Is glycine effective against elevated blood pressure?

PURPOSE OF REVIEW: Glycine, a non-essential amino acid, has been found to protect against oxidative stress in several pathological situations, and it is required for the biosynthesis of structural proteins such as elastin. As hypertension is a disease in which free radicals and large vessel elasticity are involved, this article will examine the possible mechanisms by which glycine may protect against high blood pressure. RECENT FINDINGS: The addition of glycine to the diet reduces high blood pressure in a rat model of the metabolic syndrome. Also, glycine supplemented to the low protein diet of rat dams during pregnancy has a beneficial effect on blood pressure in their offspring. The mechanism by which glycine decreases high blood pressure can be attributed to its participation in the reduction of the generation of free radicals, increasing the availability of nitric oxide. In addition, as glycine is required for a number of critical metabolic pathways, such as the synthesis of the structural proteins collagen and elastin, the perturbation of these leads to impaired elastin formation in the aorta. This involves changes in the aorta's elastic properties, which would contribute to the development of hypertension. SUMMARY: The use of glycine to lower high blood pressure could have a significant clinical impact in patients with the metabolic syndrome and with limited resources. On the other hand, more studies are needed to explore the beneficial effect of glycine in other models of hypertension and to investigate possible side-effects of treatment with glycine.     

Which plasma antioxidants are most related to fruit and vegetable consumption?

Substantial evidence suggests that fruit and vegetable intake reduces the risk of some cancers and other chronic diseases. While a varied diet containing fruits and vegetables may confer benefits greater than those of any single nutrient, it would be useful to have data on the plasma nutrients most influenced by fruit and vegetable intake. The authors examined the correlation between fruit and vegetable intake as measured by the abbreviated CLUE II food frequency questionnaire and several plasma antioxidants. This study includes 116 male subjects aged 35-72 years who were nonsmokers and nonusers of vitamin supplements and who provided blood samples in the CLUE II Study in Washington County, Maryland. Plasma was assayed for ascorbic acid, beta-carotene, beta-cryptoxanthin, and alpha- and gamma-tocopherol. Lipid- and energy-adjusted partial correlation for the relation with fruit and vegetable intake was r = 0.64 for ascorbic acid, r = 0.44 for beta-carotene, and r = 0.50 for beta-cryptoxanthin. While this study does not address efficacy, the stronger association of ascorbic acid with fruit and vegetable intake seen here may imply that ascorbic acid is an important component of the protective effect seen for fruits and vegetables in numerous epidemiologic studies.     

Which fractures are most attributable to osteoporosis?

Background

Determining anatomic sites and circumstances under which a fracture may be a consequence of osteoporosis is a topic of ongoing debate and controversy that is important to both clinicians and researchers.

Methods

We conducted a systematic literature review and generated an evidence report on fracture risk based on specific anatomic bone sites and fracture diagnosis codes. Using the Research and Development/University of California at Los Angeles appropriateness process, we convened a multidisciplinary panel of 11 experts who rated fractures according to their likelihood of being because of osteoporosis based on the evidence report. Fracture sites (as determined by International Classification of Diseases Clinical Modification codes) were stratified by four clinical risk factor categories based on age, sex, race/ethnicity (African American and Caucasian), and presence or absence of trauma.

Results

Consistent with current clinical experience, the fractures rated most likely because of osteoporosis were the femoral neck, pathologic fractures of the vertebrae, and lumbar and thoracic vertebral fractures. The fractures rated least likely because of osteoporosis were open proximal humerus fractures, skull, and facial bones. The expert panel rated open fractures of the arm (except proximal humerus) and fractures of the tibia/fibula, patella, ribs, and sacrum as being highly likely because of osteoporosis in older Caucasian women but a lower likelihood in younger African American men.

Conclusion

Osteoporosis attribution scores for all fracture sites were determined by a multidisciplinary expert panel to provide an evidence-based continuum of the likelihood of a fracture being associated with osteoporosis.     

