The effect of leisure-time physical activity on the risk of acute myocardial infarction depending on Body Mass Index: a population-based case-control study

BACKGROUND: High body mass index (BMI) and lack of physical activity have been recognized as important risk factors for coronary heart disease. The aim of the present study was to evaluate whether leisure-time physical activity compensates for the increased risk of acute myocardial infarction associated with overweight and obesity. METHODS: Data from the SHEEP (Stockholm Heart Epidemiology Program) study were used. The SHEEP study is a large Swedish population-based case-control study, comprising 1204 male and 550 female cases, and 1538 male and 777 female controls, conducted in Stockholm County, Sweden, during the period 1992–1994. Odds ratios (OR), together with 95 % confidence intervals (95% CI), were calculated using unconditional logistic regression, as estimates of the relative risks. RESULTS: Regular leisure-time physical activity was associated with a decreased risk of myocardial infarction among lean, normal-weight and overweight subjects, but not among obese subjects. Obese (BMI ≥ 30) and physically active persons had an almost twofold risk of myocardial infarction, compared with normal-weight and sedentary persons (OR 1.85, 95% CI 1.07–3.18). The results were similar for men and women. CONCLUSION: While regular leisure-time physical activity seems to provide protection against myocardial infarction among lean, normal-weight and overweight subjects, this does not appear to be the case in obese subjects

Oxidative stress in the developing brain: effects of postnatal glucocorticoid therapy and antioxidants in the rat.

In premature infants, glucocorticoids ameliorate chronic lung disease, but have adverse effects on long-term neurological function. Glucocorticoid excess promotes free radical overproduction. We hypothesised that the adverse effects of postnatal glucocorticoid therapy on the developing brain are secondary to oxidative stress and that antioxidant treatment would diminish unwanted effects. Male rat pups received a clinically-relevant tapering course of dexamethasone (DEX; 0.5, 0.3, and 0.1 mg x kg(-1) x day(-1)), with or without antioxidant vitamins C and E (DEXCE; 200 mg x kg(-1) x day(-1) and 100 mg x kg(-1) x day(-1), respectively), on postnatal days 1-6 (P1-6). Controls received saline or saline with vitamins. At weaning, relative to controls, DEX decreased total brain volume (704.4±34.7 mm(3) vs. 564.0±20.0 mm(3)), the soma volume of neurons in the CA1 (1172.6±30.4 µm(3) vs. 1002.4±11.8 µm(3)) and in the dentate gyrus (525.9±27.2 µm(3) vs. 421.5±24.6 µm(3)) of the hippocampus, and induced oxidative stress in the cortex (protein expression: heat shock protein 70 [Hsp70]: +68%; 4-hydroxynonenal [4-HNE]: +118% and nitrotyrosine [NT]: +20%). Dexamethasone in combination with vitamins resulted in improvements in total brain volume (637.5±43.1 mm(3)), and soma volume of neurons in the CA1 (1157.5±42.4 µm(3)) and the dentate gyrus (536.1±27.2 µm(3)). Hsp70 protein expression was unaltered in the cortex (+9%), however, 4-HNE (+95%) and NT (+24%) protein expression remained upregulated. Treatment of neonates with vitamins alone induced oxidative stress in the cortex (Hsp70: +67%; 4-HNE: +73%; NT: +22%) and in the hippocampus (NT: +35%). Combined glucocorticoid and antioxidant therapy in premature infants may be safer for the developing brain than glucocorticoids alone in the treatment of chronic lung disease. However, antioxidant therapy in healthy offspring is not recommended

Association of the Gene Polymorphisms IFN-γ +874, IL-13 −1055 and IL-4 −590 with Patterns of Reinfection with Schistosoma mansoni

Approximately 200 million people have schistosomiasis in parts of Africa, South America, the Middle East, the Caribbean and Asia. Several studies of multiple treatments and reinfections indicate that some people develop resistance to reinfection. Of all the immunologic findings associated with such studies, the most consistent observation is that resistance (usually defined as lower levels of infection upon reinfection) correlates with high IgE and low IgG4 antibodies against schistosome antigens. Our studies test whether single nucleotide polymorphisms residing in the gene or promoter regions of cytokines pivotal in controlling production of these antibody isotypes are different amongst those that develop resistance to reinfection as opposed to those that do not. Through genotyping of these polymorphisms in a cohort of occupationally exposed car washers, we found that men with certain genotypic patterns of polymorphisms in IL-4, IFN-γ, and IL-13 were significantly more likely to be resistant to reinfection than those with different patterns. These data provide initial insights into the potential genetic foundation of propensities of people to develop resistance to reinfection by schistosomes, and offer a basis for further molecular studies of how these polymorphisms might work at the transcriptional and gene product level in cells stimulated by schistosome antigens