Ivar L. Frithsen

Association of polychlorinated biphenyls with hypertension in the 1999–2002 National Health and Nutrition Examination Survey

The association of 11 polychlorinated biphenyls (PCBs) with hypertension was investigated using the National Health and Nutrition Examination Survey (NHANES), 1999-2002. The unweighted number of participants assessed for hypertension ranged from 2074 to 2556 depending on the chemical(s) being analyzed. In unadjusted logistic regressions all 11 PCBs were associated with hypertension. After adjustment for age, gender, race, smoking status, body mass index, exercise, total cholesterol, and family history of coronary heart disease, seven of the 11 PCBs (PCBs 126, 74, 118, 99, 138/158, 170, and 187) were significantly associated with hypertension. The strongest adjusted associations with hypertension were found for dioxin-like PCBs 126 and 118. PCB 126>59.1 pg/g lipid adjusted had an odds ratio of 2.45 (95% CI 1.48-4.04) compared to PCB 126<or=26.1 pg/g lipid adjusted. PCB 118>27.5 ng/g lipid adjusted had an odds ratio of 2.30 (95% CI 1.29-4.08) compared to PCB 118<or=12.5 ng/g lipid adjusted. Moreover, participants with one or more elevated PCBs had an odds ratio of 1.84 (95% CI 1.25-2.70) compared to no PCBs elevated in an adjusted logistic regression. The prevalence of one or more elevated PCBs was 22.76% or 32 million of 142 million persons >or=20 years old in the non-institutionalized US population. We hypothesize that association of seven PCBs with hypertension indicates elevated PCBs are a risk factor for hypertension. What clinicians can do, given the results of this study, is limited unless the appropriate laboratory methods can be made more widely available for testing patients.

Commentary on the association of polychlorinated biphenyls with hypertension.

Since preparing ‘‘Association of polychlorinated biphenyls withhypertension in the 1999–2002 National Health and NutritionExamination Survey’’ (Everett et al., 2008, doi:10.1016/j.envres.2008.05.006), polychlorinated biphenyl (PCB) data for the2003–2004 National Health and Nutrition Examination Survey(NHANES) has been made available to the public. Hence it isnow possible to analyze the association of PCBs and hypertensionin 6 years of the NHANES (1999–2004). We have evaluated thesame 11 PCBs as we did in Everett et al. (2008) again in the1999–2004 NHANES. We use the same lowerand uppercut-pointsfor each PCB. The definition of hypertension, laboratory analysesof PCBs, and control variables used remain the same as before.The unweighted number of persons assessed for hypertensionranged from 3398 to 3712 depending on the chemical beinganalyzed. When three chemicals were evaluated together todetermine one or more PCBs elevated (the PCBs with significantseparate adjusted logistic regressions) the unweighted number ofparticipants was 3326. For the analysis of one or more elevatedPCBs, 69.6% had no PCBs elevated and 30.4% had one or more PCBselevated.Demographic characteristics of the 1999–2004 NHANES areshown in Table 1. The proportion of participants that haveelevated PCBs (as shown in Table 2) varied by age, gender, race-ethnicity, and body mass index (BMI). The demographic trends arethe same as before except for the BMI categories. The proportionwith elevated PCBs is higher in each age, gender, race-ethnicityand BMI category than before.Adjusted logistic regressions for the 1999–2002 NHANES andthe 1999–2004 NHANES are shown in Table 2. The adjustedassociations for the 1999–2004 datawere significant for PCBs 126,74 and 118. Interestingly, none of the non-dioxin-like PCBs weresignificantly associated with hypertension in the 1999–2004NHANES.One or more elevated PCBs had an adjusted odds ratio of 1.45(95% CI 1.07–1.97) compared to no PCBs elevated in an adjustedlogistic regression. When the number of PCBs elevated wasanalyzed as a continuous variable (0–3 elevated PCBs) the oddsratio per elevated PCB was 1.26 (95% CI 1.07–1.47). The proportionof the 1999–2004 NHANES with one elevated PCB was 16.5%, withtwo elevated PCBs was 8.7%, and with three elevated PCBs was5.2%. The prevalence of one or more elevated PCBs was 30.4% or 46million out of 152 million persons X20 years old in the non-institutionalized US population.

