The State Scientific Automated Medical Registry, Kazakhstan: an important resource for low-dose radiation health research.

Direct quantitative assessment of health risks following exposure to ionizing radiation is based on findings from epidemiological studies. Populations affected by nuclear bomb testing are among those that allow such assessment. The population living around the former Soviet Union's Semipalatinsk nuclear test site is one of the largest human cohorts exposed to radiation from nuclear weapons tests. Following research that started in the 1960s, a registry that contains information on more than 300,000 individuals residing in the areas neighboring to the test site was established. Four nuclear weapons tests, conducted from 1949 to 1956, resulted in non-negligible radiation exposures to the public, corresponding up to approximately 300 mGy external dose. The registry contains relevant information about those who lived at the time of the testing as well as about their offspring, including biological material. An international group of scientists worked together within the research project SEMI-NUC funded by the European Union, and concluded that the registry provides a novel, mostly unexplored, and valuable resource for the assessment of the population risks associated with environmental radiation exposure. Suggestions for future studies and pathways on how to use the best dose assessment strategies have also been described in the project. Moreover, the registry could be used for research on other relevant public health topics.

Differential Impact of Index Stroke on Dementia Risk in African-Americans Compared to Whites.

OBJECTIVE: To compare whites and African-Americans in terms of dementia risk following index stroke. METHODS: The data consisted of billing and International Classification of Diseases, Ninth Revision diagnosis codes from the South Carolina Revenue and Fiscal Affairs office on all hospital discharges within the state between 2000 and 2012. The sample consisted of 68,758 individuals with a diagnosis of ischemic stroke prior to 2010 (49,262 white [71.65%] and 19,496 African-Americans [28.35%]). We identified individuals in the dataset who were subsequently diagnosed with any of 5 categories of dementia and evaluated time to dementia diagnosis in Cox Proportional Hazards models. We plotted cumulative hazard curves to illustrate the effect of race on dementia risk after controlling for age, sex, and occurrence of intervening stroke. RESULTS: Age at index stroke was significantly different between the 2 groups, with African-Americans being younger on average (70.0 [SD 12.5] in whites versus 64.5 [SD 14.1] in African-Americans, P < .0001). Adjusted hazard ratios revealed that African-American race increased risk for all 5 categories of dementia following incident stroke, ranging from 1.37 for AD to 1.95 for vascular dementia. Age, female sex, and intervening stroke likewise increased risk for dementia. CONCLUSIONS: African-Americans are at higher risk for dementia than whites within 5 years of ischemic stroke, regardless of dementia subtype. Incident strokes may have a greater likelihood of precipitating dementia in African-Americans due to higher prevalence of nonstroke cerebrovascular disease or other metabolic or vascular factors that contribute to cognitive impairment.

Stroke genomics in people of African ancestry: charting new paths.

One in six people worldwide will experience a stroke in his/her lifetime. While people in Africa carry a disproportionately higher burden of poor stroke outcomes, compared to the rest of the world, the exact contribution of genomic factors to this disparity is unknown. Despite noteworthy research into stroke genomics, studies exploring the genetic contribution to stroke among populations of African ancestry in the United States are few. Furthermore, genomics data in populations living in Africa are lacking. The wide genomic variation of African populations offers a unique opportunity to identify genomic variants with causal relationships to stroke across different ethnic groups. The Stroke Investigative Research and Educational Network (SIREN), a component of the Human Health and Heredity in Africa (H3Africa) Consortium, aims to explore genomic and environmental risk factors for stroke in populations of African ancestry in West Africa and the United States. In this article, we review the literature on the genomics of stroke with particular emphasis on populations of African origin.

The clinical course of sarcoidosis: presentation, diagnosis, and treatment in a large white and black cohort in the United States.

BACKGROUND: Although numerous reports have described the clinical features of sarcoidosis in various ethnic and racial groups, many have been limited by small size, homogenous populations, and relatively short follow-up periods. We report the clinical characteristics of a large, race-sex-age diverse cohort of sarcoidosis clinic patients followed in a large university medical center for an extended period of time. METHODS: This study included clinical data for sarcoidosis patients followed over a 12-year period at a sarcoidosis clinic at the Medical University of South Carolina. RESULTS: 1774 sarcoidosis patients were identified. Black females were more common (44%) than other race/gender combinations (p = 0.01). The diagnosis of sarcoidosis occurred > 3 months after the onset of symptoms in 48% of the cohort and > 1 year after the onset of symptoms in 25%. Anti-sarcoidosis treatment was required in 61% of the patients. Pulmonary function improved over time and the median corticosteroid requirement lessened. Compared to whites, blacks had more advanced radiographic stages of sarcoidosis (p < 0.0001), more organ involvement (p < 0.0001), and more frequently required anti-sarcoidosis medication (p < 0.0001). Compared to women, men had more advanced radiographic stages of sarcoidosis (p < 0.0001). CONCLUSIONS: The analysis indicates that sarcoidosis tends to improve over time in terms of pulmonary function and medication requirements. The disease was found to be more severe in blacks than whites. Treatment was not necessarily required. These results provide a comprehensive model of the course and treatment of sarcoidosis in the clinical setting.

