Use of outcomes in monitoring healthcare – how many outcome measures are needed in monitoring diabetes in primary care?

Objectives

To investigate the relationship between patient experience assessed through surveys of random samples of practice populations and intermediate outcome targets in those patients with diabetes, collected in the Quality and Outcomes Framework pay-for-performance scheme.

Design

Cross-sectional study.

Setting

The East Midlands region of England.

Participants

Six hundred and twenty-nine general practices.

Main outcome measures

Logistic regression models were used to assess whether practice-level reports of patient experience of access and consultations were associated with achievement of treatment targets (HbA1c of 7.5% and 10% or lower, BP 145/85 mmHg or lower, and cholesterol 5 mmol/L or lower) in people with diabetes. Survey respondent characteristics (ethnicity, age, sex) and practice size, deprivation, and prevalence of diabetes and obesity were also assessed within the models.

Results

Patient experience of practice populations explained little of the variation in diabetes treatment targets. In the practice survey, the proportion of respondents who had seen a nurse in the last 6 months was associated with increased likelihood of achieving HbA1c of 7.5%, and being involved in decision-making or having tests and treatment explained were associated with achievement of HbA1c of 10% or less, cholesterol of 5 mmol/L or less, and BP of 145/85 or less.

Conclusions

Although patient experience at practice level should be included in monitoring outcomes, it should not replace monitoring clinical outcomes in diabetes. A mix of clinical and patient experience measures will have to be used to monitor outcomes in general practice.     

Effect of sodium restriction on blood pressure of unstable or uncontrolled hypertensive patients in primary care

BACKGROUND/OBJECTIVES

The aims of the present study are: 1) to quantify sodium consumption of patients with unstable or uncontrolled hypertension, 2) to investigate if reduced sodium intake can lower BP in these patients, and 3), to assess the acceptability and feasibility of this approach.

SUBJECTS/METHODS

This study included 25 adults (age: 50+ years) with frequently elevated BP or patients with uncontrolled, uncomplicated hypertension despite drug treatment in a general practice setting. BP and salt intake (24h urinary excretion and food records) were measured at baseline and after a sodium reduced diet.

RESULTS

Mean (± SD) systolic (SBP) over diastolic (DBP) blood pressure (mmHg) at baseline was 150.7 (± 9.5)/84.149 (± 5.6). Mean urinary sodium excretion was 146 mmol/24h. A reduction of 28 mmol sodium excretion decreased SBP/DBP to 135.5 (± 13.0)/82.5 (± 12.8) (P < 0.001). After one month of no dietary advice, only in 48%, SBP was still ≤140 mmHg.

CONCLUSION

Assessment of sodium intake using food records, 24h urine collections and probing questions to identify use of sodium containing supplements or drugs are essential for tailored advice targeted at sodium intake reduction. The results of the present study indicate that reduced sodium intake can lower BP after 4 weeks in unstable or uncontrolled hypertensive patients.     

Period Prevalence and Sociodemographic Factors of Hypertension in Rural Maharashtra: A Cross-Sectional Study

Background:

Hypertension is most common cardiovascular disease and it account for large proportion of all cardiovascular deaths and disability worldwide.

Research Questions:

What is the level of prevalence of hypertension in rural area? What are the soociodemographic factors associated with hypertension?

Objectives:

To find out prevalence of hypertension in rural area.

Study Design:

A community-based cross-sectional study setting: Rural Health Training Centre Paithan, field practice area of govt. medical college Aurangabad, Maharashtra.

Participants:

1297 persons aged 19 years and above.

Study Period:

June 2005 to December 2006.

Materials and Methods:

A house-to-house survey was conducted by the author himself, interviewed the participants by systematic random sampling method, using pretested structured standard questionnaire. Two independent blood pressure (BP) readings were taken in sitting position by visiting each participant at their home. Hypertension was defined as systolic BP more than or equal to 140 mm of Hg or diastolic BP more than or equal to 90 mm of Hg or those individuals currently taking antihypertensive treatment.

Statistical Tests:

Percentiles, Chi Square test, Chi-Square for linear trend, multiple logistic regression analysis on SPSS software Version 10.

Results:

Overall prevalence of hypertension in the study subjects was 7.24%. Multiple logistic regression analysis identified various factors significantly associated with hypertension were age, sex, BMI, additional salt intake, smoking, DM, alcohol consumption, and higher socioeconomic status.

