Arch G. Mainous

Adherence to healthy lifestyle habits in US adults, 1988-2006.

BACKGROUND Lifestyle choices are associated with cardiovascular disease and mortality. The purpose of this study was to compare adherence to healthy lifestyle habits in adults between 1988 and 2006. METHODS Analysis of adherence to 5 healthy lifestyle trends (>or=5 fruits and vegetables/day, regular exercise >12 times/month, maintaining healthy weight [body mass index 18.5-29.9 kg/m(2)], moderate alcohol consumption [up to 1 drink/day for women, 2/day for men] and not smoking) in the National Health and Nutrition Examination Survey 1988-1994 were compared with results from the National Health and Nutrition Examination Survey 2001-2006 among adults aged 40-74 years. RESULTS Over the last 18 years, the percent of adults aged 40-74 years with a body mass index >or=30 kg/m(2) has increased from 28% to 36% (P <.05); physical activity 12 times a month or more has decreased from 53% to 43% (P <.05); smoking rates have not changed (26.9% to 26.1%); eating 5 or more fruits and vegetables a day has decreased from 42% to 26% (P <.05), and moderate alcohol use has increased from 40% to 51% (P <.05). Adherence to all 5 healthy habits has gone from 15% to 8% (P <.05). Although adherence to a healthy lifestyle was lower among minorities, adherence decreased more among non-Hispanic Whites over the period. Individuals with a history of hypertension/diabetes/cardiovascular disease were no more likely to be adherent to a healthy lifestyle than people without these conditions. CONCLUSIONS Generally, adherence to a healthy lifestyle pattern has decreased during the last 18 years, with decreases documented in 3 of 5 healthy lifestyle habits. These findings have broad implications for the future risk of cardiovascular disease in adults.

Prehypertension and Cardiovascular Morbidity

PURPOSE The Seventh Report of the Joint National Commission (JNC 7) on High Blood Pressure established prehypertension (120 to 139 mm Hg systolic or 80 to 89 mm Hg diastolic) as a new risk category. We aim to determine the risk of major cardiovascular events associated with blood pressure in the prehypertensive range in a longitudinal, population-based cohort. METHODS Analyses were conducted on participants in the National Health and Nutrition Examination Survey I (1971–1975) observed for 18 years for major cardiovascular disease events. Cox proportional hazard ratios were calculated to assess relative risk of cardiovascular disease, including stroke, myocardial infarction, and heart failure, in participants with prehypertension and normal blood pressure (<120/80 mm Hg). RESULTS Prehypertension was associated with increased risk for cardiovascular disease (1.79 [95% confidence interval (CI) 1.40–2.24]) in unadjusted analysis. After adjustment for cardiovascular risk factors, the relationship of prehypertension to cardiovascular disease was diminished but persisted (1.32 [95% CI 1.05–1.65]). Ninety-three percent of prehypertensive individuals had at least 1 cardiovascular risk factor. Low prehypertension (120–129/80–84 mm Hg) was associated with increased cardiovascular disease in unadjusted analyses (1.56 [95% CI 1.23–1.98]) but was not statistically significant in adjusted analyses (1.24 [95% CI 0.96–1.59]). High-normal blood pressure (130–139/85–89 mm Hg) remained a predictor of cardiovascular disease in unadjusted (2.13 [95% CI 1.64–2.76]) and adjusted (1.42 [95% CI 1.09–1.84]) analyses. CONCLUSIONS In a longitudinal, population-based, US cohort, prehypertension was associated with increased risk of major cardiovascular events independently of other cardiovascular risk factors. These findings, along with the presence of cardiovascular risk factors in the majority of participant sample with prehypertension, support recommendations for physicians to actively target lifestyle modifications and multiple risk reduction in their prehypertensive patients.

Physician-Patient Relationship and Medication Compliance: A Primary Care Investigation

PURPOSE We assessed the relationship between 4 attributes of the physician-patient relationship and medication compliance. METHODS We conducted a waiting room survey of patients consulting 22 general practitioners in 14 randomly selected practices in Auckland, New Zealand (81% response rate). A total of 370 consecutive patients (75% response rate) completed survey instruments about 4 attributes of the physician-patient relationship. Continuity of care (assessed from use of a usual physician, length of continuity, and perceived importance of continuity) and trust in the physician were ascertained before the consultation. After the consultation the Patient Enablement Index measured the physician’s ability to enable patients in self-care, and concordance between the patient and physician was measured by a 6-item inventory of perceived agreement about the presenting problem and management, were ascertained immediately after the consultation. Compliance with prescribed medication therapy was ascertained by telephone follow-up 4 days after the consultation. RESULTS Overall, 220 patients (61%) received a prescription, and 79% of these patients were taking the medication at follow-up. In a univariate analysis adjusted for clustering, only trust and physician-patient concordance were significantly related to compliance. In analysis further adjusted for health and demographic factors, physician-patient concordance was independently related to compliance (odds ratio = 1.34, 95% confidence interval, 1.04–1.72). CONCLUSIONS Primary care consultations with higher levels of patient-reported physician-patient concordance were associated with one-third greater medication compliance. An emphasis on understanding and facilitating agreement between physician and patient may benefit outcomes in primary care.