DASH lowers blood pressure in obese hypertensives beyond potassium, magnesium and fibre.

The mechanism underlying blood pressure (BP) reduction in the high fruits and vegetables arm of the Dietary Approaches to Stop Hypertension (DASH) study is unknown but may include potassium, magnesium and fibre. This study was designed to separate minerals and fibre from other components of DASH on BP in abdominally obese individuals with metabolic syndrome with pre-hypertension to stage 1 hypertension (obese hypertensives). A total of 15 obese hypertensives and 15 lean normotensives were studied on a standardized usual diet, randomized to DASH or usual diet supplemented with potassium, magnesium and fibre to match DASH, then crossed over to the complementary diet. All diets were 3 weeks long, isocaloric and matched for sodium and calcium. In obese hypertensives, BP was lower after 3 weeks on DASH than usual diet (-7.6+/-1.4/-5.3+/-1.4 mm Hg, P<0.001/0.02) and usual diet supplemented (-6.2+/-1.4/-3.7+/-1.4 P<0.005/0.06), whereas BP was not significantly different on usual and supplemented diets. BP values were not different among the three diets in lean normotensives. Small artery elasticity was lower in obese hypertensives than in lean normotensives on the usual and supplemented diets (P<0.02). This index of endothelial function improved in obese hypertensives (P<0.02) but not lean normotensives on DASH, and was no longer different from values in lean normotensives (P>0.50). DASH is more effective than potassium, magnesium and fibre supplements for lowering BP in obese hypertensives, which suggest that high fruits and vegetables DASH lowers BP and improves endothelial function in this group by nutritional factors in addition to potassium, magnesium and fibre.

Nuclear magnetic resonance-determined lipoprotein subclass profile in the DCCT/EDIC cohort: associations with carotid intima-media thickness.

AIMS: To relate nuclear magnetic resonance lipoprotein subclass profiles (NMR-LSP) and other lipoprotein-related factors with carotid intima-media thickness (IMT) in Type 1 diabetes. METHODS: Lipoprotein-related factors were determined in sera (obtained in 1997-1999) from 428 female [age 39 +/- 7 years (mean +/- SD)] and 540 male (age 40 +/- 7 years) Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) participants. NMR quantifies chylomicrons, three very low-density lipoprotein (VLDL) subclasses, intermediate density lipoprotein (IDL), three low-density lipoprotein (LDL) subclasses, two high-density lipoprotein (HDL) subclasses, mean VLDL, LDL and HDL size, and LDL particle concentration. Conventional lipids, ApoA1, ApoB and Lp(a) and in vitro LDL oxidizibility were also measured. IMT was determined (in 1994-1995) using high-resolution B-mode ultrasound. Relationships between IMT and lipoproteins were analysed by multiple linear regression, controlling for age, diabetes-related factors, and cardiovascular disease (CVD) risk factors. RESULTS: IMT associations with lipoproteins were stronger for the internal than the common carotid artery, predominantly involving LDL. Internal carotid IMT was positively (P < 0.05) associated with NMR-based LDL subclasses and particle concentration, and with conventional LDL-cholesterol and ApoB in both genders. Common carotid IMT was associated, in men only, with large VLDL, IDL, conventional LDL cholesterol and ApoB. CONCLUSIONS: NMR-LSP reveals significant associations with carotid IMT in Type 1 diabetic patients, even 4 years after IMT measurement. NMR-LSP may aid early identification of high-risk diabetic patients and facilitate monitoring of interventions. Longer DCCT/EDIC cohort follow-up will yield CVD events and IMT progression, permitting more accurate assessment of pre-morbid lipoprotein profiles as determinants of cardiovascular risk in Type 1 diabetes.

Sarcoidosis: social predictors of severity at presentation.