Conclusions:

The overall prevalence of hypertension in study subjects was 7.24%.     

ST segment depression in hypertensive patients: A comparison of exercise test versus Holter ECG

Introduction:

This study compared ST segment depression (ST depression) during cycle ergometry (ergometry) versus simultaneous 24-hour ambulatory blood pressure measurement and electrocardiogram recording (24-h ABPM/ECG) during everyday life.

Methods:

In a German multicenter study, ergometry and 24-h ABPM/ECG records of 239 hypertensive patients were retrospectively analyzed. ST depression was defined as an ST segment depression (1 mm limb or chest recordings V1 to V6) in an incremental cycle ergometry, or 1 mm in the 24-h ABPM/ECG recording under everyday conditions. Blood pressure parameters at the onset of ST depression in the context of the respective method were compared.

Results:

18 patients had ST depression only in ergometry (group B), 23 had ST depression only during 24-h ABPM/ECG monitoring (group C) and 28 patients had ST depression with both methods (group D). Group A had no ST depression with any method. In group D, at the onset of ST depression with 24-h ABPM/ECG investigation, all parameters except diastolic blood pressure were significantly lower compared with the corresponding parameters at the onset of ST depression with ergometry (systolic blood pressure: 148 ± 19 vers 188 ± 35 mmHg, p × 0.001; heart rate: 93 ± 12 vs 120 ± 21 beat/min, p < 0.0001; double product: 13,714 ± 2315 vs 22,992 ± 3,985 mmHg/min), p < 0.0001).

Conclusion:

ST depressions during everyday life detected by 24-h ABPM/ECG are characterized by a substantially lower triggering threshold for blood pressure level parameters compared with ergometry. The two methods detecting ischemia do not replace but complement each other.     

Effect of a UK pay-for-performance program on ethnic disparities in diabetes outcomes: interrupted time series analysis

PURPOSE

We wanted to examine the long-term effects of the Quality and Outcomes Framework (QOF), a major pay-for-performance program in the United Kingdom, on ethnic disparities in diabetes outcomes.

METHODS

We undertook an interrupted time series analysis of electronic medical record data of diabetes patients registered with 29 family practices in South West London, United Kingdom. Main outcome measures were mean hemoglobin A_1c (HbA_1c), total cholesterol, and blood pressure.

RESULTS

The introduction of QOF was associated with initial accelerated improvements in systolic blood pressure in white and black patients, but these improvements were sustained only in black patients (annual decrease: −1.68 mm Hg; 95% CI, −2.41 to −0.95 mm Hg). Initial improvements in diastolic blood pressure in white patients (−1.01 mm Hg; 95% CI, −1.79 to −0.24 mm Hg) and in cholesterol in white (−0.13 mmol/L; 95% CI, −0.21 to −0.05 mmol/L) and black (−0.10 mmol/L; 95% CI, −0.20 to −0.01 mmol/L) patients were not sustained in the post-QOF period. There was no beneficial impact of QOF on HbA_1c in any ethnic group. Existing disparities in risk factor control remained largely intact (for example; mean HbA_1c: white 7.5%, black 7.8%, south Asian 7.8%; P <.05) at the end of the study period.

CONCLUSION

A universal pay-for-performance scheme did not appear to address important disparities in chronic disease management over time. Targeted quality improvement strategies may be required to improve health care in vulnerable populations.     

Ambulatory blood pressure in hypertensive patients with left ventricular hypertrophy: efficacy of first-line combination perindopril/indapamide therapy

Background

Ambulatory blood pressure (BP) is more sensitive than office BP and is highly correlated with the left ventricular mass (LVM) of hypertensive patients with left ventricular hypertrophy (LVH).

Methods

In this prospectively designed ancillary study of the PICXEL trial, the effects of first-line combination perindopril/indapamide on ambulatory BP were compared with those of monotherapy with enalapril in 127 patients. Hypertensive patients with LVH received once daily either perindopril 2 mg/indapamide 0.625 mg (n = 65) or enalapril 10 mg (n = 62) for 52 weeks. Dose adjustments were allowed for uncontrolled BP. Twenty-four-hour ambulatory BP and echocardiographic parameters were measured at baseline, week 24, and week 52.

