At-risk Population Groups Research Articles

Cigarette Smoking and Dental Caries among Professional Truck Drivers in Mexico

Background: Professional truck drivers are at high risk of chronic diseases. Further examination of tobacco use and its impact on oral health is warranted – both in terms of the direct association between tobacco use and poor oral health, and in terms of tobacco use being an indicator of poor health behaviors. Objective: To estimate the possible association between smoking and dental caries experience in a population with high tobacco use. Methods: Drivers’ licenses are periodically re-issued by the Mexican government and as part of the licensing process a physical exam takes place. We administered a free, standardized questionnaire together with an oral examination (WHO criteria) included in the physical exam, targeting a random sample of applicants in Mexico City. Results: A total of 824 dentate males (mean age 35.5 ± 10 years) took part in the study, of whom 49.2% were current smokers and 23.2% were former smokers. Caries experience was mean DMFT 8.95 (± 6.05). Only 18.0% of participants had ‘excellent’ or ‘good’ oral hygiene. The prevalence of ‘large’ cavities increased as the number of cigarettes/day increased from 14.6% (1–3 cigarettes/day) to 33.3% (≧10 cigarettes/day). Using multiple linear regressions, we found that older age, poorer oral hygiene, higher education, and greater tobacco exposure were significantly associated with higher caries experience (DMFT). An interaction was observed with oral hygiene and tobacco: drivers that smoked and had ‘poor’ oral hygiene showed the highest number of large cavities and missing teeth. Health promotion interventions are needed in this at-risk population group.

Prevalence of newly diagnosed type 2 diabetes, impaired glucose tolerance and abnormal fasting glucose in a high risk population. Data from the RIAD study using new diagnostic criteria for diabetes

In 1997 the American Diabetes Association (ADA) introduced new criteria for the diagnosis of type 2 diabetes mellitus, reducing the upper limit of normal fasting blood sugar from 140 to 126 mg/dl. A level of between 110 and 126 < mg/dl (6.1-7.0 mmol/l) was added as a new category, "impaired fasting glucose" (IFG) as an at-risk factor. It was the aim of this study to determine what effect these new criteria will have on the prevalence of type 2 diabetes and other glucose tolerance stages in the German population. The analysis was based on data collected in the "Risk-factors in IGT for atherosclerosis and diabetes" (RIAD) study. 1139 persons of an at-risk population group (aged 40-70 years) were investigated. Most of them were relatives of diabetics and/or themselves had obesity and/or dyslipidaemia. All known diabetics were excluded. All subjects underwent an oral glucose test with 75 g glucose, and plasma glucose values were used for classifying them into different glucose tolerance stages. According to the new ADA criteria, confirmed by WHO in 1998, the prevalence of type 2 diabetes mellitus was shifted from 11% to 15.1%, that of IGT from 28.8% to 26.2%. An impaired fasting glucose was found in 27.1% of the population cohort, 9.2% of whom had 2-hour plasma glucose levels corresponding to the diabetes criteria. Men in the first age decade (40-49 years) had a 14% prevalence of previously undetected type 2 diabetes, double that in women. Hyperlipidaemia, hypertension and obesity were significantly more common in diabetics and persons with IGT than in normoglycaemic persons. The prevalence of previously unknown type 2 diabetes is very high in this at-risk part of the population. Using the criteria for impaired fasting glucose, 9.2% diabetics would remain undetected. We, therefore, support the recommendation that an oral glucose tolerance test be performed in those of the population aged over 45 years and in younger at-risk persons so that any indicated treatment can be initiated at the earliest. Measurement of fasting glucose is adequate in the population aged under 45 years not at special risk.

