertension, and valsartan/hydrochlorothiazide is better tolerated.

Adult↗
PubMed2005

Higher prevalence of anemia with diabetes mellitus in moderate kidney insufficiency: The Kidney Early Evaluation Program.

BACKGROUND: The Kidney Early Evaluation Program (KEEP 2.0) cross-sectional, community-based study, targeted individuals at increased risk for kidney disease and measured blood glucose, creatinine, and hemoglobin. METHODS: KEEP 2.0 screening data were used to determine the prevalence of anemia by level of kidney function and diabetes status. Estimated glomerular filtration rate (EGFR) was calculated using serum creatinine values, and categorized as > or =90, 60-89, 30-59 and <30 mL/min/1.73 m(2). Anemia was defined as hemoglobin <12 g/dL in men and in women aged >50 years, and <11 g/dL in women < or =50 years. Diabetes was defined as participant-reported diagnosis, fasting glucose >125 mg/dL, or nonfasting glucose >200 mg/dL. RESULTS: Data were available on 5380 participants screened from August 2000 through December 2001. Diabetes was present in 26.9% of participants, and anemia in 7.7%; 15.9% of participants had at least moderately reduced kidney function (EGFR <60 mL/min/1.73 m(2)). In participants with diabetes, anemia prevalence at the 4 levels of descending EGFR were 8.7%, 7.5%, 22.2%, and 52.4%, compared with 6.9%, 5.0%, 7.9%, and 50.0% in persons without diabetes. In a multivariable model, participants of non-white race/ethnicity, those with diabetes and those with EGFR <30 or 30-59 mL/min/1.73 m(2) had significantly increased odds of anemia. In addition, a significant sex-diabetes interaction was identified; odds of anemia were 4-fold greater in men than women with diabetes relative to sex-matched participants without diabetes. CONCLUSION: Diabetes was independently correlated with anemia, more so in men than women, and may be linked to premature expression of anemia in persons with moderate reductions in kidney function.

Adult↗
PubMed2005

Therapeutic considerations in the African-American patient with hypertension: considerations with calcium channel blocker therapy.

African Americans have a higher prevalence, earlier onset, and more rapid progression of hypertensive end-organ disease, as well as excessive hypertensive mortality compared with other racial/ethnic groups. Most differences in hypertension and pressure-related complications between African Americans and whites appear to be quantitative and not qualitative. Improving the diagnosis, treatment, and control of hypertension in this highly vulnerable population is a major health care goal for the new millennium. In this regard the dietary pattern to be promoted for reduction of hypertension risk in African Americans is one of increased consumption of dairy products, fruit, and vegetables as well as a continued emphasis on decreased Na+ intake. When pharmacologic therapy is considered, multi-drug approaches are generally required, with diuretics, angiotensin-converting enzyme inhibitors (or angiotensin receptor blockers), and calcium channel blocker therapy as oft-selected components of most such treatment regimens.

Adult↗
PubMed2004

Determinants of blood pressure response to quinapril in black and white hypertensive patients: the Quinapril Titration Interval Management Evaluation trial.

Race has been considered an important factor in determining blood pressure response to treatment and selection of antihypertensive drug therapy. Data collected during a clinical trial that evaluated rapidity of medication up-titration with blood pressure response to monotherapy with the angiotensin-converting enzyme (ACE) inhibitor quinapril were used to characterize response in 533 black and 2046 white participants. Our objectives were to examine the influence of race and other factors on blood pressure response and to assess the degree to which nonrace factors account for apparent racial differences in response. Average systolic and diastolic blood pressure responses (baseline minus follow-up) to treatment were assessed with treatment groups combined. Crude systolic and diastolic blood pressure responses averaged 4.7 and 2.4 mm Hg less, respectively, in black compared with white participants; however, the response distributions largely overlapped. In multivariate linear regression models adjusted for study design variables and measured participant characteristics, the racial difference in systolic response was reduced by 51% to 2.3 mm Hg, and diastolic response by 21% to 1.9 mm Hg. In these models, participant characteristics, including age, gender, body size, and pretreatment blood pressure severity, significantly predicted either attenuated or enhanced blood pressure response to treatment. Our findings demonstrate that a large source of variability of blood pressure response to treatment is within, not between, racial groups, and that factors that vary at the level of the individual contribute to apparent racial differences in response to treatment.

Adult↗
PubMed2003

Efficacy and tolerability of eplerenone and losartan in hypertensive black and white patients.

OBJECTIVES: The purpose of this study was to evaluate the efficacy and tolerability of monotherapy with the selective aldosterone blocker eplerenone in both black and white patients with hypertension. BACKGROUND: Essential hypertension and cardiovascular-renal-target organ damage is more prevalent in black than white adults in the U.S. METHODS: Black (n = 348) and white (n = 203) patients with mild-to-moderate hypertension were randomized to double-blind treatment with eplerenone 50 mg, the angiotensin II receptor antagonist losartan 50 mg, or placebo once daily. Doses were increased if blood pressure remained uncontrolled. The primary end point was change in mean diastolic blood pressure (DBP) after 16 weeks of therapy. RESULTS: Adjusted mean changes from baseline in DBP were -5.3 +/- 0.7, -10.3 +/- 0.7, and -6.9 +/- 0.6 mm Hg in the placebo, eplerenone-treated, and losartan-treated groups, respectively (mean +/- SE, p < 0.001 eplerenone vs. placebo, p < 0.001 eplerenone vs. losartan). In black patients, DBP decreased by -4.8 +/- 1.0, -10.2 +/- 0.9, and -6.0 +/- 0.9 mm Hg for the placebo, eplerenone-treated, and losartan-treated groups, respectively (mean +/- SE, p < 0.001 eplerenone vs. placebo, p < 0.001 eplerenone vs. losartan), whereas in white patients, DBP decreased by -6.4 +/- 1.0, -11.1 +/- 1.1, and -8.4 +/- 1.0 mm Hg, respectively (p = 0.001 eplerenone vs. placebo, p = 0.068 for eplerenone vs. losartan). For reduction of systolic blood pressure (SBP), eplerenone was superior to placebo and losartan in all patients combined and in black patients, and was superior to placebo in white patients. Eplerenone was as effective as losartan in reducing SBP and DBP in the high renin patient, but more effective than losartan in the low renin patient. Similarly, eplerenone was at least as effective as losartan in patients with differing baseline levels of aldosterone. Both eplerenone and losartan were well tolerated. CONCLUSIONS: The antihypertensive effect of eplerenone was equal in black and white patients and was superior to losartan in black patients.

Adult↗