Results

At study end, both treatments significantly improved ambulatory BP compared with baseline (p ≤ 0.01). Perindopril/indapamide treatment reduced 24-hour and daytime systolic BP (SBP) and pulse pressure (PP) significantly more than enalapril treatment (p < 0.01). No significant between-group differences were noted for diastolic BP (DBP) or for night-time measurements. Trough/peak ratios were higher with perindopril/indapamide than with enalapril (88.5 vs 65.8 for SBP and 86.7 vs 63.9 for DBP, respectively). The global smoothness index was higher with perindopril/indapamide than with enalapril (6.6 vs 5.2 for SBP and 5.6 vs 4.9 for DBP, respectively). With perindopril/indapamide treatment, LVM index was significantly reduced (−9.1 g/m² from baseline; p vs baseline <0.001). More patients required dose increases with enalapril (87%) than with perindopril/indapamide (71%). No unusual safety elements were noted.

Conclusions

First-line perindopril/indapamide combination decreased ambulatory SBP and PP, and LVM more effectively than enalapril.     

Influence of albuminuria and glomerular filtration rate on blood pressure response to antihypertensive drug therapy

Background

Albuminuria and glomerular filtration rate (GFR), two factors linked to kidney and vascular function, may influence longitudinal blood pressure (BP) responses to complex antihypertensive drug regimens.

Methods

We reviewed the clinic records of 459 patients with hypertension in an urban, academic practice.

Results

Mean patient age was 57-years, 89% of patients were African American, and 69% were women. Mean patient systolic/diastolic BP (SBP/DBP) at baseline was 171/98 mmHg while taking an average of 3.3 antihypertensive medications. At baseline, 27% of patients had estimated (e)GFR <60 ml/min/1.73², 28% had micro-albuminuria (30–300 mg/g) and 16% had macro-albuminuria (>300 mg/g). The average longitudinal BP decline over the observation period (mean 7.2 visits) was 25/12 mmHg. In adjusted regression models, macro-albuminuria predicted a 10.3 mmHg lesser longitudinal SBP reduction (p < 0.001) and a 7.9 mmHg lesser longitudinal DBP reduction (p < 0.001); similarly eGFR <60 ml/min/1.73² predicted an 8.4 mmHg lesser longitudinal SBP reduction (p < 0.001) and a 4.5 lesser longitudinal DBP reduction (p < 0.001). Presence of either micro- or macro-albuminuria, or lower eGFR, also significantly delayed the time to attainment of goal BP.

Conclusions

These data suggest that an attenuated decline in BP in drug-treated hypertensives, resulting in higher average BP levels over the long-term, may mediate a portion of the increased risk of cardiovascular-renal disease linked to elevated urinary albumin excretion and reduced eGFR.     

Organic and Inorganic Mercury in Neonatal Rat Brain after Prenatal Exposure to Methylmercury and Mercury Vapor

Background

Many populations are exposed to multiple species of mercury (Hg), predominantly organic Hg as methylmercury (MeHg) from fish, and inorganic Hg as Hg vapor from dental amalgams. Most of our knowledge of the neurotoxicity of Hg is based on research devoted to studying only one form at a time, mostly MeHg.

Objectives

In this study we investigated the effects of prenatal exposure to MeHg and Hg vapor on Hg concentrations in the brain of neonatal rats.

Methods

Female Long-Evans hooded rats were exposed to MeHg (0, 3, 6, or 9 ppm as drinking solution), Hg vapor (0, 300, or 1,000 μg/m³ for 2 hr/day), or the combination of both, from 30 days before breeding through gestational day 18. On postnatal day 4, whole brains were taken from one male and one female from each of four litters in each treatment group to assess organic and inorganic Hg in the brain by cold vapor atomic absorption spectrometry.

Results

Statistical analysis using linear mixed effects models showed that MeHg dose was the primary determinant of both organic and inorganic brain Hg levels. For both outcomes, we also found significant interactions between MeHg and Hg vapor exposure. These interactions were driven by the fact that among animals not exposed to MeHg, animals exposed to Hg vapor had significantly greater organic and inorganic brain Hg levels than did unexposed animals.

Conclusion

This interaction, heretofore not reported, suggests that coexposure to MeHg and Hg vapor at levels relevant to human exposure might elevate neurotoxic risks.     