Dietary Magnesium and C-reactive Protein Levels

Objective: Current dietary guidelines recommend adequate intake of magnesium (310–420mg daily) in order to maintain health and lower the risk of cardiovascular disease. Recent evidence from animal and clinical studies suggests that magnesium may be associated with inflammatory processes. The objective of this study was to determine whether dietary magnesium consumption is associated with C-reactive protein (CRP), a marker of inflammation, in a nationally representative sample. Methods: Analysis of adult (≥17 years) participants in a cross-sectional nationally representative survey (National Health and Nutrition Examination Survey 1999–2000 [NHANES]) who were not taking magnesium or magnesium-containing supplements. The primary outcome measure was high sensitivity CRP (elevated ≥3.0mg/L). Results: Among US adults, 68% consumed less than the recommended daily allowance (RDA) of magnesium, and 19% consumed less than 50% of the RDA. After controlling for demographic and cardiovascular risk factors, adults who consumed <RDA of magnesium were 1.48–1.75 times more likely to have elevated CRP than adults who consumed ≥RDA (Odds Ratio [OR] for intake <50% RDA = 1.75, 95% Confidence Interval [CI] 1.08–2.87). Adults who were over age 40 with a BMI >25 and who consumed <50% RDA for magnesium were 2.24 times more likely to have elevated CRP (95% CI 1.13–4.46) than adults ≥RDA. Conclusions: Most Americans consume magnesium at levels below the RDA. Individuals with intakes below the RDA are more likely to have elevated CRP, which may contribute to cardiovascular disease risk.

Inflammatory markers and exercise: Differences related to exercise type

PURPOSE To examine the relationship between elevated inflammatory markers (CRP, fibrinogen, and white blood cell levels) and various forms of exercise for the adult U.S. population while controlling for factors that might influence the relationship. METHODS An analysis of the adults age 17 and over who participated in the National Health and Nutrition Examination Survey (NHANES) III was conducted. The main goal of the analysis was to determine whether exercise type was associated with systemic markers of inflammation. Bivariate statistics using chi-square to evaluate different types of exercise according to the presence of elevated and nonelevated inflammatory markers was initially performed. In addition, multivariate models were constructed using each type of exercise activity as the predictor variable and each inflammatory marker as the dependent variable. RESULTS A total of 4072 people were included in the analysis. In bivariate analyses, compared with nonexercisers in a specific exercise type, a significant lower likelihood of elevated inflammatory markers was found among regular participants in jogging, swimming, cycling, aerobic dancing, calisthenics, and weight lifting but not for gardening. After controlling for possible confounding factors including age, race, sex, body mass index, smoking, and health status in logistic regression analysis, only regular participants in jogging and aerobic dancing remained significantly less likely to have elevated cardiovascular markers. CONCLUSIONS The results of this study indicate that some forms of physical activity are associated with a lower likelihood of elevation of inflammatory markers, although we cannot exclude the possibility that differences may be due to exercise intensity or duration. Future research should be directed toward further exploration of the effects of different types of exercise activity on inflammatory markers and the role of exercise in the prevention of cardiovascular disease.

Changes in Age at Diagnosis of Type 2 Diabetes Mellitus in the United States, 1988 to 2000

PURPOSE The prevalence of diabetes in the United States is increasing. There is also concern that diabetes may be occurring at a greater frequency in youth and in young adults. We describe US population trends in self-reported age at diagnosis of type 2 diabetes mellitus. METHODS We undertook a secondary analysis of data from the National Health and Nutrition Examination Survey (NHANES) 1999–2000 and NHANES III (1988–1994). Both surveys are stratified, multistage probability samples targeting the civilian, noninstitutionalized US population, which allow calculation of population estimates. We included adults aged 20 years and older. We compared self-reported age at diagnosis of type 2 diabetes between the 2 survey periods. RESULTS The mean age at diagnosis decreased from 52.0 to 46.0 years (P <.05). Racial and ethnic differences in age at diagnosis found in 1988 to 1994 are no longer found in 1999 to 2000. CONCLUSIONS The age at diagnosis of type 2 diabetes mellitus has decreased with time. This finding likely represents a combination of changing diagnostic criteria, improved physician recognition of diabetes, and increased public awareness. Younger age at diagnosis may also reflect a true population trend of earlier onset of type 2 diabetes.