Good progress in tobacco control in NSW

In response to the NSW Tobacco Action Plan 2005–2009, Greater Southern Area Health Service (GSAHS) has developed a local plan. This short report describes how activities promoted in the state plan were prioritised and six outcomes identified as the focus for the GSAHS Tobacco Control Plan 2006–2009. Andrew J. GowA, Kylie M. WeirA,D and Andrew J. N. MarichA,B,C APopulation Health, Greater Southern Area Health Service BNSW Public Health Officer Training Program, NSW Department of Health CCentre for Health Protection, NSW Department of Health DCorresponding author. kylie.weir@gsahs.health.nsw.gov.au • the intervention or activity builds on existing programs and models of service delivery • the intervention or activity addresses health inequities. The resulting GSAHS Tobacco Control Plan 2006–2009 has identified the following six key outcome areas: 1. Achieve totally smoke-free status at all NSW Health sites within the GSAHS 2. Support health workers to deliver brief interventions for smoking cessation to GSAHS clients, support inpatients and outpatients with smoking-cessation treatment and nicotine-dependence management 3. Reduce smoking in pregnant women and environmental tobacco smoke exposure for infants and children 4. Reduce smoking rates in at-risk population groups including Aboriginal and Torres Strait Islander peoples and people on low incomes 5. Reduce the inappropriate sale of tobacco by retailers 6. Reduce the impact of environmental tobacco smoke within the hospitality industry and in public places. To date, action under the GSAHS Tobacco Control Plan 2006–2009 has occurred to varying extents in most of the key outcome areas. Significant effort has been directed to achieving totally smoke-free status at all GSAHS sites, with a self-imposed deadline of 1 July 2007. This process has given impetus to the second key outcome area, particularly with regard to establishing procedures to manage nicotine-dependant inpatients and encouraging participation in cessation training. Good progress is also being made in key outcome areas 5 and 6, with GSAHS environmental health staff maintaining a rigorous program of education combined with inspection to ensure compliance with the law by the retail and hospitality industries. Key outcome areas 3 and 4 continue to provide challenges. The slower progress here reflects the complexity of these tasks. Tobacco control initiatives with these subpopulations must address layers of determinants, including social norms and socioeconomic disadvantage. In contrast, the achievement of totally smoke-free environments and restrictions on the sale of tobacco are more easily addressed through legislation and policy enforcement. The clarity of focus provided by the GSAHS Tobacco Control Plan 2006–2009 has encouraged concerted effort on specified priorities. In a context of close competition for resources, with a dispersed population over a large 10.1071/NB07081 48 | Vol. 19(3–4) NSW Public Health Bulletin Vol. 19(3–4) NSW Public Health Bulletin | 49 Tobacco Control Plan 2006–2009 geographical area, clearly articulating a limited number of priorities that are realistic and achievable has been beneficial.

Zinc Status of Iranian Preschool Children

Zinc deficiency is one of the most prevalent micronutrient deficiencies in developing countries, including Iran. The main direct causes of zinc deficiency are insufficient zinc intake, absorption or metabolic disorder, and increase in need during acute growth periods. To determine the prevalence of zinc deficiency in preschool boys and girls in urban and rural populations in order to assist policy makers. Children of preschool age (i.e., 6 years old in Iran) were studied because interventions in this age group are believed to result in greater improvement in learning skills once these children enter school. A national cross-sectional study was carried out on 4,374 randomly selected healthy preschool children from Iranian families in 2001. Serum zinc concentration was measured by atomic absorption spectrometry. The cutoff point for zinc deficiency was set at a serum level of 10 micromol/L (65 microg/dL). The prevalence of zinc deficiency was estimated at approximately 19.3%. The highest prevalence was seen in the region that includes Sistan and Baluchistan, South Khorasan, and the southeast area of Kerman and the lowest in the region of Boushehr, Hormozgan, and South Khoozestan. The prevalence of zinc deficiency was significantly higher in rural areas than in urban areas. No significant difference in prevalence was seen between boys and girls. In the long run, nutritional security and increased access to and intake of foods with high levels of zinc are the most sustainable strategies to overcome zinc deficiency. Fortification of staple foods, improved quality of traditional bread, and supplementation for at-risk population groups are considered short- and mid-term interventions. Nutrition education and behavioral change may be long-term strategies.