Inverse association of des-acyl ghrelin with worksite blood pressure in overweight/obese male workers

Background

Job strain, defined as a combination of high job demands and low job control, has been reported to elevate blood pressure (BP) during work. Meanwhile, a recent experimental study showed that ghrelin blunted the BP response to such mental stress. In the present study, we examined the hypothesis that des-acyl ghrelin may have some beneficial effects on worksite BP through modulating the BP response to work-related mental stress, i.e., job strain.

Methods

Subjects were 34 overweight/obese male day-shift workers (mean age 41.7 ± 6.7 years). No subjects had received any anti-hypertensive medication. A 24-h ambulatory BP monitoring was recorded every 30 min on a regular working day. The average BP was calculated for Work BP, Morning BP, and Home BP. Job strain was assessed using the short version of the Japanese Job Content Questionnaire.

Results

Des-acyl ghrelin showed significant inverse correlations with almost all BPs except Morning SBP, Morning DBP, and Home DBP. In multiple regression analysis, des-acyl ghrelin inversely correlated with Work SBP after adjusting for confounding factors. Des-acyl ghrelin was also negatively associated with BP changes from Sleep to Morning, Sleep to Work, and Sleep to Home.

Conclusions

Des-acyl ghrelin was inversely associated with Worksite BP, suggesting a unique beneficial effect of des-acyl ghrelin on Worksite BP in overweight/obese male day-shift workers.     

Progression from prehypertension to hypertension and risk of cardiovascular disease

Background

Subjects with prehypertension (pre-HT; 120/80 to 139/89 mm Hg) have an increased risk of cardiovascular disease (CVD); however, whether the risk of pre-HT can be seen at the pre-HT status or only after progression to a hypertensive (HT; ≥140/90 mm Hg) state during the follow-up period is unknown.

Blood Mercury Concentrations in CHARGE Study Children with and without Autism

Background

Some authors have reported higher blood mercury (Hg) levels in persons with autism, relative to unaffected controls.

Objectives

We compared blood total Hg concentrations in children with autism or autism spectrum disorder (AU/ASD) and typically developing (TD) controls in population-based samples, and determined the role of fish consumption in differences observed.

Methods

The Childhood Autism Risk from Genetics and the Environment (CHARGE) Study enrolled children 2–5 years of age. After diagnostic evaluation, we analyzed three groups: AU/ASD, non-AU/ASD with developmental delay (DD), and population-based TD controls. Mothers were interviewed about household, medical, and dietary exposures. Blood Hg was measured by inductively coupled plasma mass spectrometry. Multiple linear regression analysis was conducted (n = 452) to predict blood Hg from diagnostic status controlling for Hg sources.

Results

Fish consumption strongly predicted total Hg concentration. AU/ASD children ate less fish. After adjustment for fish and other Hg sources, blood Hg levels in AU/ASD children were similar to those of TD children (p = 0.75); this was also true among non-fish eaters (p = 0.73). The direct effect of AU/ASD diagnosis on blood Hg not through the indirect pathway of altered fish consumption was a 12% reduction. DD children had lower blood Hg concentrations in all analyses. Dental amalgams in children with gum-chewing or teeth-grinding habits predicted higher levels.

Conclusions

After accounting for dietary and other differences in Hg exposures, total Hg in blood was neither elevated nor reduced in CHARGE Study preschoolers with AU/ASD compared with unaffected controls, and resembled those of nationally representative samples.     

Leveraging Electronic Health Records to Develop Measurements for Processes of Care

Objectives

To assess the reliability of data in electronic health records (EHRs) for measuring processes of care among primary care physicians (PCPs) and examine the relationship between these measures and clinical outcomes.

Data Sources/Study Setting

EHR data from 15,370 patients with diabetes, 49,561 with hypertension, in a group practice serving four Northern California counties.

Study Design/Methods

Exploratory factor analysis (EFA) and multilevel analyses of the relationships between processes of care variables and factor scales with control of hemoglobin A1c, blood pressure (BP), and low density lipoprotein (LDL) among patients with diabetes and BP among patients with hypertension.

