Predisposition to LDL oxidation during copper-catalyzed oxidative modification and its relation to alpha-tocopherol content in humans.

The predisposition to LDL oxidation during copper-catalyzed oxidative modification and its relationship with LDL alpha-tocopherol concentration was studied in 41 control subjects. The results show that the predisposition of LDL to oxidation expressed as duration of the inhibition period and rate of the propagation period varied greatly in the controls, but did not correlate with the values of LDL alpha-tocopherol. On the contrary the experiments with alpha-tocopherol incorporated in LDL demonstrate that even small increases of incorporated alpha-tocopherol, under circumstances where other variables were probably largely unaffected, increased proportionally the length of the inhibition period and reduced the rate of the propagation period. The values of LDL alpha-tocopherol achieved after the enrichment turned out to be positively correlated with the duration of the inhibition period and negatively with the rate of the propagation period. Finally the results of this study also show that there was a variability in the LDL alpha-tocopherol decay of different subjects under the same oxidative stress. In our conditions however, the time in which alpha-tocopherol contributed to the LDL protection was much shorter than the mean length of the inhibition period. The results demonstrate that the variability in the predisposition to LDL oxidation during copper-catalyzed oxidative modification is not determined only by the concentration of alpha-tocopherol in LDL and that therefore its value as a sole indicator of antioxidant status is probably inadequate.

Prevalence of asthma and asthma-like symptoms in an adult population sample from Verona. ECRHS Verona. European Community Respiratory Health Survey.

The aim of the study was to assess the prevalence of asthma and asthma-like symptoms in the general population of Verona. A screening questionnaire, with seven questions on respiratory symptoms, was sent by mail to 3000 randomly selected subjects, aged 20-44 yrs. After three subsequent mailings, nonresponders were interviewed by telephone. The overall response rate was 92%. At least one respiratory symptom was reported by 44% subjects. The prevalence of the most frequent symptoms differed according to the type of contact: early respondents (i.e. those who responded by mail) were more likely to report symptoms than late respondents (i.e. those who were interviewed by telephone). Wheezing was reported by 11.3% of males and 8.0% of females (p < 0.01). The allergic rhinitis and hay-fever prevalence was 16.9% with no differences owing to sex or age. The prevalence of an "episode of asthma" (defined as a self-reported attack of asthma or treatment for asthma) and of "current asthma" (defined as a self-reported attack of asthma, treatment for asthma or wheezing other than due to a cold with dyspnoea in the last 12 months) was 4.1 and 4.7%, respectively. No differences were found on the basis of age and sex. The prevalence of asthma was greater in urban (5.0%) than in suburban (2.7%) areas (p < 0.05), where lower pollution levels were registered. The greater prevalence in urban areas suggests that some factors related to the urban environment could play a role in the development of asthma and asthma-like disorders.

Influence of weight reduction on plasma high-density-lipoprotein cholesterol concentrations in severe obesity: interrelationships with plasma insulin levels.

The influence of caloric restriction and of weight loss during a weight-maintaining diet on lipid profile and in particular on high density lipoprotein (HDL) is controversial. In this study we analyzed the effect of a period of very low caloric diet (VLCD) and of a period of hypocaloric diet followed by 30 days of weight stabilization on lipoprotein levels, especially on HDL cholesterol and its subfractions (HDL2 and HDL3) and on the summated means of glucose (sigma glucose) and insulin levels (sigma IRI) after an oral tolerance test in a group of obese females. Body weight decreased significantly during the VLCD and hypocaloric diet. Total cholesterol decreased significantly after the VLCD and hypocaloric diet, but after the period of the weight-maintaining diet it was superimposable to the initial value. Very low density lipoprotein (VLDL) and low density lipoprotein (LDL) cholesterol behaved like total cholesterol. HDL2, HDL3 and HDL cholesterol decreased significantly after the period of VLCD. Then, after the hypocaloric diet the values of HDL2, HDL3 and HDL cholesterol returned towards the initial values and only after the period of the weight-maintaining diet did their values increase significantly. sigma glucose did not vary significantly at any time of the study, while sigma IRI reduced significantly both after the hypocaloric diet and the weight-maintaining diet. HDL2 and HDL cholesterol changes were found to be positively correlated to the variations of sigma IRI both at day 45 and 75 of the study.(ABSTRACT TRUNCATED AT 250 WORDS)