Smoke exposure as a risk factor for asthma in childhood: a review of current evidence.

Asthma is a common chronic multifactorial disease that affects >300 million people worldwide. Outdoor and indoor pollution exposure has been associated with respiratory health effects in adults and children. Smoking still represents a huge public health problem and millions of children suffer the detrimental effects of passive smoke exposure. This study was designed to review the current evidences on exposure to passive smoke as a risk factor for asthma onset in childhood. A review of the most recent studies on this topic was undertaken to provide evidence about the magnitude of the effect of passive smoking on the risk of incidence of asthma in children. The effects of passive smoking are different depending on individual and environmental factors. Environmental tobacco smoke (ETS) is one of the most important indoor air pollutants and can interact with other air pollutants in eliciting respiratory outcomes during childhood. The increased risk of respiratory outcomes in children exposed to prenatal and early postnatal passive smoke might be caused by an adverse effect on both the immune system and the structural and functional development of the lung; this may explain the subsequent increased risk of incident asthma. The magnitude of the exposure is quite difficult to precisely quantify because it is significantly influenced by the child's daily activities. Because exposure to ETS is a likely cause for asthma onset in childhood, there is a strong need to prevent infants and children from breathing air contaminated with tobacco smoke.

The value of FeNO measurement in childhood asthma: uncertainties and perspectives.

Asthma is considered an heterogeneous disease, requiring multiple biomarkers for diagnosis and management. Fractional exhaled nitric oxide in exhaled breath (FeNO) was the first useful non-invasive marker of airway inflammation in asthma and still is the most widely used. The non-invasive nature and the relatively easy use of FeNO technique make it an interesting tool to monitor airway inflammation and rationalize corticosteroid therapy in asthmatic patients, together with the traditional clinical tools (history, physical examination and lung function tests), even if some controversies have been published regarding the use of FeNO to support the management of asthma in children. The problem of multiple confounding factors and overlap between healthy and asthmatic populations preclude the routine application of FeNO reference values in clinical practice and suggest that it would be better to consider an individual "best", taking into account the context in which the measurement is obtained and the clinical history of the patient. Besides, there is still disagreement about the role of FeNO as a marker of asthma control, due to the complexity of balance among the different items involved in its determination and the lack of homogeneity in the population groups studied in the few studies conducted so far. Heterogeneity of problematic severe asthma greatly limits utility of FeNO alone as a biomarker of inflammation to optimize the disease management on an individual basis. None of the studies conducted so far demonstrated that the use of FeNO was better than current asthma guidelines in controlling asthma exacerbations. In summary, there is a large variation in FeNO levels between individuals, which may reflect the natural heterogeneity in baseline epithelial nitric oxide synthase activity and/or the contribution of other noneosinophilic factors to epithelial nitric oxide synthase activity. FeNO is a promising biomarker, but at present some limits are highlighted. We would recommend that further research can be carried out by organizing studies aimed to obtain reliable reference values of FeNO and in order to better interpret FeNO measurements in clinical settings, taking also into account the influence of genetic and environmental factors.

Medium-term effects of bisoprolol administration on renal hemodynamics and function in mild to moderate essential hypertension.

Arterial hypertension is a significant cause of end-stage renal failure; effective treatment of hypertensive patients reduces the rate of progression of this disorder. ss-Blockers, particularly nonselective agents, are associated with deterioration of renal function in patients with chronic renal failure. Previous studies on the interaction of the beta1-selective adrenergic antagonist bisoprolol with kidney function have been performed only acutely and over the short term. This study was designed to evaluate the antihypertensive efficacy and effects on renal hemodynamics and function of bisoprolol during medium-term (6 mo) treatment of patients with mild to moderate essential hypertension. After a 2-wk run-in period on placebo, 87 consecutive hypertensive patients (46 men, 41 women) according to ESH-ESC (European Society of Hypertension/European Society of Cardiology) guidelines, aged from 27 to 64 y (mean age, 50+/-11 y), without renal or cardiovascular disease, were enrolled and assigned to treatment with bisoprolol 5 mg once daily for 6 mo. At recruitment and at 6 mo after treatment, renal function was assessed and renal hemodynamics evaluated in all patients through radioisotope studies. The medium-term effects of bisoprolol included a significant reduction in blood pressure and heart rate (P<.001) without significant adverse drug reactions. Moreover, bisoprolol produced no alteration in renal function or hemodynamics, or in cardiac output. Data presented here indicate that bisoprolol 5 mg given once daily to treat patients with mild to moderate essential hypertension is effective and safe for treatment and for preservation of renal performance when given on a medium-term basis.