Principal Findings

Volume of e-messages, number of days to the third-next-available appointment, and team communication emerged as reliable factors of PCP processes of care in EFA (Cronbach''s alpha = 0.73, 0.62, and 0.91). Volume of e-messages was associated with higher odds of LDL control (≤100) (OR = 1.13, p < .05) among patients with diabetes. Frequent in-person visits were associated with better BP (OR = 1.02, p < .01) and LDL control (OR = 1.01, p < .01) among patients with diabetes, and better BP control (OR = 1.04, p < .01) among patients with hypertension.

Conclusions

The EHR offers process of care measures which can augment patient-reported measures of patient-centeredness. Two of them are significantly associated with clinical outcomes. Future research should examine their association with additional outcomes.     

Strategies for controlling blood pressure among low-income populations in Georgia

Background

In Georgia an estimated 32% of blacks and 28% of whites have high blood pressure. In 2004 the rate of death from stroke in Georgia was 12% higher than the national average, and blacks in the state have a 1.4 times greater rate of death from stroke than that of whites.

Context

The Georgia legislature funds the Stroke and Heart Attack Prevention Program (SHAPP) to provide treatment and medications for indigent Georgians. The median rate of blood pressure (BP) control among SHAPP enrollees is approximately 60%, compared with the national average of 35%.

Methods

SHAPP was evaluated through interviews with key health care and administrative staff and through focus groups of patients in two clinics.

Consequences

Outcomes for patients were increased knowledge of their BP and improved compliance with taking medication and keeping clinic appointments.

Interpretation

Successful components of SHAPP include an easy enrollment process; affordable medication; use of evidence-based, documented protocols and patient tracking systems; routine follow-up of patients; and effective communication between staff and patients. Challenges and recommendations for improvement are identified.     

Effect of candesartan cilexetil on diabetic and non-diabetic hypertensive patients: meta-analysis of five randomized double-blind clinical trials

Objective

To study the effect of candesartan cilexetil (CC) in the management of blood pressure (BP) in diabetic and non-diabetic hypertensive patients.

Methods

A selection of five randomized double-blind clinical trials in which patients were treated for hypertension with CC was analyzed. All of these were similar in design: i) a 4-week placebo run-in period, ii) a 4-to 6-week period (V1) with CC 8 mg once daily (od), after which the dosage was doubled if BP was not normalized (BP >140/90 or BP >130/80 mmHg in diabetes), and iii) a 4- to 6-week period (V2) with CC 8 or 16 mg od. Efficacy was measured at V1 and V2.

Results

702 patients were screened. The population consisted of 397 males (56.6%) with a mean age of 60 ± 11 years, with 153 diabetic (21.8%) and 549 non-diabetic (78.2%) patients. At baseline, mean BP values were 160/94/65 mmHg for SPB, DBP, and pulse pressure (PP) respectively, with differences between diabetic and non-diabetic patients. SBP, DBP, and PP values showed a significant reduction at V1 (p < 0.001) and V2 (p < 0.001) compared with baseline for all hypertensive patients. Mean changes at V2 in SBP and PP values were higher in diabetic than non-diabetic patients (p < 0.001), and to a lesser degree on DBP values (p = 0.034).

Conclusions

CC was effective in lowering BP in diabetic and non-diabetic hypertensive patients. CC is a promising therapy to manage hypertensive diabetic patients, as demonstrated by the significant BP reduction.

Short abstract

The effect of candesartan cilexetil (CC) on controlling blood pressure (BP) in hypertensive diabetic and non-diabetic patients was analyzed. Five randomized double-blind trials were pooled treating hypertension by CC (n = 702), including 153 diabetic (21.8%) and 549 non-diabetic (78.2%) patients. After treatment with CC (8–16 mg), significant reductions in SBP, DBP, and pulse pressure (PP) values were observed after 4–6 weeks (p < 0.001) and after 8–12 weeks (p < 0.001) compared with baseline for all hypertensive patients. Mean BP reductions after 8–12 weeks were higher in diabetic patients than non-diabetic (p < 0.001). CC is a promising therapy to treat hypertensive patients, both diabetic and non-diabetic.     

Adolescent hypertension identified with correct cuff and its cardiovascular and gestational problems after 29 years

Objective

to identify, in 2011, rates of hypertension, cardiovascular and gestational problems in subjects presenting high blood pressure in 1982, when correct cuff size was used, according to the American Heart Association Arm Circumference/Cuff Width ratio of 0.40.

