ABSTRACT
BACKGROUND & AIMS: The incidences of the inflammatory bowel diseases (IBDs) Crohn's disease (CD) and ulcerative colitis (UC) are increasing, indicating gene-environment interactions. Migrants from low-IBD-prevalence countries to a high-prevalence country may help identify the relative contribution of environmental risk factors compared with native Caucasians. METHODS: This prospective case-control study evaluated IBD environmental risk factors of Middle Eastern migrants (MEM) in Australia compared with matched Caucasian IBD subjects, MEM controls, Caucasian controls, and controls in the Middle East using adjusted odds ratios (aOR). RESULTS: A total of 795 subjects were recruited: 154 MEM cases (75 CD; 79 UC), 153 MEM controls, 162 Caucasian cases (85 CD; 77 UC), 173 Caucasian controls, and 153 controls in Lebanon. Smoking increased CD risk in MEM and Caucasians and reduced UC risk in Caucasians (aOR, 0.77; 95% CI, 0.41-0.98) but not MEM (aOR, 1.45; 95% CI, 0.80-2.62). Antibiotic use reduced the risk of MEM CD (aOR, 0.27; 95% CI, 0.11-0.67) and UC (aOR, 0.38; 95% CI, 0.18-0.80), but increased the risk in Caucasians (CD: aOR, 5.24; 95% CI, 2.13-12.90; and UC: aOR, 6.82; 95% CI, 2.67-17.38). Most hygiene markers (rural dwelling, pet ownership, pet feeding, and farm animal contact) reduced CD and UC risk in MEM (P < .05). In contrast, in Caucasians these hygiene markers lacked significance. Other significant risk factors include IBD family history, appendectomy, tonsillectomy, and breastfeeding. CONCLUSIONS: Differential IBD environmental risk factors exist between migrants and native Caucasians, indicating a dynamic interplay between environmental factors and IBD risk for immigrants that is distinct to those factors most relevant in native Caucasians.
Subject(s)
Environmental Exposure , Inflammatory Bowel Diseases/epidemiology , Adolescent , Adult , Animals , Australia/epidemiology , Case-Control Studies , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Middle East/epidemiology , Prospective Studies , Racial Groups , Risk Factors , Transients and Migrants , Young AdultABSTRACT
BACKGROUND: Renal artery stenosis is a common, correctable cause of hypertension and renal impairment, with multiple screening tests available to aid diagnosis. Data assessing the accuracy of screening tests are mostly derived from tight 'experimental' protocols and the application of these tests to large-scale clinical practice is not clear. Our aim was to investigate physician preferences and diagnostic accuracy of screening tests for renal artery stenosis when applied to clinical practice in a large, Australian tertiary referral centre. METHODS: We investigated all renal angiograms performed at our institution between September 2002 and September 2004, as referred by renal physicians. We accessed hospital and physician records of all patients to document demographics, clinical history, screening investigations, source of screening and angiogram results. The series involved 75 consecutive patients who had 79 screening investigations (four patients had two screening tests). RESULTS: The case series showed that 19 (24%) patients did not have any screening investigations prior to angiography. Duplex ultrasonography was the most utilised screening test, being used in 20 (33%) of the remaining 60 screening tests. Computed tomographic angiography (CTA) was used in 19 (32%), magnetic resonance imaging in 13 (22%) and renal scintigraphy was used in four (7%) screening procedures. Magnetic resonance angiography was the most accurate screening test with a positive predictive value of 92%, followed by duplex ultrasonography with 88% and CTA was relatively inaccurate, with a positive predictive value (PPV) of 58% (P = 0.036). Clinical suspicion alone was inaccurate with a PPV of 40%, except in previously treated renal artery stenosis (PPV 89%). CONCLUSION: Duplex ultrasonography was the most utilised screening investigation amongst the physicians of our referral base. Magnetic resonance angiography and duplex ultrasonography had good positive predictive values, while CTA may not be as reliable as previously reported when applied to a large, non-selective clinical practice.