Latent Tuberculous Infection

without clinical evidence ofactive disease but is at risk of reactivation. Targeted tuberculin skintesting and treatment of LTBI are an integral component of the TBElimination Strategy of the U.S. Public Health Service and is a commonclinical question encountered by the primary care provider. There are fourmajor steps in the effective management of screening and treating LTBI:1. Screening at-risk populations2. Ruling-out active TB3. Weighing benefits of treatment against risk of toxicity4. Monitoring periodically and encouraging complianceThe task begins with a targeted approach for screening at-risk popula-tions. Recent guidelines have recognized the poor positive-predictivevalue of tuberculin skin testing in populations with a low prevalence ofTB and routine skin testing is not recommended. Patients at high risk forprogressing to active TB have either been infected recently (within 2years) or have concurrent medical conditions that place them at increasedrisk of reactivation of a LTBI, as summarized in Table 1. The presump-tion should be to treat those patients that are in the targeted at-riskpopulation groups with a positive screening test unless they are atsignificant risk of complications to treatment. In addition, contacts of anactive TB patient who are children 5 years, HIV-infected, or immuno-suppressed should have active TB excluded and be started on LTBItreatment regardless of their initial screening test result.

Antivirals for treatment and prevention of human seasonal influenza

While immunisation is the primary public health strategy for prevention of influenza, antivirals are important complementary measures for controlling seasonal/epidemic human influenza, especially when there is a mismatch between circulating and vaccine strains and in at-risk population groups.

Analytical Performance Evaluation of a Linear Array-Based β-Hemoglobinopathy Mutation Assay.

Routine clinical evaluation of β-globin phenotypes usually includes HPLC screening and alkaline/acid electrophoresis and/or isoelectric focusing. Although common structural variants are easily identified in the routine environment, specific β-thalassemia mutations are not and these can be the basis for prognosis and also for subsequent prenatal diagnosis for at-risk family members. Herein, we report evaluation of the performance of a linear array-based β- hemoglobinopathy mutation assay provided by Roche Molecular Diagnostics (Pleasanton, CA) that detects 6 β-globin variants (S, C, E, Knossos, D-Los Angeles and O-Arab) and 42 β-thalassemia mutations (90% predicted detection in any at-risk population group). The assay consists of one multiplex PCR with biotinylated primers, amplicon hybridization to a reverse line blot array, and colorimetric detection of a streptavidin-HRP conjugate. We tested 50 archived, abnormal and 92 sequential clinical samples, all previously tested in our routine assays. The results of the DNA and HPLC/electrophoresis were 100% consistent with the linear array, although Hb-S, C, D-Los Angeles and E were the only structural variants present in our collection. We verified the presence of Hb-S and excluded Hb-O-Arab in an ambiguous compound heterozygote for which HPLC and electrophoresis could not distinguish possible Hb-C-Harlem from Hb-O-Arab. Of 15 putative β-thalassemia minor samples, 10 had 6 different β-thalassemia mutations. Based on our experience, the daily throughput for a single technologist performing this mutation analysis is approximately 200 samples; it is, thus, an appropriate second-tier assay for newborn screening programs. The assay is robust, reliable and is also an excellent screen prior to sequencing for rare mutations.

Methionine Synthase Reductase 66A→G Polymorphism Is Associated with Increased Plasma Homocysteine Concentration When Combined with the Homozygous Methylenetetrahydrofolate Reductase 677C→T Variant

Methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) are important for homocysteine remethylation. This study was designed to determine the influence of genetic variants (MTHFR 677C-->T, MTHFR 1298A-->C, and MTRR 66A-->G), folate, and vitamin B-12 status on plasma homocysteine in women (20-30 y; n = 362). Plasma homocysteine was inversely (P < 0.0001) associated with serum folate and plasma vitamin B-12 regardless of genotype. Plasma homocysteine was higher (P < 0.05) for women with the MTHFR 677 TT/1298 AA genotype combination compared with the CC/AA, CC/AC, and CT/AA genotypes. Women with the MTHFR 677 TT/MTRR 66 AG genotype had higher (P < 0.05) plasma homocysteine than all other genotype combinations except the TT/AA and TT/GG genotypes. There were 5.4-, 4.3-, and 3.8-fold increases (P < 0.001) in risk for plasma homocysteine in the top 5, 10, and 20%, respectively, of the homocysteine distribution for subjects with the MTHFR 677 TT compared with the CC and CT genotypes. Predicted plasma homocysteine was inversely associated with serum folate (P = 0.003) and plasma vitamin B-12 (P = 0.002), with the degree of correlation dependent on MTHFR 677C-->T genotype. These data suggest that coexistence of the MTHFR 677 TT genotype with the MTRR 66A-->G polymorphism may exacerbate the effect of the MTHFR variant alone. The potential negative effect of combined polymorphisms of the MTHFR and MTRR genes on plasma homocysteine in at-risk population groups with low folate and/or vitamin B-12 status, such as women of reproductive potential, deserves further investigation.