Methods

high blood pressure was defined in 2011 as systolic = 115 mmHg and diastolic = 80mmHg, resulting in 20 subjects between 39 and 43 years old. (Risk Group). They were compared to 20 subjects from the original sample with lower blood pressure values (Control group).

Results

the rates of hypertension, cardiovascular and gestational problems were significantly higher (Fisher: p=0.02) in the Risk Group, with one case of cardiovascular death. Our findings arouse speculations about whether, if a proper cuff had been used in clinical practice, the complications and death could have been avoided.

Conclusions

data suggest compliance with the use of cuff width corresponding to 40% of arm circumference, despite polemics concerning cuff availability and difficulties of using many sizes.     

The Ahmed Glaucoma Valve in Refractory Glaucoma: Experiences in Southwest Ethiopia

Background

The management of refractory glaucoma is a challenging task for any glaucoma surgeon. This study is aimed to evaluate the efficacy of Ahmed Glaucoma Valve implantation in refractory glaucomas in South-West Ethiopia.

Methods

A retrospective review was conducted on the charts of consecutive patients treated with Ahmed glaucoma valve implantation at Jimma University Specialized Hospital between August 2012 and August 2014. Success was defined as Intraocular Pressure (IOP) less than 22 mm Hg and greater than 5mm Hg at 6 months, with at least 30% reduction from baseline, without medical therapy (complete success) or either with or without medication (qualified successes).

Results

A total of 12 eyes of 11 patients were included. The mean age of patients was 40.7 (SD= 19.0) years; 63.6% of them were males. The main types of glaucoma were pseudoexfoliative (3 eyes), uveitic (2 eyes), chronic angle closure (2 eyes) and Juvenile Open Angle (JOAG) (2 eyes). The mean IOP was reduced from preoperative level (32.75±7.14 mmHg) to (15.75 ±4.35 mmHg) at six postoperative months, (P<0.001); 66.7% eyes had complete successes while 83.3% had qualified success. Intra-operative complications were encountered in 2(16.7%) eyes, while 5/12 (41.7%) eyes had post-operative complications-hypotony (one with choroidal effusion) and progression of cataract in 2 eyes each. Hypertensive phase was diagnosed in 2(16.7%) eyes.

Conclusion

The Ahmed glaucoma valve implant appears to be effective and relatively safe for treating complicated glaucomas with success rate comparable with those reported from other studies. KEYWORDS: Ahmed glaucoma valve, refractory glaucoma, complications, Ethiopia     

Community-based Randomized Controlled Trial of Non-pharmacological Interventions in Prevention and Control of Hypertension among Young Adults

Context:

Hypertension is a major chronic lifestyle disease. Several non-pharmacological interventions are effective in bringing down the blood pressure (BP). This study focuses on the effectiveness of such interventions among young adults.

Aims:

To measure the efficacy of physical exercise, reduction in salt intake, and yoga, in lowering BP among young (20-25) pre-hypertensives and hypertensives, and to compare their relative efficacies.

Settings and Design:

The study was done in the urban service area of JIPMER. Pre-hypertensives and hypertensives, identified from previous studies, constituted the universe. The participants were randomized into one control and three interventional groups.

Materials and Methods:

A total of 113 subjects: 30, 28, 28 and 27 in four groups respectively participated for eight weeks: control (I), physical exercise (II) - brisk walking for 50-60 minutes, four days/week, salt intake reduction (III) - to at least half of their previous intake, and practice of yoga (IV) - for 30-45 minutes/day on at least five days/week.

Statistical Analysis Used:

Efficacy was assessed using paired t test and ANOVA with Games Howell post hoc test. An intention to treat analysis was also performed.

Results:

A total of 102 participants (29, 27, 25 and 21 in groups I, II, III and IV) completed the study. All three intervention groups showed a significant reduction in BP (SBP/DBP: 5.3/6.0 in group II, 2.6/3.7 in III, and 2.0/2.6 mm Hg in IV respectively). There was no significant change (SBP/DBP: 0.2/0.5 mmHg) of BP in control group (I). Physical exercise was most effective (considered individually); salt intake reduction and yoga were also effective.

Conclusions:

Physical exercise, salt intake reduction, and yoga are effective non-pharmacological interventions in significantly reducing BP among young hypertensives and pre-hypertensives. These can therefore be positively recommended for hypertensives. There is also a case to deploy these interventions in the general population.     

