Prehypertension: an opportunity for a new public health paradigm

From 2005 to 2006, approximately 3 of 8 adults in the United States had blood pressure (BP) in the prehypertensive range of 120 to 139/80 to 89 mm Hg and roughly 1 in 8 adults had BP in the range of 130 to 139/85 to 89 mm Hg, which is referred to as high normal BP or stage 2 prehypertension. Adults with stage 2 prehypertension are also roughly twice as likely as adults with normotension to suffer cardiovascular disease. The Seventh Report of the Joint National Committee on Hypertension recommended only lifestyle changes for most prehypertensive patients. BP in the range of 120 to 129/80 to 84 mm Hg is also associated with increased risk but roughly half of that of stage 2 prehypertension.     

Dietary salt restriction and blood pressure in clinical trials

Dietary salt has long been recognized as a major factor affecting blood pressure such that sodium intake is a component of lifestyle modification guidelines for control of high blood pressure. These recommendations are based on results from epidemiologic observational studies and clinical trials of various sodium diets among normotensives and hypertensives. Nonetheless, results from the different studies vary such that specific recommendations regarding sodium intake are difficult to interpret. The results from several recent major trials indicated greater associations of blood pressure and sodium intake than earlier studies as well as meta-analyses of numerous clinical trials. The studies of sodium intake and blood pressures are complicated by measurements of intake, salt sensitivity, hypertension treatment, effects of sodium independent of blood pressure, and length of interventions. Limitations in the methodology of different studies have reduced the value of the results to provide specific and reliable sodium intake levels essential for clinical and lifestyle guidelines.     

Infection of human T-cell leukemia virus type I and development of human T-cell leukemia lymphoma in patients with hematologic neoplasms: a possible linkage to blood transfusion

Among 354 adult patients with either hematological malignancy or aplastic anemia, eight were positive for anti-HTLV-I antibodies; six of eight had received multiple transfusions. There was an approximately 3.5-fold increase (P less than .001) of HTLV-I seropositivity in the patients with hematologic disease (8 of 354, 2.23%) compared to the healthy adults older than 20 years (34 of 5252, .65%). Two hematological patients, one with Hodgkin's disease and one with acute promyelocytic leukemia, were found to be positive for HTLV-I, and developed and died of adult T-cell leukemia/lymphoma (ATL) subsequently. Both were long-term survivors of the primary disease and had received multiple transfusions. The latent period from blood transfusion to onset of ATL was 6 months and 11 years, respectively. Immunocompromised patients, who were seropositive for HTLV-I, may be at increased risk for ATL compared to healthy carriers of HTLV-I, and the latent period may be shorter.     

Cross-sectional associations of C-reactive protein with vascular risk factors and vascular complications in the DCCT/EDIC cohort

OBJECTIVE: To determine the relationships between C-reactive protein (CRP) levels and features of Type 1 diabetes. RESEARCH DESIGN AND METHODS: Serum CRP was measured by nephelometry in a cross-sectional study of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) cohort (n=983) and nondiabetic subjects (n=71). RESULTS: CRP levels [geometric mean (95% CI)] were higher in diabetic than in control subjects, 1.6 (1.5-1.7) vs. 1.2 (1.1-1.5) mg/l, P=.019. CRP was higher in diabetic women (n=438) than in men (n=545) [2.0 (1.8-2.3) vs. 1.3 (1.2-1.5), P<.001]. Diabetic subjects formerly in the DCCT intensive treatment group had higher CRP levels than those who were randomized to the conventional treatment group [1.8 (1.6-1.9), n=479 vs. 1.5 (1.3-1.6), n=456, P=.010], attributable to greater BMI in the prior intensive group. In diabetes, CRP correlated with HbA(1c) (r=0.13, P<.0001) and with insulin resistance traits: BMI (r=0.34, P<.0001), waist-to-hip ratio (WHR; males: r=0.35, P<.0001; females: r=0.22, P<.0001), diastolic blood pressure (r=0.07, P=.025), triglycerides (r=0.19, P<.0001), apoB (r=0.22, P<.0001), LDL particle concentration (r=0.26, P<.0001), and LDL particle size (r=-0.22, P<.0001). CRP was not associated with complications. Significant independent predictors of CRP in diabetes were gender, BMI, WHR, concurrent HbA(1c), and oral contraceptive pill use. CONCLUSIONS: CRP was elevated relative to nondiabetic subjects, and in diabetes was higher in females. Elevated CRP in Type 1 diabetes was associated with poor glycemic control, larger body habitus, and other factors that comprise the insulin resistance syndrome. Nevertheless, CRP levels were not associated with complications. Longitudinal studies are warranted.     