Cobalamin Status (Holo-Transcobalamin, Methylmalonic Acid) and Folate as Determinants of Homocysteine Concentration

Concern has emerged in America about subtle cobalamin (Cbl; vitamin B12) deficiency, especially in at-risk population groups such as the elderly and vegetarians (1). An optimal test to diagnose vitamin B12 deficiency is still not available (2)(3)(4). The determination of total serum vitamin B12 has a low diagnostic accuracy (2)(5). Measurements of homocysteine (HCY) and methylmalonic acid (MMA) have shown more specificity and sensitivity for subnormal Cbl status, but have disadvantages. HCY, for example, is also increased in folate and vitamin B6 deficiencies, as well as in renal insufficiency (4); in addition, MMA is expensive to measure, and it, too, increases in renal insufficiency (2)(4)(5). To improve specificity and sensitivity in diagnosis of vitamin B12 deficiency, holo-transcobalamin (holoTC) assays have been introduced (6). Because only transcobalamin II promotes the specific cellular uptake of Cbl, the Cbl subfraction attached to transcobalamin II represents the biologically active vitamin B12 fraction (6)(7)(8). Our previous observations in Syrian individuals revealed a high prevalence of Cbl deficiency (≈49%) when we used MMA as a metabolic marker for Cbl status (9). The present work …

Obesity Is Associated with Reduced Self-Rated General Health Status: Evidence from a Representative Sample of White, Black, and Hispanic Americans

Background. Although the evidence linking obesity with many chronic diseases is well established, the relationship with self-rated health is not clear. Self-rating of health is a broad summary measure of different domains of health that include psychosocial domain. The aims of this study were to examine the relationship between obesity and self-rated health and the degree of agreement between patients' self-rated health status and physicians' impression of patients' health in a representative sample of healthy noninstitutionalized American adults.Methods. Data (n = 10, 298) used for this analysis were obtained from the Third National Health and Nutrition Examination Survey. Normal weight was defined as BMI 18.5–24.9 kg/m2 and preobesity was defined as BMI 25–29.9 kg/m2. Moderate (class I) obesity was defined as BMI 30–34.9 kg/m2 and severe (class II) obesity as BMI ≥35 kg/m2. Self-rated health conditions were categorized as excellent, very good, good, fair, or poor. Agreement between physicians' impression and self-rated health and a linear relationship between obesity and individual perceived health were quantified using κ and γ statistics, respectively. Using the logistic regression analysis, odds of reporting reduced health in preobese, class I obese, and class II obese individuals were compared with those for normal-weight individuals, adjusting for age, current smoking, and alcohol intake. The contribution of obesity to ethnic differences in reduced self-rated health was determined by comparing blacks with whites and Hispanics with whites fitted in multiple logistic regression models.Results. Among both men and women, there was a statistically significant linear association between obesity and self-rated health (P < 0.05). The proportion of subjects reporting excellent health tended to decrease with increasing level of obesity in the three ethnic groups. In the three ethnic groups, the degrees of concordance between self-rated health and physicians' impressions were poor and decreased with increasing obesity level. In each ethnic group, class II obesity was associated with approximately twofold increased odds of reporting reduced health compared with normal-weight individuals. Compared to whites, black and Hispanic races/ethnicities were respectively associated with 23 and 175% increased odds of reduced self-rated health among men. The corresponding values for women were 45 and 177%, respectively.Conclusion. The results of this study provide evidence that obesity has a negative impact on self-rated health among adults, even in the absence of chronic disease conditions. The results of this investigation also underscore the need to craft national preventive strategies to curb obesity in these at-risk population groups.