Modification by ALAD of the Association between Blood Lead and Blood Pressure in the U.S. Population: Results from the Third National Health and Nutrition Examination Survey

Background

Environmental lead exposure has been found to be associated with an increased risk of hypertension. Individuals vary greatly in susceptibility to lead toxicity, and genetic susceptibility has often been cited as the probable cause for such variation.

Objective

The main objective is to determine the role of the aminolevulinic acid dehydratase (ALAD) gene, which encodes the main carrier protein of lead in blood, in the association between lead exposure and blood pressure (BP) and hypertension in the U.S. population.

Methods

We analyzed data from individuals ≥ 17 years of age who participated in the Third National Health and Nutrition Examination Survey for whom DNA was available (n = 6,016). Multivariable logistic and linear regressions stratified by race/ethnicity were used to examine whether hypertension and BP were associated with ALAD and blood lead levels (BLL).

Results

BLL was associated with systolic BP in non-Hispanic whites and with hypertension and systolic and diastolic BP in non-Hispanic blacks. BLL was not associated with BP outcomes in Mexican Americans. Non-Hispanic white ALAD2 carriers in the highest BLL quartile (3.8–52.9 μg/dL) had a significantly higher adjusted prevalence odds ratio for hypertension compared with ALAD1 homozygous individuals. We also found a significant interaction between lead concentration and the ALAD2 allele in non-Hispanic whites and non-Hispanic blacks in relation to systolic BP.

Conclusions

BLL may be an important risk factor for hypertension and increased systolic and diastolic BP. These associations may be modified by ALAD genotype.     

Fish consumption and mercury exposure among Louisiana recreational anglers

Background

Methylmercury (MeHg) exposure assessments among average fish consumers in the United States may underestimate exposures among U.S. subpopulations with high intakes of regionally specific fish.

Objectives

We examined relationships among fish consumption, estimated mercury (Hg) intake, and measured Hg exposure within one such potentially highly exposed group, recreational anglers in the state of Louisiana, USA.

Methods

We surveyed 534 anglers in 2006 using interviews at boat launches and fishing tournaments combined with an Internet-based survey method. Hair samples from 402 of these anglers were collected and analyzed for total Hg. Questionnaires provided information on species-specific fish consumption during the 3 months before the survey.

Results

Anglers’ median hair Hg concentration was 0.81 μg/g (n = 398; range, 0.02–10.7 μg/g); 40% of participants had levels >1 μg/g, which approximately corresponds to the U.S. Environmental Protection Agency’s reference dose. Fish consumption and Hg intake were significantly positively associated with hair Hg. Participants reported consuming nearly 80 different fish types, many of which are specific to the region. Unlike the general U.S. population, which acquires most of its Hg from commercial seafood sources, approximately 64% of participants’ fish meals and 74% of their estimated Hg intake came from recreationally caught seafood.

Conclusions

Study participants had relatively elevated hair Hg concentrations and reported consumption of a wide variety of fish, particularly locally caught fish. This group represents a highly exposed subpopulation with an exposure profile that differs from fish consumers in other regions of the United States, suggesting a need for more regionally specific exposure estimates and public health advisories.     

Reducing radiation exposure using commonly available objects

Objectives

One and a half years have passed since the Fukushima Daiichi nuclear power plant disaster. The environmental radiation dose rate was not critical, but an existing exposure situation has been identified in a large part of Fukushima Prefecture. Although people continue to live and work in the contaminated area, they are not provided with sufficient information to reduce their exposure to radiation by themselves. In this study, we attempt to evaluate the efficiency of radiation shielding by using everyday items widely available to people.

Methods

NaI scintillation and Geiger–Müller survey meters were used to measure the radiation dose of (1) contaminated soil and (2) soil covered with commonly available items.

Results

In the soil at a depth of 10 cm from the surface, the radiation dose rate decreased from 3.36 to 0.65 μSv/h, and the count rate decreased from 3,120 to 352 cpm. Both the radiation dose rate and count rate reduced when the soil was covered with everyday items, such as a magazine more than 20 mm thick, a polystyrene foam board, and a wooden board of the same thickness.

Conclusions

To protect residents from unnecessary radiation exposure in the existing exposure situation, covering contaminated soil with a wooden board or a magazine, either of them 20 mm thick, is useful to reduce the radiation dose.