RESUMEN
BACKGROUND: Epidemiological data and the effect of sun exposure on atopic eczema (AE) suggest that vitamin D (vitD) may be involved in the pathogenesis. OBJECTIVES: To investigate if vitD levels were associated with the presence or severity of AE in the first 2 years of life in children living in south-east Norway. METHODS: Infants, recruited to a clinical trial on acute bronchiolitis (n = 404) and from the general population (n = 240), were examined at 1-13 months (first visit) and at 2 years of age (second visit). Caregivers were interviewed using a structured questionnaire. AE was diagnosed clinically, based on well-established criteria. Disease severity was assessed using the SCORing Atopic Dermatitis index. Blood samples were taken for vitD measurements, using liquid chromatography-tandem mass spectrometry and for common filaggrin mutation analyses. Complete data on AE and vitD were available in 596 and 449 children at the first and second visit, respectively. RESULTS: Atopic eczema was diagnosed in 67 children (11%) at the first visit and in 103 children (23%) at the second. Mean vitD levels were 58·2 nmol L(-1) at the first visit and 66·9 nmol L(-1) at the second. Using vitD level tertiles in multivariate regression analysis, there was no association between vitD levels and AE at either visit, regardless of filaggrin mutation. In children without AE at the first visit, vitD levels did not predict AE at the second. CONCLUSIONS: In this cohort of young children in Norway, we found no association between vitD levels and the presence or severity of AE.
Asunto(s)
25-Hidroxivitamina D 2/metabolismo , Calcifediol/metabolismo , Dermatitis Atópica/epidemiología , Preescolar , Estudios Transversales , Dermatitis Atópica/sangre , Dermatitis Atópica/genética , Proteínas Filagrina , Humanos , Lactante , Recién Nacido , Proteínas de Filamentos Intermediarios/genética , Mutación/genética , Noruega/epidemiología , Estudios Prospectivos , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/epidemiología , Deficiencia de Vitamina D/genéticaRESUMEN
The curvilinearity of the atrial pressure-volume curve implies that atrial compliance decreases progressively with increasing left atrial (LA) pressure (LAP). We predicted that reduced LA compliance leads to more rapid deceleration of systolic pulmonary venous (PV) flow. With this rationale, we investigated whether the deceleration time (t dec) of PV systolic flow velocity reflects mean LAP. In eight patients during coronary surgery, before extracorporeal circulation, PV flow by ultrasonic transit time and invasive LAP were recorded during stepwise volume loading. The t dec was calculated using two methods: by drawing a tangent through peak deceleration and by drawing a line from peak systolic flow through the nadir between the systolic and early diastolic flow waves. LA compliance was calculated as the systolic PV flow integral divided by LAP increment. Volume loading increased mean LAP from 11 +/- 3 to 20 +/- 5 mmHg (P < 0.001) (n = 40), reduced LA compliance from 1.16 +/- 0.42 to 0.72 +/- 0.40 ml/mmHg (P < 0.004) (n = 40), and reduced t dec from 320 +/- 50 to 170 +/- 40 ms (P < 0.0005) (n = 40). Mean LAP correlated well with t dec (r = 0.84, P < 0.0005) (n = 40) and LA compliance (r = 0.79, P < 0.0005) (n = 40). Elevated LAP caused a decrease in LA compliance and therefore more rapid deceleration of systolic PV flow. The t dec has potential to become a semiquantitative marker of LAP and an index of LA passive elastic properties.