Risk assessment used to evaluate the US position on Listeria monocytogenes in seafood

Human listeriosis has been associated with consumption of food including seafood. Surveillance information on the presence of Listeria monocytogenes in seafood products is presented as a background for steps that are being taken to inform risk managers of risks associated with particular food products. United States policy for L. monocytogenes in food has been shaped by our increasing knowledge of the epidemiology of outbreaks and sporadic cases of human listeriosis, the potentially severe public health consequences, and the characteristics of the organism. A quantitative risk assessment of the scientific knowledge we have about the organism and the epidemiology of listeriosis should be the basis for changes in this policy. Risk assessment uses quantitative scientific and epidemiological information in a structured format to determine the risks associated with particular hazards. A quantitative risk assessment is being performed using currently available data by the US Food and Drug Administration, in collaboration with the US Food Safety and Inspection Service, to determine the risk of listeriosis from various foods, including seafood, for specific intervention methods, and for general and at-risk population groups. The questions being considered include those on level of consumption, epidemiology, dose response, and the virulence, biology, and ecology of the organism. Risk managers can use the resulting information to form a defendable science-based policy on L. monocytogenes in food.

Homocysteine: cholesterol of the 90s?

Homocysteine is a sulfur-containing amino acid generated through the demethylation of methionine. It is largely catabolized by trans-sulfuration to cysteine but it may also be remethylated to methionine. Dubbed ‘the cholesterol of the 90s’ by the lay press, homocysteine is thought to be thrombophilic and to damage the vascular endothelium. Total plasma homocysteine (tHcy) is now established as a clinical risk factor for coronary artery disease, as well as other arterial and venous occlusive disease in adult populations. Regulation of homocysteine is dependent on nutrient intake, especially folate, vitamins B6 and B12. It is also controlled by common genetic variations (polymorphisms) in how vitamins are utilized as cofactors in the reactions controlling homocysteine metabolism. Moreover, concentrations are age- and sex-dependent and are altered by renal function, hormonal status, drug intake and a variety of other common clinical factors. Considerable care must be taken in assaying tHcy. Plasma should be separated shortly after collection, to avoid artifactual increases due to synthesis by blood cells in vitro. Reference methods have not been validated and criteria for establishing reference ranges should take into account the variable prevalence of physiological hyperhomocysteinemia. Determination of tHcy should probably be limited to centres with relevant expertise and ability to maintain the high degree of precision required for reliable interpretation. Molecular testing for the genetic polymorphisms is still in the research phase but the ease and reliability of molecular diagnosis will speed its introduction into clinical laboratory practice – particularly in relation to diagnosis of thrombophilic disorders. Clinical research initiatives are being driven by the benefit that should be achieved by correction with vitamin supplements, particularly folate and B vitamins, but it must be recognized that prospective controlled studies to validate clinical benefit are only now being initiated. At the moment, it is safe to say that hyperhomocysteinemia is one of the few prevalent biochemical risk factors for thromboembolic disease that might be corrected by vitamin supplements. Such a possibility lies behind the growing momentum to recommend increased supplements of folate and B vitamins to at-risk population and patient groups today.

Stilbestrol, adenosis, and adenocarcinoma

A registry of cases of clear-cell adenocarcinoma of the genital tract in women under 30 years of age was established in 1971. The first year's data amply confirmed the hypothesis that a simultaneous, nation-wide outbreak of this lesion had occurred and that, in 85 per cent of cases, exposure of the individual before the fourth month in utero to diethylstilbestrol or one of its congeners could be documented as an antecedent circumstance. General awareness of this new entity on the part of physicians and personal concern manifested by mothers who know that they were thus treated during pregnancy are bringing hundreds of the at-risk population group to medical attention. Gross and microscopic morphologic anomalies are being found in approximately 30 per cent of these girls and occasionally asymptomatic early carcinomas are detected. A study of 16 patients who give a history of no prior exposure to hormones of any description reveals a difference between them and the group with known exposure. This is in keeping with the literature published prior to the availability of diethylstilbestrol which indicated that primary vaginal adenocarcinoma in young women was unique, whereas such lesions of the cervix were only uncommon.