Which literature retrieval method is most effective for GPs?

BACKGROUND: Evidence-based medicine requires new skills of physicians, including literature searching. OBJECTIVE: To determine which literature retrieving method is most effective for GPs: the printed Index Medicus; Medline through Grateful Med; or Medline on CD-ROM. METHODS: The design was a randomized comparative study. In a continuing medical education course, three groups of health care professionals (87 GPs and 16 other health care professionals) used one of the literature retrieval methods to retrieve citations on four search topics related to general practice. For the analysis in pairs, we used the search results of the 75 participants who completed all four assignments. As outcome measures, we used precision, recall and an overall search quality score; we also had a post-course questionnaire on personal characteristics, experience with computers, handling medical literature and satisfaction with course instruction and search results. RESULTS: The recall and overall search quality scores in the Index Medicus groups (n = 32) were higher (P = <0.001) than those in the CD-ROM groups (n = 31). In addition, the search quality scores in the Grateful Med groups (n = 12) were higher (P < 0.003) than those in the CD-ROM groups. There were no differences in precision. CONCLUSION: In the period 1994-1997, the printed Index Medicus was the most effective literature retrieval method for GPs. For inexperienced GPs, there is a need for training in electronic literature retrieval methods.     

How often do office blood pressure measurements fail to identify true hypertension? An exploration of white-coat normotension

BACKGROUND: The often-observed differences between ambulatory (ABP) and office blood pressure (OBP) measurements have brought attention to the problem of misdiagnoses. Although there has been much focus on white-coat hypertension (elevated OBP with normal ABP means), few studies have examined "white-coat normotension" (WCN; normal OBP with elevated ABP means). OBJECTIVES: To describe patients with WCN in terms of prevalence and quantitative differences between ABP and OBP; to identify psychological and demographic features that discriminate them from true normotensive patients; and to offer possible corrections for diagnostic limitations of OBP measurements in clinical practice. DESIGN AND METHODS: Five OBP measurements and 10- to 12-hour daytime ABP monitoring in 319 presumed healthy participants. RESULTS: Prevalence rates of WCN were 23% for systolic BP and 24% for diastolic BP. Participants with WCN were more often male, past smokers, and older and consumed more alcohol. Increasing the number of office readings and discarding the first office reading did not improve the accuracy of OBP measurements. Participants with BP of 10 mm Hg above or below the 140/90 office reading cutoff showed the lowest accuracy, with more than 50% of normotensive diagnoses being incorrect. CONCLUSIONS: Office measures of BP lack sensitivity, missing a sizable portion of individuals who have hypertensive mean ABP measurements. Subjects with WCN differ from true normotensive subjects on several demographic and lifestyle variables. Only those office readings averaging 20 points above or below the 140/90 cutoff represent safe diagnostic information.     

Which health conditions cause the most unhappiness?

This paper assesses the effects of different health conditions on happiness. Based on new data for Latin America, we examine the effects of different conditions across age, gender, and income cohorts. Anxiety and pain have stronger effects than physical problems, likely because people adapt better to one-time shocks than to constant uncertainty. The negative effects of health conditions are very large when compared with the effects of income on happiness. And, while higher peer income typically elicits envy, better peer health provides positive signals for life and health satisfaction. Health norms vary widely across countries.     

How is reward sensitivity related to bodyweight in children?

Previous research assumes that there are two seemingly opposing hypotheses for the relation between reward sensitivity (RS) and bodyweight: hyper-responsiveness model and Reward Deficiency Syndrome (RDS), leading to the proposition of a feed forward process of weight gain. High RS may contribute to overeating and weight-gain among normal weight individuals. Over time the excessive food-intake may evolve in a down-regulation of dopamine (RDS), resulting in overeating as a form of self-medication and the progression to obesity. This process was evidenced in adults showing a curvi-linear relationship between self-reported RS and BMI. The aim of the current study was to investigate the association between self-reported RS and BMI in children (10-15 years). The results confirm the non-linear relationship between RS and bodyweight and support the suggestion of the same feed forward process in children. These findings imply that it is crucial to reduce the intake of high palatable foods in high RS children to prevent the decrease in RS and reduce the risk for future weight gain.     