Evidence that prehypertension is a risk factor for Type 2 diabetes

Whether or not blood pressure categories below 140/90 mmHg are associated with incident Type 2 diabetes or cardiovascular disease is subject to debate. Currently, a blood pressure of 120–139/80–89 mmHg is recognized as prehypertension. This article evaluates the association of prehypertension with incident Type 2 diabetes in the San Antonio Heart study. The authors found that prehypertension in the entire cohort was not related to incident Type 2 diabetes in fully adjusted analyses, but that a blood pressure of 130–139/85–89 mmHg was related to incident diabetes. These results, and conclusions of other studies, suggest that the prehypertension category should be divided for diabetes risk assessment.

Uncomplicated Skin and Soft Tissue Infections

Uncomplicated skin and soft tissue infections (SSTI) include the following: impetigo, folliculitis, carbuncles, furuncles, simple abscesses, and cellulitis/erysipelas [1]. This chapter outlines the common bacterial etiologies of these infections as well as reviews current guidelines for their treatment as related to outpatient management. Information regarding the management of bites from animals and from humans will also be presented. Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) will be discussed as an important consideration in the treatment of skin and soft tissue infections.

Roles of Environmental Pollution and Pesticides in Diabetes and Obesity

Abstract There are several factors that contribute to the development of type 2 diabetes, such as obesity, sedentary lifestyle, and family history, which are widely accepted in the medical community. However, the role of environmental contaminants or pollutants in diabetes is not yet well understood. The strongest body of epidemiological evidence is that linking certain persistent organic pollutants (POPs) to diabetes. POPs include dioxins, furans, polychlorinated biphenyls (PCBs) and organochlorine pesticides. A metaanalysis of six studies of dioxins and furans produced a relative risk (RR) of 1.91 (95% CI 1.44–2.54) for diabetes when comparing the highest category versus the lowest category. A metaanalysis of 13 cross-sectional studies of PCBs and diabetes produced an RR of 2.90 (95% CI 2.14–3.92), and a metaanalysis of 8 prospective studies of PCBs and diabetes produced an RR of 1.65 (95% CI 1.16–2.34). Comparing the top versus the bottom tertile, a metaanalysis of any organochlorine pesticide and diabetes in 22 studies found a summary odds ratio of 1.68 (95% CI 1.37–2.07). Bisphenol A (BPA) is an endocrine disrupter that is found in many consumer products; human exposure is believed to be mainly from food product packaging containing BPA. A metaanalysis of BPA and type 2 diabetes, using five studies, produced a summary RR of 1.45 (95% CI 1.13–1.87) comparing the fourth quartile with the first quartile of urinary BPA. Phthalates are chemicals added to plastics to increase their flexibility, transparency, durability, and longevity. A metaanalysis of four studies produced a summary RR of 1.48 (95% CI 0.98–2.25) for diabetes when comparing the highest category of total phthalates with the lowest category. Although this summary RR is not significant, there is evidence that some individual phthalate metabolites are related to diabetes. Other environmental pollutants that have been studied include carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter and sulfur dioxide in air pollution, and toxic heavy metals such as arsenic, cadmium, and mercury. Notably, a metaanalysis of 12 studies of arsenic in drinking water and type 2 diabetes had a pooled RR of 1.75 (95% CI 1.20–2.54). There is growing support for the “developmental obesogen” theory. It promotes the concept that certain chemicals may be capable of disrupting developmental processes related to metabolic homeostasis during early life and thus increasing the risk for obesity and other related metabolic diseases. However, most of the work relating environmental pollutants to obesity has produced inconsistent results. An exception is DDE (dichlorodiphenyldichloroethylene), a metabolite of dichlorodiphenyltrichloroethane. For DDE, there are seven studies showing positive associations with adiposity and two studies having null relationships.