Coinfection with hepatitis C virus,oxidative stress and antioxidant status in HIV‐positive drug users in Miami*

Background

The pathogenesis of HIV/hepatitis C virus (HCV) coinfection is poorly understood. We examined markers of oxidative stress, plasma antioxidants and liver disease in HIV/HCV‐coinfected and HIV‐monoinfected adults.

Methods

Demographics, medical history, and proof of infection with HIV, hepatitis A virus (HAV), hepatitis B virus (HBV) and HCV were obtained. HIV viral load, CD4 cell count, complete blood count (CBC), complete metabolic panel, lipid profile, and plasma concentrations of zinc, selenium, and vitamins A and E were determined. Malondialdehyde (MDA) and glutathione peroxidase concentrations were obtained as measures of oxidative stress. Aminotransferase to platelet ratio index (APRI) and fibrosis index (FIB‐4) markers were calculated.

Results

Significant differences were found between HIV/HCV‐coinfected and HIV‐monoinfected participants in levels of alanine aminotransferase (ALT) (mean±standard deviation: 51.4±50.6 vs. 31.9±43.1 U/L, respectively; P=0.014), aspartate aminotransferase (AST) (56.2±40.9 vs. 34.4±30.2 U/L; P<0.001), APRI (0.52±0.37 vs. 0.255±0.145; P=0.0001), FIB‐4 (1.64±.0.91 vs. 1.03±0.11; P=0.0015) and plasma albumin (3.74±0.65 vs. 3.94±0.52 g/dL; P=0.038). There were no significant differences in CD4 cell count, HIV viral load or antiretroviral therapy (ART) between groups. Mean MDA was significantly higher (1.897±0.835 vs. 1.344± 0.223 nmol/mL, respectively; P=0.006) and plasma antioxidant concentrations were significantly lower [vitamin A, 39.5 ± 14.1 vs. 52.4±16.2 μg/dL, respectively (P=0.0004); vitamin E, 8.29±2.1 vs. 9.89±4.5 μg/mL (P=0.043); zinc, 0.61±0.14 vs. 0.67±0.15 mg/L (P=0.016)] in the HIV/HCV‐coinfected participants than in the HIV‐monoinfected participants, and these differences remained significant after adjusting for age, gender, CD4 cell count, HIV viral load, injecting drug use and race. There were no significant differences in glutathione peroxidase concentration, selenium concentration, body mass index (BMI), alcohol use or tobacco use between groups. Glutathione peroxidase concentration significantly increased as liver disease advanced, as measured by APRI (β=0.00118; P=0.0082) and FIB‐4 (β=0.0029; P=0.0177). Vitamin A concentration significantly decreased (β=?0.00581; P=0.0417) as APRI increased.

Conclusion

HIV/HCV coinfection is associated with increased oxidative stress and decreased plasma antioxidant concentrations compared with HIV monoinfection. Research is needed to determine whether antioxidant supplementation delays liver disease in HIV/HCV coinfection.

     

Controlling hypertension and reducing its associated morbidity and mortality in the Caribbean: implications of race and ethnicity

Cardiovascular diseases and stroke, especially hypertension, represent a significant global disease burden for both morbidity and mortality, with a disproportionately higher impact in vulnerable low‐ to middle‐income countries. International initiatives such as the Centers for Disease and Prevention and the Pan American Health Organization Standardized Hypertension Treatment Project have been developed to address this burden on the Caribbean and Latin America populations. The disparity in disease burden observed in low‐ to middle‐income countries is explained, in part, by differences in disease risks for different racial and ethnic groups with high blood pressure more prevalent and hypertension‐related morbidity significantly higher in men and women of African heritage. In addition to the race and ethnic differences in indicators of socioeconomic status, access to care and health service delivery, the physiologic mechanism of high blood pressure including salt‐sensitivity, may also play a significant role in the disparities in hypertension and hypertension‐related outcomes. This article focuses on potential racial and ethnic differences in influences on the pathophysiology of hypertension in the Caribbean region of the world. The identification of such differences may be used in the development of population hypertension control strategies and treatment approach that address the excess disease burden in these populations. The consideration of strategies, such as salt reduction and hypertension awareness and treatment, are particularly relevant to the high‐risk Caribbean region.