Which reproductive technologies are most relevant to studying, managing and conserving wildlife?

The advent of in vitro fertilisation (IVF) and embryo transfer in the 1970s led to speculation about the potential value of these and other 'reproductive technologies' to conserving endangered species. So far, and for the most part, assisted breeding techniques that are routine in domesticated species are not easily adapted to wildlife. Species differences in reproductive form (anatomy/morphology) and function (mechanisms regulating reproductive success) limit the practical applicability for offspring production. Thus, the limiting factor is the lack of basic knowledge about thousands of unstudied species, the foundation that is essential to allowing reproduction to be enhanced and/or controlled. There now is excellent evidence that reproductive technologies are most useful as tools for studying how different species reproduce, especially defining novel and unique mechanisms. The present paper reviews the status and relevance of various reproductive technologies that are useful or have potential for wildlife. Modern examples of progress are provided indicating how these tools are being used to understand ways that wildlife species reproduce and, in some cases, how such knowledge has been used for successful assisted breeding, improved management and conservation.     

Which adolescents are most receptive to tobacco industry marketing? implications for counter-advertising campaigns

This study sought to identify adolescents most receptive to tobacco advertising based on individual differences in novelty-seeking personality and other key variables. Confidential self-report surveys were completed by 1,071 high school freshmen at 5 public high schools. The survey included validated measures of novelty-seeking personality, smoking habits, peer and family smoking, and tobacco advertising receptivity. Multiple logistic regression analysis was used to evaluate the independent associations of these variables and demographics with receptivity to tobacco advertising. Of the ninth graders, 44% had moderate to high levels of advertising receptivity and 54% had minimal to low levels of receptivity. Higher levels of receptivity were associated with ever smoking (odds ratio [OR] = 2.59, confidence interval [CI] = 1.99-3.39) and novelty-seeking personality (OR = 2.14, CI = 1.57-2.93). The association of novelty-seeking personality and tobacco advertising receptivity was most pronounced among adolescents who had never had a puff of a cigarette. Counter-advertising messages should consider individual differences in novelty-seeking, because novelty-seekers may be most receptive to tobacco industry promotional campaigns.     

How much effect of different antihypertensive medications on cardiovascular outcomes is attributable to their effects on blood pressure?

The debate over whether certain antihypertensive medications have benefits beyond what would be expected from their blood pressure lowering spurred the Antihypertensive and Lipid‐Lowering Treatment to Prevent Heart Attack Trial, which randomized 42,418 participants to chlorthalidone (15,255), amlodipine (9048), lisinopril (9054), or doxazosin (9061). We compared chlorthalidone, the active control, with each of the other three agents with respect to the primary outcome, fatal coronary heart disease or nonfatal myocardial infarction, and several other clinical endpoints. The arms were similar with respect to the primary endpoint, although some differences were found for other endpoints, most notably heart failure. Although the desire was to achieve similar blood pressure reductions in the four arms, we found some systolic blood pressure and diastolic blood pressure differences. A natural question is to what degree can observed treatment group differences in cardiovascular outcomes be attributed to these blood pressure differences. The purpose of this paper was to delineate the problems inherent in attempting to answer this question, and to present analyses intended to overcome these problems. Copyright © 2012 John Wiley & Sons, Ltd.     

Which is the real Kaiser?

Fans of Kaiser Permanente, the nation's oldest and largest HMO, consider the company a cost-effective healthcare delivery system that supports its patients, caregivers and the practice of high-quality medicine. Its detractors see Kaiser as an evil HMO empire that hoards money, mistreats doctors and skimps on care. The dichotomy shows that Kaiser is like a giant mirror, reflecting the struggles and uncertainties of the evolving U.S. healthcare system.