To determine relationships among social predictors and sarcoidosis severity at presentation, demographic characteristics, socioeconomic status, and barriers to care, A Case-Control Etiologic Study of Sarcoidosis (ACCESS) was set up. Patients self-reported themselves to be Black or White and were tissue-confirmed incident cases aged > or =l8-yrs-old (n=696) who had received uniform assessment procedures within one of 10 medical centres and were studied using standardised questionnaires and physical, radiographical, and pulmonary function tests. Severity was measured by objective disease indicators, subjective measures of dyspnoea and short form-36 subindices. The results of the study showed that lower income, the absence of private or Medicare health insurance, and other barriers to care were associated with sarcoidosis severity at presentation, as were race, sex, and age. Blacks were more likely to have severe disease by objective measures, while women were more likely than males to report subjective measures of severity. Older individuals were more likely to have severe disease by both measures. In conclusion, it was found that low income and other financial barriers to care are significantly associated with sarcoidosis severity at presentation even after adjusting for demographic characteristics of race, sex, and age.

Low birth weight as a risk factor for hypertension.

While the geographic and demographic disparities in the prevalence of hypertension have been recognized for decades, the reasons for these differences in disease risks remain unknown. The demographic and geographic patterns of hypertension are similar to those of low birth weight, giving support to the "Barker Hypothesis" which proposes a fetal origin of adult-onset disease. In fact, ecologic and observational studies throughout the world have detected significant associations of low birth weight and increased risks of hypertension. Nonetheless, the mechanisms for the association have not been fully described and documented. With some supportive evidence, proposed mechanisms include reduced nephrogenesis with a higher threshold for pressure natriuresis and greater susceptibility to progressive renal disease, impaired development of the endothelium, and increased sensitivity to glucocorticoids. Still, considerable work needs to be done to explain the birth weight/blood pressure relationship. The findings to date and the clinical significance warrant continued research in this intriguing area of study.

Health care improvement and cost reduction opportunities in hypertensive Medicaid beneficiaries.

Hypertension and its complications are more frequent and occur about a decade earlier in life among high-risk groups, especially in the Southeast. Moreover, socioeconomic status is inversely related to hypertension and cardiovascular complications. Low-income, young and middle-aged adults living in the Southeast may be at especially high risk. Data on inpatient admissions among hypertensive Medicaid beneficiaries living in this region may provide insights on the burden of hypertension-related disease and on opportunities for successful intervention. A study of hospitalization rates and costs among 44,440 hypertensive Medicaid beneficiaries in South Carolina from 1993-1996 showed that 16,883 (38%) were continuously enrolled in Medicaid. Of this group, 63% were African American and 74% were women. Among the continuously enrolled patients, 7637, or about 45%, were hospitalized during the 4-year period. These 7637 individuals accounted for 20,698 hospital admissions, i.e., 2.7 admissions per person, over the 4-year interval. Nearly two thirds of the hospitalizations included a cardiovascular or renal diagnosis. Hospital claims paid reached nearly $90 million for the 7637 hypertensive Medicaid recipients during the 4-year period. Among patients discharged from the hospital with congestive heart failure, 33% filled a prescription for an angiotensin-converting enzyme inhibitor within 90 days; 13% of patients discharged with an acute myocardial infarction filled a prescription for a beta blocker within 90 days. The data confirm that hypertensive Medicaid beneficiaries in the Southeast are hospitalized at high rates. Cardiovascular and renal morbidity account for the majority of the inpatient admissions. The findings suggest that the application of evidence-based guidelines would improve health, avoid cost, and reduce racial disparities in health outcomes.

Health among commercial airline pilots.

BACKGROUND: The airline pilot works within a complex exposure environment that may present physiological challenges to long-term health. METHODS: This study investigated self-reported disease outcomes among a large group of active and retired commercial airline pilots in the United States and Canada. A survey methodology was used, including the collection of historical information. RESULTS: Of 10,678 surveys mailed, 6609 were returned (6533 men, 63 women). Given the limitations of survey methodology, increased disease rates among pilots were suggested for melanoma, motor neuron disease, and cataracts. However, rates for other diseases were in general lower than those for the U.S. population. CONCLUSIONS: Further study has been initiated to verify and follow reported cases, to expand the study to a larger group, and to collect more in-depth information on flight histories, occupational exposures, and lifestyle factors.

Low birth weight contributes to the excess prevalence of end-stage renal disease in African Americans.