Nasal Carriage of Staphylococcus aureus and Methicillin-Resistant S aureus in the United States, 2001–2002

PURPOSE Staphylococcus aureus is a common cause of invasive infections, yet most assessments of prevalence are based on health care–based samples. We computed population-based estimates of nasal carriage of S aureus and risk factors for carriage, as well as population-based estimates of nasal carriage of methicillin-resistant S aureus (MRSA). METHODS We used the National Health and Nutrition Examination Survey (NHANES) 2001–2002 to estimate carriage of S aureus and MRSA for the non-institutionalized US population including children and adults. RESULTS An estimated 86.9 million persons (32.40% of the population) were colonized with S aureus. The prevalence of MRSA among S aureus isolates was 2.58%, for an estimated population carriage of MRSA of 0.84% or 2.2 million persons. Among individuals with S aureus isolates, individuals aged 65 years or older had the highest MRSA prevalence (8.28%). Among all the racial/ethnic groups studied, Hispanics had the highest prevalence of colonization with S aureus but, when colonized, were less likely to have MRSA. CONCLUSIONS This first nationally representative assessment of carriage of S aureus indicates that nearly one third of the population is currently colonized by this organism. Although the prevalence of MRSA remains low, more than 2.2 million people carry this resistant organism; thus, vigilance in promoting appropriate microbial transmission protocols should remain a priority.

Dietary Fiber for the Treatment of Type 2 Diabetes Mellitus: A Meta-Analysis

Background: The evidence of the relationship between fiber intake and control of diabetes is mixed. The purpose of this study was to determine if an increase in dietary fiber affects glycosylated hemoglobin (HbA1c) and fasting blood glucose in patients with type 2 diabetes mellitus. Methods: Randomized studies published from January 1, 1980, to December 31, 2010, that involved an increase in dietary fiber intake as an intervention, evaluated HbA1c and/or fasting blood glucose as an outcome, and used human participants with known type 2 diabetes mellitus were selected for review. Results: Fifteen studies met inclusion and exclusion criteria. The overall mean difference of fiber versus placebo was a reduction of fasting blood glucose of 0.85 mmol/L (95% CI, 0.46–1.25). Dietary fiber as an intervention also had an effect on HbA1c over placebo, with an overall mean difference of a decrease in HbA1c of 0.26% (95% CI, 0.02–0.51). Conclusion: Overall, an intervention involving fiber supplementation for type 2 diabetes mellitus can reduce fasting blood glucose and HbA1c. This suggests that increasing dietary fiber in the diet of patients with type 2 diabetes is beneficial and should be encouraged as a disease management strategy.

Elevation of C-Reactive Protein in People With Prehypertension

The objective of this study was to determine the relationship of C‐reactive protein (CRP) and blood pressure (BP) across the range of BP categories including prehypertension. The Third National Health and Nutrition Examination Survey (NHANES III) data collected from 1988 to 1994 were analyzed. In unadjusted analyses, there was a step‐wise increase in the probability of elevated CRP across a wide range of BP categories. Prehypertensive participants had a higher prevalence of elevated CRP than normotensive people (27.4% vs. 19.8%; p<05). After adjustment for age, gender, race, smoking, body mass index, exercise, diabetes, and medication usage, participants with systolic BP 120–139 mm Hg or diastolic BP 80–89 mm Hg were more likely to have elevated CRP than people with systolic BP <120 (odds ratio, 1.36; 95% confidence interval, 1.14–1.62; odds ratio, 1.20; 95% confidence interval, 1.02–1.41, respectively). CRP and BP are positively related across a wide range of BP categories. A substantial proportion of prehypertensive individuals have elevated CRP independent of multiple confounders.

The association between weight fluctuation and mortality: results from a population-based cohort study.

Previous studies evaluating the association between weight fluctuation and mortality are limited and have conflicting results. This study will further evaluate the association between weight fluctuation and mortality in a nationally representative cohort by performing survival analysis of NHANES I and NHANES I Epidemiologic Follow-up Study (n=8479; weighted sample=68,200,905). This cohort was followed from 1971 to 1992 and categorized using weight change over five time points into stable non-obese, stable obese, weight gain, weight loss and weight fluctuation groups. All-cause mortality (ACM) and cardiovascular mortality (CM) were evaluated. Respondents with weight fluctuation had higher ACM (HR: 1.83, 95% CI: 1.25–2.69) and CM hazards ratios (HR: 1.86, 95% CI: 1.10–3.15) than the stable non-obese group, even after controlling for pre-existing disease, initial BMI and excluding those in poor health or incapacitated. Increased mortality was also seen in the weight loss group (ACM HR: 3.36, 95% CI: 2.47–4.55), (CM HR 4.22, 95% CI: 2.60–6.84). The stable obese group did not have increased ACM, but did have increased CM prior to the exclusion of those in poor health or incapacitated. (HR: 2.17, 95% CI: 1.10–4.28). Weight fluctuation is associated with a higher risk of all-cause and cardiovascular disease mortality in the US population, even after adjustment for pre-existing disease, initial BMI and the exclusion of those in poor health or incapacitated. Thus, health care providers should promote a commitment to maintaining weight loss to avoid weight fluctuation and consider patients’ weight histories when assessing their risk status.