The risk of hypertension and related target organ damage is much greater in African Americans than in Caucasians. The risk of hypertensive end-stage renal disease is approximately five-fold higher in African Americans. Many studies have shown that low birth weight is strongly associated with increased risk of hypertension, stroke, and myocardial infarction. However, until recently the relationship between birth weight and hypertension-related diseases was not clearly established in African Americans. Moreover, it was also unclear if low birth weight in humans heightened the risk for end-stage renal disease. This is a critical gap in the literature, since low birth weight occurs at twice the rate in African Americans as among Caucasians. We identified a significant relationship between end-stage renal disease and low birth weight in both African Americans and Caucasians. Given the higher rates of low birth weight in African Americans, differences in fetal development may, therefore, contribute to the racial disparity in end-stage renal disease. Continued study of the biological factors linking early development with later risk of hypertension-related diseases is important and may shed light on racial disparities in health outcomes. (c)2001 by Le Jacq Communications, Inc.

Predicting patient intent to return from satisfaction scores.

This study describes the development of a patient satisfaction assessment instrument used at the Medical University of South Carolina Outpatient Services clinics. Three years of responses were analyzed and a logistic regression model is presented to identify components of care that predict patient intent to return for additional care. Waiting time and understanding doctor's explanation were the only items that were significant predictors of intent to return. Additionally, the calculated probability of a return visit was used to calculate the potential impact of changes in mean satisfaction scores on the number of patient visits to the hospital ambulatory clinics.

A current assessment of rurally linked exposures as potential risk factors for sarcoidosis.

PURPOSE: To identify and quantify the risk of developing sarcoidosis associated with specific rural exposures previously recognized as potential risk factors for this disease. METHODS: A matched case-control design was carried out with a 2-to-1 ratio of controls to cases. Case exposure histories were determine from a detailed questionnaire collecting self-reported information covering the period from birth through disease development and comparing that to exposure histories for the corresponding period in age-, race-, and gender-matched controls identified using Random Digit Dial survey methodology. Conditional logistic regression was used to analyze the matched data while controlling for several baseline variables. RESULTS: A number of exposures were found to be univariately associated with the development of sarcoidosis including: the use of wood stoves, the use of fireplaces, the use of nonpublic water supplies, and living or working on a farm. A dose-response gradient was detected from exposure to wood stoves and fireplaces continued to be significantly associated with sarcoidosis in multivariable models. CONCLUSIONS: The results of this study provide further support for the hypothesis that behaviors associated with rural living play some role in the development of sarcoidosis. This study further suggests that exposures involving the handling or burning of wood such as using wood stoves or fireplaces for home heating may, in part, explain this rural association.

Non-invasive measurement of blood pressures in the Yucatan micropig (Sus scrofa domestica), with and without midazolam-induced sedation.

Current literature suggests that the effects of midazolam, a water-soluble benzodiazepine, on blood pressure in swine are minimal. The hypothesis of the study reported here was that a light sedative dose would induce a decrease in blood pressure in this species. Healthy female Yucatan Micropigs (n = 20), 16 to 30 (mean, 22) kg, aged four six months, were individually placed in a humane restraint sling and allowed to acclimate. Systolic (SBP), diastolic (DBP), and mean (MBP) blood pressures (mmHg) and heart rate (HR; beats per min [bpm]) were measured by use of oscillometry. The pressure cuff was placed at the base of the tail, and five sets of values were recorded at five-min intervals, beginning at 10 and ending 30 min after cuff placement. Following a three- to four-day rest period, this procedure was repeated with the addition of a dose of 0.5 mg of midazolam HCl/kg of body weight given intramuscularly at the time of cuff placement. A paired one-way Student's t-test was used to compare the means of the five measures between control and midazolam treatment. Mean (+/- SD) differences for SBP, DBP, MBP, and HR were 18.9 (+/- 3.97), 17.8 (+/- 5.27), and 18.6 (+/- 5.09) mmHg and 20.7 (+/- 3.73) bpm, respectively. All four parameters were significantly reduced in the midazolam-sedated group (P < 0.001). The maximal decrease in SBP, DBP, and MBP occurred at 15 and 20 min after dosing. Mean values based on the means of the five measures were 128 (+/- 12.6), 80 (+/- 9.4), and 99 (+/- 9.2) mmHg and 135 (+/- 17.4) bpm, and 109 (+/- 15.4), 63 (+/- 12.6), and 80 (+/- 13.6) mmHg and 115 (+/- 15.5) bpm for SBP, DBP, MBP, and HR in the control (n = 20) and midazolam (n = 20) groups, respectively. The control values can serve as normal oscillometric values for this age, sex, and breed of Micropig. We conclude that midazolam, given intramuscularly at a sedative dosage, negatively affects cardiovascular parameters measured by use of a blood pressure cuff, in sexually mature female Micropigs, compared with values in untreated pigs, which is similar to reports for humans.

Biochemical and metabolic effects of very-low-salt diets.

In cross-cultural studies, very low sodium intakes are associated with a low prevalence of hypertension and minimal increase of blood pressure with aging. Disorders of lipid and carbohydrate metabolism are rare. In short-term clinical studies, very low sodium intake (<50 mmol/d) has been associated with greater values for total and low-density lipoprotein cholesterol, fasting and post-glucose insulin, uric acid, plasminogen activator inhibitor-1, and activity of the renin-angiotensin system. Thus, the long-term safety of the very-low-salt diets suggested by these observations, in which sodium is one of many differences between population groups, is not entirely consonant with the short-term clinical trials data in which sodium is studied as an isolated intervention. This may reflect transient effects of abrupt and large changes in sodium consumption. Nevertheless, differences in diet composition and nutrient intake other than sodium including potassium, magnesium, and a range of antioxidants may also contribute to the discrepancies between ecological observations and clinical studies. Further research on the effects of selective changes of dietary sodium versus more global changes in diet composition on biochemical and hemodynamic variables could provide the basis for an even more effective public health policy.

Flight deck magnetic fields in commercial aircraft.

BACKGROUND: Airline pilots are exposed to magnetic fields generated by the aircraft's electrical system. The objectives of this study were (1) to directly measure flight deck magnetic fields in terms of personal exposure to the pilots when flying on different aircraft types over a 75-hour flight-duty month, and (2) to compare magnetic field exposures across flight deck types and job titles. METHODS: Measurements were taken using personal dosimeters carried by either the Captain or the First Officer on Boeing 737/200, Boeing 747/400, Boeing 767/300ER, and Airbus 320 aircraft. RESULTS: Approximately 1,008 block hours were recorded at a sampling frequency of 3 seconds. Total block time exposure to the pilots ranged from a harmonic geometric mean of 6.7 milliGauss (mG) for the Boeing 767/300ER to 12.7 mG for the Boeing 737/200. CONCLUSIONS: Measured flight deck magnetic field levels were substantially above the 0.8-1 mG level typically found in the home or office and suggest the need for further study to evaluate potential health effects of long-term exposure.

Perspectives of those impacted: airline pilot's perspective.

The airline pilot operates within an environment that consists of circadian dysrhythmia, reduced atmospheric pressure, mild hypoxia, low humidity, and exposure to sound, vibration, cosmic-radiation, and magnetic-field exposure. These occupational exposures present physiological challenges to the long term health of the airline pilot. In particular, exposure to cosmic radiation and its carcinogenic potential have recently received considerable attention. Given the complexity of the environment and possible synergistic exposures, there is an immediate requirement for comprehensive research into both cosmic-radiation and magnetic-field exposures in airline pilots. In response, the Airline Pilots Association International in conjunction with the Medical University of South Carolina (Department of Biometry and Epidemiology) has initiated an extensive research program into these occupational exposures. These investigations include ground based calculations, flight-dose estimates, epidemiological survey and exposure assessment, and biological marker analysis.

The impact of birth weight on the racial disparity of end-stage renal disease.

PURPOSE: Blacks have a high rate of end-stage renal disease (ESRD) and low birthweight (LBW) than whites. LBW has been associated with ESRD. The purpose of this study was to assess impact of LBW on the racial difference in ESRD.METHODS: Patients born in SC after 1950 and diagnosed with ESRD between 1991-1996 were identified from the ESRD registry. Birth weight was compared for 858 black and 372 white patients and 2460 controls matched for age, sex, and race. LBW was defined as birthweight <2500 g.RESULTS: Among patients with ESRD, mean birthweight was lower in blacks than whites (3179 vs 3367 g, p < 0.001). LBW was more common in blacks than whites with ESRD (13.9 vs 7.5%, p = 0.02). The risk ratio for LBW among ESRD patients was 1.4 (95% C.I. 1.1 to 1.8) for blacks and 1.5 (95% C.I. 0.9 to 2.5) for whites. The population attributable risk (PAR) for ESRD due to LBW was greater for blacks than whites (33.6 vs 4.2 per 100,000).CONCLUSIONS: Birthweights were lower and LBW was more common among blacks than whites with ESRD. Moreover, LBW contributed more to the PAR of ESRD in blacks than whites. Thus, LBW may contribute to the greater risk for ESRD in African Americans than Caucasians. This preliminary study indicates that further research on the link between LBW and ESRD could be instructive in understanding the racial health disparities.